A multi-cohort genome-wide association study in African ancestry individuals reveals risk loci for primary open-angle glaucoma.

Primary open-angle glaucoma (POAG), the leading cause of irreversible blindness worldwide, disproportionately affects individuals of African ancestry. We conducted a genome-wide association study (GWAS) for POAG in 11,275 individuals of African ancestry (6,003 cases; 5,272 controls). We detected 46 risk loci associated with POAG at genome-wide significance. Replication and post-GWAS analyses, including functionally informed fine-mapping, multiple trait co-localization, and in silico validation, implicated two previously undescribed variants (rs1666698 mapping to DBF4P2; rs34957764 mapping to ROCK1P1) and one previously associated variant (rs11824032 mapping to ARHGEF12) as likely causal. For individuals of African ancestry, a polygenic risk score (PRS) for POAG from our mega-analysis (African ancestry individuals) outperformed a PRS from summary statistics of a much larger GWAS derived from European ancestry individuals. This study quantifies the genetic architecture similarities and differences between African and non-African ancestry populations for this blinding disease.

Exfoliation syndrome in sub-Saharan Africa.

The goal of this review is to estimate the burden of exfoliation syndrome (XFS) and exfoliation glaucoma (XFG) in sub-Saharan Africa and to identify the gaps in knowledge of disease prevalence in this region. PubMed, Medline, African Journals Online and Google engine search were carried out using the following terms "pseudoexfoliation" or "exfoliation syndrome Africa", "pseudoexfoliation" or "exfoliation syndrome" + "glaucoma Africa," "glaucoma prevalence Africa," "pattern of glaucoma presentation Africa," "pseudoexfoliation" or "exfoliation syndrome" + "cataract Africa," "ophthalmic conditions Africa." Studies were included if they described the proportion or prevalence/incidence of XFG and XFS in sub-Saharan Africa or if they investigated lysyl oxidase-like 1 (LOXL1) variants in XFS among Africans. 22 papers were identified and classified as clinic-based studies (n = 16) and population-based (n = 4) studies. Two other studies were considered important, and therefore, included in the review. Clinic-based studies demonstrate that XFS is a common cause of glaucoma, as is true in many other parts of the world. Furthermore, XFS often co-exists with cataract and climatic droplet keratopathy. Its prevalence ranged from 5.1 to 7.7 % in patients >40 years in population-based studies, a value that is considerably higher than that reported in African Americans. XFS was strongly associated with increasing age in the prevalence studies. The burden of XFS in sub-Saharan Africa is high. More investigation is needed to determine why clinic-based studies report virtually no XFS in some countries (Ghana and Tanzania), while nearby countries report greater proportions (Nigeria and Ethiopia).

Outcomes of trabeculectomy with 5-Fluorouracil at a nigerian tertiary hospital.

PURPOSE: To report the outcomes of trabeculectomy with adjunctive 5-Fluorouracil (5- FU) at a Nigerian tertiary hospital. METHODS: In this prospective study, all patients with glaucoma undergoing trabeculectomy with 5-FU at the University College Hospital, Ibadan, Nigeria, from June 2009 to May2010 were enrolled. Each patient had a complete ophthalmic evaluation. Intraocular pressure (IOP), visual acuity (VA) and complications post-trabeculectomy were assessed at one year. Success of the procedure was defined as complete when no additional medications were required to achieve an IOP of ≤18mmHg, or qualified when additional medications were required to achieve the same goal. RESULTS: A total of 47 eyes of 31 patients with mean age of 48.9±19.6 (range 14-77; median 52) years including 21 (67.7%) male subjects underwent trabeculectomy with 5-FU. Mean presenting IOP was 31.8±12.2 mmHg. Mean deviation (MD) on Humphrey visual fields was -15.9±9.7dB with the majority of the patients (18 subjects 58.1%) presenting with advanced glaucoma based on MD worse than -12dB and severe glaucomatous optic neuropathy (cup to disc ratio of 0.9-1.0). At 1 year postoperatively, 95.1% achieved qualified success while 83% had complete success. CONCLUSION: This prospective study adds to the existing knowledge that trabeculectomy with 5-FU is effective at controlling IOP in Nigerian patients.

Exfoliation syndrome in Nigeria.

PURPOSE: The purpose of this study was to estimate the prevalence of exfoliation syndrome (XFS) and its association with ocular disease in patients attending the eye clinic of the University College Hospital (UCH) in Ibadan, Nigeria. MATERIALS AND METHODS: A total of 448 consecutive new patients, aged 30-90 years who presented to the eye clinic of UCH between December 2009 and November 2010 were evaluated. Each patient had a complete ophthalmic examination. Patients with exfoliative material on the anterior lens surface and/or pupillary margin in either or both eyes were considered to have XFS. Means, standard deviation, and 95% confidence intervals were calculated. RESULTS: All the patients examined were from the southern part of Nigeria. Majority (94.2%) were of the Yoruba tribe from southwestern Nigeria, while 5.8% were from southeastern Nigeria. The mean age of the study cohort was 58.5 ± 13.8, 54.8% were males, 12 (2.7%) had XFS. All patients with XFS were of the Yoruba tribe, with a mean age 65.6 ± 5.6 years. There was a male predilection (66.7%). All eyes with XFS had lenticular opacities. XFS was bilateral in eight patients (66.7%) of whom seven patients (87.5%) had glaucoma and lenticular opacities bilaterally. CONCLUSION: This is the first report of the existence of XFS in Nigeria. Larger studies are necessary in this population to further investigate the disease.