Instrument-integrated optical coherence tomography for quantitative assessment of tissue alteration in retinal endolaser photocoagulation

Retinal endolaser photocoagulation (REPC) is a common vitreoretinal procedure, yet quantitative and intraoperative assessment of treatment outcomes remains challenging with microscopic imaging or conventional microscope-integrated optical coherence tomography (miOCT) systems. In this work, we evaluate a novel endolaser probe with instrument-integrated optical coherence tomography (iiOCT) for tissue monitoring in retinal endolaser photocoagulation (REPC) procedures. Retinal tissue changes in ex vivo porcine eyes were quantified from iiOCT M-scans (consecutive A-scans acquired over time), enabling both structural and phase-sensitive characterization of laser-induced responses. We also developed mixed-effect models incorporating iiOCT-derived metrics to predict reference dosimetry metrics from microscopic images and miOCT C-scans. The ordinal model reliably classified lesion visibility (accuracy = 0.884), outperforming a laser-parameters-only model. The linear model effectively predicted lesion size (average R 2 = 0.87), with the inclusion of the iiOCT-derived M-metric improving R 2 by approximately 8.3%. This proposed system bridges the gap between miOCT- and iiOCT-based dosimetry and establishes a foundation for real-time intraoperative feedback to improve the safety and efficacy of retinal endolaser surgery.