To assess the influence of time interval since last injection and time from baseline on central retinal thickness (CRT) in neovascular age-related macular degeneration (nAMD) with fluid refractory to monthly anti-VEGF treatment.
This retrospective study included nAMD eyes with incomplete response to anti-VEGF defined by the presence of intra- or subretinal fluid on optical coherence tomography despite maximal (monthly) anti-VEGF dosing. The outcome measure was CRT, and two time variables (time from last injection ant time from baseline) were the independent factors included in the individual correlation analyses. In addition, an association analysis was performed.
Sixty eyes of 56 patients (67.9% females, mean age: 78.7 ± 6.8 years) were included with a mean included time period of 35.6 months. A significant positive correlation between CRT and the time from last injection occurred in 24 (40%) and 25 (42%) eyes by univariate and multivariate analysis, respectively. Time from baseline was significantly correlated with CRT in 29 (48.3%) and 30 (50%) eyes by univariate and multivariate analysis, respectively. This correlation was positive in 12 (20%) and negative in 18 eyes (30%). No association with such correlation was found.
So-called refractory nAMD frequently shows a correlation of CRT with the interval in days from the preceding anti-VEGF injection, revealing that there is a subgroup of short-term responsiveness of the residual fluid. Moreover, slower CRT changes may occur over the years, either decrease or increase. In case of a slow CRT increase, this might require a diagnostic workup and therapeutic change.