Abstract
Purpose :
It has been theorized that removal of the vitreous affects the pharmacokinetic properties of intravitreal anti-VEGF therapy. This retrospective cohort study assessed the frequency of anti-VEGF administration before and after pars plana vitrectomy (PPV) in eyes with neovascular age-related macular degeneration (nAMD).
Methods :
The study included 18 eyes with nAMD being treated with anti-VEGF injections that underwent PPV. Indications for PPV were recorded. At the five visits before (Pre-5, Pre-4, Pre-3, Pre-2, and Pre-1) and after PPV (Post-1, Post-2, Post-3, Post-4, Post-5, and final), functional and anatomic (optical coherence tomography) outcomes were assessed. The interval between visits was recorded. Statistical analyses included paired t-test, McNemar’s test, and generalized estimating equations.
Results :
The most common indications for PPV included 5 (28%) exudative/hemorrhagic retinal detachments (RD), 5 (28%) dislocated lens/retained lens fragments, and 3 (17%) rhegmatogenous RDs. In the visits preceding vitrectomy, there were average intervals of 50.7 (±24.0), 55.8 (±26.2), 58.9 (±28.5), and 58.9 (±35.5) days between the visits [Pre-5 to Pre-4], [Pre-4 to Pre-3], [Pre-3 to Pre-2], and [Pre-2 to Pre-1], respectively. After vitrectomy, the intervals between visits were 39.8 (±13.3), 46.7 (±24.0), 40.8 (±18.2), and 42.6 (±18.4) days between the [Post-1 to Post 2], [Post-2 to Post-3], [Post-3 to Post-4] and [Post-4 to Post-5] visits, respectively. When comparing the intervals between visits before vitrectomy to those after vitrectomy, there was a significant difference, p=0.03. Average LogMAR vision was 0.56 (± 0.60), 0.59 (±0.60), 0.62 (± 0.67), and 0.73 (± 0.72) at the Pre-5, Pre-4, Pre-3, and Pre-2, visits, respectively. There was no significant difference in vision from that of the Pre-1 visit [1.24 (±0.85)] when compared to the vision of the Post-1 visit [0.99 (± 0.66)], p-value= 0.29. In the subsequent Post-2, Post-3, and Post-4 visits, the average LogMAR vision was 0.88 (±0.67), 0.86 (±0.65), and 0.94 (±0.73), respectively.
Conclusions :
A shortening of treatment intervals was observed after PPV in eyes receiving anti-VEGF injections for nAMD. After PPV, close monitoring of anti-VEGF treatment response is prudent given the potential pharmacokinetic effects of post-vitrectomy physiology.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.