prevalence of visual acuity impairment and its associated factors ...

Malaysian Journal of Public Health Medicine 2012, Vol. 12(1): 39-44

ORIGINAL ARTICLE PREVALENCE OF VISUAL ACUITY IMPAIRMENT AND ITS ASSOCIATED FACTORS AMONG SECONDARY SCHOOL STUDENTS IN BERANANG, SELANGOR Aniza I1, Azmawati MN1, Jamsiah M1, Idayu BI1, Mae Lynn CB2 1

Community Health Department, UKMMC. Ophthalmology Department, UKMMC.

2

ABSTRACT Prevalence of visual impairment among students is increasing in trends especially in rural area. A cross sectional study was conducted among secondary school students in Taman PKNS Beranang, Selangor in March 2008 with the objective of determining the prevalence of visual acuity impairment and its influencing factors. A total of 77 secondary school students were interviewed using guided questionnaire. The prevalence of visual acuity impairment among the respondents was 25.0% and study found that being female and have been watching television at a distance of less than two meters were significantly associated with visual acuity impairment. In conclusion, the problem occurred maybe due to the students sit nearer to the television ( 2100

4(5.2)

Malaysian Journal of Public Health Medicine 2012, Vol. 12(1): 39-44 The prevalence of impaired visual acuity was 25% (19) among respondents. Out of 19 respondents, a total of 20% (5) respondents were wearing spectacles. Out of the 14 respondents who were not using spectacles, only 21% (3) respondents) had good vision as compared to 79% (11) respondents who did not have good vision. Nevertheless, for respondents who were wearing spectacles, the correction of the visual acuity is adequate if the respondents were able to read the optotypes at 6/6 in the Snellen Chart. The correction of visual acuity is considered inadequate if respondents fail to read the optotypes at 6/6 in the Snellen Chart when using glasses. Of the 5 students who were using glasses, all of them seemed to have adequate correction of visual acuity. A total of 55 respondents (71%) had the perception that their vision was clear as compared to 22 respondents (29%) who had the perception that their vision was unclear. Out of those who perceived that their vision was unclear, 23%(5) were wearing spectacles while the rest 77% (17) were not wearing spectacles. The study also showed that 11 respondents had both parents with reduce visual acuity while 16 respondents had both parents with reduce visual acuity. Majority of respondents (87%) would switch off the light while sleeping as compared to 13 % who did not. Most of respondents had a good distance when reading and watching television in which 52 respondents (67.5%) had a reading distance of 30 centimeters or more. Only 25 (32.5%) had a reading distance of less than 30 centimeters. A total of 25 (28.6%) respondents had a distance of watching television of less than 2 meters. Minimum duration of watching television in a week was one hour while maximum duration of watching television was 49 hours. Median duration was 5(IQR=1) hours. The median usage of computers in a day is 3(IQR=1) hours. The duration of computer usage for the purpose of playing games in a week was 1 hour (for the least duration of hours) and 8 hours (for the longest duration of hours). This was almost similar to the amount of time used to play video games on the television in a week which was

1 hour (for the least duration of hours) maximum of 14 hours (for the longest duration of hours). The mean duration of using the television and computer for playing games were 2 and 5 hours respectively. The number of respondents who used computers was 36 respondents (47%), whilst 41 respondents (53%) did not. Of all the respondents who used the computers, 22 of them used the computers for other purposes such as serving the internet. There was significant difference in the rate of impaired visual acuity among male and female respondents (p=0.019). It is also noted that there was no difference between impaired visual acuity among respondents who had a reading distance of less than 30 cm and with respondent who had reading distance of 30 cm or more (p>0.05). In contrast there was significant difference between visual acuity impairment among respondents who had a distance of watching television of less than 2 meters with respondents who had a distance of watching television of more than 2 meters (p=0.037) (Table 2).

Malaysian Journal of Public Health Medicine 2012, Vol. 12(1): 39-44 Table 2. Impaired visual acuity and associated factors Impaired visual acuity Factors

Yes (19)

Level of education

Gender

Parents with visual acuity

impaired

Lights on during sleep

Reading distance

Watching TV Distance

Self esteem

No(58)

n

%

n

%

Lower Secondary

12

25.5

35

74.5

Upper Secondary

7

23.3

23

76.7

Male

4

11.8

30

88.2

Female

15

34.9

28

65.1

Yes

6

22.2

21

77.8

No

13

26.0

37

74.0

Yes

0

10

100.0

No

19

28.4

48

71.7

< 30 cm

6

24.0

19

76.0

_30 cm

13

25.0

39

75.0

< 2 meters

9

40.1

13

59.1

> 2 meters

10

18.2

45

81.8

Yes

5

20.0

20

80.0

No

14

28.8

38

71.2

p value*

0.827

0.019#

0.714

0.122

0.924

0.037#

0.509

*Chi Square test, #significant at p2 meter). In educating vision care among school children, School Health Education Unit shall take the responsibility in ensuring the vision care among school children is at the optimum level.

