Microperimetric biofeedback rehabilitation in patients with stargardt disease: first Russian experience

BACKGROUND: Stargardt disease is the most common form of hereditary macular degeneration, with a frequency of about 1 case per 17 thousand people. There are about 5.5 million patients with this condition worldwide. Current clinical practice has treatment for Stargardt disease. Rehabilitation of patients is limited by various optical approaches and does not include techniques to improve fixation.

AIM: This study aimed to evaluate the effectiveness of visual rehabilitation of patients with Stargardt disease with unstable fixation using microperimetric biofeedback training.

METHODS: A single-center, uncontrolled, clinical trial was conducted. Inclusion criteria were the following: patients with genetically confirmed Stargard disease; peripheral eccentric fixation; written informed voluntary consent completed and signed by patients or legal representatives. All patients underwent microperimetric acoustic biofeedback training (session duration 10–12 minutes, for 10 days). Fixation stability was assessed using an MP-3 microperimeter. Fixation parameters, including the ellipse density and area, and visual performance were determined before the training initiation, immediately after and 1 month post-training.

RESULTS: A total of 5 patients with a genetically confirmed Stargardt disease were enrolled. After training, two eyes shifted their trained retinal loci toward the area with better structural and functional characteristics compared with the initial fixation loci. Three eyes improved the existing preferred fixation locus. Fixation stability significantly increased in the 2° and 4° areas, and the ellipse area encompassing 68%, 95%, and 99% of fixation points was significantly reduced in all patients. Changes in fixation characteristics after microperimetric biofeedback training correlated with improved visual performance. Visual performance increased significantly after training and remained stable 1 month after the end of training.

CONCLUSION: The effectiveness of visual microperimetric biofeedback rehabilitation in patients with Stargardt disease and unstable fixation was assessed for the first time in Russia. The obtained results demonstrated an increase in best corrected visual acuity, improved fixation and visual parameters, with the achieved effect maintained up to 1 month of follow-up.