Bilateral Optic Disc Edema in a Patient with Lead Poisoning

Purpose: Heavy metals, such as lead can cause optic neuropathy. Optic disc neuropathy due to lead intoxication has previously been reported. We report a rare case of lead toxicity-induced optic neuropathy presenting with bilateral hemorrhagic optic disc swelling. Case Report: The patient was a 42-year-old man with a history of chronic oral opium use, who had a gradually progressing blurred vision in both eyes over 40 days, with ataxia, paresthesia, and a toxic level of serum lead. He had been treated with lead chelators for lead poisoning. His color vision was impaired in both eyes. Humphrey’s visual field test revealed double arcuate scotoma with enlargement of the blind spot. Funduscopy revealed bilateral optic disc swelling, which was confirmed on optical coherence tomography and fluorescein angiography. Conclusion: In cases of optic disc edema, a comprehensive history should be taken to detect the cause. Further, in cases of chronic oral opium use, lead toxicity should be considered

Bilateral Anterior Ischemic Optic Neuropathy Accompanied with Unilateral Central Retinal Artery Occlusion in a Biopsy-proven Case of Giant Cell Arteritis

This is a Photo Essay and does not have an abstract. Please download the PDF or view the article HTML

Pneumosinus Dilatans Causing Field of Vision Deviation: A Case Report

Pneumosinus dilatans (PSD) is a rare condition which may cause visual impairment. Here we present the case of a 15-year-old boy with PSD. The vision was 10/10 and the intraocular pressure was in normal range for both eyes. Other eye examinations were normal except for a slight discoloration of the optic nerve. Optical coherence tomography showed a decrease in the thickness of the nerve fiber layer and the patient's primary field of vision had a mean deviation of -3.44 and -6.39 in the right and left eyes.&nbsp

Comparing Two Inferior Oblique Weakening Procedures: Disinsertion versus Myectomy

Purpose: To compare two methods for treating inferior oblique overaction (IOOA): disinsertion versus myectomy of the muscle. Methods: In this prospective interventional case series, patients were randomly assigned to undergo either IO myectomy or disinsertion. The changes in vertical and horizontal deviations following these two surgical procedures were evaluated. The postoperative IO function of grade 0 or +1 and the fundus extorsion of grade 0 or +1 was considered as the successful outcome. Results: Thirty-six patients (50 eyes) with a mean age of 12.67 ± 4.05 years were included. In the myectomy group, the mean preoperative hyperdeviation in adduction was 29.5 ± 9.32 prism diopter (PD), which decreased to 9.15 ± 7.86 PD after surgery (P = 0.001). In the disinsertion group, these measurements were 32.73 ± 12.42 and 12.65 ± 9.34 PD before and after the surgery, respectively (P = 0.001). The success rate of surgery based on the IOOA grading was 87.4% and 92.3% in the myectomy and disinsertion groups, respectively (P = 0.780). The successful correction rate of abnormal fundus torsion was 91.6% in the myectomy and 88.4% in the disinsertion group (P = 0.821). In comparison, 48% of the cases in the myectomy group and 50% in the disinsertion group were within the normal range of torsional position postoperatively (P = 0.786). There was no statistically significant difference in terms of changes in the horizontal or vertical deviations, V-pattern, and dissociated vertical deviation between the two groups. Conclusion: Both surgical techniques seem to be effective for treatment of inferior oblique muscle overaction

Visual Outcomes of Adding Erythropoietin to Methylprednisolone for Treatment of Retrobulbar Optic Neuritis

