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Publications


2020

Gichuhi, S, Arunga S.  2020.  HIV and the eye., 2020. Community eye health. 33(108):76-78. AbstractWebsite

This article summarizes the presentation of ocular HIV in East Africa.
The main ocular effects of HIV are related to immune-suppression and impaired tumour-surveillance. HIV compromises cell-mediated immunity increasing the risk of infection with bacteria (e.g. tuberculosis and syphilis); fungi (e.g. candida and cryptococcus); parasites (e.g. toxoplasmosis); and viruses (e.g. herpes zoster, human papilloma virus, Kaposi sarcoma-associated herpes virus, cytomegalovirus and Epstein-Barr virus).
Patients with lower CD4 counts are more likely to have ocular manifestations1, however use of antiretroviral therapy (ART) has modified the epidemiology of ocular manifestations, and variations in the predominant subtype of HIV may also lead to geographical differences in ocular disease.

Naidoo, K, Kempen JH, Gichuhi S, Braithwaite T, Casson RJ, Cicinelli MV, Das A, Flaxman SR, Jonas JB, Keeffe JE, Leasher J, Limburg H, Pesudovs K, Resnikoff S, Silvester AJ, Tahhan N, Taylor HR, Wong TY, Bourne RRA.  2020.  Prevalence and causes of vision loss in sub-Saharan Africa in 2015: magnitude, temporal trends and projections., 2020 Mar 30. The British journal of ophthalmology. AbstractWebsite

Background: This study aimed to assess the prevalence and causes of vision loss in sub-Saharan Africa (SSA) in 2015, compared with prior years, and to estimate expected values for 2020.

Methods: A systematic review and meta-analysis assessed the prevalence of blindness (presenting distance visual acuity <3/60 in the better eye), moderate and severe vision impairment (MSVI; presenting distance visual acuity <6/18 but ≥3/60) and mild vision impairment (MVI; presenting distance visual acuity <6/12 and ≥6/18), and also near vision impairment (

Mwangi, N, Bascaran C, Ramke J, Kipturgo M, Kim M, Ng'ang'a M, Gichuhi S, Mutie D, Moorman C, Muthami L, Foster A.  2020.  Peer-support to increase uptake of screening for diabetic retinopathy: process evaluation of the DURE cluster randomized trial., 2020. Tropical medicine and health. 48:1. AbstractWebsite

Background: There is limited evidence on how implementation of peer support interventions influences effectiveness, particularly for individuals with diabetes. We conducted a cluster randomized controlled trial to compare the effectiveness of a peer-led health education package versus usual care to increase uptake of screening for diabetic retinopathy (DR).

Methods: Our process evaluation used a mixed-method design to investigate the recruitment and retention, reach, dose, fidelity, acceptability, and context of implementation, and was guided by the Consolidated Framework for Implementation Research (CFIR). We reviewed trial documents, conducted semi-structured interviews with key informants (n = 10) and conducted four focus group discussions with participants in both arms of the trial. Three analysts undertook CFIR theory-driven content analysis of the qualitative data. Quantitative data was analyzed to provide descriptive statistics relevant to the objectives of the process evaluation.

Results: The trial had positive implementation outcomes, 100% retention of clusters and 96% retention for participants, 83% adherence to delivery of content of group talks (fidelity), and 78% attendance (reach) to at least 50% (3/6) of the group talks (dose). The data revealed that intervention characteristics, outer setting, inner setting, individual characteristics, and process (all the constructs of CFIR) influenced the implementation. There were more facilitators than barriers to the implementation. Facilitators included the relative advantage of the intervention compared with current practice (intervention characteristics); awareness of the growing prioritization of diabetes in the national health policy framework (outer setting); tension for change due to the realization of the vulnerability to vision loss from DR (inner setting); a strong collective sense of accountability of peer supporters to implement the intervention (individual characteristics); and regular feedback on the progress with implementation (process). Potential barriers included the need to queue at the eye clinic (intervention characteristic), travel inconveniences (inner setting), and socio-political disruption (outer setting).

Conclusions: The intervention was implemented with high retention, reach, fidelity, and dose. The CFIR provided a valuable framework for evaluating contextual factors that influenced implementation and helped to understand what adaptations may be needed during scale up.

Arunga, S, Kintoki GM, Mwesigye J, Ayebazibwe B, Onyango J, Bazira J, Newton R, Gichuhi S, Leck A, Macleod D, Hu VH, Burton MJ.  2020.  Epidemiology of Microbial Keratitis in Uganda: A Cohort Study., 2020 04. Ophthalmic epidemiology. 27(2):121-131. AbstractWebsite

: To describe the epidemiology of Microbial Keratitis (MK) in Uganda.: We prospectively recruited patients presenting with MK at two main eye units in Southern Uganda between December 2016 and March 2018. We collected information on clinical history and presentation, microbiology and 3-month outcomes. Poor vision was defined as vision < 6/60).: 313 individuals were enrolled. Median age was 47 years (range 18-96) and 174 (56%) were male. Median presentation time was 17 days from onset (IQR 8-32). Trauma was reported by 29% and use of Traditional Eye Medicine by 60%. Majority presented with severe infections (median infiltrate size 5.2 mm); 47% were blind in the affected eye (vision < 3/60). Microbiology was available from 270 cases: 62% were fungal, 7% mixed (bacterial and fungal), 7% bacterial and 24% no organism detected. At 3 months, 30% of the participants were blind in the affected eye, while 9% had lost their eye from the infection. Delayed presentation (overall = .007) and prior use of Traditional Eye Medicine (aOR 1.58 [95% CI 1.04-2.42], = .033) were responsible for poor presentation. Predictors of poor vision at 3 months were: baseline vision (aOR 2.98 [95%CI 2.12-4.19], < .0001), infiltrate size (aOR 1.19 [95%CI 1.03-1.36], < .020) and perforation at presentation (aOR 9.93 [95% CI 3.70-26.6], < .0001).: The most important outcome predictor was the state of the eye at presentation, facilitated by prior use of Traditional Eye Medicine and delayed presentation. In order to improve outcomes, we need effective early interventions.

2019

Arunga, S, Wiafe G, Habtamu E, Onyango J, Gichuhi S, Leck A, Macleod D, Hu V, Burton M.  2019.  The impact of microbial keratitis on quality of life in Uganda., 2019. BMJ open ophthalmology. 4(1):e000351. AbstractWebsite

Background: Microbial keratitis (MK) is a frequent cause of sight loss in sub-Saharan Africa. However, no studies have formally measured its impact on quality of life (QoL) in this context.
Methods: As part of a nested case-control design for risk factors of MK, we recruited patients presenting with MK at two eye units in Southern Uganda between December 2016 and March 2018 and unaffected individuals, individually matched for sex, age and location. QoL was measured using WHO Health-Related and Vision-Related QoL tools (at presentation and 3 months after start of treatment in cases). Mean QoL scores for both groups were compared. Factors associated with QoL among the cases were analysed in a linear regression model.
Results: 215 case-controls pairs were enrolled. The presentation QoL scores for the cases ranged from 20 to 65 points. The lowest QoL was visual symptom domain; mean 20.7 (95% CI 18.8 to 22.7) and the highest was psychosocial domain; mean 65.6 (95% CI 62.5 to 68.8). At 3 months, QoL scores for the patients ranged from 80 to 90 points while scores for the controls ranged from 90 to 100. The mean QoL scores of the cases were lower than controls across all domains. Determinants of QoL among the cases at 3 months included visual acuity at 3 months and history of eye loss.
Conclusion: MK severely reduces QoL in the acute phase. With treatment and healing, QoL subsequently improves. Despite this improvement, QoL of someone affected by MK (even with normal vision) remains lower than unaffected controls.

Dean, W, Gichuhi S, Buchan J, Matende I, Graham R, Kim M, Arunga S, Makupa W, Cook C, Visser L, Burton M.  2019.  Survey of ophthalmologists-in-training in Eastern, Central and Southern Africa: A regional focus on ophthalmic surgical education., 2019. Wellcome open research. 4:187. AbstractWebsite

There are 2.7 ophthalmologists per million population in sub-Saharan Africa, and a need to train more. We sought to analyse current surgical training practice and experience of ophthalmologists to inform planning of training in Eastern, Central and Southern Africa. This was a cross-sectional survey. Potential participants included all current trainee and recent graduate ophthalmologists in the Eastern, Central and Southern African region. A link to a web-based questionnaire was sent to all heads of eye departments and training programme directors of ophthalmology training institutions in Eastern, Central and Southern Africa, who forwarded to all their trainees and recent graduates. Main outcome measures were quantitative and qualitative survey responses. Responses were obtained from 124 (52%) trainees in the region. Overall level of satisfaction with ophthalmology training programmes was rated as 'somewhat satisfied' or 'very satisfied' by 72%. Most frequent intended career choice was general ophthalmology, with >75% planning to work in their home country post-graduation. A quarter stated a desire to mainly work in private practice. Only 28% of junior (first and second year) trainees felt surgically confident in manual small incision cataract surgery (SICS); this increased to 84% among senior trainees and recent graduates. The median number of cataract surgeries performed by junior trainees was zero. 57% of senior trainees were confident in performing an anterior vitrectomy. Only 29% of senior trainees and 64% of recent graduates were confident in trabeculectomy. The mean number of cataract procedures performed by senior trainees was 84 SICS (median 58) and 101 phacoemulsification (median 0). Satisfaction with post-graduate ophthalmology training in the region was fair. Most junior trainees experience limited cataract surgical training in the first two years. Focused efforts on certain aspects of surgical education should be made to ensure adequate opportunities are offered earlier on in ophthalmology training.

