[Relationship between central corneal thickness, intra ocular pressure and visual field in normal tension and primary open angle glaucoma]

Glaucoma is one of the most important cause of blindness wordwide. Exact determination of intra ocular pressure is important for the diagnosis and decision making about glaucoma treatment. Central corneal thickness is considered as effective factor on intra ocular pressure and visual field defect. This study was carried out to determine the relationship between central corneal thickness, intra ocular pressure and visual field in normal tension and primary open angle glaucoma. This descriptive study was carried out on 45 eyes with normal tension glaucoma and 45 eyes with primary open angle glaucoma in Al-Zahra ophthalmology hospital in Zahedan, Iran during 2010. Intra ocular pressure and central corneal thickness were measured by Goldman tonometer and pachymeter and visual field exanimated by Humphrey perimeter. Data were analyzed using SPSS-16, paired t-test, ANOVA, Mann-Whitney and Pearson correlation tests. There was significant correlation between central corneal thickness and intra ocular pressure [r=0.309, P<0.05]. A significant difference was detected in intra ocular pressure between two type of glaucoma [P<0.05]. Mean value of central corneal thickness in patient with mild visual field defect was higher than severe visual field defect but there was not significant statistical difference between central corneal thickness and visual field defect in subjects with glaucoma. This study indicated that increasing corneal thickness is accompanied with intra occular presure

Visual function following treatment of optic neuritis

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. 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. 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. 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