Purpose: To compare the short-term visual function results and safety of erythropoietin as an add-on to the standard corticosteroid therapy in retrobulbar optic neuritis (RON). Methods: In this prospective pilot study, adult patients with isolated RON with less than 10 days of onset were enrolled. Patients were consecutively assigned to standard intravenous methylprednisolone treatment either in combination with intravenous erythropoietin (20,000 units/day for three days) (group-1) or alone (group-2). Primary outcome measure was best-corrected visual acuity (BCVA), which was assessed up to 120 days from the day the treatment was begun. Systemic evaluations were performed during and after treatment. Results: Sixty-two patients with RON (mean age = 26.6 ± 5.77 years; range = 18–40 years) were enrolled into the study (group-1, n = 35; group-2, n = 27). BCVA three months after the treatment was 0.19 ± 0.55 logMAR and 0.11 ± 0.32 logMAR in group-1 and group-2, respectively (95% CI: –0.61–0.16; P = 0.62). Change in BCVA after three months was 2.84 ± 3.49 logMAR in group-1 and 2.46 ± 1.40 logMAR in group-2 (95% CI: –0.93–1.91; P = 0.57). Pace of recovery was not significantly different between the groups. No complications were detected among patients. Conclusion: Intravenous erythropoietin as an add-on did not significantly improve the visual outcome in terms of visual acuity, visual field, and contrast sensitivity compared to traditional intravenous corticosteroid. This pilot study supports the safety profile of intravenous human recombinant erythropoietin, and it may help formulate future investigations with a larger sample size

Erythropoietin Protects against Retinal Damage in A Rat Model of Optic Neuropathy via Glial Suppression

Objective: Traumatic optic neuropathy (TON) causes partial or complete blindness because death of irreplaceableretinal ganglion cells (RGCs). Neuroprotective functions of erythropoietin (EPO) in the nervous system have beenconsidered by many studies investigating effectiveness of this cytokine in various retinal disease models. It has beenfound that changes in retinal neurons under conditions of glial cells are effective in vision loss, therefore, the presentstudy hypothesized that EPO neuroprotective effect could be mediated through glial cells in TON model.Materials and Methods: In this experiment study, 72 rats were assessed in the following groups: intact and optic nervecrush which received either the 4000 IU EPO or saline. Visual evoked potential and optomotor response and RGCnumber were assessed and regenerated axons evaluated by anterograde test. Cytokines gene expression changeswere compared by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Density of astrocytes cells,assessed by fluorescence intensity, in addition, possible cytotoxic effect of EPO was measured on mouse astrocyteculture in vitro.Results: In vitro data showed that EPO was not toxic for mouse astrocytes. Intravenous injection of EPO improvedvision, in terms of visual behavioral tests. RGCs protection was more than two times in EPO, compared to the vehiclegroup. More regenerated axons were determined by anterograde tracing in the EPO group compared to the vehicle.Moreover, GFAP immunostaining showed while the intensity of reactive astrocytes was increased in injured retina,systemic EPO decreased it. In the treatment group, expression of GFAP was down-regulated, while CNTF was upregulatedas assessed by qRT-PCR in the 60th day post-crush.Conclusion: Our study showed that systemic administration of EPO can protect degenerating RGCs. Indeed,exogenous EPO exerted neuroprotective and neurotrophic functions by reducing reactive astrocytic gliosis. Therefore,reduction of gliosis by EPO may be considered as therapeutic targets for TON

Authors' Reply to Bilateral Optic Disc Edema in a Patient with Lead Poisoning

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Normal Values of Standard Full Field Electroretinography in an Iranian Population

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 </style> <![endif]--> <p>PURPOSE: To determine normal values of standard full-field electroretinography (ERG) and to evaluate their variations with age in an Iranian population. METHODS: 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. RESULTS: 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. CONCLUSIONS: ERG parameters are significantly diminished with age. Our results may serve as a reference against which standard ERG responses can be compared.</p&gt

Correlation between Retinal Nerve Fiber Layer Thickness by Optical Coherence Tomography and Perimetric Parameters in Optic Atrophy

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 </style> <![endif]--> <p>PURPOSE: 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. METHODS: 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. RESULTS: Mean global RNFL thickness was 44.9±27.5 µm 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. CONCLUSION: 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.</p&gt