[Evaluation of relation between the retinal nerve fiber layer and expanded disability status scale [EDSS] in patients with relapsing-remitting form of multiple sclerosis referring to Rasool-e- Akram Hospital]

Early diagnosis of multiple sclerosis [MS] disability is very important in managing patients. The aim of this study is to use Heidelberg Retinal Tomography [HRT] to evaluate the Retinal Nerve Fiber Layer [RNFL] of MS patient as a predictor factor of their disability scales. In this cross-sectional study a total of 69 patients with Relapsing-Remitting MS [RR.MS] were selected based on the revised McDonald criteria. They were examined by a neurologist to calculate their Expanded Disability Status Scale [EDSS] scores. Patients' demographic information and related data such as history of Optic Neuritis [ON] and used Interferones were collected. Patients were referred to ophthalmology department in Rasool-e-Akram Hospital for assessment of their RNFL thickness using HRT method. Data was analyzed by SPSS software and p<0.05 was considered to be significant. The range of patient's age was 17 to 59 years. The mean of EDSS scores of men and women were 2.69 micrometer and 2.86 micrometer that showed no significant difference [p=0.63]. Spearman Correlation showed that there is no significant correlation between EDSS and mean RNFL thickness in both left and right eyes [p=0.081 for the right and p=0.052 for the left]. Also, there was no significant correlation between EDSS and mean RNFL thickness of both eyes in patients with or without optic neuritis [p=0.66, 0.28]. Mean RNFL thickness of both eyes showed no significant difference in patients with and without optic neuritis [0.209]. This study pointed out that no decrease was detected in RNFL thickness by increasing EDSS scores using HRT method. There are evidence that both HRT and Optical Coherence Tomography [OCT] methods can show decrease of RNFL but OCT appears to be more sensitive

Normal values of standard full field electroretinography in an Iranian population

To determine normal values of standard full-field electroretinography [ERG] and to evaluate their variations with age in an Iranian population. Through convenient sampling, 170 normal subjects 1-80 years of age were selected from residents of Tehran. ERG amplitudes and implicit time values were measured according to recommendations by the International Society for Clinical Electrophysiology of Vision. Evaluations consisted of light-adapted ERG including single-white flash and 30-Hz flicker response; and dark-adapted ERG including rod, maximal dark-adapted and cone responses. No significant difference in ERG values was observed between men and women, or between right and left eyes. ERG amplitudes were lower [P=0.04] and implicit time values were greater [P=0.03] in subjects 70-80 years of age as compared to younger individuals. ERG parameters are significantly diminished with age. Our results may serve as a reference against which standard ERG responses can be compared

Radiation chiasma neuropathy after radiotherapy for treatment of paranasal sinus lymphoma

To present a patient with radiation chiasma neuropathy, secondary to radiotherapy of paranasal sinus lymphoma who was referred for evaluation of gradual decrease of vision in both eyes. The patient was a 38-year-old male, with history of right maxillary sinus lymphoma, who underwent surgery, chemotherapy and radiation therapy. One year after radiotherapy, he noticed gradal decrease in his right eye vision. He referred to our center 6 months after onset of visual symptoms [1.5 years after radiotherapy]. On his first examination, visual acuity [VA] of right eye was no light perception [NLP], and right optic disc was severely atrophic. Other examinations of right eye were unremarkable. The VA of left eye was 10/10 with correction, color vision was normal, slit lamp exam and tonometry was normal as well, but bow tie atrophy of left optic disc was detected. Visual field of left eye revealed temporal hemianopia. MRI showed thickening and enhancement of optic chiasm, especially in right side. In follow-up the enhanced lesion enlarged posteriorly and involved both optic tracts and optic radiations. In spite of treatment with high dose corticosteroid and hyperbaric oxygen, within two years following radiotherapy, vision of left eye gradually decreased to NLP too. Radiation-induced optic neuropathy is an important differential diagnosis of decreased vision in a case with history of head and neck radiotherapy. Since this complication is very important with ominous consequence, ophthalmologists and radiotherapists should be aware of that; and decrease the chance of its occurrence by lowering the dosage, daily fractionation, stereotactic methods, and precise aiming of radiation beam

Correlation between retinal nerve fiber layer thickness by optical coherence tomography and perimetric parameters in optic atrophy

To investigate the correlation between retinal nerve fiber layer [RNFL] thickness determined by optical coherence tomography [OCT] and visual field [VF] parameters in patients with optic atrophy. This study was performed on 35 eyes of 28 patients with optic atrophy. RNFL thickness was measured by OCT [Carl Zeiss, Jena, Germany] and automated perimetry was performed using the Humphrey Field Analyzer [Carl Zeiss, Jena, Germany]. The correlation between RNFL thickness and VF parameters was evaluated. Mean global RNFL thickness was 44.9 +/- 27.5] which was significantly correlated with mean deviation score on automated perimetry [r=0.493, P=0.003]; however, no significant correlation was observed between visual field pattern standard deviation and the corresponding quadrantic RNFL thickness. In a similar manner, no significant association was found between visual acuity and RNLF thickness. Mean global RNFL thickness as determined by OCT seems to be correlated with VF defect depth as represented by the mean deviation score on Humphrey VF testing. OCT may be used as an objective diagnostic tool in the evaluation of patients with optic atrophy

Vitreopapillary traction in nonarteritic anterior ischemic optic neuropathy

To describe the association between vitreous traction on the optic disc and nonarteritic anterior ischemic optic neuropathy [NAION]. Eighty three eyes of 83 patients with NAION were evaluated by optical coherence tomography [OCT] for detecting vitreous adhesion to the optic nerve head with separation from the adjacent retina [partial posterior vitreous detachment]. Eyes which were negative for such adhesion underwent ultrasonography to detect complete posterior vitreous detachment [PVD]. Fifty male and 33 female subjects with mean age of 51.9 +/- 10 years were studied. Partial PVD with optic nerve head adhesion was found in 54 patients [65.1%] using OCT. Ultrasonography detected complete PVD in all other eyes with optically empty spaces on OCT. Vitreous traction on the optic nerve head from partial PVD may play a causative role in some cases of NAION. This traction may impair vascular supply and/or axoplasmic flow leading to signs and symptoms of NAION