Arunga, S, Kintoki GM, Gichuhi S, Onyango J, Ayebazibwe B, Newton R, Leck A, Macleod D, Hu VH, Burton MJ.  2019.  Risk Factors of Microbial Keratitis in Uganda: A Case Control Study., 2019 Oct 22. Ophthalmic epidemiology. :1-7. AbstractWebsite

Purpose: Microbial keratitis (MK), is a frequent cause of sight loss worldwide, particularly in low and middle-income countries. This study aimed to investigate the risk factors of MK in Uganda.
Methods: Using a nested case control, we recruited healthy community controls for patients presenting with MK at the two main eye units in Southern Uganda between December 2016 and March 2018. Controls were individually matched for age, gender and village of the cases on a 1:1 ratio. We collected information on demographics, occupation, HIV and Diabetes Mellitus status. In STATA version 14.1, multivariable conditional logistic regression was used to generate odds ratios for risk factors of MK and a likelihood ratio test used to assess statistical significance of associations.
Results: Two hundred and fifteen case-control pairs were enrolled. The HIV positive patients among the cases was 9% versus 1% among the controls, = .0003. Diabetes 7% among the cases versus 1.4% among the controls, = .012. Eye trauma was 29% versus 0% among the cases and controls. In the multivariable model adjusted for age, sex and village, HIV (OR 83.5, 95%CI 2.01-3456, = .020), Diabetes (OR 9.38, 95% CI 1.48-59.3, = .017) and a farming occupation (OR 2.60, 95%CI 1.21-5.57, = .014) were associated with MK. Compared to a low socio-economic status, a middle status was less likely to be associated with MK (OR 0.29, 95%CI 0.09-0.89, < .0001).
Conclusion: MK was associated with HIV, Diabetes, being poor and farming as the main occupation. More studies are needed to explore how these factors predispose to MK.

Cheng, C-Y, Wang N, Wong TY, Congdon N, He M, Wang YX, Braithwaite T, Casson RJ, Cicinelli MV, Das A, Flaxman SR, Jonas JB, Keeffe JE, Kempen JH, Leasher J, Limburg H, Naidoo K, Pesudovs K, Resnikoff S, Silvester AJ, Tahhan N, Taylor HR, Bourne RRA, of the of Study VLEGGBD.  2019.  Prevalence and causes of vision loss in East Asia in 2015: magnitude, temporal trends and projections., 2019 Aug 28. The British journal of ophthalmology. AbstractWebsite

BACKGROUND: To determine the prevalence and causes of blindness and vision impairment (VI) in East Asia in 2015 and to forecast the trend to 2020.
METHODS: Through a systematic literature review and meta-analysis, we estimated prevalence of blindness (presenting visual acuity <3/60 in the better eye), moderate-to-severe vision impairment (MSVI; 3/60≤presenting visual acuity <6/18), mild vision impairment (mild VI: 6/18≤presenting visual acuity <6/12) and uncorrected presbyopia for 1990, 2010, 2015 and 2020. A total of 44 population-based studies were included.
RESULTS: In 2015, age-standardised prevalence of blindness, MSVI, mild VI and uncorrected presbyopia was 0.37% (80% uncertainty interval (UI) 0.12%-0.68%), 3.06% (80% UI 1.35%-5.16%) and 2.65% (80% UI 0.92%-4.91%), 32.91% (80% UI 18.72%-48.47%), respectively, in East Asia. Cataract was the leading cause of blindness (43.6%), followed by uncorrected refractive error (12.9%), glaucoma, age-related macular degeneration, corneal diseases, trachoma and diabetic retinopathy (DR). The leading cause for MSVI was uncorrected refractive error, followed by cataract, age-related macular degeneration, glaucoma, corneal disease, trachoma and DR. The burden of VI due to uncorrected refractive error, cataracts, glaucoma and DR has continued to rise over the decades reported.
CONCLUSIONS:Addressing the public healthcare barriers for cataract and uncorrected refractive error can help eliminate almost 57% of all blindness cases in this region. Therefore, public healthcare efforts should be focused on effective screening and effective patient education, with access to high-quality healthcare.

Rono, H, Bastawrous A, Macleod D, Wanjala E, Gichuhi S, Burton M.  2019.  Peek Community Eye Health - mHealth system to increase access and efficiency of eye health services in Trans Nzoia County, Kenya: study protocol for a cluster randomised controlled trial., 2019 Aug 14. Trials. 20(1):502. AbstractWebsite

Globally, eye care provision is currently insufficient to meet the requirement for eye care services. Lack of access and awareness are key barriers to specialist services; in addition, specialist services are over-utilised by people with conditions that could be managed in the community or primary care. In combination, these lead to a large unmet need for eye health provision. We have developed a validated smartphone-based screening algorithm (Peek Community Screening App). The application (App) is part of the Peek Community Eye Health system (Peek CEH) that enables Community Volunteers (CV) to make referral decisions about patients with eye problems. It generates referrals, automated short messages service (SMS) notifications to patients or guardians and has a program dashboard for visualising service delivery. We hypothesise that a greater proportion of people with eye problems will be identified using the Peek CEH system and that there will be increased uptake of referrals, compared to those identified and referred using the current community screening approaches.

Arunga, S, Kintoki GM, Gichuhi S, Onyango J, Newton R, Leck A, Macleod D, Hu VH, Burton MJ.  2019.  Delay Along the Care Seeking Journey of Patients with Microbial Keratitis in Uganda., 2019 May 15. Ophthalmic epidemiology. :1-10. AbstractWebsite

PURPOSE:To describe the care seeking journey and causes of delay among patients with Microbial Keratitis in Uganda.
METHODS:A prospective cohort of patients presenting with microbial keratitis at the two main eye units in Southern Uganda (2016-2018). We collected information on demographics, home address, clinical history, and presentation pathway including, order of facilities where patients went to seek care, treatment advice, cost of care, and use of Traditional Eye Medicine. Presentation time was noted. We compared "direct" presenters versus "indirect" presenters and analysed predictors of delay.
RESULTS: About 313 patients were enrolled. All were self-referred. Only 19% of the patients presented directly to the eye hospital. Majority (52%) visited one facility before presenting, 19% visited two facilities, 9% visited three facilities, and 2% visited four facilities. The cost of care increased with increase in the number of facilities visited. People in a large household, further distance from the eye hospital and those who used Traditional Eye Medicine were less likely to come directly to the eye hospital. Visiting another facility prior to the eye hospital and use of Traditional Eye Medicine aOR 1.58 (95%CI 1.03-2.43), p = .038 were associated with delayed presentation to the eye hospital.
CONCLUSION: This study provided information on patient journeys to seek care. Delay was largely attributable to having visited another health facility: a referral mechanism for microbial keratitis was non-existent. There is need to explore how these health system gaps can be strengthened.

2018

Leasher, JL, Braithwaite T, Furtado JM, Flaxman SR, Lansingh VC, Silva JC, S R, Taylor HR, Bourne RRA, Vision Loss Expert Group of the Global Burden of Disease Study.  2018.  Prevalence and causes of vision loss in Latin America and the Caribbean in 2015: magnitude, temporal trends and projections.. The British journal of ophthalmology. AbstractWebsite

OBJECTIVE: To estimate the prevalence and causes of blindness and vision impairment for distance and near in Latin America and the Caribbean (LAC) in 2015 and to forecast trends to 2020.

METHODS: A meta-analysis from a global systematic review of 283 cross-sectional, population-representative studies from published and unpublished sources from 1980 to 2014 in the Global Vision Database included 17 published and 6 unpublished studies from LAC.

RESULTS: In 2015, across LAC, age-standardised prevalence was 0.38% in all ages and 1.56% in those over age 50 for blindness; 2.06% in all ages and 7.86% in those over age 50 for moderate and severe vision impairment (MSVI); 1.89% in all ages and 6.93% in those over age 50 for mild vision impairment and 39.59% in all ages and 45.27% in those over 50 for near vision impairment (NVI). In 2015, 117.86 million persons were vision impaired; of those 2.34 million blind, 12.46 million with MSVI, 11.34 million mildly impaired and 91.72 million had NVI. Cataract is the most common cause of blindness. Undercorrected refractive-error is the most common cause of vision impairment.

CONCLUSIONS: These prevalence estimates indicate that one in five persons across LAC had some degree of vision loss in 2015. We predict that from 2015 to 2020, the absolute numbers of persons with vision loss will increase by 12% to 132.33 million, while the all-age age-standardised prevalence will decrease for blindness by 15% and for other distance vision impairment by 8%. All countries need epidemiologic research to establish accurate national estimates and trends. Universal eye health services must be included in universal health coverage reforms to address disparities, fragmentation and segmentation of healthcare.

