Disc Area in High Myopia

Abstract

Abstract: : Purpose:To determine if there is an association between disc size and refractive error in highly myopic eyes. Methods:The data of all patients undergoing confocal scanning laser ophthalmoscopy with the Heidelberg Retina Tomograph II (HRT II) aged 18 to 85 scanned between October 2001 and September 2004 were reviewed. Eyes with refraction error (RE) ≥ 7 diopters of myopia and a reliable HRT II scan (TSD ≤40) were included. Central corneal thickness (CCT) and HRT stereometric parameters were analyzed. Eyes without CCT measurements were excluded. Results:80 eyes (80 patients) were included in this study. Mean RE was –9.2 ± 1.97 diopters (range –7.00 to –15.5 diopters). Mean disc area for all patients was 2.31 ± 0.9 mm² (range 0.81 to 5.37 mm²) and mean CCT was 550 ± 40 µm (range 460 to 654 µm). Disc area increased with increasing RE (r = –0.26, P = 0.02 (Pearson correlation coefficient)). CCT was not related to refractive error (P = 0.65) or disc area (P = 0.79). Conclusions:Increasing myopic refractive error ≥ 7 diopters is associated with an increase in disc area. This may have implications for glaucoma risk in these eyes.

Keywords: anatomy • myopia • optic disc