Refractive outcomes among glaucoma patients undergoing phacoemulsification cataract extraction with and without Kahook Dual Blade goniotomy

Background:Glaucoma patients undergoing phacoemulsification alone have a higher rate of refractive surprise compared to patients without glaucoma.This risk is further increased with combined filtering procedures.Indeed,there are few and conflicting reports on the effect of combined phacoemulsification and micro-invasive glaucoma surgery(MIGS).Here,we look at refractive outcomes of glaucoma patients undergoing phacoemulsification with and without Kahook Dual Blade(KDB)goniotomy.Methods:Retrospective chart review of 385 glaucomatous eyes of 281 patients,which underwent either phacoemulsification alone(n=309)or phacoemulsification with KDB goniotomy(n=76,phaco-KDB)at the University of Colorado.The main outcome was refractive surprise defined as the difference in target and postoperative refraction spherical equivalent greater than±0.5 Diopter(D).Results:Refractive surprise greater than±0.5 D occurred in 26.3%of eyes in the phaco-KDB group and 36.2%in the phacoemulsification group(p=0.11).Refractive surprise greater than±1.0 D occurred in 6.6%for the phacoKDB group and 9.7%for the phacoemulsification group(p=0.08).There was no significant difference in risk of refractive surprise when pre-operative IOP,axial length,keratometry or performance of KDB goniotomy were assessed in univariate analyses.Conclusion:There was no difference between refractive outcomes of glaucomatous patients undergoing phacoemulsification with or without KDB goniotomy.