Nangia, V, Jonas JB, George R, Lingam V, Ellwein L, Cicinelli MV, Das A, Flaxman SR, Keeffe JE, Kempen JH, Leasher J, Limburg H, Naidoo K, Pesudovs K, Resnikoff S, Silvester AJ, Tahhan N, Taylor HR, Wong TY, Bourne RRA.  2018.  Prevalence and causes of blindness and vision impairment: magnitude, temporal trends and projections in South and Central Asia., 2018 Nov 08. The British journal of ophthalmology. AbstractWebsite

BACKGROUND:To assess prevalence and causes of vision loss in Central and South Asia.

METHODS: A systematic review of medical literature assessed the prevalence of blindness (presenting visual acuity<3/60 in the better eye), moderate and severe vision impairment (MSVI; presenting visual acuity <6/18 but ≥3/60) and mild vision impairment (MVI; presenting visual acuity <6/12 and ≥6/18) in Central and South Asia for 1990, 2010, 2015 and 2020.

RESULTS: In Central and South Asia combined, age-standardised prevalences of blindness, MSVI and MVI in 2015 were for men and women aged 50+years, 3.72% (80% uncertainty interval (UI): 1.39-6.75) and 4.00% (80% UI: 1.41-7.39), 16.33% (80% UI: 8.55-25.47) and 17.65% (80% UI: 9.00-27.62), 11.70% (80% UI: 4.70-20.32) and 12.25% (80% UI:4.86-21.30), respectively, with a significant decrease in the study period for both gender. In South Asia in 2015, 11.76 million individuals (32.65% of the global blindness figure) were blind and 61.19 million individuals (28.3% of the global total) had MSVI. From 1990 to 2015, cataract (accounting for 36.58% of all cases with blindness in 2015) was the most common cause of blindness, followed by undercorrected refractive error (36.43%), glaucoma (5.81%), age-related macular degeneration (2.44%), corneal diseases (2.43%), diabetic retinopathy (0.16%) and trachoma (0.04%). For MSVI in South Asia 2015, most common causes were undercorrected refractive error (accounting for 66.39% of all cases with MSVI), followed by cataract (23.62%), age-related macular degeneration (1.31%) and glaucoma (1.09%).

CONCLUSIONS: One-third of the global blind resided in South Asia in 2015, although the age-standardised prevalence of blindness and MSVI decreased significantly between 1990 and 2015.

Mwangi, N, Minnies D, Parsley S, Patel D, Gichuhi S, Muthami L, Moorman C, Macleod D, Bascaran C, Foster A.  2018.  Developing open online learning resources: Lessons from a short course on the control of blindness from diabetic retinopathy., 31st Aug 2018. College of Ophthalmologists in Eastern Central & Southern Africa (COECSA). , Addis Ababa Abstract

Background: A need identified during another study prompted the development of the open online course on control of blindness from diabetic retinopathy. In our technological age, potential for learning online can provide a unique opportunity to develop context-specific content for local relevance. We report on the lessons learnt in the development of this short online course for an international audience of diverse eye care practitioners.

Methods: We developed this online short course through a formal planning process facilitated by UNESCO. The participants included eye health educators, learning designers, and content experts. The course curriculum was informed by learning from an ongoing doctorate program, as well as by clinical, public health and educational experience.

Results: Lessons learnt include:
1. Identifying the need and content – Learning and research from a doctorate research program can inform content development.
2. Identifying the relevance – the content needs to be customized for the target audience and local context.
3. Developing the learning design – promoting digital teaching skills and co-creation of content are valuable entry points.
4. Accommodating appropriate peer review and mentorship may enhance learning and quality assurance.
5. Resource planning activities need to be documented as a learning point.
6. There are significant costs in course development, such as time spent in content development, and ongoing maintenance eg maintaining the online platform.
7. Sources of quality open access resources in eye care are limited.

Conclusion: Content development is a unique learning experience, and it is essential to develop and support context specific learning resources. Open educational practice supports a collaborative process that enhances relevance and quality of training. The online format emphasizes the importance of learning design requirements to bridge the transactional distance between the participant and the educator.

Mwangi, N, Gachago M, Gichangi M, Gichuhi S, Githeko K, Jalango A, Karimurio J, Kibachio J, Muthami L, Ngugi N, Nduri C, Nyaga P, Nyamori J, Zindamoyen ANM, Bascaran C, Foster A.  2018.  Adapting clinical practice guidelines for diabetic retinopathy in Kenya: process and outputs., 2018 Jun 15. Implementation science : IS. 13(1):81. Abstract

The use of clinical practice guidelines envisages augmenting quality and best practice in clinical outcomes. Generic guidelines that are not adapted for local use often fail to produce these outcomes. Adaptation is a systematic and rigorous process that should maintain the quality and validity of the guideline, while making it more usable by the targeted users. Diverse skills are required for the task of adaptation. Although adapting a guideline is not a guarantee that it will be implemented, adaptation may improve acceptance and adherence to its recommendations.

Mwangi, N, Ng'ang'a M, Gakuo E, Gichuhi S, Macleod D, Moorman C, Muthami L, Tum P, Jalango A, Githeko K, Gichangi M, Kibachio J, Bascaran C, Foster A.  2018.  Effectiveness of peer support to increase uptake of retinal examination for diabetic retinopathy: study protocol for the DURE pragmatic cluster randomized clinical trial in Kirinyaga, Kenya., 2018 Jul 13. BMC public health. 18(1):871. Abstract

All patients with diabetes are at risk of developing diabetic retinopathy (DR), a progressive and potentially blinding condition. Early treatment of DR prevents visual impairment and blindness. The natural history of DR is that it is asymptomatic until the advanced stages, thus annual retinal examination is recommended for early detection. Previous studies show that the uptake of regular retinal examination among people living with diabetes (PLWD) is low. In the Uptake of Retinal Examination in Diabetes (DURE) study, we will investigate the effectiveness of a complex intervention delivered within diabetes support groups to increase uptake of retinal examination.

Do, DV, Gichuhi S, Vedula SS, Hawkins BS.  2018.  Surgery for postvitrectomy cataract., 2018 01 10. The Cochrane database of systematic reviews. 1:CD006366. AbstractWebsite

BACKGROUND:
Cataract formation or acceleration can occur after intraocular surgery, especially following vitrectomy, a surgical technique for removing the vitreous that is used in the treatment of many disorders that affect the posterior segment of the eye. The underlying problem that led to vitrectomy may limit the benefit from removal of the cataractous lens.

OBJECTIVES:
To evaluate the effectiveness and safety of surgery versus no surgery for postvitrectomy cataract with respect to visual acuity, quality of life, and other outcomes.

SEARCH METHODS:
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 5), MEDLINE Ovid (1946 to 17 May 2017), Embase.com (1947 to 17 May 2017), PubMed (1946 to 17 May 2017), Latin American and Caribbean Health Sciences Literature database (LILACS) (January 1982 to 17 May 2017), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com); last searched May 2013, ClinicalTrials.gov (www.clinicaltrials.gov); searched 17 May 2017, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en); searched 17 May 2017. We did not use any date or language restrictions in the electronic searches for trials.

SELECTION CRITERIA:
We planned to include randomized controlled trials (RCTs) and quasi-RCTs that had compared surgery versus no surgery to remove the lens from eyes of adults in which cataracts had developed following vitrectomy.

DATA COLLECTION AND ANALYSIS:
Two review authors independently screened the search results according to the standard methodological procedures expected by Cochrane.

MAIN RESULTS:
We found no RCTs or quasi-RCTs that had compared surgery versus no surgery to remove the lens from eyes of adults in which cataracts had developed following vitrectomy.

AUTHORS' CONCLUSIONS:
There is no evidence from RCTs or quasi-RCTs on which to base clinical recommendations for surgery for postvitrectomy cataract. There is a clear need for RCTs to address this evidence gap. Such trials should stratify participants by their age, the retinal disorder leading to vitrectomy, and the status of the underlying disease process in the contralateral eye. Outcomes assessed in such trials may include changes (both gains and losses) of visual acuity, quality of life, and adverse events such as posterior capsular rupture and retinal detachment. Both short-term (six-month) and long-term (one- or two-year) outcomes should be examined.
Update of Surgery for post-vitrectomy cataract. [Cochrane Database Syst Rev. 2013]

2017

Nyawira, M, Muchai G, Gichangi M, Gichuhi S, Githeko K, Atieno J, Karimurio J, Kibachio J, Ngugi N, Nyaga PT, Nyamori J, Zindamoyen ANM, Bascaran C, Foster A.  2017.  Clinical guidelines for diabetic retinopathy in Kenya: an executive summary of the recommendations. J Ophthalmol East Cent & S Afr. . 21(2):33-39. Abstract

All persons living with Diabetes Mellitus (DM) have a lifetime risk of developing Diabetic Retinopathy (DR), a
potentially blinding microvascular complication of DM. The risk increases with the duration of diabetes. The
onset and progression of DR can be delayed through optimization of control of blood glucose, blood pressure and lipids. The risk of blindness from DR can be reduced through cost-effective interventions such as screening for DR and treatment of sight-threatening DR with laser photocoagulation and anti-VEGF medications.
Several factors make it important to provide guidance to clinicians who provide services for diabetes and
diabetic retinopathy in Kenya. First, the magnitude of both DM and DR is expected to increase over the next
decade. Secondly, as the retina is easily accessible for examination, the early signs of retinopathy may provide clinicians with the best evidence of microvascular damage from diabetes. This information can be used to guide subsequent management of both DM and DR. Thirdly, there are notable gaps in service delivery for the detection,treatment and follow-up of patients with DR, and the services are inequitable. Strengthening of service delivery will require close collaboration between diabetes services and eye care services.
Following a systematic and collaborative process of guideline development, the first published national
guidelines for the management of diabetic retinopathy have been developed. The purpose of this paper is to
highlight the recommendations in the guidelines, and to facilitate their adoption and implementation.

