Objectives: This study evaluated acoustic biofeedback training using microperimetry in patients with foveal scars and an eligible retinal locus for better fixation.
Materials and methods: A total of 29 eligible patients were enrolled in the study. The acoustic biofeedback training module in the MAIA (Macular Integrity Assessment, CenterVue®, Italy) microperimeter was used for training. To determine the treatment efficacy, the following variables were compared before and after testing: best corrected visual acuity (BCVA); MAIA microperimeter full threshold 4-2 test parameters of average threshold value, fixation parameters P1 and P2, and bivariate contour ellipse area (BCEA) for 63% and 95% of fixation points; contrast sensitivity (CSV 1000E Contrast Sensitivity Test); reading speed using the Minnesota Low-Vision Reading Test (MNREAD reading chart); and quality of life (NEI-VFQ-25). In addition, fixation stability parameters were recorded during each session.
Results: The study group consisted of 29 patients with a mean age of 68.72±8.34 years. Median BCVA was initially 0.8 (0.2-1.6) logMAR and was 0.8 (0.1-1.6) logMAR after 8 weeks of preferred retinal locus training (p=0.003). The fixation stability parameter P1 improved from a mean of 21.28±3.08% to 32.69±3.69% (p=0.001) while mean P2 improved from 52.79±4.53% to 68.31±3.89% (p=0.001). Mean BCEA 63% decreased from 16.11±2.27°2 to 13.34±2.26°2 (p=0.127) and mean BCEA 95% decreased from 45.87±6.72°2 to 40.01±6.78°2 (p=0.247) after training. Binocular reading speed was 38.28±6.25 words per minute (wpm) before training and 45.34±7.35 wpm after training (p<0.001). Statistically significant improvement was observed in contrast sensitivity and quality of life questionnaire scores after training.
Conclusion: Beginning with the fifth session, biofeedback training for a new trained retinal locus improved average sensitivity, fixation stability, reading speed, contrast sensitivity, and quality of life in patients with macular scarring.
Keywords: Low vision rehabilitation; microperimetry; preferred retinal locus training.