Background: Down syndrome is a common chromosomal anomaly. Few reported studies make reference to the ocular status in Asian children with Down syndrome. The purpose of this study was to determine the visual and binocular status of a sample of Down syndrome children in Malaysia.
Methods: A total of 73 Malaysian children with Down syndrome (38 boys and 35 girls) in the Kuala Lumpur area aged one to 12 years were examined. Cycloplegic refraction was performed on each eye and binocular visual acuity was assessed using the Cardiff acuity card or the LogMAR chart. Binocular functions were assessed using the cover test and Lang's stereo acuity test.
Results: The mean age of the subjects was 6.01 +/- 3.41 years. Refraction of the right eye showed that 10 per cent of the subjects were myopic, 20 per cent were hyperopic and 70 per cent had no significant refractive error. The mean spherical equivalent was +0.92 +/- 2.32 DS for the right eye and +0.99 +/- 2.21 DS for the left. The mean of binocular LogMAR VA was 0.36 +/- 0.22 (6/12). Cover test revealed that 21 subjects had strabismus (of those, 33 per cent had unilateral esotropia, 52 per cent had alternating esotropia, nine per cent had unilateral exotropia and five per cent had alternating exotropia). Only 22 subjects gave clear positive response to the stereotest. Other ocular findings included ptosis (one per cent), abnormal head posture (seven per cent) and nystagmus (six per cent).
Conclusion: Malaysian children with Down syndrome have a high incidence of refractive error and strabismus. Regular visual examination is important so that corrective lenses can be prescribed to improve vision and to enhance the quality of life of these children in Malaysia.