[Evaluation of dose distributions in PTV and organs at risk in left-sided breast cancer, treated by tangential wedged technique in Tohid radiotherapy center in Sanandaj]

Background and Aim: The goal of radiotherapy is delivering enough doses to the tumor and the lowest dose to the organ at risks [OAR]. The aim of this study was to evaluate the received dose and homogenous dose in the target volume. Also we evaluated the dose received by the heart and lung during the treatment of breast cancer by using tangential wedge beam technique

Material and Method: Twenty patients with left sided breast cancer and conserved breast were divided into two groups: patients with large breasts and patients with small breasts. Treatment design was performed by Iso-gary software The Dose Volume Histograms [DVHs] was used to measure the doses received by the target volume, heart and lungs

Result: Dose homogeneity index [DHI] was equal for both groups. Homogeneity index [HI] of small breasts was lower significantly [p=0.001] and the dose distribution was better. The percentage of heart and lung involvement in the patients with big breasts at all dose levels was more but the difference wasn't significant

Conclusion: HI for target volume and dose received by organs at risks were higher in the patients with big breasts. Therefore treatment planning for the patients with bigger breasts needs more attention. Also calculation of evaluation indexes is more essential for these patients. Doses received by the heart and lung were compatible with standard levels and also the radiation risk for the heart and lung was within the acceptable level

An evaluation of some oxidative and enzymatic biomarkers in different stages of naturally occurring copper poisoning in sheep

The early stage of Copper poisoning is difficult to be clinically diagnosed in sheep and has not been docu-mented clearly yet. To assess biomarkers in predicting early Copper poisoning in sheep, blood samples were collected from several groups of animals from a naturally Copper poisoning occurrence in an industrial region. Animals were divided into four experimental groups; Group A: far from polluted region [Control group], Group B: inside polluted region, apparently healthy and without any clinically jaundice manifestation, Group C: slightly with jaundice signs and hemolytic crisis phase, and Group D: with clear jaundice signs. After collecting blood samples from each group, the serum was analyzed for evaluation of liver enzymes and oxidative stress parameters in different stages of Copper poisoning. In each blood sample, CPK, GOT, AST, ALT, total thiol [T-SH] group, and total proteins were determined. The Copper concentration in the serum, liver, and kidney of the dead animals in group D were also determined. There were significant differences in the blood parameters in group C illustrated by elevated level of serum AST, CPK, and GOT activities and total thiol [as biomarker of oxidative stress] when compared to control groups. In group D, these enzymes, in addition to T-SH, and the total protein were significantly [p< 0.05] different from those of the control and the other groups. Measurement of Copper in serum, liver, and kidney of group D [at the end stage of hemolytic phase] confirmed Copper poisoning in these groups. Based on the findings of the present study, the measurement of the liver enzyme activities and total thiol just closed to critical hemolytic phase could be reliable biomarkers for predicting Copper poisoning in sheep

Framework for assessing stewardship of the oral health system in Islamic Republic of Iran

This study designed a framework for assessing the stewardship function of the oral health system in Islamic Republic of Iran. The modified RAND Corporation/University of California Los Angeles [RAND-UCLA] Appropriateness Method was used in a 2-step process that combined literature evidence and the collective judgement of experts. After a comprehensive literature review, policy instruments related to stewardship components were extracted as candidate standards and categorized according to the 6 sub-functions of stewardship [accountability; defining strategic direction; alignment of policy objectives and organizational structure; regulation; intersectoral leadership; and generation of intelligence]. Five key informants then rated the appropriateness of the 85 standards on a 5-point Likert scale. The 38 highest ranked standards, including at least 2 standards in each of the 6 sub-functions, formed a set of proposed standards for evaluating the current stewardship of oral health system. Piloting of the instrument will be reported separately

[Efficacy of endosonographic method in determining the stage and depth of gastrointestinal cancers]

The staging of gastrointestinal cancer has an important role in the treatment of tumor. This study was done to determine the efficacy of endosonography method for determining the stage and deepth of esophagus and stomach cancers. In this descriptive study, endosonographic staging was performed in 23 patients [15 male and 8 female] with esophagus and stomach cancers, confirmed with pathologic findings in Taleghani hospital, Tehran, Iran during 2002-04. The results of surgical staging compared to preoperative endosonographic method. Mean age of 23 patients was 57.2 years [43-72 years]. 30% and 70% of the patients had esophageal and gastric cancers, respectively. The accuracy of endosonographic staging of esophagus and stomach cancers was 82%. The accuracy of diagnosis, positive and negative predictive value of cancers in assessment of the depth of the tumor by endosonography procedure were 79.4%, 69.6% and 84.9%, respectively. Endosonography is a precise method for evaluating depth and staging of tumor and lymph node involvement

