Comparative efficacy of Nd : YAG laser peripheral iridotomy and surgical iridectomy in modulating perioperative subclinical inflammation after DMEK

PURPOSE: To compare the effect of preoperative Nd:YAG laser peripheral iridotomy (PI) and intraoperative surgical iridectomy on subclinical inflammation before and after Descemet membrane endothelial keratoplasty (DMEK), using validated anterior segment optical coherence tomography (AS-OCT) inflammatory biomarkers. METHODS: Among 132 eyes eligible for analysis, this matched cohort study included 40 eyes (20 per group) undergoing DMEK for Fuchs endothelial dystrophy or pseudophakic bullous keratopathy. Patients received either a preoperative laser PI or intraoperative surgical iridectomy. Eyes were matched according to gender, age, presence of preoperative posterior stromal ripples, baseline visual acuity and corneal thickness. Pre- and post-operative inflammation was quantified using AS-OCT measured aqueous-to-air relative intensity (ARI) and anterior chamber (AC) cell reflectivity. Post-operative trends in subclinical inflammation were compared using generalized additive models (GAM). Visual, pachymetric and endothelial outcomes, as well as post-operative complications, were compared. RESULTS: The laser PI group showed greater baseline ARI (p < 0.001) consistent with higher preoperative subclinical inflammation, while surgical iridectomy eyes exhibited greater cell counts after DMEK and at final follow-up (both p = 0.05). Post-operative inflammatory spikes resolved by 6-8 weeks, with faster normalization and lower peak values in the laser PI group. Visual acuity improvement, central corneal thickness reduction, endothelial cell loss and complication rates were comparable. CONCLUSIONS: Preoperative laser PI was associated with lower early post-operative subclinical inflammation compared with intraoperative surgical iridectomy, without compromising visual or endothelial outcomes. These findings suggest that a less invasive PI approach may mitigate early post-operative immune activation, promoting smoother AC homeostasis after DMEK.