Racial Disparities in Outcomes of Cataract Vs. Cataract Plus iStent in Open-Angle Glaucoma

Abstract

Purpose : The benefit of cataract and cataract plus iStent^® (Glaukos Corp. Laguna Hills, CA) surgeries in reducing intraocular pressure (IOP) has been noted in open-angle glaucoma (OAG), yet the impact of race has not been studied. The purpose of our study is to compare intraocular pressure (IOP) and number of glaucoma medications (meds) in cataract extraction alone (CE) vs. cataract extraction plus iStent (CE+iStent) in Caucasians (CA) vs. African Americans (AA) at 1 year.

Methods : 88 OAG patients (58 CA, 30 AA) who underwent CE and 147 (99 CA, 48 AA) who underwent CE+iStent at Edward Hines, Jr. VA and Loyola University Medical Center from 2015 to 2019 were retrospectively reviewed. IOP and meds were recorded at baseline and postoperative months 1, 3, 6, and 12. IOP spikes (>21 mmHg) on postoperative day 1 were recorded. Independent samples t-test analyses were performed.

Results : In the total patient sample, baseline IOP was significantly higher in CE+iStent group vs. CE (p=0.0001). IOP at 1 year was significantly higher after CE+iStent vs. CE (p=0.013). Meds at 1 year were significantly less after CE+iStent vs. CE (p=0.019).

Regarding race, baseline IOP was significantly higher in CE+iStent group vs. CE (p=0.039 CA; p=0.0005 AA). CE resulted in a significant decrease in IOP at 1 year in CA (p=0.001). CE+iStent resulted in a significant decrease in IOP at 1 year in both CA (p<0.0001) and AA (p=0.012). Comparing CE+iStent to CE at 1 year, IOP was higher after CE+iStent for both races (p=0.178 CA; p=0.011 AA).

CE+iStent resulted in a significant decrease in meds at 1 year in CA (p=0.002) but not AA (p=0.082). Comparing CE+iStent to CE at 1 year, meds were significantly reduced with CE+iStent in CA (p=0.004) but not AA (p=0.841).

29.2% of AA and 14.4% of CA had severe OAG in CE+iStent group vs. only 16.7% of AA and 13.8% of CA in CE group.

39.7% of CA and 36.7% of AA had an IOP spike on postop day 1 in CE group compared to 20.2% of CA and 33.3% of AA in CE+iStent group.

Conclusions : This study shows significant benefit in lowering pressure and medication burden after cataract extraction alone and with iStent. Racial differences are seen in postoperative outcomes, and further research is needed to understand how race impacts these surgical outcomes. A limitation of the study is smaller sample size.

This is a 2021 ARVO Annual Meeting abstract.

 

IOP Average in CE vs. CE+iStent for CA, AA, and CA+AA patients

 

Med Average in CE vs. CE+iStent for CA, AA, CA+AA patients