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.