A Study of Visual Functions Amongst Primary Open-Angle Glaucoma Patients in Abuja, Nigeria

Abstract

Background: To objectively measure visual function amongst Primary Open Angle Glaucoma (POAG) patients and compare these with  age and sex-matched controls by describing the characteristics of visual function in relation to the severity of POAG.

Methodology: A case-control study was carried out among 106 POAG patients and an equal number of age-sex matched controls  attending Asokoro District Hospital, Abuja, and Eye Foundation Hospital Abuja from Nov 2012 to April 2013. The objective measures of  visual function assessed include visual acuity (VA), contrast sensitivity (CS), colour vision (CV), and visual fields (MD) in the better eye  (BE)].

Results: All measures of visual function were found to be reduced comparing cases to controls and this was statistically significant. VABE  (0.39±0.73; 0.0017±0.02p<0.001); MDBE (-8.02±6.80; 0.17±0.3P<0.001); CSBE (1.46±0.59; 1.90±0.16p<0.001): Colour vision defects (54.7%;  6.6% p<0.001). In comparing mild; moderate; severe glaucoma: VABE (0.0053±0.03; 0.057±0.08; 0.766±0.90 p<0.001); MDBE (-3.46±1.93;-8.17±3.55;-16.43±6.01p <0.001); CSBE (1.88±0.26; 1.69± 0.37; 1.11±0.59 p<0.001): Color vision defects (20.6%; 31.6%; 86.9%) respectively (BE: Better Eye). While looking at the two independent groups above, mild and moderate were not statistically significant except for the  visual field, but comparing mild with severe and moderate with severe, they had a statistically significant relationship across all the visual  functions tested. In comparing controls with mild, color vision and visual field had a statistically significant difference. Comparing the  groups with mild and moderate glaucoma, only visual fields as a visual function were statistically significant. Whereas comparing both  groups with the severe group independently, they had statistically significant in all the visual functions tested.

Conclusion: In conclusion,  visual function was reduced in glaucoma patients as compared to controls. Visual acuity, contrast sensitivity and colour vision differed  significantly in comparing mild with severe and moderate with severe. Color vision differed significantly in comparing mild to controls.