Gichuhi, S, Gichangi M, Nyamori J, Gachago M, Nyenze EM, Nyaga PT, Karimurio J.  2017.  Evaluation of the Kenyatta National Hospital diabetic retinopathy screening program 2015-2016. J Ophthalmol East Cent & S Afr. . 21(2):40-44. Abstract

Objective: This operational evaluation was conducted to determine the effect of having a screening fundus
camera in the diabetes clinic on the demand for eye clinic diabetic retinopathy services at the Kenyatta National Hospital (KNH).
Methods: A before-after evaluation design was used. The reference point was installation of a screening retinal fundus camera in the KNH diabetes clinic in May 2016. The ‘before’ period was January to June 2015 and the ‘after’ period was June to November 2016. The one-year gap between the evaluation periods was used for program development and user training. The primary measure of outcome was a comparison of the mean numbers of patients seen and treated before and after starting the screening program. Data was obtained from the medical records on both the diabetes and eye clinics.
Results: The total number of diabetic patients screened in the two periods was 3011 (monthly mean=502,
SD=44) and 2739 (monthly mean=457, SD=38) respectively. The total number referred to the eye clinic increased from 494 (monthly mean=82, SD=16) to 1065 (monthly mean=178, SD=30) while the total number of patients treated with lasers or intravitreal injections increased from 107 (monthly mean=18, SD=5) to 333 (monthly mean=56, SD=39).
Conclusions: Starting a diabetic retinopathy screening program using a fundus camera used based at the
diabetes clinic doubled the number of patients referred for further evaluation at the eye clinic (2.2-fold increase) and tripled the number of diabetics who received treatment for diabetic retinopathy (3.1-fold increase).

Bourne, RRA, Flaxman SR, Braithwaite T, Cicinelli MV, Das A, Jonas JB, Keeffe J, Kempen JH, Leasher J, Limburg H, Naidoo K, Pesudovs K, Resnikoff S, Silvester A, Stevens GA, Tahhan N, Wong TY, Taylor HR.  2017.  Magnitude, temporal trends, and projections of the global prevalence of blindness and distance and near vision impairment: a systematic review and meta-analysis. The Lancet Global Health. 5:e888-e897., Number 9 AbstractWebsite

Global and regional prevalence estimates for blindness and vision impairment are important for the development of public health policies. We aimed to provide global estimates, trends, and projections of global blindness and vision impairment. We did a systematic review and meta-analysis of population-based datasets relevant to global vision impairment and blindness that were published between 1980 and 2015. We fitted hierarchical models to estimate the prevalence (by age, country, and sex), in 2015, of mild visual impairment (presenting visual acuity worse than 6/12 to 6/18 inclusive), moderate to severe visual impairment (presenting visual acuity worse than 6/18 to 3/60 inclusive), blindness (presenting visual acuity worse than 3/60), and functional presbyopia (defined as presenting near vision worse than N6 or N8 at 40 cm when best-corrected distance visual acuity was better than 6/12). Globally, of the 7·33 billion people alive in 2015, an estimated 36·0 million (80% uncertainty interval [UI] 12·9–65·4) were blind (crude prevalence 0·48%; 80% UI 0·17–0·87; 56% female), 216·6 million (80% UI 98·5–359·1) people had moderate to severe visual impairment (2·95%, 80% UI 1·34–4·89; 55% female), and 188·5 million (80% UI 64·5–350·2) had mild visual impairment (2·57%, 80% UI 0·88–4·77; 54% female). Functional presbyopia affected an estimated 1094·7 million (80% UI 581·1–1686·5) people aged 35 years and older, with 666·7 million (80% UI 364·9–997·6) being aged 50 years or older. The estimated number of blind people increased by 17·6%, from 30·6 million (80% UI 9·9–57·3) in 1990 to 36·0 million (80% UI 12·9–65·4) in 2015. This change was attributable to three factors, namely an increase because of population growth (38·4%), population ageing after accounting for population growth (34·6%), and reduction in age-specific prevalence (−36·7%). The number of people with moderate and severe visual impairment also increased, from 159·9 million (80% UI 68·3–270·0) in 1990 to 216·6 million (80% UI 98·5–359·1) in 2015. There is an ongoing reduction in the age-standardised prevalence of blindness and visual impairment, yet the growth and ageing of the world's population is causing a substantial increase in number of people affected. These observations, plus a very large contribution from uncorrected presbyopia, highlight the need to scale up vision impairment alleviation efforts at all levels. Brien Holden Vision Institute.

Gichuhi, S, Kabiru J, Zindamoyen AM'bongo, Rono H, Ollando E, Wachira J, Munene R, Onyuma T, Sagoo MS, Macleod D, Weiss HA, Burton MJ.  2017.  Delay along the care-seeking journey of patients with ocular surface squamous neoplasia in Kenya., 2017 Jul 14. BMC health services research. 17(1):485. AbstractWebsite

BACKGROUND:

In Africa, accessing eye health services is a major challenge. Ocular surface squamous neoplasia (OSSN) is a substantial ocular health problem in Africa related to solar UV light exposure and HIV infection among other risk factors. The disease causes visual loss and even death in advanced cases. This study was conducted to assess referral pathway and treatment delay for patients with OSSN in Kenya.
METHODS:

Adults with conjunctival lesions presenting to four eye centres were asked about their occupations, when they noticed the growth, health facilities visited in seeking care, cost of consultation, surgery, medicines and histopathology and dates at each step. The time-to-presentation was divided into quartiles and correlates analysed using ordinal logistic regression.
RESULTS:

We evaluated 158 first-time presenters with OSSN. Most were women (102 [65%]), living with HIV (78/110 tested [71%]), with low to medium income (127 [80%]). Most of the HIV patients (49/78 [63%]) were in antiretroviral care programs. About half (88/158, [56%]) presented directly to the study centres while the rest were referred. Indirect presenters sought care earlier than direct presenters (median 2.0 months vs 5.5 months) and travelled a shorter distance to the first health facility (median 20 km vs 30 km) but had surgery later (median 12.5 months vs 5.5 months). Visits beyond the first health facility for indirect presenters markedly increased delay (median 7.3, 29.0, 37.9, and 32.0 months for 1-4 facilities, respectively). Delay was associated with number of health facilities visited (adjusted ordered OR = 9.12; 95%CI 2.83-29.4, p < 0.001) and being female (adjusted ordered OR = 2.42; 95%CI 1.32-4.44, p = 0.004). At the time of presentation at the study centres for surgery the median tumour diameter in both directly and indirectly presenting patients was 6 mm (p = 0.52) and the histological spectrum of OSSN was similar between the groups (p = 0.87).
CONCLUSIONS:

Referral delays definitive treatment for OSSN. Women were more likely to experience delay. Despite regular contact with the health system for those with known HIV infection, delays occurred. Early detection and referral of OSSN in the HIV service might reduce delays, but reassuringly delay did not give rise to a larger proportion with more advanced grade of OSSN.

2016

Gichuhi, S, Sagoo MS.  2016.  Squamous cell carcinoma of the conjunctiva., 2016. Community eye health. 29(95):52-53.Website
Gichuhi, S, Macharia E, Kabiru J, Zindamoyen AM'bongo, Rono H, Ollando E, Wachira J, Munene R, Onyuma T, Jaoko WG, Sagoo MS, Weiss HA, Burton MJ.  2016.  Risk factors for ocular surface squamous neoplasia in Kenya: a case-control study., 2016 Dec. Tropical medicine & international health : TM & IH. 21(12):1522-1530. AbstractWebsite

OBJECTIVE:
To determine modifiable risk factors of ocular surface squamous neoplasia (OSSN) in Kenya using disease-free controls.

METHODS:
Adults with conjunctival lesions were recruited at four eye care centres in Kenya and underwent excision biopsy. An equal number of controls having surgery for conditions not affecting the conjunctiva and unrelated to ultraviolet light were group-matched to cases by age group, sex and eye care centre. Associations of risk factors with OSSN were evaluated using multivariable logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs). Continuous variables were compared using the t-test or the Wilcoxon-Mann-Whitney U-test depending on their distribution.

RESULTS:
A total of 131 cases and 131 controls were recruited. About two-thirds of participants were female, and the mean age of cases and controls was 42.1 years and 43.3 years, respectively. Risk factors for OSSN were HIV infection without antiretroviral therapy (ART) use (OR = 48.42; 95% CI: 7.73-303.31) and with ART use (OR = 19.16; 95% CI: 6.60-55.57), longer duration of exposure to the sun in the main occupation (6.9 h/day vs. 4.6 h/day, OR = 1.24; 95% CI: 1.10-1.40) and a history of allergic conjunctivitis (OR = 74.61; 95% CI: 8.08-688.91). Wearing hats was protective (OR = 0.22; 95% CI: 0.07-0.63).