[Celiac disease as a potential cause of idiopathic portal hypertension: a case report]

Celiac disease can be associated with various extra intestinal symptoms such as primary biliary cirrhosis and auto immune hepatitis but idiopathic portal hypertension is a very rare phenomenon. IPH patient typically has splenomegally, esophageal varices and sometimes Icter and ascitis. A case of IPH in a 38 year old woman with celiac disease. She had been suffering from Ascites, Splenomegally, malaise and apathy for several years and had undergone treatment for cryptogenic cirrhosis. Diagnostic re-examination of the patient such as Serology tests and markers from Wilson disease, auto immune and viral hepatitis showed negative reports, but her liver function test and ESR were prolonged In upper GI endoscopy esophageal varices was detected. Abdominal sonography reported moderate to severe splenomegally and rise of portal vein diameter but did not show any evidence of thrombosis. Liver biopsy revealed no sign of cirrhosis. But duodenal biopsy and serologic finding were compatible with celiac disease. Her symptoms improved on a gluten-free diet and her liver function test and ESR were normal

[Celiac disease as a potential cause of liver enzyme dysfunction]

Celiac disease is one of the most common cause of malabsorption syndrome. The symptom of this disease associated secondary to malabsorbtive problems. Celiac can be accompanied with liver enzyme dysfunction with various extra intestinal findings. This case was a 27-year old man presented with abnormal liver function test over period of 1 year. He did not have another symptom such as diarrhea, weight loss or skin lesion. In medical examination, there was no ascites, peripheral edema or jaundice. Diagnostic re-examination of the patient include serology tests and Viral hepatitis, Wilson disease and auto imuune responses showed to be normal. Abdominal and biliary sonography had normal results. Liver biopsy revealed no sign of any pathology, but duodenal biopsy and serologic findings were compatible by Celiac disease. The symptom improved on a gluten-free diet and his liver enzyme function tests became normal subsequently

[New criteria to assess the risk of acute angle closure]

To compare anterior segment and ocular biometric parameters of unaffected fellow eyes of patients with a previous attack of acute angle closure [AAC], primary angle closure suspect [PACS] eyes, and normal eyes; and to assess the risk of developing AAC in PACS. In this prospective comparative observational case series, 16 unaffected fellow eyes of patients with a previous attack of AAC [group I], 40 PACS eyes [group II] and 32 normal eyes [group III] were evaluated. Pentacam and A-scan echography were performed in all cases. Anterior chamber angle [ACA], anterior chamber volume [ACV], anterior chamber depth [ACD], central corneal thickness [CCT], keratometry [KR], lens thickness [LT] and axial length [AL] were measured in all eyes as main outcome measures. Age, CCT and LT were comparable among the study groups [all P values>0.05]. Mean ACA was 24.8, 22.9 and 35.4 in groups I, II, and III respectively [P<0.001]. Corresponding values for ACV were 72, 76 and 172 microl, respectively [P<0.001]. Central ACD measured from the endothelium was 1.80, 1.91, and 3.09 mm in groups I, II, and III respectively [P<0.001]. Using receiver operating characteristic [ROC] curves, ACV

[Mitomycin-C drops versus subconjunctival 5-fluorouracil for management of early bleb failure]

To compare the efficacy and safety of topical Mitomycin-C [MMC] drops versus subconjunctival 5-Fluourouracil [5-FU] injections for management of early bleb failure after trabeculectomy or combined phacoemulsification and trabeculectomy with posterior chamber intraocular lens implantation [PT+PCIOL]. In a comparative study, 37 eyes of 37 patients with impending early bleb failure were randomly allocated to MMC 0.02% eye drops [19 eyes] or subconjunctival 5-FU injections [5mg each dose] [18 eyes] for 2 to 4 weeks or. Main outcome measures included intraocular pressure [IOP], and bleb morphology according to the Indiana Bleb Appearance Grading Scale. Other outcome measures included success rate, number of glaucoma medications, best corrected visual acuity [BCVA] and complications. Complete success was defined as 5

[Early drainage of delayed suprachoroidal hemorrhage following glaucoma surgery]

