Prevalence and systemic associations of retinal vascular occlusions in Sub­Saharan Africa

Background: Retinal vascular occlusions are a common cause of visual impairment. Studies on retinal vascular occlusions in sub Saharan Africa (SSA) have primarily been retrospective and on retinal vein occlusion (RVO) only. The aim of this study, therefore, was to determine the prevalence and pattern of retinal vascular occlusions and their systemic associations in SSA. Materials and Methods: This was a hospital based, cross sectional study involving all new patients presenting at the general ophthalmic and specialty retina clinics in four hospitals in Nigeria over a 1 year period. All the patients underwent a comprehensive eye examination. The demographic and clinical data of patients with retinal vascular occlusions were entered into an excel sheet and analyzed using the Statistical Package for the Social Sciences (SPSS) software version 22.0. Statistical significance was indicated by P < 0.05. Results: A total of 8614 new patients were seen, and a diagnosis of retinal vascular occlusion was made in 90 eyes of 81 patients giving a disease prevalence of 0.9%. Eighty one eyes of 72 (88.9%) patients had RVO, while 9 eyes of 9 (11.1%) patients had retinal artery occlusion (RAO). The mean age of patients with RVO and RAO was 59.5 years and 52.4 years, respectively. Increasing age, hypertension, and diabetes were the significant associations with retinal vascular occlusion with P < 0.0001. Conclusion: Retinal vascular occlusions are an increasing cause of retinal disease in SSA and tend to occur at an earlier age. They are associated with hypertension, diabetes, and increasing age. Further studies will, however, be required to establish the demographic and clinical profile of patients with RAO in the region

Refractive Errors and Spectacle Use Behavior among Medical Students in a Nigerian Medical School.

Aim: To determine the prevalence of refractive errors and spectacle use behavior among medical students in University of Calabar Teaching Hospital, Nigeria. Study Design: Cross sectional study. Place and Duration of Study: Department of Ophthalmology, University of Calabar Teaching Hospital, Calabar, Cross River State, Nigeria, between April 2010 and July 2010. Methodology: The study population consisted of fifth year medical students. Subjects had cycloplegic auto refraction with Topcon auto refractor during their rotation in ophthalmology at the Ophthalmology department of the University of Calabar Teaching Hospital. A spherical equivalents (SE) ≥ +0.50D were determined as hyperopia; SE of >-0.50D myopia and >-0.50D cylinder as astigmatism. Statistical analysis, which included chi-square test was carried out with Statistical Package for Social Sciences (SPSS) version 20.0. Results: Sixty-six (79.5%) of subjects had a form of refractive error; 63.6%%, 16.7% and 19.7% were myope, hyperope or simple estigmat, respectively. The prevalence of ametropia was 82% in female and 78% in males. The association between refractive errors and gender was not statistically significant (p = 0.35, 95% Confidence Interval [CI], 0.34-0.36).Minus spherical errors ranged from -0.16 to -5.25 diopters (D) and plus spherical errors ranged from +0.25 to +1.00D, spherical equivalent between -0.25D and - 2.75D being the most common type (85.5%). Eight students (12.1%) were wearing glasses at the time of the study corresponding with 10 (15.2%) who had eye pains while reading. Conclusion: The prevalence of refractive errors among fifth year medical students of the University of Calabar was high and eyeglasses were worn by students who were symptomatic.