A total of 735 articles were retrieved using electronic databases search: PubMed, Google Scholar, and CINHAL. 77 articles were excluded due to duplication, and 5, 59 articles were excluded as they were not related to the title, review, abstract and duplication. 99 full text articles were assessed for eligibility, and 57 articles were excluded for based on quality appraisal tool. 3 articles record identified through cross reference search of included studies. Finally, 45 articles were included in systematic review and meta-analysis (Figure 1).
Characteristics of included studies
A total of 45 cross-sectional studies were included in this systematic review and meta-analysis: 4 studies in Saudi Arabia study [40-43], 2 studies in Nigeria [44, 45], 3 studies in Ghana [46-48], 4 studies in Pakistan [49-52], 3 studies in Spain [53-55], 7 studies in Ethiopia [56-62], 1 study in Jordan [63], 2 studies in China [64, 65], 1 study in Iran [66], 3 studies in Egypt [67-69], 8 studies in India [18, 70-76], 1 study in Nepal [77], 1 study in Seri Lanka [29], 2 studies in Brazil [78, 79], 1 study in Beirut [80], 1 study in Japan [81], and 1 study in Thailand [82]. A total of 17, 526 sample size were included. The sample size ranged from 74 in China [64] to 2,210 in Seri Lanka [29] (Table 1).
Table 1: Characteristics of included studies in the meta-analysis of computer vision syndrome, 2022
Author/s/year (reference)
|
Country
|
Study design
|
Sample size
|
Response rate (%)
|
Prevalence (%)
|
Study subjects
|
Abudawood GA, et al. 2020 [41]
|
Saudi Arabia
|
Cross sectional
|
587
|
100
|
95.1
|
Students
|
Agbonlahor O. et al.2019 [44]
|
Nigeria
|
Cross sectional
|
215
|
84
|
65.1
|
Government employ
|
Akowuah PK, et al.2021[83]
|
Ghana
|
Cross sectional
|
362
|
92.5
|
64.4
|
Students
|
Al Dandan O, et al. 2021[42]
|
Saudi Arabia
|
Cross sectional
|
198
|
75.3
|
50.5
|
Radiologists
|
Al Subaie M, et al. 2017 [43]
|
Saudi Arabia
|
Cross sectional
|
416
|
100
|
43.5
|
Population ≥ 15 years
|
Arshad S, et al. 2019 [84]
|
Pakistan
|
Cross sectional
|
320
|
100
|
58.1
|
Students
|
Artime‐Ríos E, et al.2021 [53]
|
Spain
|
Cross sectional
|
622
|
-
|
56.7
|
Health workers
|
Boadi-Kusi SB, et al. 2021 [48]
|
Ghana
|
Cross sectional
|
139
|
86.9
|
71.2
|
Bank workers
|
Boadi-Kusi SB, et al. 2020 [47]
|
Ghana
|
Cross sectional
|
200
|
65
|
51.5
|
University staff
|
Cantó‐Sancho N, et al. 2021 [54]
|
Spain
|
Cross sectional
|
244
|
100
|
76.6
|
Students
|
Derbew H, et al. 2021 [56]
|
Ethiopia
|
Cross sectional
|
351
|
98
|
74.6
|
Bank workers
|
Dessie A, et al. 2018 [57]
|
Ethiopia
|
Cross sectional
|
607
|
93.1
|
69.5
|
Government employ
|
Gammoh Y. et al. 2021 [63]
|
Jordan
|
Cross sectional
|
382
|
92
|
94.5
|
Students
|
Gondol BN, et al. 2020 [58]
|
Ethiopia
|
Cross sectional
|
272
|
100
|
81.3
|
Government employ
|
Han CC, et al. 2013 [65]
|
China
|
Cross sectional
|
1469
|
97.9
|
57.04
|
Students
|
Hashemi H, et al. 2017 [66]
|
Iran
|
Cross sectional
|
1040
|
97.2
|
49.4
|
Students
|
Kamal NN, et al. 2018 [67]
|
Egypt
|
Cross sectional
|
218
|
96.3
|
84.8
|
Bank workers
|
Lakachew Assefa N. et al. 2017 [59]
|
Ethiopia
|
Cross sectional
|
304
|
98.2
|
73.03
|
Bank workers
|
Lemma MG. et al. 2020 [60]
|
Ethiopia
|
Cross sectional
|
455
|
93
|
68.8
|
Secretaries
|
Lemma MT,et al. 2021 [61]
|
Ethiopia
|
Cross sectional
|
217
|
96.8
|
75.6
|
Secretaries
|
Logaraj M, et al. 2014 [70]
|
India
|
Cross sectional
|
215
|
100
|
81.8
|
Students
|
Mansoori N, et al. 2017 [50]
|
Pakistan
|
Cross sectional
|
150
|
100
|
28
|
students
|
Mohan A, et al. 2021 [85]
|
India
|
Cross sectional
|
217
|
83.14
|
50.2
|
Children
|
NAGWA E, et al. 2019 [68]
|
Egypt
|
Cross sectional
|
260
|
100
|
75
|
Students
|
Noreen K, et al. 2021 [52]
|
Pakistan
|
Cross sectional
|
326
|
95.04
|
98.7
|
Students
|
Noreen K, et al. 2016 [51]
|
Pakistan
|
Cross sectional
|
198
|
86.5
|
67.2
|
Students
|
Nwankwo B, et al. 2021 [45]
|
Nigeria
|
Cross sectional
|
153
|
100
|
54.2
|
Students
|
Poudel S, et al. 2020 [77]
|
Nepal
|
Cross sectional
|
263
|
94.9
|
82.5
|
IT office workers
