Longitudinal Response Selectivity (LRS): A Multidomain Framework for Distinguishing Intended Iris Stromal Pigment Modification from Accompanying Tissue Responses

Background: Laser-directed iris pigment modification involves a short initiating exposure followed by pigmentary and tissue responses that may evolve on different timescales. Endpoint iris colour does not uniquely characterize the accompanying anatomical, inflammatory, sensory, or physiological responses. Objective: To define Longitudinal Response Selectivity (LRS) within the Selective Stromal Melanin Modulation (SSMM) framework and specify an empirical approach to its assessment. Framework: LRS denotes the longitudinal distinguishability of intended stromal pigment modification from accompanying tissue responses across observation periods and treatment stages. The framework separates the intended pigmentary observation P(t,k) from measured response domains Rj(t,k), incorporating measurement reliability, stage-relative timing, within-eye correlation, and clinical co-interventions. A multidomain observation panel and four testable propositions are specified. Research implications: Appropriate evaluation requires calibrated regional iris imaging, domain-specific tissue and clinical measurements, prospectively defined observation times, and statistical methods that account for correlated ocular measurements. Conclusions: LRS provides a falsifiable longitudinal assessment construct linking selective targeting to response-guided clinical decisions. Its evaluation depends on the ability to separate measurement variation, pigmentary change, and accompanying biological response rather than on a single numerical endpoint.