Abstract
Purpose :
To identify predictive factors associated with highly fluctuating macular thickness in neovascular age-related macular degeneration (nAMD), and to explore the effects of fluid fluctuation on visual outcomes.
Methods :
This was a real-world retrospective cohort study conducted at five tertiary centers in Thailand (2016-2018). We included one eye per each treatment-naïve nAMD patient who received anti-VEGF injections based on a treat-and-extend regimen for a duration ranged from 1 to 3 years. Other maculopathies including macular atrophy and subretinal fibrosis were excluded from the study. The standard deviation (SD) of 1-mm central subfield thickness (CST) from month 3 to 24 in each patient was organized into ascending order from lowest to highest, and thereafter split equally into three groups: low, moderate, and high CST fluctuation group.
Results :
Of 558 eyes, baseline CST was 363±137µm, 384±183µm, and 490±210µm in the low, moderate, and high CST fluctuation group (186 eyes in each group), respectively. Correspondingly, the SD of CST from month 3-24 was 11.8± 6.3, 40.6±10.6, and 114.7±59.3. After controlling for age, baseline CST and a total number of injections, the Generalized Estimating Equations showed that eyes with low fluid fluctuation significantly gained more ETDRS letters than those in the moderate and high fluctuation group (mean differences=6.7 and 10.7 letters, respectively) at 12 months follow-up. These differences between the groups increased further at 24 months (10.1 and 14.0 letters, Figure 1). Baseline CST of ≥405 µm was significantly associated with highly fluctuating CST during the maintenance phase (adjusted odds ratio (AOR)=3.27, sensitivity and specificity of detection=62% and 68%). Such correlations were not observed in baseline BCVA, the presence of polypoidal lesion, and Bevacizumab uses. Among different subtypes of retinal fluid, the presence of intraretinal fluid (IRF) coincided with subretinal fluid (SRF) at the baseline visit was the strongest predictor for high CST fluctuation over the treatment course (AOR=2.48) (Table 1).
Conclusions :
The presence of baseline SRF and IRF predicted highly fluctuating retinal fluid over the 2-year course of nAMD treatment. Apart from the retinal fluid per se, unstable macular thickness during anti-VEGF therapy may be an additional factor contributing to poor visual outcomes.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.