Causes of visual impairment and blindness in children in three ecological regions of Nepal: Nepal Pediatric Ocular Diseases Study

Figures & data

Table 1 Age and sex distribution of children in the three ecological regions

	Terai	Hills	Mountains	Total
	Number (%)	Number (%)	Number (%)	Number (%)
Age group (years)
0–5	2,036 (39.1)	1,264 (40.3)	585 (30.4)	3,885 (37.8)
>5–10	3,172 (60.9)	1,872 (59.7)	1,341 (69.6)	6,385 (62.2)
Sex
Female	2,516 (48.3)	1,583 (50.5)	989 (51.3)	5,088 (49.5)
Male	2,692 (51.7)	1,553 (49.5)	937 (48.7)	5,182 (50.5)

Table 2 Crude and age-adjusted prevalence of blindnessa and visual impairmentb

Region	Blindness, % (95% CI)		Visual impairment, % (95% CI)
	Crude	Age-adjusted	Crude	Age-adjusted
Terai	0.07 (0.02–0.13)	0.08 (0.02–0.13)	0.09 (0.04–0.15)	0.08 (0.02–0.13)
Hills	0.06 (0.01–0.11)	0.07 (0.02–0.11)	0.16 (0.06–0.24)	0.17 (0.07–0.24)
Mountains	0.05 (0.02–0.11)	0.06 (0.01–0.11)	0	0

Notes:

a Presenting VA of <6/60 in the better eye.

b Presenting VA of <6/18 in the better eye.

Abbreviations: CI, confidence interval; VA, visual acuity.

Table 3 The causes of visual impairmenta and blindnessb

Diseases	Visual impairment, N (%)	Blindness, N (%)
Amblyopia	8 (80)	3 (42.9)
Congenital cataract/aphakia	1 (10)	2 (28.6)
Microphthalmus	0	1 (14.3)
Retinal diseases	0	1 (14.3)
Strabismus (congenital fibrosis)	1 (10)	0
Total	10 (100)	7 (100)

Notes:

a Presenting VA of <6/18 in the better eye.

b Presenting VA of <6/60 in the better eye.

Abbreviation: VA, visual acuity.

Table 4 Pattern of ocular diseases causing blindness and visual impairment according to the geographic distribution

Pattern of diseases	Total		Terai		Hills		Mountains
	N	%	N	%	N	%	N	%
Amblyopia	35	9.4	13	11.2	13	16.7	9	5.0
Congenital cataract/aphakia	6	1.6	3	2.6	2	2.6	1	0.6
Microphthalmus	3	0.8	3	2.6	0	0.0	0	0.0
Retinal diseases	3	0.8	3	2.6	0	0.0	0	0.0
Strabismus (congenital fibrosis)	50	13.4	12	10.3	16	16.7	22	12.2

Table 5 Causes of unilateral blindness

	Unilateral blindness, N (%)
Corneal opacity	7 (39)
Coloboma	2 (11)
Congenital cataract	2 (11)
Microphthalmus	2 (11)
Optic atrophy	2 (11)
Phthisis bulbi	1 (5.5)
Anophthalmus	2 (11)
Total	18 (100)