Biofeedback rehabilitation of eccentric fixation in patients with Stargardt disease

To evaluate the efficacy of biofeedback (BF) microperimetric rehabilitation in patients with Stargardt disease (STGD).

Eighteen patients with STGD with unstable fixation located in the superior retina and best-corrected visual acuity (BCVA) between 20/100 and 20/320 in the better eye were recruited. All the patients underwent Nidek MP-1 microperimetry and fixation analysis. Twelve patients underwent 8 consecutive BF training sessions of 10 minutes each, performed once a week in the better eye. Six patients did not receive any training and were used as controls. In both groups, BCVA, reading speed, contrast sensitivity, bivariate contour ellipse area (BCEA), and retinal sensitivity were evaluated in the better eye at baseline and after 10 weeks. Paired and unpaired t tests were used as appropriate.

In the control group, after the follow-up period, fixation pattern did not show any modification and the other parameters worsened or remained unchanged. On the contrary, the BF group showed significantly improved stabilization of fixation (mean BCEA 68.2% from 5.63°2 to 1.58°2), improved mean BCVA (from 34.00 to 37.67 letters), higher mean reading speed (from 66.67 to 84.00 words/min), higher contrast sensitivity (from 16.33 to 18.75 letters), and improved retinal sensitivity (from 10.68 to 12.29 dB). The comparison of the results obtained in the 2 groups was statistically significant for all the considered parameters except for retinal sensitivity.

Biofeedback rehabilitation with the MP-1 increases quality of vision in patients with STGD, leading to a stabilization of fixation and a consequent improvement of patients’ visual function and reading abilities