Abstract
Purpose :
The worldwide prevalence of high myopia is increasing, along with growing evidence of the progression of glaucoma associated with high myopia. The aim of this study is to evaluate the surgical outcome of Ahmed glaucoma valve (AGV) implantation with mitomycin C (MMC) in highly myopic eyes with an axial length (AL) of ≥26.0mm and to confirm whether high myopia itself is a risk factor for surgical failure.
Methods :
This was a retrospective review of 68 eyes from 59 patients diagnosed with primary open-angle glaucoma who underwent AGV implantation with MMC. 23 eyes (33.8%) categorized as high myopia group and 45 eyes (66.2%) were categorized as non-high myopia group. Surgical success defined as intraocular pressure (IOP) ≤21 mmHg (criteria A) or ≤15 mmHg (criteria B) with a lower IOP cutoff 6 mmHg, IOP reduction ≥20% from baseline, no secondary glaucoma surgery, and no loss of light perception. Cox proportional hazard model was used to identify risk factors for surgical failure.
Results :
The 1- and 2- year cumulative probability of success was significantly higher in the non-high myopia group compared to the high myopia group based on criteria A (p = 0.014 and 0.024, respectively). Based on criteria B, the success rate did not differ significantly (p = 0.088). Patients with non-high myopia had significantly lower IOP than those with high myopia at postoperatively 1 and 2 years (p = 0.029 and 0.031, respectively). The only significant risk factor for surgical failure based on criteria A was a phakic eye (hazard ratio (HR) = 0.033, p = 0.033), and AL had a significant influence based on criteria B (HR = 4.41, p = 0.046).
Conclusions :
In our study, the success rate of AGV implantation is lower in highly myopic eyes compared to non-high myopic eyes, and the postoperative IOP remained significantly lower in non-high myopic eyes throughout the 2-year follow-up period. Moreover, a longer AL had a significant impact on surgical failure when defining successful postoperative IOP as 6-15 mmHg.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.