Socio-demographic characteristics of study participants
A total of 416 participants were included in the study with a 98.6% response rate. The median age of participants was 36 years with interquartile range (IQR: 27-52 years). Among the study participants 247 (59.4%) were females (See Table 1).
Table 1: Socio-demographic characteristics of adults aged 18 years at Debre Berhan town, North Shewa, Ethiopia, 2018 (n=416, n= number of study participants).
Variable
|
Frequency
|
Percentage (%)
|
Age (years)
18-39
40-64
>64
|
235
123
58
|
56.5
29.6
13.9
|
Gender
Male
Female
|
169
247
|
40.6
59.4
|
Religion
Orthodox
Muslim
Protestant
Catholic
|
345
27
32
12
|
82.9
6.5
7.7
2.9
|
Ethnicity
Amhara
Oromo
Tigrie
Guragie
|
359
27
13
17
|
86.3
6.5
3.1
4.1
|
Marital status
Single
Married
|
178
238
|
42.8
57.2
|
Family history of eye problem
Yes
No
|
16
400
|
3.8
96.2
|
Socio-economic characteristics of study participants
The median family monthly income was 101.07 US$ with inter quartile range of [IQR: 57.27-151.67]. Most of the study participants 354 (85.1%) had no health insurance (See Table 2).
Table 2: Socio-economic characteristics of adults aged 18 years at Debre Berhan town, North Shewa, Ethiopia, 2018 (n=416, n= number of study participants).
Variables
|
Categories
|
Frequency
|
Percentage (%)
|
Health insurance
|
Yes
No
|
62
354
|
14.9
85.1
|
Occupations
|
Employed
Not employed
|
155
261
|
37.3
62.7
|
Educational status
|
Illiterate
Literate
|
55
361
|
13.2
86.8
|
Family monthly income (US$)
|
<57.31
57.31-101.07
101.11- 151.61
>151.61
|
106
127
84
99
|
25.5
30.5
20.2
23.8
|
Systemic co-morbidities and behavioral characteristics of study participants
Among the study participants 405 (97.8%) were non-smokers. History of systemic hypertension and diabetic mellitus were found in 21 (5.0%) and 9 (2.2%) participants respectively. Two hundred eighty three 68.0% of participants had no history of eye checkup (See Table 3).
Table 3: Systemic co-morbidity and behavioral characteristics of adults aged 18 years at Debre Berhan town, North Shewa, Ethiopia, 2018 (n=416, n= number of study participants)
Variables
|
Category
|
Frequency
|
Percentage (%)
|
Known history of hypertension
|
Yes
No
|
21
395
|
5.0
95.0
|
Known history of diabetes
|
Yes
No
|
9
407
|
2.2
97.8
|
Cigarette smoking
|
Yes
No
|
11
405
|
2.6
97.4
|
History of eye trauma
|
Yes
No
|
28
388
|
6.7
93.3
|
History of eye check up
|
Yes
No
|
133
283
|
32.0
68.0
|
Eye glass wear
|
Yes
No
|
101
315
|
24.3
75.7
|
Prevalence of visual impairment among adults
The prevalence of VI among adults aged 18 years was 16.8% [95% CI: 13.5%, 20.2%]. Nearly a third 22 (31.4%) of the participants with VI were in the VI category. Among the overall prevalence of visually impaired adults 27 (6.49%) had bilateral VI and 43 (10.34%) had monocular VI (See Table 4).
Table 4: Frequencies of visual impairment categories among adults aged 18 years with visual impairment at Debre Berhan town, North Shewa, Ethiopia, 2018 (n=70, n= number of adults with visual impairment)
Visual impairment category
|
Frequency
|
Percentage (%)
|
<6/18-6/60
|
Bilateral moderate VI
|
22
|
31.4
|
<6/60-3/60
|
Bilateral sever VI
|
2
|
2.9
|
<3/60-NLP
|
Bilateral blindness
|
3
|
4.3
|
<6/18-6/60, other eye 6/6-6/18
|
Monocular moderate VI
|
21
|
30.0
|
<6/60-3/60, other eye 6/6-6/60
|
Monocular sever VI
|
4
|
5.7
|
<3/60-NLP, other eye 6/6- 3/60
|
Monocular blindness
|
18
|
25.7
|
Total
|
|
70
|
100.0
|
Refractive error was the most common cause of bilateral VI and cataract caused most of the unilateral VI (See Figure 1).
