Bio

DR. GICHUHI STEPHEN

Areas Of Specialization

1. Anterior segment diseases

2. Evidence-based medicine

Research Interests

  • Ocular surface squamous neoplasia

Publications


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.

Kiage, D, Kherani IN, Gichuhi S, Damji KF, Nyenze M.  2013.  The Muranga Teleophthalmology Study: Comparison of Virtual (Teleglaucoma) with in-Person Clinical Assessment to Diagnose Glaucoma.. Middle East Afr J Ophthalmol.. 20(2):150-157. Abstract

PURPOSE:

While the effectiveness of teleophthalmology is generally accepted, its ability to diagnose glaucomatous eye disease remains relatively unknown. This study aimed to compare a web-based teleophthalmology assessment with clinical slit lamp examination to screen for glaucoma among diabetics in a rural African district.

MATERIALS AND METHODS:

Three hundred and nine diabetic patients underwent both the clinical slit lamp examination by a comprehensive ophthalmologist and teleglaucoma (TG) assessment by a glaucoma subspecialist. Both assessments were compared for any focal glaucoma damage; for TG, the quality of photographs was assessed, and vertical cup-to-disk ratio (VCDR) was calculated in a semi-automated manner. In patients with VCDR > 0.7, the diagnostic precision of the Frequency Doubling Technology (FDT) C-20 screening program was assessed.

RESULTS:

Of 309 TG assessment photos, 74 (24%) were deemed unreadable due to media opacities, patient cooperation, and unsatisfactory photographic technique. While the identification of individual optic nerve factors showed either fair or moderate agreement, the ability to diagnose glaucoma based on the overall assessment showed moderate agreement (Kappa [κ] statistic 0.55% and 95% confidence interval [CI]: 0.48-0.62). The use of FDT to detect glaucoma in the presence of disc damage (VCDR > 0.7) showed substantial agreement (κ statistic of 0.84 and 95% CI 0.79-0.90). A positive TG diagnosis of glaucoma carried a 77.5% positive predictive value, and a negative TG diagnosis carried an 82.2% negative predicative value relative to the clinical slit lamp examination.

CONCLUSION:

There was moderate agreement between the ability to diagnose glaucoma using TG relative to clinical slit lamp examination. Poor quality photographs can severely limit the ability of TG assessment to diagnose optic nerve damage and glaucoma. Although further work and validation is needed, the TG approach provides a novel, and promising method to diagnose glaucoma, a major cause of ocular morbidity throughout the world.

Gichuhi, S, Irlam JH.  2013.  Interventions for squamous cell carcinoma of the conjunctiva in HIV-infected individuals. [update of 2007]. : Cochrane Collaboration Abstract

BACKGROUND:

Squamous cell carcinoma of the conjunctiva is described in the ophthalmic literature as a rare, slow-growing tumour of the eye, normally affecting elderly men around 70 years of age. In Africa, however, the disease is different. The incidence is rising rapidly, affecting young persons (around 35 years of age), and usually affecting women. It is more aggressive, with a mean history of three months at presentation. This pattern is related to the co-existence of the HIV/AIDS pandemic, high HPV exposure, and solar radiation in the region. Various interventions exist, but despite therapy, there is a high recurrence rate (up to 43%) and poor cosmetic results in late disease. This review was conducted to evaluate the interventions for treatment of conjunctival squamous cell carcinoma in HIV-infected individuals.

OBJECTIVES:

To evaluate the effect of interventions for treating squamous cell carcinoma of the conjunctiva in HIV-infected individuals on local control, recurrence, death, time to recurrence, and adverse events.

SEARCH METHODS:

Using a sensitive search strategy, we attempted to identify all relevant trials, regardless of language or publication status, from the following electronic databases; PubMedPubMed, EMBASE and The Cochrane Library. We also searched clinical trial registries; WHO International Clinical Trials Registry Platform (ICTRP) and the US National Institutes of Health Clinicaltrials.gov. We searched the international conference proceedings of HIV/AIDS and AIDS-related cancers from the AIDS Education Global Education System (AEGIS). Searches were conducted between January and February 2012.

SELECTION CRITERIA:

Randomised controlled trials (RCTs) involving HIV-infected individuals with ocular surface squamous neoplasia.

DATA COLLECTION AND ANALYSIS:

We independently screened the results of the search to select potentially relevant studies and to retrieve the full articles. We independently applied the inclusion criteria to the potentially relevant studies. No studies were identified that fulfilled the selection criteria.

