Risk Topology in Elective Eye-Color Modification: A Compartment-Based Framework for Corneal Keratopigmentation and Staged Laser Iris Depigmentation

Elective eye-color modification procedures share an aesthetic endpoint but act through distinct ocular compartments. Contemporary corneal keratopigmentation (KTP) introduces exogenous pigment into a corneal stromal plane, while laser iris depigmentation (LID) alters endogenous iris pigmentation and may induce time-dependent pigment and anterior-segment responses. This Scientific Perspective advances a compartment-based risk topology distinguishing the corneal tissue–material interface of KTP from the iris–aqueous interface of staged LID. It integrates over 40 referenced publications and records, including an additional 30 peer-reviewed articles on corneal ectasia, ulceration, microbial keratitis, perforation in historically compromised eyes, light sensitivity, pigment stability and diagnostic constraints. Clinical outcomes are distinguished by cosmetic versus therapeutic indication and by technique, with no invented pooled adverse-event rates. The proposed comparison architecture pairs common measures of visual function and patient-reported symptoms with procedure-specific assessments of corneal structural stability, endothelial integrity, optical aperture geometry, pigment response and intraocular-pressure kinetics. Published KTP evidence is more extensive than protocol-specific LID evidence, but evidence maturity alone cannot establish comprehensive comparative safety. The paper proposes an anatomically grounded, evidence-stratified and temporally resolved agenda for prospective studies; it does not introduce new patient-level data or claim comparative efficacy.