Abstract
Purpose :
To evaluate the diagnostic accuracy of OCT angiography (OCTA) macular perfusion in glaucoma and investigate relationships with other clinical diagnostic tests.
Methods :
One eye of nondiabetic subjects was analyzed. Glaucomatous eyes (GEs) had defects on 2 reliable VFs with cupping and/or NFL loss. Control eyes (CEs) had a normal exam and IOP <22mmHg. Subjects underwent 6mm macula OCTA (NIDEK AngioScan) scans. Average (%VDa) and quadrant (%VDi, %VDs, %VDn, %VDt) %vessel densities were calculated from thresholded superficial plexus images. Additional testing included OCT cube scans (ONH, macula), IOP, 24-2 SAP (Humphrey Field Analyzer), pERG, and VEP (Diopsys NOVA system).
Results :
16 CEs and 10 GEs were evaluated. Mean(±SD) age was CE: 48±10 yrs and GE: 57±12 (p=0.1). Among GEs 4 were mild, 3 moderate, and 3 severe (HAP criteria). 6 were OAG, 2 ACG, and 2 mixed mechanism. Mean %VDa and %VDn of GEs (48.5% and 52.4%, respectively) were significantly lower than CEs (52.1%, p=.04; 57.4%, p=.05; 2-sided t-test). A significant interaction was found between glaucoma status and age for %VDa, %VDs, %VDi, and %VDn (2-way ANOVA). For GEs, age at or above the median (≥53yo) was associated with decreased %VD in these regions compared to subjects <53yo (p<.001, p=.027, p<.001, p=.001, respectively). For CEs, age had no significant effect on %VD (p=.28, p=.70, p=.11, p=.70, respectively). %VDa had the greatest diagnostic accuracy (AUC=0.78). A threshold of 49.6% resulted in 70% sensitivity and 93% specificity. %VDa and %VDn positively correlated with SAP MD (r=0.71, p=0.02; r=0.68, p=0.03) and average NFL thickness (r=0.90, p=.001; r=0.93, p<.001). GCC subfield minima correlated with %VDa and %VDi (r=0.93, p<.001; r=0.95, p<.001). VEP LC p100 amplitude correlated with %VDn (r=0.71, p=0.05). pERG HC magD/Mag ratio correlated with %VDa, %VDi and %VDn (r=0.83, p=0.003; r=0.74, p=0.02; r=0.71, p=0.03), while LC magD/mag ratio correlated with %VDa and %VDt (r=0.67, p=0.05; r=0.82, p=0.007).
Conclusions :
Our results suggest that macular %VD, particularly nasally, is lower in glaucomatous eyes and is most severely affected in older individuals. Global %VDa has greater diagnostic utility than any quadrant. %VDa and %VDn are correlated with average NFL thickness and MD, both used to stage disease.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.