CONCLUSION:
Measures to prevent and control HIV, reduce sun exposure such as wearing hats and control allergic conjunctivitis are recommended.

Gichuhi, S, Macharia E, Kabiru J, Zindamoyen AM, Rono H, Ollando E, Wachira J, Munene R, Maina J, Onyuma T, Sagoo MS, Weiss HA, Burton MJ.  2016.  Topical fluorouracil after surgery for ocular surface squamous neoplasia in Kenya: a randomised, double-blind, placebo-controlled trial.. Lancet Glob Health. . 4(6):e378-85. AbstractWebsite

BACKGROUND:

Ocular surface squamous neoplasia (OSSN) is an aggressive eye tumour particularly affecting people with HIV in Africa. Primary treatment is surgical excision; however, tumour recurrence is common. We assessed the effect of fluorouracil 1% eye drops after surgery on recurrence.
METHODS:

We did this multicentre, randomised, placebo-controlled trial in four centres in Kenya. We enrolled patients with histologically proven OSSN aged at least 18 years. After standard surgical excision, participants were randomly allocated to receive either topical fluorouracil 1% or placebo four times a day for 4 weeks. Randomisation was stratified by surgeon, and participants and trial personnel were masked to assignment. Patients were followed up at 1 month, 3 months, 6 months, and 12 months. The primary outcome was clinical recurrence (supported by histological assessment where available) by 1 year, and analysed by intention to treat. The sample size was recalculated because events were more common than anticipated, and trial enrolment was stopped early. The trial was registered with Pan-African Clinical Trials Registry (PACTR201207000396219).
FINDINGS:

Between August, 2012, and July, 2014, we assigned 49 participants to fluorouracil and 49 to placebo. Four participants were lost to follow-up. Recurrences occurred in five (11%) of 47 patients in the fluorouracil group and 17 (36%) of 47 in the placebo group (odds ratio 0·21, 95% CI 0·07-0·63; p=0·01). Adjusting for passive smoking and antiretroviral therapy had little effect (odds ratio 0·23; 95% CI 0·07-0·75; p=0·02). Adverse effects occurred more commonly in the fluorouracil group, although they were transient and mild. Ocular discomfort occurred in 43 of 49 patients in the fluorouracil group versus 36 of 49 in the placebo group, epiphora occurred in 24 versus five, and eyelid skin inflammation occurred in seven versus none.
INTERPRETATION:

Topical fluorouracil after surgery substantially reduced recurrence of OSSN, was well-tolerated, and its use recommended.
FUNDING:

British Council for Prevention of Blindness and the Wellcome Trust.

2015

Gichuhi, S, Macharia E, Kabiru J, Zindamoyen AM, Rono H, Ollando E, Wanyonyi L, Wachira J, Munene R, Onyuma T, Jaoko WG, Sagoo MS, Weiss HA, Burton MJ.  2015.  Toluidine Blue 0.05% Vital Staining for the Diagnosis of Ocular Surface Squamous Neoplasia in Kenya.. JAMA Ophthalmology. 133(11):1314-1321. AbstractWebsite

IMPORTANCE:
Clinical features are unreliable for distinguishing ocular surface squamous neoplasia (OSSN) from benign conjunctival lesions.

OBJECTIVE:
To evaluate the adverse effects, accuracy, and interobserver variation of toluidine blue 0.05% vital staining in distinguishing OSSN, confirmed by histopathology, from other conjunctival lesions.

DESIGN, SETTING, AND PARTICIPANTS:
Cross-sectional study in Kenya from July 2012 through July 2014 of 419 adults with suspicious conjunctival lesions. Pregnant and breastfeeding women were excluded.

EXPOSURES:
Comprehensive ophthalmic slitlamp examination was conducted. Vital staining with toluidine blue 0.05% aqueous solution was performed before surgery. Initial safety testing was conducted on large tumors scheduled for exenteration looking for corneal toxicity on histology before testing smaller tumors. We asked about pain or discomfort after staining and evaluated the cornea at the slitlamp for epithelial defects. Lesions were photographed before and after staining.

MAIN OUTCOMES AND MEASURES:
Diagnosis was confirmed by histopathology. Six examiners assessed photographs from a subset of 100 consecutive participants for staining and made a diagnosis of OSSN vs non-OSSN. Staining was compared with histopathology to estimate sensitivity, specificity, and predictive values. Adverse effects were enumerated. Interobserver agreement was estimated using the κ statistic.

RESULTS:
A total of 143 of 419 participants (34%) had OSSN by histopathology. The median age of all participants was 37 years (interquartile range, 32-45 years) and 278 (66%) were female. A total of 322 of the 419 participants had positive staining while 2 of 419 were equivocal. There was no histological evidence of corneal toxicity. Mild discomfort was reported by 88 (21%) and mild superficial punctate keratopathy seen in 7 (1.7%). For detecting OSSN, toluidine blue had a sensitivity of 92% (95% CI, 87%-96%), specificity of 31% (95% CI, 25%-36%), positive predictive value of 41% (95% CI, 35%-46%), and negative predictive value of 88% (95% CI, 80%-94%). Interobserver agreement was substantial for staining (κ = 0.76) and moderate for diagnosis (κ = 0.40).

CONCLUSIONS AND RELEVANCE:
With the high sensitivity and low specificity for OSSN compared with histopathology among patients with conjunctival lesions, toluidine blue 0.05% vital staining is a good screening tool. However, it is not a good diagnostic tool owing to a high frequency of false-positives. The high negative predictive value suggests that a negative staining result indicates that OSSN is relatively unlikely.

Gichuhi, S, Macharia E, Kabiru J, Zindamoyen AM, Rono H, Ollando E, Wanyonyi L, Wachira J, Munene R, Onyuma T, Sagoo MS, Weiss HA, Burton MJ.  2015.  Clinical Presentation of Ocular Surface Squamous Neoplasia in Kenya.. JAMA Ophthalmology. 133(11):1305-1313. AbstractWebsite

IMPORTANCE:
There is a trend toward treating conjunctival lesions suspected to be ocular surface squamous neoplasia (OSSN) based on the clinical impression.

OBJECTIVE:
To describe the presentation of OSSN and identify clinical features that distinguish it from benign lesions and subsequently evaluate their recognizability.

DESIGN, SETTING, AND PARTICIPANTS:
Prospective multicenter study in Kenya from July 2012 through July 2014 of 496 adults presenting with conjunctival lesions. One histopathologist examined all specimens. Six additional masked ophthalmologists independently examined photographs from 100 participants and assessed clinical features.

EXPOSURES:

Comprehensive history, slit lamp examination, and photography before excision biopsy.

MAIN OUTCOMES AND MEASURES:
Frequency of clinical features in OSSN and benign lesions were recorded. Proportions and means were compared using χ2, Fisher exact test, or t test as appropriate. Interobserver agreement was estimated using the κ statistic. Examiners' assessments were compared with a reference.

RESULTS:
Among 496 participants, OSSN was the most common (38%) histological diagnosis, followed by pterygium (36%) and actinic keratosis (19%). Patients with OSSN were slightly older (mean [SD] age, 41 [11.6] vs 38 [10.9] years; P = .002) and tended to have lower levels of education than patients with benign lesions (P = .001). Females predominated (67% of OSSN vs 64% of benign lesions; P = .65). Human immunodeficiency virus infection was common among patients with OSSN (74%). The most common location was the nasal limbus (61% OSSN vs 78% benign lesions; P < .001). Signs more frequent in OSSN included feeder vessels (odds ratio [OR], 5.8 [95% CI, 3.2-10.5]), moderate inflammation (OR, 3.5 [95% CI, 1.8-6.8]), corneal involvement (OR, 2.7 [95% CI, 1.8-4.0]), leukoplakia (OR, 2.6 [95% CI, 1.7-3.9]), papilliform surface (OR, 2.1 [95% CI, 1.3-3.5]), pigmentation (OR, 1.5 [95% CI, 1.0-2.2]), temporal location (OR, 2.0 [95% CI, 1.2-3.2]), circumlimbal location (6.7% vs 0.3%; P < .001), severe inflammation (6.7% vs 0.3%; P < .001), and larger mean (SD) diameter (6.8 [3.2] vs 4.8 [2.8] mm; P < .001). All OSSN signs were also observed in benign lesions. There was slight to fair inter-observer agreement in assessment of most signs and diagnosis (κ, 0.1-0.4). The positive predictive value of clinical appearance in identifying OSSN was 54% (interquartile range, 51%-56%) from photographs in which prevalence was 32%.

CONCLUSIONS AND RELEVANCE:
With overlapping phenotypes and modest inter-observer agreement, OSSN and benign conjunctival lesions are not reliably distinguished clinically. Point-of-care diagnostic tools may help.

