Cell – Vessel Mismatch in Glaucoma: Correlation of Ganglion Cell Layer Soma and Capillary Densities

Abstract

Purpose The purpose of this study was to characterize the relationship between retinal ganglion cell layer (GCL) soma density and capillary density in glaucomatous eyes. Methods Six glaucoma subjects with known hemifield defects and 6 age-matched controls were imaged with adaptive optics – optical coherence tomography (AO-OCT) at 6 locations: 3 degrees, 6 degrees, and 12 degrees temporal to the fovea above and below the midline. GCL soma density and capillary density were measured at each location. Coefficients of determination (pseudo R 2 ) and slopes between GCL soma and capillary density were determined from mixed-effects regressions and were compared between glaucoma and control subjects, between more and less affected hemifield in subjects with glaucoma, and between subjects with early and moderate glaucoma, both in a local, bivariate model and then a global, multivariable model controlling for eccentricity and soma size. Results The global correlation between GCL soma and capillary density was stronger in control versus subjects with glaucoma (R 2 = 0.59 vs. 0.22), less versus more affected hemifields (R 2 = 0.55 vs. 0.01), and subjects with early versus moderate glaucoma subjects (R 2 = 0.44 vs. 0.18). When controlling for eccentricity and soma size, we noted an inverse soma-capillary density local relationship in subjects with glaucoma (−388 ± 190 cells/mm 2 per 1% change in capillary density, P = 0.046) and more affected hemifields (−602 ± 257 cells/mm 2 per 1% change in capillary density, P = 0.03). Conclusions An inverted soma-capillary density local relationship in areas affected by glaucoma potentially explains weaker global correlations observed between GCL soma and capillary density, suggesting cell–vessel mismatch is associated with the disease.

Novel Application of Long Short-Term Memory Network for 3D to 2D Retinal Vessel Segmentation in Adaptive Optics—Optical Coherence Tomography Volumes

“…The data from both glaucoma and control subjects were combined for this study and no analysis differentiated the disease state. The full details of subject clinical assessment and AO imaging are found in previously published papers [8,22]. Pupillary dilation and cycloplegia were achieved with 1% tropicamide in subjects, who were subsequently imaged using the FDA multimodal adaptive optics (mAO) device previously described [8,30].…”

“…AO-OCT has provided great capability to simultaneously measure RGC and vessel characteristics. We have previously leveraged AO-OCT to determine the association between RGC density and vessel density using a laborious and semi-automated process [22].…”