A Population-based survey of the prevalence and types of glaucoma in Nigeria: results from the Nigeria National Blindness and Visual Impairment Survey

Table 4 Reasons why there was no photo disc grading in 4349 (34 %) eyes among those who had full examination (n = 12,794 eyes)

Reason	Right eye	Left eye	All eyes	%
Eye disease
Cataract	552	469	1021	24 %
Corneal opacity	304	295	599	14 %
Other ocular pathology	166	192	358	8 %
			1978	46 %
Participants factors
Uncooperative	27	31	58	1 %
Other e.g., home visit	31	27	58	1 %
			116	2 %
Technical reasons
Faulty camera	471	472	943	22 %
No electricity	144	144	288	7 %
			1231	28 %
Other
No reason stated	271	312	583	14 %
Ungradable photos^a	228	213	441	10 %
			1024	24 %
Total	2194	2155	4349	100 %

^aPhotos were taken but VCDR could not be assessed because of blurred image due to media opacity or poor positioning of the participant

ISSN: 1471-2415