Background: Optic neuritis is a common cause of Visual loss in young adults and often the first manifestation of multiple sclerosis. Recent studies have shown that treatment with intravenous methylprednisolone results in more rapid recovery of vision, but without any long term difference in Visual acuity. This study was carried out to evaluate clinical characteristics of patients with optic neuritis and Visual outcome after intravenous methylprednisolone treatment.Methods: In a case series study, 40 cases with optic neuritis were evaluated. Before and after treatment with methylprednisolone according to optic neuritis treatment trial, Visual acuity, contrast sensitivity, color vision, streopsis and Visual field were analyzed.Results: 67.5% of the patients were females. The most common age group was between 20 and 40 (60%). Blind spot enlargement and other Visual field defects were also returned to relatively normal value after the treatment. Central scotoma was the most common field defect (70%) and mild Dutan defect was the most common color vision (60%) defect in this study. Visual acuity, contrast sensitivity, color vision, streopsis and Visual field were significantly reduced in optic neuritis, relatively returning to the normal level after treatment.Conclusion: It seems that the assessment of other Visual functions, besides Visual acuity, is important in a patient with optic neuritis, because patients usually remain aware of Visual deficits other than decreased Visual acuity.

Purpose: To evaluate changes in different aspects of Visual function including Visual acuity, Visual field, contrast sensitivity, colour vision and stereopsis in patients with optic neuritis before and after medical intervention.Methods: In a noncomparative interventional case series on 31 eyes of 30 patients with optic neuritis, the following aspects of Visual function were compared before and after treatment. Medical intervention was conducted following the Optic Neuritis Treatment Trial (ONTT) guidelines. Visual function was assessed by evaluating changes in Visual acuity, Visual field (Goldmann in all patients and automated in some patients), contrast sensitivity using Cambridge low contrast grating, colour vision using Ishihara plates and stereopsis using Titmus stereoacuity test.Results: Visual acuity was significantly lower (3/10) in the affected eyes than unaffected eyes (8/10) [P<0.001]. Contrast sensitivity was also significantly better in the unaffected eyes. Mean stereoacuity was 310 sec/arc. The Visual field impairment was also significantly higher than that of the unaffected eye and also normal population sample. Weak deutan defects were present in 60% of the patients. After medical treatment, Visual acuity, Visual field defects, contrast sensitivity, colour and stereopsis were significantly improved.Conclusion: Different aspects of Visual function including Visual acuity, Visual field, contrast sensitivity, colour vision, and stereopsis are impaired in optic neuritis. Medical treatment with intravenous methylprednisolone followed by oral steroids is effective in improving these parameters. However, some deficits may persist after therapy. Since spontaneous recovery after optic neuritis is common, clinical trials are needed to determine the true effect of treatment versus follow-up.

Background: Along with the rapid growth of technology its related tools such as computer, monitors and video display terminals (VDTs) grow as well. Based on the studies, the most common complaint reported is of the VDT users.Methods: This study attempts to design a proper tool to assess the Visual fatigue of the VDT users. First draft of the questionnaire was prepared after a thorough study on the books, papers and similar questionnaires. The validity and reliability of the questionnaire was confirmed using the content validity index (CVI) beside that of the Cronbach’s Coefficient Alpha. Then, a cross-sectional study was carried out on 248 of the VDT users in different professions. A theoretical model with four categories of symptoms of Visual fatigue was derived from the previous studies and questionnaires. Having used the AMOS16 software, the construct validity of the questionnaire was evaluated using the confirmatory factor analysis. The correlation co-efficiency of the internal domains was calculated using the SPSS 11.5 software. To assess the quality check index and determining the Visual fatigue levels, Visual fatigue of the VDT users was measured by the questionnaire and Visual fatigue meter (VFM) device. Cut-off points were identified by receiver operating characteristic curves.Results: CVI and reliability co-efficiency were both equal to 0.75. Model fit indices including root mean of squared error approximation, goodness of fit index and adjusted goodness of fit index were obtained 0.026, 0.96 and 0.92 respectfully. The correlation between the results measured with the questionnaire and VFM-90.1 device was −0.87. Cut‑off points of the questionnaire were 0.65, 2.36 and 3.88. The confirmed questionnaire consists of four main areas: Eye strain (4 questions), Visual impairment (5 questions) and the surface impairment of the eye (3 questions) and the out of eye problems (3 questions).Conclusions: The Visual fatigue questionnaire contains 15 questions and has a very remarkable validity and reliability. Using this questionnaire and its findings, one will be able to identify, assess and finally prevent the effective factors of VDT users’ Visual fatigue.