To evaluate the effect of early drainage of delayed suprachoroidal hemorrhage [SCH] after glaucoma surgery. These study reports seven cases of delayed supra-choroidal hemorrhage following glaucoma surgery managed with early drainage. In this series instead of waiting for 7 to 14 days for clot lysis, the SCH was drained from the suprachoroidal space immediately after diagnosis. Seven eyes of 7 patients with delayed SCH including 4 men and 3 women were enrolled in the study. Median age was 42.57 +/- 29.61 years and mean follow up duration was 21.43 +/- 13.35 months. Immediately after diagnosis, choroidal tap and anterior chamber reformation were performed for all the patients. Intraocular pressure [IOP] decreased significantly after intervention. At final follow up, mean visual acuity was 1.08 +/- 0.31 LogMAR. Immediate surgical drainage of suprachoroidal hemorrhage seems to be an effective and safe method for treatment of delayed SCH; and it may decrease the inflammation from the entrapped blood in suprachoroidal space and reduce complications and additional procedures. Larger trials are recommended for further evaluation

[Superior versus inferior Ahmed glaucoma valve implantation]

To compare the efficacy and safety of Ahmed Glaucoma Valve [AGV] implantation in the superior versus inferior quadrants. This prospective parallel cohort study was performed on 106 eyes of 106 patients with refractory glaucoma. Main outcome measures included intraocular pressure [IOP] and rate of complications. Other outcome measures included best-corrected visual acuity [BCVA], number of glaucoma medications and success rate [defined as at least 30% IOP reduction and 5

[ Confocal Scan Features of Keratic Precipitates in Fuchs' Heterochromic Iridocyclitis]

To report confocal scan features of keratic precipitates [KPs] in Fuchs' heterochromic iridocyclitis [FHIC]. In this descriptive study, corneal confocal scan was performed to characterize KPs in patients with FHIC referred to Labbafinejad Medical Center from November 2005 to March 2007. Polymerase chain reaction [PCR] for Herpes Simplex virus, Herpes Zoster virus, Toxoplasma gondii, Cytomegalovirus and Rubella virus was performed on aqueous humor samples taken in 4 patients who underwent phacoemulsification. Confocal scan was performed in 40 eyes of 34 patients including 18 male and 16 female subjects with mean age of 30.7 +/- 10.5 [range 18-57] years. FHIC was bilateral in 6 and unilateral in 28 patients. The distribution of KPs was diffuse in 31 eyes and limited to the inferior cornea in 9 eyes. The morphology of KPs included: globular, 34 eyes [85%]; infiltrating, 31 eyes [77.5%]; dendritiform, 31 eyes [77.5%]; stippled, 27 eyes [67.5%]; and cruciform, 25 eyes [62.5%]. None of the cases demonstrated smooth-rounded KPs. PCR of aqueous specimens was negative for the above-mentioned infectious agents in 4 eyes who had infiltrating and dendritiform KPs on confocal scan. Confocal features of KPs in FHIC are diverse and include globular, infiltrating and dendritiform, stippled and cruciform. Presence of infiltrating and dendritfrom KPs in FHIC may be suggestive of a possible infectious etiology, however the results of PCR were negative in the limited numbers of such patients in our series

[Bilateral terrien's marginal degeneration, total peripheral corneal ectasia and posterior polymorphous dystrophy in a patient with rheumatoid arthritis]

To report bilateral Terrien's marginal degeneration, circumferential peripheral corneal ectasia and posterior polymorphous dystrophy in a patient with rheumatoid arthritis. A 24-year-old male patient, who was known case of rheumatoid arthritis from 8 years before, presented with decreased vision since four years ago. Comprehensive ophthalmic eye examination revealed bilateral circumferential peripheral corneal thinning and bulging with vascularization and lipid deposition in addition to band-like lesions in Descemet's membrane. Previous records revealed no gross abnormalities up to four years ago. Corneal lesions were consistent with bilateral circumferential Terrien's marginal degeneration concomitant with posterior polymorphous dystrophy. To our knowledge, this is the first report of concomitant bilateral Terrien's marginal degeneration with total peripheral corneal ectasia and posterior polymorphous dystrophy in a patient with rheumatoid arthritis. Circumferential involvement, younger age at presentation and bilateral total peripheral corneal ectasia in this case are not typical for classic Terrien's marginal degeneration. The underlying rheumatoid arthritis may have aggravated the condition leading to this atypical and severe presentation of Terrien's marginal degeneration

[Evaluating the effects of globalization on poverty measures]