2014

Gichuhi, S, Ohnuma S, Sagoo MS, Burton MJ.  2014.  Pathophysiology of ocular surface squamous neoplasia.. Experimental Eye Research. 129:172-182. Abstractfull text

The incidence of ocular surface squamous neoplasia (OSSN) is strongly associated with solar ultraviolet (UV) radiation, HIV and human papilloma virus (HPV). Africa has the highest incidence rates in the world. Most lesions occur at the limbus within the interpalpebral fissure particularly the nasal sector. The nasal limbus receives the highest intensity of sunlight. Limbal epithelial crypts are concentrated nasally and contain niches of limbal epithelial stem cells in the basal layer. It is possible that these are the progenitor cells in OSSN. OSSN arises in the basal epithelial cells spreading towards the surface which resembles the movement of corneo-limbal stem cell progeny before it later invades through the basement membrane below. UV radiation damages DNA producing pyrimidine dimers in the DNA chain. Specific CC → TT base pair dimer transformations of the p53 tumour-suppressor gene occur in OSSN allowing cells with damaged DNA past the G1-S cell cycle checkpoint. UV radiation also causes local and systemic photoimmunosuppression and reactivates latent viruses such as HPV. The E7 proteins of HPV promote proliferation of infected epithelial cells via the retinoblastoma gene while E6 proteins prevent the p53 tumour suppressor gene from effecting cell-cycle arrest of DNA-damaged and infected cells. Immunosuppression from UV radiation, HIV and vitamin A deficiency impairs tumour immune surveillance allowing survival of aberrant cells. Tumour growth and metastases are enhanced by; telomerase reactivation which increases the number of cell divisions a cell can undergo; vascular endothelial growth factor for angiogenesis and matrix metalloproteinases (MMPs) that destroy the intercellular matrix between cells. Despite these potential triggers, the disease is usually unilateral. It is unclear how HPV reaches the conjunctiva.

Nguena, MB, van den Tweel JG, Makupa W, Hu VH, Weiss HA, Gichuhi S, Burton MJ.  2014.  Diagnosing ocular surface squamous neoplasia in East Africa: case-control study of clinical and in vivo confocal microscopy assessment.. Ophthalmology. 121(2):484-491. Abstract

OBJECTIVE:

To examine the reliability of clinical examination and in vivo confocal microscopy (IVCM) in distinguishing ocular surface squamous neoplasia (OSSN) from benign conjunctival lesions.
DESIGN:

Case-control study.
PARTICIPANTS:

Sixty individuals with conjunctival lesions (OSSN and benign) and 60 age-matched controls with normal conjunctiva presenting to Kilimanjaro Christian Medical Centre, Moshi, Tanzania.
METHODS:

Participants were examined and photographed, and IVCM was performed. Patients with conjunctival lesions were offered excisional biopsy with histopathology and a human immunodeficiency virus (HIV) test. The IVCM images were read masked to the clinical appearance and pathology results. Images were graded for several specific features and given an overall categorization (normal, benign, or malignant). A group of 8 ophthalmologists were shown photographs of conjunctival lesions and asked to independently classify as OSSN or benign.
MAIN OUTCOME MEASURES:

Comparison of the histopathology diagnosis with the clinical and IVCM diagnosis.
RESULTS:

Fifty-two cases underwent excisional biopsy with histopathology; 34 were on the OSSN spectrum, 17 were benign, and 1 was lymphoma. The cases and controls had comparable demographic profiles. Human immunodeficiency syndrome infection was more common in OSSN compared with benign cases (58.8% vs. 5.6%; odds ratio, 24.3, 95% confidence interval [CI], 2.8-204; P = 0.003). Clinically, OSSN lesions more frequently exhibited feeder vessels and tended to have more leukoplakia and a gelatinous appearance. Overall, the ophthalmologists showed moderate agreement with the histology result (average kappa = 0.51; 95% CI, 0.36-0.64). The masked grading of IVCM images reliably distinguished normal conjunctiva. However, IVCM was unable to reliably distinguish between benign lesions and OSSN because of an overlap in their appearance (kappa = 0.44; 95% CI, 0.32-0.57). No single feature was significantly more frequent in OSSN compared with benign lesions. The sensitivity and specificity of IVCM for distinguishing OSSN from benign conjunctival lesions were 38.5% and 66.7%, respectively.
CONCLUSIONS:

In East Africa, conjunctival pathology is relatively common and can present significant diagnostic challenges for the clinician. In this study, neither clinical examination nor IVCM was found to reliably distinguish OSSN from benign conjunctival pathology because of an overlap in the features of these groups. Therefore, IVCM cannot currently replace histopathology, and management decisions should continue to rely on careful clinical assessment supported by histopathology as indicated.

VLEG, GBD.  2014.  Prevalence and causes of vision loss in East Asia: 1990-2010.. British Journal of Ophthalmology. 98(5):599-604. Abstract

AIMS:

To describe the prevalence and causes of visual impairment and blindness in East Asia in 1990 and 2010.

METHOD:

Data from population-based studies conducted from 1980 to 2012 were identified, and eligibility for inclusion was assessed. Data on prevalence of blindness (presenting visual acuity <3/60 in the better eye) and moderate to severe visual impairment (MSVI; presenting visual acuity <6/18 to 3/60 in the better eye) and causes were extracted.

RESULTS:

The age-standardised prevalence of blindness was 0.7% (95% CI 0.6 to 0.9) in 1990 and 0.4% (95% CI 0.3 to 0.5) in 2010, while that of MSVI was 3.6% (95% CI 2.3 to 4.4) and 2.3% (95% CI 1.7 to 2.8), respectively. These prevalence estimates were lower than those of other countries globally. The absolute numbers affected by blindness and MSVI in 2010 were 5.2 million and 33.3 million, respectively, and were higher among women than men. Cataract was the leading cause of blindness, whereas uncorrected refractive error was the leading cause of MSVI.

CONCLUSIONS:

There has been a significant reduction in prevalence of blindness in East Asia, but a substantial absolute number of people remain blind and visually impaired, largely caused by cataract and uncorrected refractive error.

VLEG, GBD.  2014.  Prevalence and causes of vision loss in Southeast Asia and Oceania: 1990-2010.. British Journal of Ophthalmology. 98(5):586-591. Abstract

BACKGROUND:

To assess prevalence and causes of vision impairment in Southeast Asia and Oceania in 1990 and 2010.

METHODS:

Based on a systematic review of medical literature, prevalence of moderate and severe vision impairment (MSVI; presenting visual acuity <6/18 but ≥3/60 in the better eye) and blindness (presenting visual acuity <3/60) was estimated for 1990 and 2010.

RESULTS:

In Oceania, the age-standardised prevalence of blindness and MSVI did not decrease significantly (1.3% to 0.8% and 6.6% to 5.1%) respectively, but in Southeast Asia, blindness decreased significantly from 1.4% to 0.8%, a 43% decrease. There were significantly more women blind (2.18 million) compared with men (1.28 million) in the Southeast Asian population in 2010, but no significant gender differences in MSVI in either subregion. Cataract was the most frequent cause of blindness in Southeast Asia and Oceania in 1990 and 2010. Uncorrected refractive error, followed by cataract, macular degeneration, glaucoma and diabetic retinopathy were the most common causes for MSVI in 1990 and 2010. With the increasing size of the older population, there have been relatively small increases in the number of blind (2%), and with MSVI (14%) in Southeast Asia, whereas increases have been greater in Oceania of 14% for blindness and of 31% for MSVI.

CONCLUSIONS:

The prevalence of blindness has reduced significantly from 1990 to 2010, with moderate but non-significant lowering of MSVI. Cataract and uncorrected refractive error are the main causes of vision impairment and blindness; cataract continues as the main cause of blindness, but at lower proportions.

VLEG, GBD.  2014.  Prevalence and causes of vision loss in Central and South Asia: 1990-2010.. British Journal of Ophthalmology. 98(5):592-598. Abstract

BACKGROUND:

To examine the prevalence, patterns and trends of vision impairment and its causes from 1990 to 2010 in Central and South Asia.

METHODS:

Based on the Global Burden of Diseases Study 2010 and ongoing literature searches, we examined prevalence and causes of moderate and severe vision impairment (MSVI; presenting visual acuity <6/18, ≥3/60) and blindness (presenting visual acuity <3/60).

RESULTS:

In Central Asia, the estimated age-standardised prevalence of blindness decreased from 0.4% (95% CI 0.3% to 0.6%) to 0.2% (95% CI 0.2% to 0.3%) and of MSVI from 3.0% (95% CI 1.9% to 4.7%) to 1.9% (95% CI 1.2% to 3.2%), and in South Asia blindness decreased from 1.7% (95% CI 1.4% to 2.1%) to 1.1% (95% CI 0.9% to 1.3%) and MSVI from 8.9% (95% CI 6.9% to 10.9%) to 6.4% (95% CI 5.2% to 8.2%). In 2010, 135 000 (95% CI 99,000 to 194,000) people were blind in Central Asia and 10,600,000 (95% CI 8,397,000 to 12,500,000) people in South Asia. MSVI was present in 1,178,000 (95% CI 772,000 to 2,243,000) people in the Central Asia, and in 71,600,000 (95% CI 57,600,000 to 92,600,000) people in South Asia. Women were generally more often affected than men. The leading causes of blindness (cataract) and MSVI (undercorrected refractive error) did not change from 1990 to 2010.

