The Peripapillary Sclera Follows a V-Shaped Configuration That is More Pronounced in Glaucoma Eyes

Abstract

Purpose : To compare the shape of the anterior surface of the peripapillary sclera (PPS) between glaucoma and healthy controls.

Methods : The optic nerve heads of 259 glaucoma subjects (134 primary open angle glaucoma [POAG] and 125 primary closed angle glaucoma [PACG]) and 518 healthy controls were imaged with spectral domain optical coherence tomography (Spectralis, Heidelberg, Germany). The shape of the PPS/Bruch’s membrane (BM) was defined through the angle between a line parallel to the nasal anterior PPS/BM boundary and one parallel to the temporal side. A negative value indicated that the PPS/BM followed an inverted v-shaped configuration (peak pointing towards the vitreous); whereas a positive value indicated that it followed a v-shaped configuration (peak pointing towards the orbital tissues). The PPS shape was compared between glaucoma and healthy controls and among two primary glaucoma subtypes.

Results : The mean PPS angle in healthy controls, POAG and PACG were 4.96±6.52, 6.34±6.89, and 7.23±6.68 degrees, respectively. The v-shaped PPS was significantly associated with age (β=0.17, P<0.001), poorer best corrected visual acuity (β=4.41, P=0.002), central corneal thickness (β=-0.02, P=0.013), peripapillary choroidal thickness (β=-0.02, P<0.001), lamina cribrosa depth (β=0.02, P<0.001), and BM angle (β=0.41, P<0.001). The PPS angle of glaucoma, POAG and PACG subjects was higher than in healthy controls (β=2, P<0.001, β=1.38, P=0.032, β=2.27, P=0.001, respectively). The PPS angle significantly increased by 0.19 degrees in healthy controls and 0.18 degrees in POAG eyes for every 1-year increase in age.

Conclusions : The v-shaped PPS was more pronounced in glaucoma eyes than in healthy eyes. This posterior bowing of the peripapillary sclera with glaucoma may have an impact on the biomechanical environment of the optic nerve head and could be a potential risk factor for glaucoma.

This is a 2020 ARVO Annual Meeting abstract.