MAIN RESULTS:

No RCTs of interventions currently used against conjunctival squamous cell carcinoma in HIV-infected individuals were identified.There is one ongoing RCT in Kenya that was registered in July 2012.

AUTHORS' CONCLUSIONS:

Implications for practice: Current clinical practice in treatment of squamous cell carcinoma of the conjunctiva rests on a weak evidence base of case series and case reports.Implications for research: Randomised controlled trials for treatment of this disease are needed in settings where it occurs most frequently. Preventive interventions also need to be identified. HIV/AIDS research has not focused on treatment of this tumour.

Update of
Cochrane Database Syst Rev. 2007;(2):CD005643.

of Group, GBDVLE.  2013.  New Systematic Review Methodology for Visual Impairment and Blindness for the 2010 Global Burden of Disease Study. Ophthalmic Epidemiology. 20(1):33–39. Abstract

Purpose: To describe a systematic review of population-based prevalence studies of visual impairment (VI) and
blindness worldwide over the past 32 years that informs the Global Burden of Diseases, Injuries and Risk
Factors Study.
Methods: A systematic review (Stage 1) of medical literature from 1 January 1980 to 31 January 2012 identified
indexed articles containing data on incidence, prevalence and causes of blindness and VI. Only cross-sectional
population-based representative studies were selected from which to extract data for a database of age- and sex-specific data of prevalence of four distance and one near vision loss categories (presenting and best-corrected).
Unpublished data and data from studies using rapid assessment methodology were later added (Stage 2).
Results: Stage 1 identified 14,908 references, of which 204 articles met the inclusion criteria. Stage 2 added
unpublished data from 44 rapid assessment studies and four other surveys. This resulted in a final dataset of
252 articles of 243 studies, of which 238 (98%) reported distance vision loss categories. A total of 37 studies of
the final dataset reported prevalence of mild VI and four reported near VI.
Conclusion: We report a comprehensive systematic review of over 30 years of VI/blindness studies. While there
has been an increase in population-based studies conducted in the 2000s compared to previous decades, there is limited information from certain regions (eg, Central Africa and Central and Eastern Europe, and the Caribbean
and Latin America), and younger age groups, and minimal data regarding prevalence of near vision and mild
distance VI.

2012

Group, GBDVLE.  2012.  Global Burden of Visual Impairment and Blindness. Archives of Ophthalmology. 130(5):645-647.

2011

Do, DV, Hawkins BS, Gichuhi S, Vedula SS.  2011.  Surgery for post-vitrectomy cataract (Review). Abstract

Cataract formation or acceleration can occur after intraocular surgery, especially following vitrectomy, a surgical technique for removing the vitreous used in the treatment of disorders that affect the posterior segment of the eye.The underlying problemthat led to vitrectomy may limit benefit from cataract surgery. Objectives The objective of this review was to evaluate benefits and adverse outcomes of surgery for post-vitrectomy cataract with respect to visual acuity, quality of life, and other outcomes. Search strategy We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 2), MEDLINE (January 1950 to April 2011), EMBASE (January 1980 to April 2011), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to April 2011), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrial.gov) and the Australian New Zealand Clinical Trials Registry (ANZCTR) (www.anzctr.org.au). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 19 April 2011. Selection criteria We planned to include randomized and quasi-randomized 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. No studies were eligible for inclusion in the review. Main results We found no randomized or quasi-randomized trials comparing cataract surgery with no cataract surgery for patients who developed cataracts following vitrectomy surgery. 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 pathologic process in the contralateral eye. Outcomes assessed in such trials may include gain of 8 or more letters 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 months) and long-term (oneyear or two-years) outcomes should be examined.

2010

Gichuhi, S.  2010.  Cost analysis of treating a corneal ulcer., August 2010. Ophthalmological Society of East Africa (OSEA) annual conference. , Dar es Salaam, Tanzaniacost_analysis_of_treating_a_corneal_ulcer.pdf
Gichuhi S.  2010.  Partners in Prevention HSV/HIV Transmission Study Team. Acyclovir and transmission of HIV-1 from Persons infected with HIV-1 and HSV-2. . N Engl J Med. 2010 Feb 4;362(5):. Epub 2010 J. :427-39.: Elsevier AbstractWebsite

