Posterior Segment Changes in Myopic Children From a Singapore School Cohort

Abstract

Abstract: : Purpose: There has not been any study of retinal changes in a population of low to moderate myopes in childhood. This study aims to report the frequency and associations of retinal and optic disc changes in a sample of myopic Singapore school children. Methods: The data for this study were obtained from the first year results of a longitudinal study: the Singapore school cohort study of the risk factors of myopia. The children were recruited from 3 schools from different geographic locations in Singapore. 679 children, out of which 569 children of Chinese ethnic origin, were recruited. In addition 110 non-Chinese (Malay and Asian Indian) children were also recruited. All subjects were between 8-10 years old with myopia worse than –0.5D. The mean spherical equivalent was –3.20 D (SD 1.70). The distribution of spherical equivalent was skewed with lesser frequency of higher myopia. The mean axial length was 24.4 mm (SD 0.95). Cycloplegic autorefraction, ultrasonography, indirect ophthalmoscopy and color fundus photography were performed. Optic disc measurements were performed on digital images. Results: There were no retinal breaks, detachments, macular holes, staphylomas, lacquer cracks or Fuch spots. No cases of posterior vitreous detachment were found on ultrasonography. Lattice degeneration was noted in 3 eyes of 2 subjects. The temporal parapapillary crescent (TPC) was a prominent finding in more than 90% of the children The median TPC to disc area ratio was 0.32. The TPC to disc area ratio was associated with female gender, older age, more severe myopia and increased axial length. The median vertical cup-disc ratio and the cup-disc area ratio were 0.34 (range 0.13-0.63) and 0.17 (range 0.01-0.49) respectively. A greater cup-disc ratio was associated with a flatter cornea and with Asian-Indian ethnicity. Conclusions: In this sample of myopes, retinal changes were relatively infrequent. The para-papillary crescent was the major optic disc finding. Evaluation of cup-disc ratios should take into consideration ethnic group and corneal curvature.

Keywords: retina • optic disc • refractive error development