MIGS, Race, and Refractive Outcomes

Abstract

Purpose : The purpose of this research is to compare refractive outcomes of glaucoma patients who underwent phacoemulsification cataract surgery (Phaco) to those who had cataract surgery with Minimally Invasive Glaucoma Surgery (Phaco + MIGS). Previously, few studies have explored the various refractive outcomes following Phaco + MIGS procedures as compared to Phaco alone.

Methods : This is a retrospective chart review of 243 patients from Edward Hines Jr. VA Hospital and Loyola University Medical Center who had MIGS procedures (iStent® (Glaukos Corp. Laguna Hills, CA) or Kahook Dual Blade® (New World Medical, Rancho Cucamonga, CA, USA) and Phaco (Phaco + MIGS, n= 163) or Phaco alone (Phaco, n= 80). The Phaco group only includes patients from the Edward Hines Jr. VA Hospital. Subgroup analysis was performed based on the severity of glaucoma and race. We performed both independent t-tests and one-way ANOVA tests.

Results : The average difference in post-operative spherical equivalent (SE) to target refraction in Phaco + MIGS vs. Phaco was 0.462 and 0.437, respectively (p = 0.5). 65.5% of patients in the Phaco + MIGS group were within 0.5 D of the target refraction compared to 67.5% of the Phaco group. 89% of eyes in the Phaco + MIGS group had a post-op SE within 1 D of the anticipated target refraction vs. 92.5% of eyes in the Phaco group. The Phaco + MIGS African American subgroup (n = 57) had 87.8% eyes within 1 D of target vs. 88.2% in the Caucasian subgroup (n = 110). The Phaco African American group (n = 27) had 92.6% compared to the Phaco Caucasian group (n = 53) with 92.5% of eyes within 1 D of target refraction. We performed a one-way ANOVA to compare the effect of severity of glaucoma on refraction. In both the Phaco + MIGS and Phaco groups, there was no significant difference (p = 0.171 vs. p = 0.241), respectively. 82% of patients in the Phaco + MIGS group with refractive surprise (> 1D from target) had visual acuity (VA) of 20/40 or worse vs. 100% of eyes in the Phaco group. In the Phaco group, average pre-op VA was 20/40 compared to 20/25 post-op. In the Phaco + MIGS group, average VA went from 20/60 pre-op to 20/30 post-op.

Conclusions : Our study showed no significant difference in refractive outcomes in patients who had Minimally Invasive Glaucoma Surgery with phacoemulsification compared to those who had phacoemulsification cataract surgery alone. There was also no significant difference in refractive outcomes based on race or the severity of glaucoma.

This is a 2021 ARVO Annual Meeting abstract.