Extreme thinning or loss of inner neural retina along the staphyloma edge in eyes with pathologic myopia.

Abstract

To investigate the morphologic changes along the edge of posterior staphyloma in highly myopic eyes with patchy chorioretinal atrophy and to identify the relationship between retinal thinning and the visual field (VF) defects found in these eyes. Retrospective, observational case series. Twenty eyes (17 patients) with pathologic myopia (myopic refractive error ≥ 8 diopters or an axial length ≥ 26.5 mm) and patchy atrophy along the staphyloma edge were analyzed retrospectively. The VFs were obtained by Goldmann kinetic perimetry. In the area of patchy atrophy, the inner retinal tissue was very thin or completely absent. Any remnants of the retinal tissue appeared to be adherent to the layer of large choroidal vessels or to the sclera. The mean thickness of the retina at its thinnest point in the area was 51.6 ± 29.0 μm in 20 eyes. The retina was thinner than 50 μm at its thinnest point in 12 (60.0%) of the 20 eyes, and the mean retinal thickness at its thinnest point in these 12 eyes was 32.1 ± 16.0 μm (range, 4 to 49 μm). Nineteen eyes (VF of 1 eye was not determined) had very similar VF findings by Goldmann perimetry, that is, a defect of the sector corresponding to the course of retinal nerve fiber over the patchy atrophy. The results show that the thickness of not only the outer retina, but also of most of the inner retina, including the nerve fiber layer, is significantly thinner at the staphyloma edge. Such damage to the inner retina along the staphyloma edge causes the VF defects in highly myopic eyes.