The prevalence and causes of decreased visual acuity – a study based on vision screening conducted at Enukweni and Mzuzu Foundation Primary Schools, Malawi

Figures & data

Table 1 Distribution of VA among the male and female pupils at Mzuzu Foundation Primary School

	Female	Male	Total	%
VA – right eye
NLP	–	–	–	–
FC at 3 m	1	0	1	0.3
6/60	–	–	–	–
6/36	0	1	1	0.3
6/15	–	–	–	–
6/12	2	1	3	0.9
6/9	5	11	16	5
6/7.5	21	14	35	11
6/6	120	114	234	73.4
6/5	4	4	8	2.5
6/4	12	9	21	6.6
Total	165	154	319	100
VA – left eye
NLP	0	1	1	0.3
FC at 3 m	–	–	–	–
6/60	1	0	1	0.3
6/36	–	–	–	–
6/15	0	1	1	0.3
6/12	2	1	3	0.3
6/9	7	9	16	5.0
6/7.5	20	18	38	11.9
6/6	117	118	228	71.5
6/5	5	3	8	2.5
6/4	13	10	23	7.2
Total	165	161	319	100

Abbreviations: FC at 3 m, finger counting at 3 m; NLP, no light perception; VA, visual acuity.

Table 2 Distribution of VA over the various age groups at Mzuzu Foundation Primary School

Age (years)	6/36	6/24	6/18	6/15	6/12	6/9	6/75	6/6	6/5	6/4
VA – right eye
4	0	0	0	0	1	3	0	0	1	0
5	0	0	0	0	0	1	0	4	0	0
6	0	0	1	4	1	13	2	66	2	2
7	0	0	0	3	0	20	7	75	5	3
8	0	0	0	3	0	4	0	22	0	0
9	0	1	0	1	1	0	0	6	0	1
10	0	0	0	0	0	1	0	4	0	0
11	0	0	0	0	0	1	0	3	0	0
12	0	0	0	0	0	1	0	2	0	1
13	0	0	0	0	0	0	0	1	0	0
14	0	0	0	0	0	2	0	0	0	0
15	0	0	0	0	0	0	0	1	0	0
16	0	0	0	0	0	1	0	0	0	0
17	1	0	0	0	0	0	0	0	0	0
18	0	0	0	0	0	0	0	1	0	0
Total	1	1	1	11	3	47	9	185	8	7
	6/36	6/24	6/12	6/9	6/7.5	6/6	6/5	6/4
VA – left eye
4	0	0	0	1	2	0	1	0
5	0	0	0	1	1	3	0	0
6	0	0	5	8	15	55	4	3
7	0	0	3	13	16	74	4	3
8	0	0	1	4	3	21	0	0
9	0	0	2	1	2	3	0	1
10	0	0	0	1	0	4	0	0
11	0	0	0	2	0	2	0	0
12	0	0	0	1	1	1	0	1
13	0	0	0	0	0	1	0	0
14	1	0	0	0	2	0	0	0
15	0	0	0	0	0	1	0	0
16	0	0	0	1	0	0	0	0
17	0	1	0	0	0	0	0	0
18	0	0	0	1	0	0	0	0
Total	1	1	11	34	42	165	9	8

Abbreviations: FC at 3 m, finger counting at 3 m; VA, visual acuity.

Table 3 Distribution of pinhole acuity at Mzuzu Foundation Primary School

Pinhole status	Female	Male	Total
Right eye
NIPH	2	1	3
IPH to 6/6	0	0	0
IPH to 6/7.5	1	1	2
No pinhole required	162	152	314
Total	165	154	319
Left eye
NIPH	3	2	5
IPH to 6/6	0	1	1
IPH to 6/7.5	0	0	0
No pinhole required	162	151	313
Total	165	154	319

Abbreviations: IPH to 6/6, improvement with pinhole to 6/6; IPH to 6/7.5, improvement with pinhole to 6/7.5; NIPH, no improvement with pinhole.

Table 4 Distribution of distance VA among the student population at Enukweni Primary School

VA	Female	Male	Total	%
VA – right eye
6/36	0	1	1	0.4
6/24	0	1	1	0.4
6/18	1	0	1	0.4
6/15	0	1	1	0.4
6/12	7	4	11	4.0
6/9	25	22	47	17.3
6/7.5	5	4	9	3.3
6/6	90	96	186	68.4
6/5	7	1	8	2.9
6/4	3	4	7	2.6
Total	138	134	272	100
VA – left eye
6/36	0	1	1	0.4
6/24	0	1	1	0.4
6/18
6/15
6/12	6	5	11	4.0
6/9	19	15	34	12.5
6/7.5	27	15	42	15.4
6/6	77	89	166	61.0
6/5	5	4	9	3.3
6/4	4	4	8	2.9
Total	138	134	272	100

Abbreviation: VA, visual acuity.

Table 5 Distribution of VA over the various age groups at Enukweni Primary School

Age (years)	6/36	6/24	6/18	6/15	6/12	6/9	6/75	6/6	6/5	6/4
VA – right eye
4	0	0	0	0	1	3	0	0	1	0
5	0	0	0	0	0	1	0	4	0	0
6	0	0	1	4	1	13	2	66	2	2
7	0	0	0	3	0	20	7	75	5	3
8	0	0	0	3	0	4	0	22	0	0
9	0	1	0	1	1	0	0	6	0	1
10	0	0	0	0	0	1	0	4	0	0
11	0	0	0	0	0	1	0	3	0	0
12	0	0	0	0	0	1	0	2	0	1
13	0	0	0	0	0	0	0	1	0	0
14	0	0	0	0	0	2	0	0	0	0
15	0	0	0	0	0	0	0	1	0	0
16	0	0	0	0	0	1	0	0	0	0
17	1	0	0	0	0	0	0	0	0	0
18	0	0	0	0	0	0	0	1	0	0
Total	1	1	1	11	3	47	9	185	8	7
	6/36	6/24	6/12	6/9	6/7.5	6/6	6/5	6/4
VA – left eye
4	0	0	0	1	2	0	1	0
5	0	0	0	1	1	3	0	0
6	0	0	5	8	15	55	4	3
7	0	0	3	13	16	74	4	3
8	0	0	1	4	3	21	0	0
9	0	0	2	1	2	3	0	1
10	0	0	0	1	0	4	0	0
11	0	0	0	2	0	2	0	0
12	0	0	0	1	1	1	0	1
13	0	0	0	0	0	1	0	0
14	1	0	0	0	2	0	0	0
15	0	0	0	0	0	1	0	0
16	0	0	0	1	0	0	0	0
17	0	1	0	0	0	0	0	0
18	0	0	0	1	0	0	0	0
Total	1	1	11	34	42	165	9	8

Abbreviation: VA, visual acuity.

Table 6 Distribution of pinhole acuity at Enukweni Primary School

Pinhole status	Female	Male	Total
Right eye
NIPH	8	3	11
IPH to 6/6	0	4	4
IPH to 6/9	1	0	1
No pinhole required	129	127	256
Total	138	134	272
Left eye
NIPH	6	3	9
IPH to 6/6	0	4	4
IPH to 6/9	0	0	0
No pinhole required	132	127	259
Total	138	134	272

Abbreviations: IPH to 6/6, improvement with pinhole to 6/6; IPH to 6/9, improvement with pinhole to 6/9; NIPH, no improvement with pinhole.