BACKGROUND: Most persons who are infected with human immunodeficiency virus type 1 (HIV-1) are also infected with herpes simplex virus type 2 (HSV-2), which is frequently reactivated and is associated with increased plasma and genital levels of HIV-1. Therapy to suppress HSV-2 reduces the frequency of reactivation of HSV-2 as well as HIV-1 levels, suggesting that suppression of HSV-2 may reduce the risk of transmission of HIV-1. METHODS: We conducted a randomized, placebo-controlled trial of suppressive therapy for HSV-2 (acyclovir at a dose of 400 mg orally twice daily) in couples in which only one of the partners was seropositive for HIV-1 (CD4 count, > or = 250 cells per cubic millimeter) and that partner was also infected with HSV-2 and was not taking antiretroviral therapy at the time of enrollment. The primary end point was transmission of HIV-1 to the partner who was not initially infected with HIV-1; linkage of transmissions was assessed by means of genetic sequencing of viruses. RESULTS: A total of 3408 couples were enrolled at 14 sites in Africa. Of the partners who were infected with HIV-1, 68% were women, and the baseline median CD4 count was 462 cells per cubic millimeter. Of 132 HIV-1 seroconversions that occurred after randomization (an incidence of 2.7 per 100 person-years), 84 were linked within couples by viral sequencing: 41 in the acyclovir group and 43 in the placebo group (hazard ratio with acyclovir, 0.92, 95% confidence interval [CI], 0.60 to 1.41; P=0.69). Suppression with acyclovir reduced the mean plasma concentration of HIV-1 by 0.25 log(10) copies per milliliter (95% CI, 0.22 to 0.29; P<0.001) and the occurrence of HSV-2-positive genital ulcers by 73% (risk ratio, 0.27; 95% CI, 0.20 to 0.36; P<0.001). A total of 92% of the partners infected with HIV-1 and 84% of the partners not infected with HIV-1 remained in the study for 24 months. The level of adherence to the dispensed study drug was 96%. No serious adverse events related to acyclovir were observed. CONCLUSIONS: Daily acyclovir therapy did not reduce the risk of transmission of HIV-1, despite a reduction in plasma HIV-1 RNA of 0.25 log(10) copies per milliliter and a 73% reduction in the occurrence of genital ulcers due to HSV-2. (ClinicalTrials.gov number, NCT00194519.) 2010 Massachusetts Medical Society

2009

Nderi, GJ, Gichuhi S, Kollman M, Matende I.  2009.  Outcome of glaucoma surgery at Mombasa Lighthouse for Christ Eye Center. East African Journal of Ophthalmology. : Elsevier Abstract

OBJECTIVES:
The main objective was to evaluate the outcome of glaucoma surgeries in a centre for eye care in Kenya.
 
DESIGN:
Retrospective case series.
 
SETTING:
The study was conducted at Mombasa Light House for Christ Eye Centre- Kenya.
 
SUBJECTS:
All patients diagnosed to have glaucoma and managed by surgery between 2004-2007.
 
MATERIALS AND METHODS:
Records from 2004 to 2007 were retrieved and data collected on the surgeries done using a structured questionnaire. 2008 was left for follow up to avail a one year minimum follow up time.
Analysis was done using SPSS version 13.
 
RESULTS:
265 operations were recorded in this period. 213 were retrieved and the outcomes analysed. There was good IOP control over the follow up period with a gradual rise post operation, though the pressures remained within normal. Most of the patients were controlled with no need for medications, or much less medication use.
 
The average intra-ocular pressure at two year follow up was 15.0mmHg against a baseline of 28.7mmHg (p< 0.001). 29 eyes (13.6%) required medication for intra-ocular pressure control. One type of medication was able to control the pressures post operatively. Surgery reduced topical antiglaucoma medication use by 72%.
 
 
CONCLUSION:
Intra-ocular pressure was well controlled surgically for the two year follow up.
 
RECOMENDATIONS:
Surgical intervention can be taken as a first option for glaucoma control in our set up, especially as most of our patients present late.

