A New Clinical Method for Visual Function Evaluation Including Estimation and Measurement of Therapeutic Effectiveness: Lessons From Infantile Nystagmus Research.

Purpose: To translate infantile nystagmus system (INS) research into easily understood, clinically relevant terminology and suggest modifications to research and clinical testing, data and clinical interpretation, and therapeutic choices and evaluation.

Methods: A clinical method is presented using only three best-corrected visual acuity measurements of patients with INS, whereby (1) a measure of the quality of visual acuity across the visual field is possible; (2) pre-therapy estimates of post-therapy improvements in peak acuity and the high-acuity range of gaze angles are possible; and (3) more realistic visual function outcome measures of therapy are available to the practitioner.

Results: The application of the high-acuity field quality spreadsheet to the analyses of patients with INS (before and after therapy) results in a quantitative measure of visual function based on three visual acuity measurements.

Conclusions: The clinician can now duplicate adequate functional visual acuity descriptions in patients with INS along with their pre-therapy estimates and outcome measures. Previously, these have only been available to researchers or the rare clinicians who have access to both eye movement data and the expanded nystagmus acuity function analysis of INS waveforms. .