Evaluation of crowded optic nerve head and small scleral canal in intrapapillary hemorrhage with adjacent peripapillary subretinal hemorrhage

Background Intrapapillary hemorrhage with adjacent peripapillary subretinal hemorrhage (IHAPSH) is a clinical syndrome most commonly affecting myopic eyes with tilted discs that usually resolves spontaneously without treatment. Subretinal hemorrhage usually occurs peripapillary on the nasally adjacent side near the optic disc. The etiology of this condition is still unknown. The purpose of this study was to determine if a crowded optic nerve head and small scleral canal are involved in the pathogenetic mechanisms of IHAPSH. Twelve subjects with IHAPSH diagnosed at the Affiliated Ophthalmology Hospital of the First Clinical College of Harbin Medical University and 24 control subjects were examined. The size of the inner aspect of the scleral canal and level of nerve fiber crowding of the optic nerve head were analyzed with optic nerve head analysis software packet of the Stratus Optical Coherence Tomography software and manual segmentation software. The Mann-Whitney U test and multiple comparisons (with the Bonferroni correction method) were performed. p values less than 0.002 (two-sided) were considered statistically significant. The area, perimeter, and the perimeter/area ratio of the optic disc, vertical and horizontal diameter of the inner aspect of the scleral canal, vertical integrated rim area (VIRA), and the rim area were calculated. The area and perimeter of the optic disc and the horizontal diameter of the inner aspect of the scleral canal were significantly lower in the affected and contralateral eyes of the subjects with IHAPSH than in the eyes of the controls. Conversely, the IHAPSH-affected and contralateral eyes had significantly higher perimeter/area ratio of the optic disc, VIRA, and rim area values than the control eyes. The VIRA and rim area were greater in the IHAPSH-affected eyes than in the contralateral eyes. Patients with IHAPSH have smaller optic discs and scleral canals than control subjects, with a higher level of nerve fiber crowding.