Mingaine M, K G, Gichuhi S, J K.  2009.  Intraocular pressure changes in eyes receiving intravitreal acetonide in Kikuyu Eye Unit. . East African Journal of Ophthalmology. : Elsevier Abstract

Objective: To determine the magnitude and pattern of intraocular pressure (IOP) changes in eyes that received intravitreal triamcinolone acetonide (IVTA) in Kikuyu Eye Unit.
Study Design: Retrospective interventional case series.
Setting: Kikuyu Eye Unit.
Subjects: Seventy-two eyes (of 61 patients) injected between January 2007 and August 2008.
Methods: Data on intraocular pressure (IOP), diagnosis, additional procedures and treatment was collected using questionnaires and analysed using SPSS version 11.5. 
Results: The mean pre-injection IOP was 16.0 (SD 5.2) mmHg, which increased to 23.8 (SD 11.5) mmHg after IVTA injection (p<0.001). IOP started increasing significantly within 2 weeks (p=0.006). The median post-injection time before IOP peak was 4.6 weeks, and IOP remained high for 24 weeks after injection. Intraocular pressure increase of 5 mmHg or more was found in 39 (54.2%) eyes, while that of 10 mmHg or more was found in 22 (30.1%). Thirty-three eyes (45.8%) had maximum post-injection IOP beyond 21 mmHg. Twenty-two eyes (30.6%) received treatment for IOP elevation. Eyes with pre-injection IOP of more than 21 mmHg were associated with significantly higher IOP increases (p<0.001) and all received pressure-lowering medication. No associations were noticed between age, sex, other procedures, diagnosis and pattern of IOP change.
Conclusions: Intraocular increase was found to be a common complication of IVTA, and the increase occurred in the first six months.
 

Kiage, DO, Damji FK, Gichuhi S, Gradin D.  2009.  Ahmed Glaucoma Valve Implant: Experience in East Africa.. Middle East African Journal of Ophthalmology. 16(3):157-161.: Elsevier AbstractWebsite

Purpose: To describe short term outcomes of Ahmed Glaucoma Valve [AGV] implantation in East African patients.Materials and Methods: In this multi-center retrospective case series we reviewed eyes of Black African patients with refractory glaucoma, treated consecutively with Ahmed Glaucoma Valve implantation, in two centers in Kenya between January 2006 and October 2007.Results: About 25 cases including 18 [72%] pediatric eyes and seven [28%] adult eyes were identified. Results have been presented with a median follow-up of two months with inter-quartile range [IQR] of one to 12 months. intraocular pressure [IOP] was reduced from a mean of 36.4 mmHg preoperatively to 16.7 mmHg and glaucoma medications were lowered from a mean of 1.32 before surgery to 0.2 after surgery. The success rate during short term follow-up was 79%. The mean visual acuity dropped slightly from 6/18 pre-operatively to 6/24. There was only one major complication of an extruded, infected valve in a child.Conclusions: The Ahmed Valve Implant is safe and effective in lowering IOP for the short term in pediatric and adult East African patients with refractory glaucoma. Further studies with more patients and longer term follow-up are needed in this population.Key words: Aqueous Rainage Devices, Glaucoma Surgery, Intraocular Pressure

Gichuhi, S, Bosire R, Mbori-Ngacha D, Gichuhi CM, Wamalwa D.  2009.  Risk factors for neonatal conjunctivitis in babies of HIV-1 infected mothers. Ophthalmic Epidemiology. 16(6):337-345.: Elsevier Abstract

PURPOSE:
To determine the prevalence and correlates of neonatal conjunctivitis in infants born to human immunodeficiency virus type 1 (HIV-1) infected mothers.

METHODS:
This was a nested case-control study within a perinatal HIV-1 cohort. HIV-1 seropositive mothers were enrolled during pregnancy and mother-infant pairs followed after delivery with assessment for neonatal conjunctivitis at 48 hours and up to 4 weeks after birth. Genital infections (chlamydia, gonorrhea, syphilis, trichomonas, bacterial vaginosis, and candida) were screened for at 32 weeks gestation. Mothers received treatment for genital infections diagnosed during pregnancy and short-course zidovudine. Newborns did not receive ocular prophylaxis at hospital deliveries. Multivariate logistic regression models were used to determine cofactors for neonatal conjunctivitis overall and stratified for infant HIV-1 status.

RESULTS:
Four hundred and fifty-two infants were assessed and 101 (22.3%) had neonatal conjunctivitis during the first month postpartum. In multivariate analyses using odds ratios (OR) and confidence intervals (CI), neonatal conjunctivitis was associated with neonatal sepsis (adjusted OR 21.95, 95% CI 1.76, 274.61), birth before arrival to hospital (adjusted OR 13.91, 95% CI 1.39, 138.78) and birth weight (median 3.4 versus 3.3 kilograms, p=0.016, OR 1.79, 95% CI 1.01, 3.15). Infant HIV-1 infection was not associated with conjunctivitis.

