Abstract
Purpose :
Vitreous detachment occurs through the liquefaction and syneresis of the central vitreous leading to rupture of the posterior hyaloid. One may posit the extent of vitreal liquefaction and subsequent detachment may modify intravitreal drug distribution and alter response parameters. The purpose of this study was to evaluate the relationship between the stage of posterior vitreous detachment (PVD) and the efficacy of intravitreal injection (IVI) of bevacizumab or aflibercept in treatment-naïve patients with exudative age-related macular degeneration (EAMD).
Methods :
Treatment-naive patients at the Edward Hines Jr. VA center who received three consecutive injections of bevacizumab or aflibercept between January 2015 and September 2023 for EAMD were reviewed to document central retinal thickness (CRT) and Snellen visual acuity (converted to logMAR). PVD stage criteria per OCT imaging was as follows: stage 0 - premacular bursa or posterior precortical vitreous pocket; stage 1a - vitreomacular adhesion or vitreomacular traction; stage 1b - posterior vitreous cortex with no macular attachment/only attachment at the optic disc; stage 2 - absence of stage 0 criteria. The interaction between PVD stage and differences in CRT and vision from baseline to each post-injection time point was assessed via a mixed-effect two-way ANOVA using a restricted maximum likelihood model.
Results :
A total of 64 eyes of 54 patients were included in the study. At baseline, 12 eyes were classified as stage zero, 9 as stage 1a, 10 as stage 1b, and 34 as stage 2. The highest proportional change in CRT was found from baseline to post-injection time point 1 for all PVD grades. All stage 2 CRT changes except between post-injection time points 2 and 3 were found to be statistically significant. Change in logMAR vision was found to be statistically significant only between baseline and post-injection 1 time point. (p = 0.0052). A significant interaction between PVD stage, CRT, or logMAR vision was not evident in our cohort (p = 0.1173).
Conclusions :
The effect of vitreous liquefaction characterized by the stage of PVD on CRT or vision following IVI was undetectable based on the cohort examined. While interpretation of study findings is restrained by reduced precision of study metrics, the data do provide useful information for additional studies adequately powered to reduce confounding effects of Type 2 error regarding effects of vitreous liquefication on IVI outcomes.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.