CONCLUSIONS:

The prevalence of blindness and MSVI in South Asia is still three times higher than in Central Asia and globally, with women generally more often affected than women. In both regions, cataract and undercorrected refractive error were major causes of blindness and MSVI.

VLEG, GBD.  2014.  Prevalence and causes of vision loss in Latin America and the Caribbean: 1990-2010.. British Journal of Ophthalmology. 98(5):619-628. Abstract

OBJECTIVE:

To present regional estimates of the magnitude and temporal trends in the prevalence and causes of blindness and moderate/severe visual impairment (MSVI) in Latin America and the Caribbean (LAC).

METHODS:

A systematic review of cross-sectional population-representative data from published literature and unpublished studies was accessed and extracted to model the estimated prevalence of vision loss by region, country and globally, and the attributable cause fraction by region.

RESULTS:

In the LAC combined region, estimated all-age both-gender age-standardised prevalence of blindness halved from 0.8% (0.6 to 1.1) in 1990 to 0.4% (0.4 to 0.6) in 2010 and MSVI decreased from 4.3% (3.1 to 5.3) to 2.7% (2.2 to 3.4). In the Caribbean, estimated all-age both-gender age-standardised prevalence of blindness decreased from 0.6% (0.4 to 0.8) in 1990 to 0.5% (0.4 to 0.6) in 2010 and MSVI decreased from 3.3% (1.3 to 4.1) in 1990 to 2.9% (1.8 to 3.8). In the LAC regions combined, there was an estimated 2.3 million blind and 14.1 million with MSVI in 2010. In 2010, cataract continues to contribute the largest proportion of blindness, except in Southern Latin America where macular degeneration is most common. In 2010, uncorrected refractive error was the most common cause of MSVI.

CONCLUSIONS:

While models suggest a decrease in age-standardised prevalence estimates, better data are needed to evaluate the disparities in the region. The increasing numbers of older people, coupled with the increase in vision loss associated with older age, will require further intervention to continue to reduce prevalence rates and to prevent a rise in absolute numbers of blind.

VLEG, GBD.  2014.  Prevalence and causes of vision loss in sub-Saharan Africa: 1990-2010.. British Journal of Ophthalmology. 98(5):612-618. Abstract

AIM:

To estimate the magnitude, temporal trends and subregional variation in the prevalence of blindness, and moderate/severe vision impairment (MSVI) in sub-Saharan Africa.

METHODS:

A systematic review was conducted of published and unpublished population-based surveys as part of the Global Burden of Disease, Risk Factors and Injuries Study 2010. The prevalence of blindness and vision impairment by country and subregion was estimated.

RESULTS:

In sub-Saharan Africa, 52 studies satisfied the inclusion criteria. The estimated age-standardised prevalence of blindness decreased by 32% from 1.9% (95% CI 1.5% to 2.2%) in 1990 to 1.3% (95% CI 1.1% to 1.5%) in 2010 and MSVI by 25% from 5.3% (95% CI 0.2% to 0.3%) to 4.0% (95% CI 0.2% to 0.3%) over that time. However, there was a 16% increase in the absolute numbers with blindness and a 28% increase in those with MSVI. The major causes of blindness in 2010 were; cataract 35%, other/unidentified causes 33.1%, refractive error 13.2%, macular degeneration 6.3%, trachoma 5.2%, glaucoma 4.4% and diabetic retinopathy 2.8%. In 2010, age-standardised prevalence of MSVI in Africa was 3.8% (95% CI 3.1% to 4.7%) for men and 4.2% (95% CI 3.6% to 5.3%) for women with subregional variations from 4.1% (95% CI 3.3% to 5.4%) in West Africa to 2.0% (95% CI 1.5% to 3.3%) in southern Africa for men; and 4.7% (95% CI 3.9% to 6.0%) in West Africa to 2.3% (95% CI 1.7% to 3.8%) in southern Africa for women.

CONCLUSIONS:

The age-standardised prevalence of blindness and MSVI decreased substantially from 1990 to 2010, although there was a moderate increase in the absolute numbers with blindness or MSVI. Significant subregional and gender disparities exist.

VLEG, GBD.  2014.  Prevalence and causes of vision loss in North Africa and the Middle East: 1990-2010.. British Journal of Ophthalmology. 98(5):605-611. Abstract

BACKGROUND:

To describe the prevalence and causes of visual impairment and blindness in North Africa and the Middle East (NAME) in 1990 and 2010.

METHODS:

Based on a systematic review of medical literature, we examined prevalence and causes of moderate and severe vision impairment (MSVI; presenting visual acuity <6/18, ≥3/60) and blindness (presenting visual acuity <3/60).

RESULTS:

In NAME, the age-standardised prevalence of blindness decreased from 2.1% to 1.1% and MSVI from 7.1% to 4.5%. In 2010, 3.119 million people were blind, and 13.700 million had MSVI. Women were generally more often affected than men. Main causes of blindness were cataract, uncorrected refractive error, macular degeneration and glaucoma. Main causes of MSVI were cataract and uncorrected refractive errors. Proportions of blindness and MSVI from trachoma significantly decreased.

CONCLUSIONS:

Although the absolute numbers of people with blindness and MSVI increased from 1990 to 2010, the overall age-standardised prevalence of blindness and MSVI among all ages and among those aged 50 years and older decreased significantly (p<0.05). Cataract and uncorrected refractive error were the major causes of blindness and MSVI.

VLEG, GBD.  2014.  Prevalence and causes of vision loss in high-income countries and in Eastern and Central Europe: 1990-2010.. British Journal of Ophthalmology. 98(5):629-638. Abstract

BACKGROUND:

To assess prevalence and causes of blindness and vision impairment in high-income regions and in Central/Eastern Europe in 1990 and 2010.

METHODS:

Based on a systematic review of medical literature, prevalence of moderate and severe vision impairment (MSVI; presenting visual acuity <6/18 but ≥3/60 in the better eye) and blindness (presenting visual acuity <3/60) was estimated for 1990 and 2010.

RESULTS:

Age-standardised prevalence of blindness and MSVI decreased from 0.2% to 0.1% (3.314 million to 2.736 million people) and from 1.6% to 1.0% (25.362 million to 22.176 million), respectively. Women were generally more affected than men. Cataract was the most frequent cause of blindness in all subregions in 1990, but macular degeneration and uncorrected refractive error became the most frequent causes of blindness in 2010 in all high-income countries, except for Eastern/Central Europe, where cataract remained the leading cause. Glaucoma and diabetic retinopathy were fourth and fifth most common causes for blindness for all regions at both times. Uncorrected refractive error, followed by cataract, macular degeneration, glaucoma and diabetic retinopathy, was the most common cause for MSVI in 1990 and 2010.

CONCLUSIONS:

In highly developed countries, prevalence of blindness and MSVI has been reduced by 50% and 38%, respectively, and the number of blind people and people with MSVI decreased by 17.4% and 12.6%, respectively, even with the increasing number of older people in the population. In high-income countries, macular degeneration has become the most important cause of blindness, but uncorrected refractive errors continue to be the leading cause of MSVI.

Gichuhi, S, Onyuma T, Macharia E, Kabiru J, Zindamoyen AM, Sagoo MS, Burton MJ.  2014.  Ocular rhinosporidiosis mimicking conjunctival squamous papilloma in Kenya - a case report.. BMC Ophthalmology. 45(14) Abstract

BACKGROUND:

Ocular rhinosporidiosis is a chronic granulomatous infection caused by a newly classified organism that is neither a fungus nor bacterium. It often presents as a benign conjunctival tumour but may mimic other ocular conditions. It is most often described in India. In Africa cases have been reported from South Africa, Kenya, Tanzania, Malawi, Uganda, Congo and Ivory Coast.

CASE PRESENTATION:

A 54 year old man was seen in Kenya with a lesion that resembled a conjunctival papilloma. We report resemblance to conjunctival papilloma and the result of vital staining with 0.05% Toluidine Blue.

CONCLUSION:

Ocular rhinosporidiosis occurs in East Africa. It may resemble conjunctival squamous papilloma. Vital staining with 0.05% Toluidine blue dye did not distinguish the two lesions well.

2013

of Group, GBD.  2013.  Causes of vision loss worldwide, 1990-2010: a systematic analysis.. Lancet Global Health. 1(6):e339–e349. Abstract

BACKGROUND:

Data on causes of vision impairment and blindness are important for development of public health policies, but comprehensive analysis of change in prevalence over time is lacking.

METHODS:

We did a systematic analysis of published and unpublished data on the causes of blindness (visual acuity in the better eye less than 3/60) and moderate and severe vision impairment ([MSVI] visual acuity in the better eye less than 6/18 but at least 3/60) from 1980 to 2012. We estimated the proportions of overall vision impairment attributable to cataract, glaucoma, macular degeneration, diabetic retinopathy, trachoma, and uncorrected refractive error in 1990-2010 by age, geographical region, and year.

