Macular and Peripapillary Vascular Dropout Are Associated with Disease Severity in Advanced Glaucoma

Abstract

Purpose : To evaluate the association between macular and peripapillary vessel density assessed by optical coherence tomography angiography (OCTA) and visual field (VF) mean deviation (MD) in advanced glaucoma eyes.

Methods : OCTA (Angiovue) vessel density and VF MD measurements from 39 eyes of 36 advanced glaucoma patients (VF MD < -10 dB) were included from the Diagnostic Innovations in Glaucoma Study. Superficial macular vessel density was measured in the whole image (mwiVD) and the parafoveal region (pfVD). Optic nerve head vessel density was measured in whole image (ONH wiVD) and the circumpapillary region (cpVD) with and without automated removal of large vessels (wiVD capillary and cpVD capillary). SDOCT global circumpapillary retinal nerve fiber layer (cpRNFL) thickness and macular ganglion cell complex (mGCC) thickness were obtained from the same scans as vessel density. Mixed effect models were used to assess the association between OCTA and SDOCT measures and VF MD while adjusting for image quality index (QI), age and within-patient inter-eye correlations.

Results : Macular and ONH vessel densities were significantly lower with worsening VF MD. For each 1 dB decrease in VF MD, a reduction in macular vessel densities of 0.44% and 0.46% for mwiVD and pfVD with R² values of 0.20 for both was seen, respectively. The association between VF MD and ONH vessel density was strongest after removal of large vessels, wiVD capillary and cpVD capillary, followed by ONH wiVD and cpVD; For each 1 dB decrease in VF MD, a reduction of 0.43%, 0.49%, 0.35%, 0.38%, with R² values 0.30, 0.24, 0.21, 0.16 was seen, respectively (all P<0.01). For each 1 dB decrease in VF MD, a reduction of 0.85 and 0.24 microns for parafoveal GCC (P=0.04) and cpRNFL (P=0.51) was seen, with R² values of 0.10 (P=0.05) and 0.01 (P=0.51), respectively. The coefficient between MD and all ONH and macula vessel density parameters and mGCC thickness remained significant after controlling for QI and age (all P≤0.05).

Conclusions : OCTA vascular measurements, particularly vessel density calculated after large vessel removal, are associated with the severity of visual field damage in advanced glaucoma eyes. While OCT RNFL and GCC thickness measures likely reach a floor in advanced glaucoma, OCTA might provide additional information in the management of advanced stages of the disease.

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