CONCLUSIONS:
Despite detection and treatment of genital infections during pregnancy, neonatal conjunctivitis was frequently diagnosed in infants born to HIV-1 infected mothers suggesting a need for increased vigilance and prophylaxis for conjunctivitis in these infants. Neonatal sepsis, birth before arrival to hospital, and higher birthweight are factors that may predict higher risk of neonatal conjunctivitis in this population.

2008

Gradin, D, Gichuhi S.  2008.  Unilateral axial length elongation with chronic traumatic cataracts in young Kenyans. . J Cataract Refract Surg . 34(9):1566-1570. AbstractWebsite

PURPOSE:
To assess whether unilateral axial elongation in chronic traumatic cataract is associated with the time interval from trauma to surgery.

SETTING:
PCEA Kikuyu Hospital Eye Unit, Nairobi, Kenya.

METHODS:
This retrospective cohort study analyzed patients with traumatic cataract operated on between 1998 and 2007. Study patients (n = 13) had a delay from trauma to surgery of more than 1 year and an interocular axial length (AL) difference greater than 1.0 mm. Randomly selected age-matched control patients (n = 14) had less than 1 year delay between trauma and surgery. The correlation between interocular AL difference and surgical delay was calculated in each group.

RESULTS:
The median interval from trauma to surgical treatment in study patients was 8 years (range 1 to 27 years). Study patients had a significantly higher median interocular AL difference (3.09 mm; interquartile range [IQR] 2.45 to 4.13 mm) than control patients (0.24 mm; IQR 0.15 to 0.30 mm) (P = .000). The length of delay from trauma to surgical treatment did not correlate strongly with the interocular AL difference in study or control patients (R(2) = 0.0143 and R(2) = 0.1697, respectively).

CONCLUSIONS:
Unilateral AL elongation may occur in young adults with chronic traumatic cataract. Delay of more than 1 year from trauma to surgery was associated with axial elongation, although the degree of elongation did not correlate with duration of delay. Surgeons are advised to implant lower-power intraocular lenses in such patients based on biometry readings to avoid postoperative refractive surprises.

Murithi, I, Gichuhi S, Njuguna MW.  2008.  Ocular injuries in children.. East Afr Med J. . 85(1):39-45. Abstract

OBJECTIVES: To describe the epidemiology, referral system and visual outcomes of eye injuries in children. DESIGN: Retrospective case series. SETTING: Kenyatta National Hospital (KNH) Nairobi, Kenya. SUBJECTS: Children aged upto 15 years with eye injuries hospitalised between January 1 st, 2000 and December 31st, 2004. RESULTS: There were 182 cases. Male: female ratio was 2:1. Median age was seven years (IQR 4-10) with bimodal peaks at four and seven years. The most common cause (35%) was sticks. One hundred and twenty seven cases (70%) were open- globe injuries. One hundred and fourty one (77%) presented with visual acuity worse than 6/60 seven eyes were badly damaged and were removed (evisceration enucleation). Ninety five children (52%) were referred from Central and Eastern provinces while 87 (48%) were from Nairobi province. Most [26 (31%)] cases in Nairobi were from Kibera, Dandora and Kariobangi. Median duration between injury and arrival at first medical facility was one day but three days from injury to KNH after referral. Only 29% got tetanus toxoid, antibiotics, analgesics or eyepads at the referring facility. Median hospitalisation was seven days with a median bill of KSh 5,275/= (US$ 70.00). Fourty four children (24%) had their bills waived for inability to pay. At the last recorded follow-up 81 (57%) children had better visual acuity, 16.9% had light perception (PL). Corneal scar was the most common complication. CONCLUSIONS: Eye injuries in KNH are severe, mostly affecting pre-school children from low-income settings. There is delay in arriving at KNH and inadequate care at the referring centres. Outcomes were poor although better than on admission. This may affect education, careers and quality-of-life. Injury-prevention programmes are recommended. PMID: 18543526 [PubMed - indexed for MEDLINE]

Kimani, K, Karimurio J, Gichuhi S, Marco S, Nyaga G, Wachira J, Ilako D.  2008.  Barriers to utilization of eye care services in Kibera and Dagoreti Divisions of Nairobi, Kenya. East African Journal of Ophthalmology. 14(2):55-61. Abstract

