Longitudinal assessment of cone structure and lesion remodeling in laser-induced retinopathy

To assess photoreceptor structural changes and lesion remodeling during spontaneous recovery of laser-induced retinopathy (LIR), and to evaluate accompanying alterations in localized retinal function.

This prospective longitudinal observational study included thirteen patients (15 eyes) with LIR. Baseline and 6-month follow-up examinations included adaptive optics scanning laser ophthalmoscopy (AO-SLO), optical coherence tomography (OCT), and microperimetry. Outcome measures were AO-SLO-based lesion area and cone metrics, OCT-derived ellipsoid zone (EZ) disruption, and retinal sensitivity.

LIR lesions on AO-SLO appeared as irregular localized dark areas containing scattered cones with weak reflectivity. OCT images showed focal outer retinal disruptions involving the EZ and interdigitation zones. Over 6 months, lesion area significantly decreased (97,128 ± 107,478 µm² to 27,560 ± 26,901 µm²; P = 0.031), perilesional cone density increased (27,942 ± 6970 to 36,700 ± 9257 cones/mm²; P = 0.010), and cone spacing decreased (4.71 ± 0.57 µm to 4.25 ± 0.57 µm; P = 0.040). EZ disruption length remained stable (203 ± 181 µm to 195 ± 173 µm; P = 0.64). Lesion-specific retinal sensitivity improved significantly (19.25 ± 4.37 dB to 26.43 ± 1.56 dB; P < 0.001), whereas mean macular sensitivity and best-corrected visual acuity showed no significant change.

AO-SLO revealed lesion contraction and perilesional cone reorganization during spontaneous recovery from LIR. These findings suggest that the human retina shows microstructural plasticity after laser injury and highlight AO-SLO's superiority in detecting early cellular-level changes in LIR.