Table 3.

Causes of Bilateral Visual Impairment and Blindness Using the World Health Organization Criteria

	Mild Visual Impairment		Moderate to Severe Visual impairment		Blindness		All
	No. (Prevalence %)	Distribution (%)	No. (Prevalence %)	Distribution (%)	No. (Prevalence %)	Distribution (%)	No. (Prevalence %)	Distribution (%)
Cataract	165 (8.6)	38.9	337 (17.6)	61.3	23 (1.2)	28.0	525 (27.4)	49.7
Uncorrected refractive error	203 (10.6)	47.9	77 (4.0)	14.0	0 (0.0)	0.0	280 (14.6)	26.5
Myopic maculopathy	7 (0.4)	1.7	37 (1.9)	6.7	17 (0.9)	20.7	61 (3.2)	5.8
Posterior capsular opacification	21 (1.1)	5.0	35 (1.8)	6.4	2 (0.1)	2.4	58 (3.0)	5.5
Cornea opacity	5 (0.3)	1.2	8 (0.4)	1.5	10 (0.5)	12.2	23 (1.2)	2.2
AMD	3 (0.2)	0.7	13 (0.7)	2.4	5 (0.3)	6.1	21 (1.1)	2.0
Vitreoretinal interface abnormality	7 (0.4)	1.7	12 (0.6)	2.2	0 (0.0)	0.0	19 (1.0)	1.8
Other posterior segment eye disease	3 (0.2)	0.7	6 (0.3)	1.1	6 (0.3)	7.3	15 (0.8)	1.4
Glaucoma	4 (0.2)	0.9	6 (0.3)	1.1	5 (0.3)	6.1	15 (0.8)	1.4
Pterygium	3 (0.2)	0.7	7 (0.4)	1.3	1 (0.1)	1.2	11 (0.6)	1.0
Diabetic retinopathy	1 (0.1)	0.2	5 (0.3)	0.9	2 (0.1)	2.4	8 (0.4)	0.8
Other optic atrophy	2 (0.1)	0.5	1 (0.1)	0.2	4 (0.2)	4.9	7 (0.4)	0.7
Amblyopia	0 (0.0)	0.0	1 (0.1)	0.2	2 (0.1)	2.4	3 (0.2)	0.3
Uveitis	0 (0.0)	0.0	1 (0.1)	0.2	1 (0.1)	1.2	2 (0.1)	0.2
Atrophy of the eyeball or prosthetic eye	0 (0.0)	0.0	0 (0.0)	0.0	1 (0.1)	1.2	1 (0.1)	0.1
Retinal detachment	0 (0.0)	0.0	0 (0.0)	0.0	0 (0.0)	0.0	0 (0.0)	0.0
Unknown eye disease	0 (0.0)	0.0	4 (0.2)	0.7	3 (0.2)	3.7	7 (0.4)	0.7
Subjects	424 (22.2)	100.0	550 (28.5)	100.0	82 (4.1)	100.0	1056 (54.8)	100.0

Notes: Mild visual impairment was defined as presenting visual acuity measurements of ≥6/18 and <6/12 in the better eye, moderate to severe visual impairment was defined as presenting visual acuity measurements of ≥3/60 and <6/18 in the better eye, and blindness was defined as presenting a visual acuity of <3/60 in the better eye.

Abbreviation: AMD, age-related macular degeneration.