Determining the size of retinal features in prematurely born children by fundus photography

Purpose: The purpose was to study the effect of prematurity on the macula-disc centre distance and whether it could be used as a reference tool for determining the size of retinal features in prematurely born children by fundus photography. Methods: The macula-disc centre distance of the left eye was measured in pixels from digital fundus photographs taken from 27 prematurely born children aged 10-11 years with Topcon fundus camera. A conversion factor for Topcon fundus camera (194.98 pixel/mm for a 50 degrees lens) was used to convert the results in pixels into metric units. Results: The macula-disc centre distance was 4.74 mm, SD 0.29. No correlation between ametropia and the macula-disc centre distance was found (r = -0.07, p > 0.05). One child (subject 20) had high myopia and retinopathy of prematurity (ROP), and the macula-disc centre distance was longer than average (6.35 mm). Discussion: The macula-disc centre distance in prematurely born children at the age of 10-11 years provides an easy-to-use reference tool for evaluating the size of retinal features on fundus photographs. However, if complications of ROP, for example temporal macular dragging or high ametropia, are present, the macula-disc centre distance is potentially altered and a personal macula-disc centre distance should be determined and used as a refined reference tool.