Abstract
Purpose :
In glaucomatous eyes, not only structural changes but reduction of blood flow is observed around the optic disc. Recently, the split-spectrum amplitude-decorrelation angiography (SSADA) algorithm have made it possible to observe the microvasculature around the optic disc nerve head, which is said to associate with the blood flow. In this study, we compared the optic disc microvascular density and structure in subjects with open angle glaucoma using optical coherence tomography angiography (OCTA), and analyzed related factors.
Methods :
Observational, cross-sectional study was performed from February to October 2015. We measured two types of OCT; OCTA with RTVue®XR™Avanti™ (OptoVue, California), and circumpapillary retinal nerve fiver layer thickness (cpRNFLT) with RS-3000 Advance®(Nidek, Japan). The scans size was 4.5mm×4.5mm in the OCTA, and 6.0mm×6.0mm in the cpRNFLT. According to Garway-Heath classification, the whole measurement value of OCT was divided into 6 sectors; nasal, inferior nasal (IN), inferior temporal (IT), superior nasal (SN), superior temporal (ST), and temporal. Patients with reliable Humphrey visual field SITA™Standard 24-2 (Carl Zeiss Meditec AG, Germany) within 3 month were included. Patients with fundus, optic nerve and visual tract disease, a history of glaucoma or intraocular surgery were excluded. By using the generalized linear mixed model, RPC density, cpRNFLT, Mean Deviation (MD), age, sex, axial length, logMAR visual acuity, diabetes, high blood pressure, smoking history, were investigated. Statistical analysis was performed using SPSS software (IBM SPSS Statistics 18, IBM Corp., New York).
Results :
Sixty-six eyes of 45 patients (male: female = 25:20) were analyzed. The RPC density and the cpRNFLT were significantly correlated with the MD value (R = 0.734, R = 0.744, p <0.05). Age, axial length, logMAR visual acuity, diabetes, high blood pressure, smoking history did not significantly related to the MD value. The OCT measurements of Nasal, IN, and ST showed the best values of Akaike's Information Criterion (AIC) for the visual field sensitivity of each sector,. AIC showed the best value in the adjacent sector in IT and temporal. The RPC density was the better model for the MD value as compared to the cpRNFLT.
Conclusions :
The RPC density and the cpRNFLT were associated with the MD value. The RPC density was the better model for the MD value.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.