Abstract
Purpose :
To investigate the factors associated with choroidal microvasculature dropout (MvD) enlargement detected by optical coherence tomography angiography (OCT-A) in glaucoma eyes.
Methods :
Ninety-one eyes of 68 primary open angle glaucoma (POAG) patients were enrolled. Only eyes with 4 good quality OCT-A and OCT scans of the optic nerve head with 2 years follow-up were included. Area of MvD were analyzed on en-face images at each visit (see Figure). Univariable and multivariable mixed effects models were constructed to identify the factors contributing to MvD area over time.
Results :
Peripapillary MvD was detected in 53 (58.2%) eyes at baseline and in an additional 17 (18.7%) eyes during follow-up, whereas MvD was not detected in 21 (23.1 %) eyes during the entire follow-up period. In eyes with MVD at baseline, mean baseline MVD area was 0.15 (0.09, 0.22) mm2. In eyes with MvD at baseline, mean (95% CI) of rate enlargement of MVD area was 0.05 (0.04, 0.06) mm2/year. In the univariable model, worse baseline VF MD (coefficient ß =0.27, 95%CI: 0.10, 0.44, P=0.002), greater intraocular pressure (IOP) fluctuations (ß=0.86, 95% CI: 0.24, 1.48, P=0.007), higher peak IOP (ß=0.17, 95% CI: -0.01, 0.35, P=0.067) and greater number of IOP lowering medications (ß =1.36, 95% CI: 0.67, 2.05, P<0.001) were associated with faster MvD area enlargement (Table 1). In the multivariable model, worse baseline VF MD, greater IOP fluctuations, higher peak IOP and greater number of IOP lowering medications remained significantly associated with faster MvD area enlargement (Table 1). No associations were found between mean IOP during follow-up and MvD changes over time. In the 17 eyes that developed MvD during follow-up, long-term IOP fluctuation [95% CI], defined as the standard deviation of IOP measurements during follow-up, was significantly greater (3.5 [2.3, 4.7] mmHg) in eyes with MvD compared to eyes that did not develop MvD (1.9 [1.5, 2.3] mmHg, P=0.012).
Conclusions :
IOP fluctuation was associated with MvD enlargement and development. Other factors, including peak IOP, worse baseline VF MD and number of glaucoma medications were significantly associated with MvD area enlargement in glaucomatous eyes. The identification of factors associated with MvD enlargement may improve our understanding of the role of choroidal microvasculature in glaucoma.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.