Figure 1. Common ocular abnormalities that caused bilateral and unilateral visual impairment among visually impaired adults aged years at Debre Berhan town, North Shewa, Ethiopia, 2018. Refractive error and cataract were the leading cause of bilateral and unilateral VI respectively.
Factors associated with visual impairment in adults
In multivariable analysis age, history of eye trauma, family history of eye problem, family size and educational status had statistically significant positive association with VI.
Adults aged 40-60 years were 3 times more likely to present with VI compared to those aged 18-39 years; adults aged >64 years were even 12 times more likely. Those who had family history of eye problems were 7 times more likely to have VI than adults with no history of family eye problems. Adults who had a history of eye trauma were 4 times more likely to have VI than those who had no previous eye trauma history. Illiterate adults were 3 times more likely to have VI than literate adults (See Table 5).
Table 5: Factors associated with visual impairment among adults aged 18 years at Debre Berhan town, Ethiopia, 2018 (n=416, n= number of study participants)
Factors
|
Visual Impairment
|
COR(95% CI)
|
AOR(95% CI)
|
p-value
|
No
|
Yes
|
Age (year)
18-39
40-64
>64
|
222
100
24
|
13
23
34
|
1.0
3.93(1.91-2.8.07)
24.19(11.25-52.01)
|
1.0
3.04(1.22-7.58)
12.18(4.47-33.20)
|
0.0001
0.017
0.0001
|
Marital status
Single
Married
|
141
205
|
37
33
|
1.63(0.97-2.73)
1.0
|
2.06(0.98-4.37)
1.0
|
0.058
|
Education level
Illiterate
Literate
|
26
320
|
29
41
|
8.71(4.68-16.20)
1.0
|
3.02(1.36-6.72)
1.0
|
0.007
|
Family income*
<57.31
57.31-101.07
101.11- 51.61
>151.61
|
74
108
75
89
|
32
19
9
10
|
3.85(1.78-8.35)
1.57(0.69-3.54)
1.07(0.41-2.77)
1.0
|
2.20(0.78-6.20)
1.40(0.52-3.76)
1.67(0.54-5.17)
1.0
|
0.491
0.137
0.506
0.373
|
Hypertension
Yes
No
|
15
331
|
6
64
|
2.07(0.77-5.53)
1.0
|
1.14(0.33-3.87)
1.0
|
0.840
|
Diabetes
Yes
No
|
5
341
|
4
66
|
4.13(1.08-15.80)
1.0
|
2.47(0.48-12.63)
1.0
|
0.278
|
Family history of eye problem
Yes
No
|
9
337
|
7
63
|
4.16(1.50-11.58)
1.0
|
7.02(1.95-25.22)
1.0
|
0.003
|
History of trauma
Yes
No
|
18
328
|
10
60
|
3.61(1.61-8.09)
1.0
|
4.44(1.64-12.04)
1.0
|
0.003
|
Occupation
Employed
Unemployed
|
141
205
|
14
56
|
1.0
2.75(1.48-5.13)
|
1.0
1.24(0.56-2.72)
|
0.595
|
Cigarette smoke
Yes
No
|
7
339
|
4
66
|
2.93(0.83-10.31)
1.0
|
2.42(0.42-12.29)
|
0.287
|
Family size
<2
2-4
4-5
>5
|
104
159
39
44
|
12
30
9
19
|
1.0
1.64(0.80-3.34)
2.00(0.78-5.12)
3.74(1.68-8.36)
|
1.0
2.25(0.83-6.14)
2.25(0.63-8.03)
4.44(1.43-13.75)
|
0.077
0.113
0.210
0.010
|
* US$, CI = Confidence Interval, COR = Crude Odds Ratio, AOR = Adjusted Odds Ratio.