Abstract
Purpose::
The aim of our study is to evaluate the improvement of fixation stability and reading speed after a rehabilitation program with Microperimeter MP-1 in patients with juvenile macular dystrophies.
Methods::
we selected 4 patients (1man and 3women) mean age 35 (range 25 to 47y.o.) with juvenile macular dystrophy (1CR /2Starg./1CD).We excluded patients with systemic hypertension, diabetes, sindromic RP, neurological and psychiatric diseases, and any other ocular pathology.To all patients was performed a complete ophthalmological examination including BCVA, indirect ophthalmoscopy, FAG, OCT, ERG, PEV, and a Conventional visual field Humphrey 10-2 program.According to literature data we selected a rehabilitation program conprehensive of an initial microperimetry using Microperimeter MP-1 (Nidek Tecnologies), a reading speed test with appropriate distance lenses, a speed reading test adding +4.00 D lens, and a 30sec fixation test. These examinations were repeated at the end of the 10 sessions of biofeedback rehabilitation.
Results::
Mean retinal sensitivity at T0 was 7,71dB (range 0,5dB to 12,8dB) Mean retinal sensitivity at T1 was 9,5 dB (range 4,75dB to 14,25dB). Mean fixation stability at T0 was respectively 34% and 66% concerning 2° and 4° around the fixation target at T1 it improved to 55% and 89% concerning 2° and 4° arount the fixation point. Mean Best Corrected Distant Visual Acuity (BCDVA) was 20/100at T0 and 20/70 at T1 and mean Best Corrected Near Visual Acuity was VII character (18 c/p) and adding a sferic lens +4.00 D was IV character (10 c/p)Reading speed was 50 w/min at T0 and 75 w/min at T1All datas were recorded and analized with Student T test, and it resulted statistically significatives P < 0,05
Conclusions::
Patients with juvenile macular distrophies show a central visual loss followed by a reduction of peripheral visual field restricted to 10 central degrees or low. Patients with macular disease and central scotomas refere several problems during daily activities that involve the central vision such as reading, sewing and cooking usually at microperimetry an unstable fixation is recorded. This study demonstrate the shifting of the central fixation area to a preferred retinal locus (PRL) that patients, at the end of the rehabilitation program, learn to use in place of their damaged fovea. In these subjects, according to the shifting of PRL we recorded an improvement of BCVA, fixation stability, and reading speed test. MP-1 biofeedback works on learning effect function, so that once ended the basal session, to maintain obtained results it is indispensable repeat the stimulation every three months.
Keywords: retinal degenerations: hereditary • perimetry • retina