|
Rafeeq U, et al. 2020 [72]
|
India
|
Cross sectional
|
120
|
100
|
69.2
|
≥ 12 years old population
|
Ranasinghe P, et al. 2016 [86]
|
Serilanka
|
Cross sectional
|
2210
|
88.4
|
67.4
|
Computer office workers
|
Ranganatha SC, et al. 2019 [73]
|
India
|
Cross sectional
|
150
|
100
|
86.7
|
Computer sciences students
|
Rathore D. , et al. 2016 [74]
|
India
|
Cross sectional
|
150
|
100
|
75.3
|
Computer users
|
Sa EC, et al. 2012 [78]
|
Brazil
|
Cross sectional
|
476
|
89.6
|
54.6
|
Call center
|
Sánchez-Brau M, et al. 2020 [55]
|
Spain
|
Cross sectional
|
109
|
95.6
|
74.3
|
Visual display workers
|
Sawaya RI, et al. 2020[80]
|
Beirut
|
Cross sectional
|
457
|
73.5
|
67.8
|
Students
|
Singh H, et al. 2016 [18]
|
India
|
Cross sectional
|
192
|
96
|
51.6
|
Students
|
Tiwari RR, et al. 2011 [75]
|
India
|
Cross sectional
|
432
|
100
|
32.2
|
Children
|
Uchino M, et el. 2013 [81]
|
Japan
|
Cross sectional
|
561
|
83.5
|
11.6
|
Visual display terminal users
|
Verma S, et al. 2021 [76]
|
India
|
Cross sectional
|
100
|
100
|
74
|
Computer operators
|
Vilela MA, et al. 2015 [79]
|
Brazil
|
Cross sectional
|
964
|
100
|
24.7
|
School children
|
Wang L, et al. 2021 [64]
|
China
|
Cross sectional
|
74
|
80.12
|
74.3
|
Students
|
Wangsan K, et al. 2022 [82]
|
Thailand
|
Cross sectional
|
527
|
100
|
81.02
|
Students
|
Zalat MM, et al. 2021 [40]
|
Saudi Arabia
|
Cross sectional
|
80
|
100
|
81.3
|
Visual display workers
|
Zayed HA, et al. 2021 [69]
|
Egypt
|
Cross sectional
|
108
|
98.18
|
82.4
|
IT professionals
|
Zenbaba D, et al. 2021 [62]
|
Ethiopia
|
Cross sectional
|
416
|
98.6
|
70.43
|
Students
|
Pooled prevalence of computer vision syndrome
The pooled prevalence of computer vision syndrome was 66% (95%, CI: 59, 74). The lowest proportion included study was 12% (95%, CI: 9, 15) in Japan [81] and the highest 99% (95%, CI:97, 100) in Pakistan [52]. The I2 test showed that there was heterogeneity among included studies (I2 = 99.42%, p-value < 0.001) (Figure 2).
Subgroup analysis by country
Subgroup analysis was performed based on country and the prevalence of computer vision syndrome was highest in Pakistan 97% (95% CI: 96, 98) and the lowest was in Japan 12% (95% CI: 9, 15). The studies that showed significant heterogeneity were studies in Saudi Arabia (I2 = 99.41%, p-value < 0.001), Ethiopia (I2 = 72.6%, p-value < 0.001), Egypt (I2 = 80.06%, p-value < 0.001), and India (I2 = 98.04%, p-value < 0.001) (Table 2).
Table 2: Subgroup analysis by country on computer vision syndrome, 2022
Sub group
|
Number of included studies
|
Prevalence (95% CI)
|
Heterogeneity statistics
|
P value
|
I2
|
By country
|
Saudi Arabia
|
4
|
68(37, 98)
|
P< 0.001
|
99.41%
|
Nigeria
|
2
|
61(56, 66)
|
P< 0.001
|
0.00%
|
Ghana
|
3
|
62(52, 73)
|
P< 0.001
|
0.00%
|
Pakistan
|
2
|
62(58, 66)
|
P< 0.001
|
0.00%
|
Spain
|
3
|
69(55, 83)
|
P< 0.001
|
0.00%
|
Ethiopia
|
7
|
73(70, 76)
|
P< 0.001
|
72.6%
|
Jordan
|
1
|
95(92, 96)
|
-
|
0.00%
|
China
|
2
|
58(56, 61)
|
P< 0.001
|
0.00%
|
Iran
|
1
|
49(46, 52)
|
-
|
0.00%
|
Egypt
|
5
|
81(74, 87)
|
P< 0.001
|
80.06%
|
India
|
8
|
65(49, 81)
|
P< 0.001
|
98.04%
|
Pakistan
|
2
|
97(96, 98)
|
P< 0.001
|
0.00%
|
Nepal
|
1
|
83(77, 87)
|
-
|
0.00%
|
Seri Lanka
|
1
|
67(65, 69)
|
-
|
0.00%
|
Brazil
|
2
|
33(30, 35)
|
P< 0.001
|
0.00%
|
Beirut
|
1
|
68(63, 72)
|
-
|
0.00%
|
Thailand
|
1
|
81(77,84)
|
-
|
0.00%
|
South Korea
|
1
|
66(63, 69)
|
-
|
0.00%
|
Italy
|
1
|
15(11, 21)
|
-
|
0.00%
|
Japan
|
1
|
12(9, 15)
|
-
|
0.00%
|
Meta regression
Meta-regression was performed to identify the source of heterogeneity across the studies by country and sample size. Meta-regression indicated that heterogeneity was not associated with country and sample size (p-value >0.05) (Additional file 2, Table S1).
Publication biases
Publication bias was checked using funnel plots, and visual inspection suggested asymmetry, as 11 studies were on the left side and 32 studies were on the right side (Additional file 3: Figure S1). Moreover, publication bias was not shown on Egger’s test (p=0.21) (Additional file 4: Table S2).