Abstract
Purpose: :
To determine visual function in patients with Albinism with three forms of vision correction (spectacle correction, un-tinted contact lenses and tinted contact lenses).
Methods: :
3 subjects (6 eyes) were fit with soft toric contact lenses that were then custom tinted to create an artificial iris. Four dependent variables that were measured include visual acuity, contrast sensitivity, effect of glare, and nystagmus eye movement recordings. Patients’ subjective evaluation of their visual comfort and clarity, and their perception of change in glare and light sensitivity was also evaluated by means of a short questionnaire. The EDTRS chart was used to measure visual acuity. The CSV-1000HGT (halogen glare test) and 1000E (Contrast Sensitivity chart) were used to measure the contrast sensitivity function and effect of glare. Nystagmus fixation characteristics and waveforms were studied with the ISCAN (RK 826PCI) that uses a video based dark pupil-to-cornea reflection method.
Results: :
Preliminary results of this ongoing study are being reported. Visual acuity was significantly improved in all eyes with tinted contact lens wear (Mean improvement = 1.4 LogMAR, X2 = 11.565, p = 0.03). Contrast sensitivity measurements, under normal testing conditions as well as with glare, showed improvement in all eyes. ISCAN trials with 3 runs in each of 5 positions of gaze showed decreased nystagmus amplitude and frequency with tinted contact lenses. Patients subjectively reported reduced sensitivity to light and decreased glare with tinted contact lenses.
Conclusions: :
The results obtained thus far show significantly improved visual acuity in patients with albinism with the use of custom tinted contact lenses. Contrast sensitivity, glare reduction, nystagmus amplitude and frequency were also improved.
Keywords: low vision • contact lens • nystagmus