Quantification of macular microvascular changes in patients with retinitis pigmentosa using optical coherence tomography angiography

Abstract

Purpose : To evaluate the microvascular changes in eyes with retinitis pigmentosa (RP) quantitatively using optical coherence tomography angiography (OCTA) and to determine the significance of the correlations of these indices with the severity of RP.

Methods : This was a retrospective, observational study. The medical records of 47 RP patients without CME, 11 RP patients with CME, and 46 controls were reviewed. The OCTA images were obtained by Cirrus 5000 with Angioplex^TM OCTA, and an automated program was used to analyze the microvascular patterns of the entire retina, and the segmented, superficial and deep retinal plexuses. The vessel density (VD) and skeleton density (SD) were used as indices of the microvascular density, while the vessel diameter index (VDI) was used as a measure of the caliber of the vessels. The width of the ellipsoid zone (EZ) in the OCT images, and the mean deviation (MD) of the Humphry Field analyzer (HFA) were used to determine the severity of the RP. Student’s t tests and Spearman correlation tests were used to determine the significance of the correlations between the vascular indices and the severity of the RP.

Results : Both the VD and SD in the superficial and deep plexuses, and the whole retina were significantly reduced, and the VDI was significantly increased in RP patients compared with the corresponding values of the controls (P<0.0001). There was no significant difference in the VDI between RP patients with and without CME. Spearman’s rank tests indicated that the RP severity was significantly and negatively correlated with the SD and the VD in all layers (P <0.0001, r ranging from 0.49 to 0.81) and significantly and positively correlated with VDI in the deep and the whole retina (P <0.0001, ranging from -0.61 to -0.75).

Conclusions : Quantitative changes in the microvascular density and morphology might be useful for examining the pathophysiology of RP.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.