OBJECTIVE: To determine the prevalence of visual impairment and amblyopia in Malaysian preschool children.
METHODOLOGY: A cross-sectional, population-based study was conducted on children aged four to six years from 51 participating kindergartens in the district of Segamat, Johor, Malaysia from 20 March 2016 to 6 April 2016. All subjects had initial eye screening consisting of LogMar visual acuity, orthoptics examination and Spot vision screener assessment. Subjects who failed the initial eye screening were invited for a formal eye assessment consisting of cycloplegic refraction and a comprehensive ocular examination. Definitions of visual impairment and amblyopia were based on the Multi-Ethnic Pediatric Eye Disease Study criteria.
RESULTS: A total of 1287 children were recruited. Mean subject age was 5.03 (SD:0.77) and males represented 52.3% of subjects. Subjects by ethnicity were Malay (54.8%), Chinese (27.7%), Indian (15.6%) and Orang Asli (1.9%). Formal eye assessment was required for 221 subjects and 88.8% required ophthalmic intervention. Refractive error, representing 95.4% of diagnosed ocular disorders, comprised of astigmatism (84%), myopia (9%) and hypermetropia (6.9%). With-the-rule astigmatism was present in 93.4% of the subjects with astigmatism. Visual impairment was present in 12.5% of our subjects, with 61% having bilateral visual impairment. Of the subjects with visual impairment, 59.1% had moderate visual impairment. The prevalence of amblyopia was 7.53%, and 66% of the amblyopic subjects had bilateral amblyopia.
CONCLUSION: Our study highlights an urgent need for initiation of preschool vision screening in Malaysia.
METHODS: Malaysia was divided into six regions, with each region consisting of 50 clusters. Multistage cluster sampling method was used and each cluster contained 50 residents aged 50 years and above. Eligible subjects were interviewed and pertinent demographic details, barriers to cataract surgery, medical and ocular history was noted. Subjects had visual acuity assessment with tumbling 'E' Snellen optotypes and ocular examination with direct ophthalmoscope. The primary cause of VI was documented. Results were calculated for individual zones and weighted average was used to obtain overall prevalence for the country. Inter-regional and overall prevalence for blindness, severe VI and moderate VI were determined. Causes of VI, cataract surgical coverage and barriers to cataract surgery were assessed.
RESULTS: A total of 15,000 subjects were examined with a response rate of 95.3%. The age and gender-adjusted prevalence of blindness, severe visual impairment and moderate visual impairment were 1.2% (95% Confidence Interval: 1.0-1.4%), 1.0% (95%CI: 0.8-1.2%) and 5.9% (5.3-6.5%) respectively. Untreated cataract (58.6%), diabetic retinopathy (10.4%) and glaucoma (6.6%) were the commonest causes of blindness. Overall, 86.3% of the causes of blindness were avoidable. Cataract surgical coverage (CSC) in persons for blindness, severe visual impairment and moderate visual impairment was 90%, 86% and 66% respectively.
CONCLUSION: Increased patient education and further expansion of ophthalmological services are required to reduce avoidable blindness even further in Malaysia.