Abstract
Purpose :
The Ahmed valve implantation (AVI) has been a useful surgical option for controlling IOP in refractory glaucoma cases. However, an ocular hypertensive phase (OHP) is a relatively common occurrence due to the wound healing changes that affect the permeability of the bleb wall surrounding the plate. Supplementing mitomycin C (MMC) during the surgical procedure is a plausible way to reduce the effects of post-operative scarring and to avoid the short-term increase of IOP after sugery. The aim of this study is to comparatively assess the post-operative surgical outcomes of AVI with and without MMC trans-operative supplementation operated in our center.
Methods :
All medical records of refractory glaucoma cases operated with an AVI in at least one eye were retrospectively analyzed. Variables assessed before and after the surgery were IOP, best-correct visual acuity (BCVA), visual field index (VFI), vertical cup to disc ratio (c/d ratio), number of antiglaucoma medications and the presence and type of post-operative complications. The presence or absence of a post-operative OHP was also analyzed. Success after the procedure was defined either as a >20% decrease in IOP from the preoperative period, or an IOP ≤ 21 mmHg without (complete) or with (qualified) glaucoma medication. For purposes of statistical analysis, we randomly chose one eye of bilateral surgical cases.
Results :
A total 57 eyes of 57 patients which undewent MMC supplemented AVI (MMC-AVI; n =31) or non-supplemented MMC AVI (ns-MMC-AVI; n = 26) were included. Demographic and general data is shown in table 1. The overall success rates at post-operative year one were statistically comparable between the MMC-AVI and the ns-MMC-AVI groups (51.7% vs. 90.5%, p=0.21), in spite of clinically significant difference. The mean IOPs were significantly lower (p = 0.027; table 1), as well as the number of antiglaucoma medications in the MMC-AVI group as compared to the ns-MMS-AVI group (2.1 ± 1.3 vs. 1.0 ± 1.1; p = 0.005).
Conclusions :
Both treatments offered reasonable IOP control, surgical success and safety for eyes with refractory glaucoma after one year of surgery. However, significantly lower post-operative IOP, les frequency of OHP, and fewer antiglaucoma medications that were present in the MMC-AVI group support the idea that MMC should be considered as a part of the process of implanting an Ahmed valve.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.