FINDINGS:

In 2010, 65% (95% uncertainty interval [UI] 61-68) of 32·4 million blind people and 76% (73-79) of 191 million people with MSVI worldwide had a preventable or treatable cause, compared with 68% (95% UI 65-70) of 31·8 million and 80% (78-83) of 172 million in 1990. Leading causes worldwide in 1990 and 2010 for blindness were cataract (39% and 33%, respectively), uncorrected refractive error (20% and 21%), and macular degeneration (5% and 7%), and for MSVI were uncorrected refractive error (51% and 53%), cataract (26% and 18%), and macular degeneration (2% and 3%). Causes of blindness varied substantially by region. Worldwide and in all regions more women than men were blind or had MSVI due to cataract and macular degeneration.

INTERPRETATION:

The differences and temporal changes we found in causes of blindness and MSVI have implications for planning and resource allocation in eye care.

Do, DV, Gichuhi S, Vedula SS, Hawkins BS.  2013.  Surgery for post-vitrectomy cataract (update of 2011). : Cochrane Eyes & Vision Group Abstract

BACKGROUND:

Cataract formation or acceleration can occur after intraocular surgery, especially following vitrectomy, a surgical technique for removing the vitreous which is used in the treatment of disorders that affect the posterior segment of the eye. The underlying problem that led to vitrectomy may limit the benefit from cataract surgery.

OBJECTIVES:

The objective of this review was to evaluate the effectiveness and safety of surgery for post-vitrectomy cataract with respect to visual acuity, quality of life, and other outcomes.

SEARCH METHODS:

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 4), Ovid MEDLINE, Ovid MEDLINE in-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily Update, Ovid OLDMEDLINE (January 1946 to May 2013), EMBASE (January 1980 to May 2013, Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to May 2013), PubMed (January 1946 to May 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrial.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 22 May 2013.

SELECTION CRITERIA:

We planned to include randomized and quasi-randomized controlled trials comparing cataract surgery with no surgery in adult patients who developed cataract following vitrectomy.

DATA COLLECTION AND ANALYSIS:

Two authors screened the search results independently according to the standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS:

We found no randomized or quasi-randomized controlled trials comparing cataract surgery with no cataract surgery for patients who developed cataracts following vitrectomy surgery.

AUTHORS' CONCLUSIONS:

There is no evidence from randomized or quasi-randomized controlled trials on which to base clinical recommendations for surgery for post-vitrectomy cataract. There is a clear need for randomized controlled trials to address this evidence gap. Such trials should stratify participants by their age, the retinal disorder leading to vitrectomy, and the status of the underlying disease process in the contralateral eye. Outcomes assessed in such trials may include gain of vision on the Early Treatment Diabetic Retinopathy Study (ETDRS) scale, quality of life, and adverse events such as posterior capsular rupture. Both short-term (six-month) and long-term (one-year or two-year) outcomes should be examined.

GBD, VLEG.  2013.  Global Prevalence of Vision Impairment and Blindness: Magnitude and Temporal Trends, 1990-2010. Ophthalmology. 120(12):2377-84. Abstract

PURPOSE:

Vision impairment is a leading and largely preventable cause of disability worldwide. However, no study of global and regional trends in the prevalence of vision impairment has been carried out. We estimated the prevalence of vision impairment and its changes worldwide for the past 20 years.

DESIGN:

Systematic review.

PARTICIPANTS:

A systematic review of published and unpublished population-based data on vision impairment and blindness from 1980 through 2012.

METHODS:

Hierarchical models were fitted fitted to estimate the prevalence of moderate and severe vision impairment (MSVI; defined as presenting visual acuity <6/18 but ≥ 3/60) and the prevalence of blindness (presenting visual acuity <3/60) by age, country, and year.

MAIN OUTCOME MEASURES:

Trends in the prevalence of MSVI and blindness for the period 1990 through 2010.

RESULTS:

Globally, 32.4 million people (95% confidence interval [CI], 29.4-36.5 million people; 60% women) were blind in 2010, and 191 million people (95% CI, 174-230 million people; 57% women) had MSVI. The age-standardized prevalence of blindness in older adults (≥ 50 years) was more than 4% in Western Sub-Saharan Africa (6.0%; 95% CI, 4.6%-7.1%), Eastern Sub-Saharan Africa (5.7%; 95% CI, 4.4%-6.9%), South Asia (4.4%; 95% CI, 3.5%-5.1%), and North Africa and the Middle East (4.6%; 95% CI, 3.5%-5.8%), in contrast to high-income regions with blindness prevalences of ≤ 0.4% or less. The MSVI prevalence in older adults was highest in South Asia (23.6%; 95% CI, 19.4%-29.4%), Oceania (18.9%; 95% CI, 11.8%-23.7%), and Eastern and Western Sub-Saharan Africa and North Africa and the Middle East (95% CI, 15.9%-16.8%). The MSVI prevalence was less than 5% in all 4 high-income regions. The global age-standardized prevalence of blindness and MSVI for older adults decreased from 3.0% (95% CI, 2.7%-3.4%) worldwide in 1990 to 1.9% (95% CI, 1.7%-2.2%) in 2010 and from 14.3% (95% CI, 12.1%-16.2%) worldwide to 10.4% (95% CI, 9.5%-12.3%), respectively. When controlling for age, women's prevalence of blindness was greater than men's in all world regions. Because the global population has increased and aged between 1990 and 2010, the number of blind has increased by 0.6 million people (95% CI, -5.2 to 5.3 million people). The number with MSVI may have increased by 19 million people (95% CI, -8 to 72 million people) from 172 million people (95% CI, 142-198 million people) in 1990.

CONCLUSIONS:

The age-standardized prevalence of blindness and MSVI has decreased in the past 20 years. However, because of population growth and the relative increase in older adults, the blind population has been stable and the population with MSVI may have increased

Gichuhi, S, Sagoo MS, Weiss HA, Burton MJ.  2013.  Epidemiology of ocular surface squamous neoplasia in Africa. Trop Med Int Health.. 18(12):1424-43. Abstract

OBJECTIVES:

To describe the epidemiology and an aetiological model of ocular surface squamous neoplasia (OSSN) in Africa.

METHODS:

Systematic and non-systematic review methods were used. Incidence was obtained from the International Agency for Research on Cancer. We searched PubMed, EMBASE, Web of Science and the reference lists of articles retrieved. Meta-analyses were conducted using a fixed-effects model for HIV and cigarette smoking and random effects for human papilloma virus (HPV).

RESULTS:

The incidence of OSSN is highest in the Southern Hemisphere (16° South), with the highest age-standardised rate (ASR) reported from Zimbabwe (3.4 and 3.0 cases/year/100 000 population for males and females, respectively). The mean ASR worldwide is 0.18 and 0.08 cases/year/100 000 among males and females, respectively. The risk increases with exposure to direct daylight (2-4 h, OR = 1.7, 95% CI: 1.2-2.4 and ≥5 h OR = 1.8, 95% CI: 1.1-3.1) and outdoor occupations (OR = 1.7, 95% CI: 1.1-2.6). Meta-analysis also shows a strong association with HIV (6 studies: OR = 6.17, 95% CI: 4.83-7.89) and HPV (7 studies: OR = 2.64, 95% CI: 1.27-5.49) but not cigarette smoking (2 studies: OR = 1.40, 95% CI: 0.94-2.09). The effect of atopy, xeroderma pigmentosa and vitamin A deficiency is unclear.

CONCLUSIONS:

Africa has the highest incidence of OSSN in the world, where males and females are equally affected, unlike other continents where male disease predominates. African women probably have increased risk due to their higher prevalence of HIV and HPV infections. As the survival of HIV-infected people increases, and given no evidence that anti-retroviral therapy (ART) reduces the risk of OSSN, the incidence of OSSN may increase in coming years.

Cheserem, EJ, Kihara AB, Kosgei RJ, Gathara D, Gichuhi, S.  2013.  Ovarian cancer in Kenyatta National Hospital in Kenya: Characteristics and management. Open Journal of Obstetrics and Gynecology. 3(1A):165-171. Abstract

Background: Ovarian cancer is the third commonest cause of cancer death from gynaecologic tumors in Kenya. Early disease causes minimal, nonspecific, or no symptoms therefore, most patients are diagnosed when the disease is at an advanced stage. Overall, prognosis for these patients remains poor but has not been described in Kenya.
Objectives: To describe the histological types, therapeutic methods used, therapeutic outcome and the survival rate at 2 years.
Methods: This was a retrospective cross-sectional descriptive study undertaking a 10-year review of case records of patients treated for cancer of the ovary between 1998 and 2008 in Kenyatta National Hospital. Results: Majority of the patients (73.3%) presented with advanced stage of disease (stages III & IV). Epithelial tumors (86.2%) are the commonest histological type, with 45.7% of them being serous type. Chemotherapy was the most (46.0%) used therapeutic option, with vomiting and diarrhea being the leading morbidity associated with it. Survival at 2 yrs from diagnosis was 50% as per the Kaplan-Meier time survival estimate.
Conclusion: There is need to improve the quality of data on cancer care and information systems in general to provide a reliable source of information to guide research and policy in oncology. Further, the late presentation to hospital calls for innovative strategies to improve ovarian cancer awareness and uptake of screening tests. There is need to lobby Governments in resource limited setting to subsidize cancer of the ovary care and invest in lower level health facilities to promote early diagnosis and decongest the referral hospital.

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