Causes of visual impairment among patients applying for the visual disability certificate in Upper Egypt: a retrospective study

Aim To explore the causes of visual impairment in patients applying for the visual disability certificate in Upper Egypt. Patients and methods This was a retrospective observational study that included patients referred to “The Ministry of Social Solidarity” with visual disability in Upper Egypt. The main outcome measures were the recording of causes of visual impairment as well as its subanalysis according to age and sex. The correlation between the degree of visual impairment in the better eye and the visual-evoked potential (VEP) and electroretinogram (ERG) abnormalities was also evaluated. Results The study included 4376 eyes of 2188 patients with a mean age of 44.76±18.78 years. The sex distribution was 1581 males and 607 females. Refractive errors (26.9%) followed by lens problems (19.7%) were the most common causes of visual impairment. The most common causes of visual impairment according to age were cataracts and glaucomas among the elderly, refractive errors among adults, and retinal and macular dystrophies among children. There was no significant difference between males and females except for refractive errors (significantly higher among males) and retinal dystrophies (significantly higher among females). A statistically significant moderate positive correlation between the degree of visual impairment in the better eye and the degree of VEP and ERG affection was observed. Conclusion Refractive errors and cataracts were the most common causes of visual impairment among individuals applying for the visual disability certificate in Upper Egypt. ERG and VEP proved to be valuable diagnostic tools for evaluating these patients.