OBJECTIVE: To determine the barriers to uptake of eye care services and to establish the pattern of utilization of eye care services in the Nairobi Comprehensive Eye Care Services (NCES) Project; the catchment area of the Mbagathi District Eye Unit of Nairobi. DESIGN: Community based survey conducted from 15th to 31st October 2007. Setting: Kibera and Dagoreti divisions of Nairobi City. SUBJECTS: Of the 4,200 people of all ages who were randomly selected; 4,056 were examined giving a response rate of 96.6%. Of those not examined, 126 (3.0%) were not available and 15 (0.4%) refused to be examined. Mean age of the study population was 22 years. RESULTS: A total of 294 subjects (7.2%) despite having some ocular disorder, had not visited any health facility to seek treatment. The majority, 144 (49%) gave the reason as no perceived need to seek treatment as the problem did not bother them; especially those with refractive error. A third, 97 (33%), gave the reason as lack of money, 22 (7.5%) said that they did not know where to seek eye care and 20 (6.8%) said they had no time to seek eye care. Only 3 said that the health facility where to go for eye care was too far. The population in the survey area has vast number of nearby secondary and tertiary eye care facilities to choose from. The majority of subjects indicated Mbagathi District Hospital (20.9%), Kikuyu Eye Unit (18.5%), Kenyatta National Hospital (12.1%) and private clinics (10.9%) as their health facilities of choice for eye care. The rest preferred Lions Sight First Eye Hospital, St Mary's Hospital, City Council Health Centers and optical shops. 7.7% of the subjects would visit a health centre or dispensary if they had an eye problem. A signifi cant proportion of respondents (7.5%) had no idea where they could seek treatment for eye disorders; most of them knew Mbagathi District Hospital and Kenyatta National Hospital but were not aware that eye care services were available at these facilities. CONCLUSION: Despite the large number of eye care facilities surrounding the NCES, community members are not able to access their services mainly because of lack of felt need (ignorance) and lack of money (poverty). RECOMMENDATIONS: There is need for eye health education and review of cost of services to the very poor communities within the NCES. It is important to strengthen the community eye care structures and referral network now that the project area has excess secondary and tertiary health facilities offering eye care services.

Karimurio, J, Kimani K, Gichuhi S, Marco S, Nyaga G, Wachira J, Ilako D.  2008.  Eye diseases and visual impairment in Kibera and Dagoreti Divisions of Nairobi, Kenya. . East African Journal of Ophthalmology. 14(1):42-50. Abstract

Objective: To determine the prevalence and pattern of eye diseases and visual
impairment in the Nairobi Comprehensive Eye Care Services (NCES) Project; the
catchment area of the Mbagathi District Eye Unit of Nairobi.
Design: Community based survey conducted from October 15th to 31st 2007
Setting: Kibera and Dagoreti divisions of Nairobi City
Subjects: 4200 people of all ages were randomly selected; 4056 were examined
(96.6% response rate). 122 (2.9%) were not available and 15 (0.4%) declined
to be examined.
Results: Females: 54.2%, Males: 45.8%. Mean age; 22.4 years, SD; 16.5. Only
241(5.9%) aged >50years old. The leading eye disorders in Kibera and Dagoretti
divisions are conjunctival disorders including allergic conjunctivitis and conjunctival
growths. This was found to affect 7.6% of the subjects. This was followed by
refractive errors found in 5.3% of the subjects. Cataract was found in 30 subjects
(0.7%). Disorders of the retina and the optic nerve were found in 1.1% of the
subjects and corneal disorders in 0.5%. The prevalence of visual impairment was
0.6%, severe visual impairment was 0.05% and blindness was 0.1%. This indicates
that most of the ocular disorders encountered were not visually threatening. The
main cause of visual impairment is refractive errors and the causes of severe visual
impairment and blindness are cataract, corneal opacity and glaucoma.
Conclusion: The population of the NCES is relatively young and the prevalence of
blindness and visual impairment is low. The main cause of visual impairment was
refractive errors and the causes of severe visual impairment and blindness were
cataract, corneal opacity and glaucoma.
Recommendations: The level of blindness in NCES is low and the project should
focus more on rendering eye care and not treatment of blindness. There is need to
address the issue of refractive errors as this was one of the main ocular problems
encountered. In this survey, it was not possible to perform detailed refraction and
hence it was recommend that a refractive error survey be conducted; especially
in school going children.

