Microperimetry clinical application in retinal diseases and rehabilitation

INTRODUCTION: Microperimetry (MP) is a procedure that examines the condition of the retina by direct observation of the ocular fundus. The use of eye-tracking system and repeat-mode in retinal examination enable the assessment of retinal sensitivity even in small loci. Retinal diseases, mostly represented by age-related macular degeneration (AMD), myopic macular degeneration and Stargardt disease are characterized by lesions of the retina and choroid. This study provides an overview of the fundamentals, current clinical applications of microperimetry and strategies of rehabilitation with microperimetry biofeedback training in retinal diseases.EVIDENCE ACQUISITION: The study is a literature review, conducted with the use of MEDLINE (PubMed). The search was carried out using the following key words: “microperimetry, maculopathies, microperimetry biofeedback training, microperimetry application, retinal diseases, PRL choice, remapping phenomenon, acoustic biofeedback, audio-luminous biofeedback, light biofeedback.” The publications used in our study are clinical trials and reviews.EVIDENCE SYNTHESIS: Microperimetry enables the evaluation of larger and more eccentric retinal area, constituting an advance in the field of diagnosing, monitoring and the choice of therapeutic regimen in retinal diseases. MP has especially wide application in AMD: in studying the impact of biomarkers, determining the progression and assessing effectiveness of the therapy. In Stargardt disease, MP can detect impairments in visual acuity before any signs of retinal damage appear on imaging. Microperimetry biofeedback training (MBFT) is a strategy of visual rehabilitation, used in variety of diseases characterized by central vision loss. Patients with central scotoma tend to develop new fixation locus- preferred fixation locus (PRL), localized on peripheral retina. Cerebral plasticity resulting in visual cortex reorganization and “remapping phenomenon” enables that adaptation. The purpose of MGBF is to enhance stability of existing PRL or to find and exercise the use of PRL chosen by the operator. It has showed promising results in improving visual performance in patients with AMD, MMD, Stargardt disease, glaucoma, epiretinal membranes and other ocular pathologies.CONCLUSIONS: Microperimetry-based evaluation of the retina finds a wide application in the course of retinal diseases. Microperimetry-guided feedback enhances visual performance in patients with retinal pathologies by increasing fixation stability and reading speed, frequently improving also retinal sensitivities, BCVA and best-corrected visual acuity, subsequently increasing the quality of their life.