Risk factors for open-angle glaucoma in Nigeria: results from the Nigeria National Blindness and Visual Impairment Survey

Abstract

BackgroundThe glaucoma-specific blindness prevalence in Nigeria (0.7 %, 95 % CI 0.6–0.9 %) among those aged ≥40 years is one of the highest ever reported. This study determined the risk factors for open-angle glaucoma (OAG) in adults examined in the Nigeria National Blindness and Visual Impairment Survey.MethodsA nationally representative sample of 13,591 people aged ≥40 years in 305 clusters in Nigeria were examined (response rate 90.4 %) between January 2005 to June 2007. Everyone had logMAR visual acuity measurement, Frequency Doubling Technology (FDT) visual field testing, autorefraction, A-scan biometry and optic disc assessment. Full ocular examination (n = 6397), included Goldmann applanation tonometry. Values for defining glaucoma using International Society of Geographical and Epidemiological Ophthalmology criteria were derived from the study population. Disc images were graded by Moorfields Eye Hospital Reading Centre. Socio-demographic factors (age, gender, ethnicity, literacy and place of residence), ocular parameters (intraocular pressure [IOP], axial length and mean ocular perfusion pressure [MOPP]) and systemic parameters (blood pressure, blood glucose and body mass index [BMI]) were assessed for association with OAG.ResultsThirteen thousand eighty-one (96 %) of 13,591 participants had vertical cup:disc ratio measured in at least one eye. 682 eyes of 462 participants were classified as OAG, with 12,738 controls. In univariate analyses the following were associated with OAG: increasing age, male gender, Igbo and Yoruba ethnic groups, illiteracy, longer axial length, higher IOP, lower MOPP, greater severity of hypertension and low BMI (underweight). In multivariate analysis, increasing age (odds ratio [OR] 1.04, 95 % CI 1.03–1.05), higher IOP (OR 1.22, 95 % CI 1.18–1.25) and Igbo ethnicity (OR 1.73, 95 % CI 1.18–2.56) were independent risk factors for OAG.ConclusionCase detection strategies for OAG should be improved for those aged ≥40 years and for ethnic groups most at risk as a public health intervention.

Improving services for glaucoma care in Nigeria: implications for policy and programmes to achieve universal health coverage

“…Ninety-four per cent were not diagnosed and not receiving care 6. Independent risk factors for OAG were higher intraocular pressure, increasing age and Igbo ethnicity 7. People of low socioeconomic status were approximately four times more likely to be blind from glaucoma,8 reflecting limited awareness of glaucoma and poor access to care.…”

Heterogeneity in arterial hypertension and ocular perfusion pressure definitions: Towards a consensus on blood pressure‐related parameters for glaucoma studies

“…; Kyari et al. ). Different sources of information were used to confirm hypertension status (measured SBP and/or DBP with a cut‐off value, measured BP as a continuous variable, self‐reported, use of medication, database).…”

“…A search was conducted in the studies included in two meta-analyses (Bae et al 2014;Zhao et al 2014) that studied the role of BP or systemic hypertension in glaucoma. An additional search allowed to include more studies, published after the search periods of the meta-analyses (Narayanaswamy et al 2013;Deb et al 2014;Kim et al 2014a, b,c;Chua et al 2015;Rasoulinejad et al 2015;Abegao Pinto et al 2016;Kim et al 2016;Kyari et al 2016;Ko et al 2016;Baskaran et al 2015). This additional search was conducted in MEDLINE and EMBASE, for all studies up until the 31st August 2017, with no language restrictions, with the search terms (glaucoma OR ocular hypertension) AND (blood pressure OR hypertension OR risk factors OR blood flow OR metabolic syndrome OR perfusion OR eye study OR survey OR prevalence).…”

Demographics and Referral Pattern of Patients with Glaucoma at a Tertiary Eye Hospital in Port Harcourt, Nigeria

“…Glaucoma affects over 60 million worldwide [7] with a reported global prevalence in above 40 years as 3.54% [8] as compared with that of Nigeria put at 5.02% [3].…”

“…The glaucoma-specific blindness prevalence in Nigeria (0.7%,95% CI 0.6-0.9) among those aged >40 years is one of the highest while the all glaucoma prevalence is 5.02%. Independent risk factors for glaucoma in Nigeria included the Igbo ( South east ) ethnic group [3].…”