Kiage, DO, Damji FK, Gichuhi S, Gradin D.  2008.  Ahmed glaucoma valve implant: experience in East Africa., May 2008. Association for Research in Vision and Ophthalmology (ARVO). agv_poster_arvo.pdf
Do, DV.  2008.  Surgery for post-vitrectomy cataract. Cochrane Database Syst Rev. 2008 Jul 16;(3):CD006366.. : Elsevier AbstractWebsite

BACKGROUND: Cataract formation or acceleration can occur after intraocular
surgery, especially following vitrectomy, a surgical technique for removing the
vitreous used in the treatment of disorders that affect the posterior segment of
the eye. OBJECTIVES: The objective of this review was to evaluate benefits and
adverse outcomes of surgery for post-vitrectomy cataract with respect to visual
acuity, quality of life, and other outcomes. SEARCH STRATEGY: We searched the
Cochrane Controlled Trials Register (CENTRAL) (which contains the Cochrane Eyes
and Vision Group Trials Register) (The Cochrane Library, Issue 4, 2007), MEDLINE,
EMBASE, Latin America and Caribbean Health Sciences (LILACS) and the UK Clinical
Research Network Portfolio Database (UKCRN).The databases were last searched on
18 January 2008. We also searched www.clinicaltrials.gov,
www.controlled-trials.com, and www.actr.org.au in December 2007, in case
pertinent trials were registered and were nearing completion. SELECTION CRITERIA:
We planned to include randomized and quasi-randomized 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. No studies were eligible for inclusion in the review. MAIN
RESULTS: We found no randomized or quasi-randomized trials comparing cataract
surgery with no cataract surgery for patients developing 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.

2007

Gichuhi, S, Irlam J.  2007.  Interventions for squamous cell carcinoma of the conjunctiva in HIV-infected individuals.. Cochrane Database Syst Rev. . 18(2):CD005643. Abstract

BACKGROUND:
Squamous cell carcinoma of the conjunctiva is a rare, slow-growing tumour of the eye, normally affecting elderly men around 70 years of age. In Africa, however, the disease is different. The incidence is rising rapidly, affecting young persons (around 35 years off age), and usually affecting women. It is more aggressive, with a mean history of three months at presentation. This pattern is related to the co-existence of the HIV/AIDS pandemic, high HPV exposure, and solar radiation in the region. Various interventions exist, but despite therapy, there is a high recurrence rate (up to 43%) and poor cosmetic results in late disease. This review was conducted to evaluate the interventions for treatment of conjunctival squamous cell carcinoma in HIV-infected individuals.

OBJECTIVES:
To evaluate the effect of interventions for treating squamous cell carcinoma of the conjunctiva in HIV-infected individuals on local control, recurrence, death, time to recurrence, and adverse events.

SEARCH STRATEGY:
Using a sensitive search strategy, we attempted to identify all relevant trials, regardless of language or publication status, from the following electronic databases; Medline/PubMed, CENTRAL, AIDSearch, EMBASE, LILACS, African Healthline, Cochrane HIV/AIDS Specialised Register, and the Cochrane Cancer Network Specialised Register. We searched the clinical trial register of the US National Institutes of Health, searched the international conference proceedings of AIDS and AIDS-related cancers, and contacted individual researchers, research organisations, and pharmaceutical companies that manufacture the drugs used as interventions. Searches were done between September 2005 and June 2006.

SELECTION CRITERIA:
Randomised controlled trials (RCTs) involving HIV-infected individuals with ocular surface squamous neoplasia.

DATA COLLECTION AND ANALYSIS:
We independently screened the results of the search to select potentially relevant studies and to retrieve the full articles. We independently applied the inclusion criteria to the potentially relevant studies. No studies were identified that fulfilled the selection criteria.

MAIN RESULTS:
No RCTs of interventions currently used against conjunctival squamous cell carcinoma in HIV-infected individuals were identified.

AUTHORS' CONCLUSIONS:

IMPLICATIONS FOR PRACTICE:
Current clinical practice in treatment of squamous cell carcinoma of the conjunctiva rests on a weak evidence base of case series and case reports.

IMPLICATIONS FOR RESEARCH:
Randomised controlled trials for treatment of this disease are needed in settings where it occurs most frequently. Preventive interventions also need to be identified. HIV/AIDS research has not focused on treatment of this tumour.

Gichuhi, S.  2007.  A success story of The Cochrane Collaboration. , Cape Town: South African Cochrane Center (African Cochrane Network meeting)

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