THE DIAGNOSIS OF OPTIC NEURITIS AND THE ROLE OF PELLI-ROBSON CONTRAST SENSITIVITY TEST

The aim of the study was to assess the usability of Pelli-Robson contrast sensitivity test in the evaluation of visual function in patients with acute optic neuritis. The study included 20 patients with acute optic neuritis aged 28-35, previously treated with pulse steroid therapy. The patients underwent standard ophthalmologic examination, Octopus 101 perimetry and Pelli-Robson contrast sensitivity test during and 6 months after an episode of acute optic neuritis. On initial testing performed during the acute optic neuritis episode, the mean contrast sensitivity logarithmic unit was 0.84 +/- 0.29 on the affected eye, 1.56 +/- 0.07 on the other eye, and 1.59 +/- 0.099 binocularly. On control testing, the respective values were 1.46 +/- 0.23, 1.71 +/- 0.07 and 1.84 +/- 0.09. In control group, contrast sensitivity testing produced the mean values of 1.79 +/- 0.04 on the right eye, 1.79 +/- 0.04 on the left eye and 1.94 +/- 0.04 binocularly. Wilcoxon test yielded a statistically significant difference between the initial and control contrast sensitivity testing for the affected eye (Z=3.92; P=0.000089), non-affected eye (Z=3.72; P=0.000196) and binocularly (Z=3.82; P=0.000132). Comparison of initial patient results and results obtained in the control group by use of t-test showed statistically significant differences for the affected eye (t-test 15.78; P=0.00), non-affected eye (t-test 12.89; P=0.0066) and binocularly (t-test 15.55; P=0.000064). Comparison of control patient results and those obtained in the control group also showed statistically significant differences for the affected eye (t-test 6.86; P=0.00), non-affected eye (t-test 4.41; P=0.000068) and binocularly (t-test 4.73; P=0.000024). In a subgroup of 11 patients with normal visual acuity on control testing, with a mean contrast sensitivity on the affected eye of 1.62 +/- 0.13, Mann-Whitney U test yielded a statistically significant difference between control contrast sensitivity on the affected eye and control group (z=4.11; P<0.000704). In conclusion, Pelli-Robson contrast sensitivity test was found to be a rapid, simple for use, reliable and sensitive tool applicable in the diagnosis and follow up of patients with acute optic neuritis.