a comparative studyof visual functions betweenanterior and retrobulbar optic neuritis

abstract background and aim: consider ing based on the presence or absence of swelling of the optic disc, optic neuritis classified nto two types of anterior and retrobulbar optic neuritis. the aim of this study was to compare the visual functions of patients with anterior optic neuritis and retrobulbar optic neuritis. materials and methods:this cross-sectional study was conducted in 48 patients with optic neuritis including 35 patients (26 females) with retrobulbar optic neuritis and 13 patients (10 females) with anterior optic neuritis. total cases aged ranging from 18 to 45 years old.the patients underwent clinical tests of visual functions, including visual acuity, contrast sensitivity and color vision. the collected data was recorded and statistical analysis was performed by spss software. the significance of the differences between two types of the diseases were calculated and compared by independent t-test. results: the anterior optic neuritis patients were slightly older than the retrobulbar optic neuritis ones (average30.6yearsvs26.6years). average defect to the visual functions was more severe in anterior optic neuritis in compare to retrobulbar. the visual functions of visual acuity (t=1.74, p=0.048) and color vision (t=-3.00, p=0.005) were significantly different between two types of the diseases. however, there was not a statistically significant difference (t=1.64, p=0.104) for contrast sensitivity as a visual function. conclusion: in the retrobulbar optic neuritis that there is not a specific appearance of fundoscopy ,the visual function of contrast sensitivity can be used as a helpful tool for primary diagnosis of the disease. especially key words: anterior optic neuritis, etrobulbar optic neuritis, visual acuity, contrasts ensitivity ,colorvision.