Histology of Myopic Dome-Shaped Macula

This is the authors' abstract. We don't add key points for this paper.

Introduction: The aim of the study was to examine the histological correlate of a dome-shaped macula in highly myopic human eyes. Case Presentation: We examined histomorphometrically the histological section of an enucleated, axially extremely elongated globe (axial length: 32.0 mm) of a Caucasian patient aged 56 years. The histological slide exhibited in the foveal region a localized scleral thickening up to 535 µm as compared to a scleral thickness of 298 µm and 310 µm in the parafoveal region. The choroid was thicker in the fovea than parafoveally (21 µm vs. 15 µm). Bruch’s membrane (BM) had a foveal defect (length: 19 µm), at one end of which BM was corrugated. The BM defect was spatially correlated with a subretinal proliferation of retinal pigment epithelium (RPE) cells. Within this subretinal fibrous mass, the RPE cells were connected with a PAS (periodic-acid-Schiff)-positive basal membrane. In the direction of the optic nerve head, BM ended at a distance of 3.8 mm from the optic disc, indicating a large parapapillary gamma zone. The BM end in direction to the optic disc showed a BM corrugation, suggesting a rupture of the lengthened and thinned choroidal peripapillary border tissue. Within parapapillary gamma zone, the peripapillary scleral flange (parapapillary delta zone) was elongated to a length of 0.42 mm and thinned to 94 µm. Conclusions: These histomorphometric findings agree with clinical, optical coherence tomography-based observations of eyes with DSMs, confirm the association of DSMs with macular BM defects, and support the notion of BM playing a role in the biomechanics of the eye.