REFERENCES 1.

Tonks A. Children who sleep with light on may damage their sight. British Medical Journal 1999; 318: 1369.

2.

Zainal M, Ismail SM, Ropilah AR, et al. Prevalence of blindness and low vision in Malaysian population: result from the National Survey 1996. British Journal Ophthalmology 2002; 86(9): 951-6.

3.

Ministry of Health Malaysia. National Eye Survey. Visual impairment in Malaysia. Malaysia’s health report, technical report of the Director General of Health Malaysia, 1996, 243-9.

4.

Reddy SC, Tajunisah I, Low KP, Karmila AB. Prevalence of eye diseases and visual impairment in urban population - a study from University of Malaya Medical Centre. Malaysian Family Physician 2008; 3(1): 25-8.

A weak correlation between duration of watching television and reduce visual acuity. The positive coefficient correlation showed that the longer the duration of watching television, the visual acuity will be further impaired. Nevertheless the association was not significant.

5.

Gilbert CE, Ellwein LB. Prevalence and causes of functional low vision in school age children: results from standardized population surveys in Asia, Africa and Latin America. Invest Ophthalmology Vis Science 2008; 49(3): 877-81.

There was no association between poor self esteem with prevalence of impaired visual acuity. Conversely this finding was in contrast with other study16 which revealed that wearing of thick glasses is associated with low self esteem.

6.

Goss DA, Grosvenor TP, Keller JT et al. Care of the Patient with Myopia. American Optometric Association, 2006.

7.

Ayed T, Sokkah M, Charfi O, El Matri L. Epidemiologic study of refractive errors in schoolchildren in socioeconomically deprived regions in Tunisia. Journal Francais de Ophtalmologie 2002; 25(7): 712-7.

8.

Hee M, Huang W, Zheng Y, Huang L, Leon E. Need and challenges of refractive correction in urban Chinese school children. American Academy of Optometry 2007; 114(2): 374-82.

Our study showed that there was no association between those who slept with the light on and reduction in visual acuity however the results was not supported by other study1,12 which stated that children and babies who slept with light off will tend to develop impaired visual acuity as they grow. However this statement might be due to bias as parents tend to forget whether light were off when their children slept. There was a significant association between distance of watching television and prevalence of impaired visual acuity and the finding was supported by a research conducted by Ministry of Health Malaysia 20022.

CONCLUSION The prevalence of impaired visual acuity among the respondents was 25% (19) and 75% (58) respondents have normal visual acuity. From the study was also revealed that female respondents and closer distance of watching television of less than 2

Malaysian Journal of Public Health Medicine 2012, Vol. 12(1): 39-44 9.

Fredrick DR. Myopia. British Medical Journal 2002; 324: 1195-9.

10.

Saw SM, Goh PP, Cheng A, Shankar A, Tan DT, Ellwein LB. Refractive Ethnicity-specific Prevalences of errors vary in Asian children in neighbouring Malaysia and Singapore. BMJ 2006; 90(10): 1230-5.

11.

Zhang MZ, Saw SM, Hong RZ, et al. Refractive errors in Singapore and Xiamen, China—a comparative study in school children aged 6 to 7 Years. American Academy of Optometry 2000; 77(6): 302-8.

12.

Saw SM, Zhang MZ, Hong RZ, Fu FZ, Pang MH, Tan DH. Near-work activity, night-lights, and myopia in the Singapore-China study. American Medical Association 2002; 120(5): 620-7.

13.

Goh PP, Yahya A, Pokharel GP, Ellwein LB. Refractive error and visual impairment in school-age children in Gombak district, Malaysia. American Academy of Ophthalmology 2005; 112(4): 678-85.

14.

Mutti DO. Can we conquer myopia? Review of Optometry 2001; 138: 80-92.

15.

Kleinstein RN, Eistein N, John FD et al. Refractive error and ethnicity in childre. Arch Ophthalmol 2003; 121: 1141-7.

16.

Dias L, Hyman L, Manny R, Fern K. The comet group evaluating the self-esteem of myopic children over a three-year period: the comet experience. American Academy of Optometry 2005; 82(4): 338-47.