Abstract
Purpose :
The Nidek MP-3 is an automatic microperimeter with non-mydriatic fundus camera providing functional assessment of specific retinal locations. It is characterized by auto-tracking and auto-alignment functions. MP-3 is implemented with biofeedback (BFB) visual stimulation allowing to select customizable tunes as acoustic signal and displacement of the visual structured stimulus. The aim of this study was to evaluate MP-3 BFB rehabilitation in patients with central vision loss or visual field defects
Methods :
A total of 7 patients, 5 with a diagnosis of Age-related Macular Degeneration (AMD) (Group A) and 2 with Homonymous Hemianopia (HH) (Group B), were enrolled. A standard protocol of functional examination before and after visual rehabilitation training was performed on all the subjects. MP-3 retinal sensitivity and Humphrey Visual Field 30-2 were detected in Group B and MP-3 fixation evaluation was obtained in Group A before and after training. Group A was trained using structured stimulus located in correspondence of the PRL for 10 minutes long in order to improve fixation stability. Group B was stimulated with the displacement of the pattern at the edge of scotoma for 15 minutes long training sessions in order to stimulate the residual vision areas. Both groups underwent 15 training sessions performed twice a week. The structured stimulus used, in terms of size and flickering frequency, was selected according to the diagnosis of the patients: high spatial frequency and 7Hz of temporal frequency for Group A and low spatial frequency and 20Hz of temporal frequency for Group B
Results :
A significant improvement of fixation stability, quantified as mean Bivariate Contour Ellipse Area (68.2%) was found for Group A: fixation improved from 2.8 (±0.8) degrees squared at the baseline to 1.1 (±0.9) degrees squared after training sessions (p=0.01). Group B showed retinal sensitivity enhancement and a reduction of the scotoma points at MP-3 examination. Visual Field presented an improvement of retinal sensitivity with a reduction of the mean deviation
Conclusions :
Our data showed that MP-3 BFB is a valid tool to rehab central and peripheral low vision patients, improving fixation behavior and restoring visual field defect respectively. Patients appreciated the customizable acoustic tunes chosen by them. More data is under collection to overcome the limit of current dataset and provide more statistical significant results.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.