Abstract
Purpose :
To investigate the prevalence and role of choroidal microvasculature dropout (CMvD) in pre-perimetric open-angle glaucoma (PPG), which is defined by glaucomatous optic nerve head (ONH) change without visual field (VF) defects, in terms of glaucomatous VF conversion.
Methods :
This retrospective, longitudinal study included 101 Korean PPG eyes with β-zone peripapillary atrophy. All eyes underwent optical coherence tomography (OCT) angiography during follow-up, and were assessed for the presence of CMvD. The ocular biometry, including intraocular pressure (IOP), retinal nerve fiber layer (RNFL) thickness measured by OCT, VF test parameters, and proportion of visual field progression (conversion) were compared between eyes with(+) and without(-) CMvD. Factors associated with conversion to VF loss were assessed using logistic regression analysis.
Results :
CMvD was found in 12 eyes out of 101 PPG eyes (11.9%). The eyes with CMvD showed higher mean and peak IOP compared to eyes without CMvD (16.1 vs. 14.3 mmHg, 21.0 vs. 17.5 mmHg, respectively, P < 0.05). Compared to CMvD (-) eyes, the baseline RNFL thickness was significantly lower in CMvD(+) eyes (77.25 vs. 86.20 um, P < 0.05). The baseline VF parameters did not differ between two groups, but they were significantly worse in CMvD(+) eyes at the last exam. The frequency of VF progression was significantly higher in CMvD(+) eyes (66.6% vs. 16.9%, P < 0.05). The rate of visual field index progression was also significantly faster in CMvD(+) eyes (-1.75 vs. -0.14 %/year, P < 0.05), although there was no significant difference in the rate of RNFL loss. The follow-up duration (odds ratio, 1.5; 95% CI, 1.01-2.12; P=0.021), baseline average RNFL thickness (odds ratio, 0.91; 95% CI, 0.85-0.99; P=0.019), and presence of CMvD (odds ratio, 7.99; 95% CI, 1.14-56.0; P=0.037) were independently associated with glaucomatous VF conversion in PPG eyes.
Conclusions :
12% of PPG eyes showed CMvD during follow up. Eyes with CMvD during follow-up showed thinner RNFL compared to those without CMvD at baseline. The presence of CMvD during follow-up was independent predictor of glaucomatous VF conversion in PPG eyes.
This is a 2020 ARVO Annual Meeting abstract.