Globalization of economy is characterized by increasing movement of labor and capital, technology, increased international trade, integration of markets and communication. Liberalization and globalization lead to increased foreign investment and increased amount and type of goods and services traded by nations. One of the challenges in globalization literature is its impacts on living condition of income groups and more specifically on poverty and income distribution of different income groups. Some believe in a positive relation between poverty and trade liberalization. However, others have got a negative relation between them. In this study the effect of globalization on poverty was investigated using both of micro and macro frameworks. In macroeconomic lens, globalization effect on Poverty Headcount and Poverty Gap criteria was studied using a variable as foreign trade - gross domestic production ratio. In microeconomic lens the results obtained for Wheat market was used. The Wheat market contains equations of import, domestic production and domestic demand simultaneously. The results of the Wheat market obtained from Mousavi's [1385] study, conducted to predict the impact of globalization on Wheat market. In the microeconomic approach in addition to the Wheat market results, household expenditure, collected by Iranian Statistical Center, was also used. In the microeconomic approach the impact of different levels of increase in Integration of International Trade [LIT] criterion [as a mean indicating level of globalization] on Wheat [Bread] consumption was investigated. Two approaches were considered in order to investigate the impact of globalization on consumption. In approach one, the total changes in Wheat consumption was regarded as summation of changes in domestic supply and import. While in second one the changes in Wheat [Bread] domestic demand was regarded as consumption changes. Different levels of increase in Integration of International Trade criterion were also 10, 20, 30, 50 and 100 percent. In addition to the increased levels of the Integration of International Trade criterion, the impacts of increase in price of bread on selected households expenditure and poverty indices including Headcount, Poverty Gap and Severity of Poverty was studied. Based on findings, globalization has no considerable impact on the percent of urban poor, while 1% rise in globalization criterion can reduce urban poverty gap by 2.95%. Inflation index also reveled that increase in prices results in decreased poverty gap in urban Iran. In the case of rural households the findings showed that globalization results in a reduced poverty head count, but it raises poverty gap. In other words participation of Iran in global market will result in more undesirable condition of rural lower income poor, needing for more protection of the mentioned groups. The impact of agriculture sector growth on rural poverty is also interesting in that more growth of it lead to more poverty. Based on the results agriculture sector growth is expected to increase both of the poor number and poverty gap. The results of Headcount criterion revealed that 36.74% of urban and 25.43% of rural households are considered as poor. The results of micro lens evaluation that was also performed using coefficients obtained from Mousavi's [1385] study and household expenditure showed that globalization of wheat market individually, and increased bread price would not result in a considerable change in poverty Headcount, Gap, and Severity

[Histopathologic evaluation of optic neurotomy with MVR blade and excimer laser in cadaver eyes]

To evaluate the histopathologic features of optic neurotomy with microvitreoretinal [MVR] blade and excimer laser in cadaver eyes. Optic neurotomy was performed in 11 cadaver eyes using 20-gauge MVR blade and in three cadaver eyes with pulsed xenon chloride [XeCl] excimer laser [308 nm] via monofile lightconducting fiber with a core diameter of 200 microns. After tissue processing, hematoxylin and eosin stained slides were used to evaluate the posterior segment of the globes, including the optic nerve head. None of the cases in the MVR neurotomy group had scleral macro- or micro-perforation and no injury was induced to the central retinal vein or artery. In 10 cases, the distance between the neurotomy site and the central retinal vessels ranged from 50 to 500 micro at all histologic levels. In one remaining case this distance was approximately 10 micro on two histologic sections and about 200 micro at a third level. Intra-neural hemorrhage was found in 18% of cases. Neurotomy was successfully induced in two of three cases attempted with the excimer laser. In one case, due to cloudy media, it was not apparent whether the laser successfully induced the neurotomy and no neurotomy was evident on sectioning. MVR induced optic neurotomy is an effective procedure to create scleral outlet relaxation, without significant surgical complications such as scleral perforation or central retinal vascular injury. This preliminary study also demonstrates that the XeCl excimer laser can make nonmechanical cuts with relative ease and reliability

[Sensorineural hearing loss in pseudoexfoliation syndrome]

To determine hearing thresholds at sound frequencies important for speech comprehension in subjects with ocular pseudoexfoliation [PXF] and to compare them with that of controls without PXF. Eighty-three subjects with ocular PXF and 83 age and sex matched controls without PXF were enrolled in this case-control study. Pure tone audiometry [bone conduction] was performed at 1, 2 and 3 kilohertz [KHz] in all subjects. Thresholds were compared to an age and sex stratified standard [ISO7029] and between study groups. Hearing loss was defined as sum of tested hearing thresholds [HTL-1, 2, 3] lower than the ISO7029 standard median. The study included 60 male and 23 female subjects in each group. Hearing loss was present in 147 of 166 [88.6%] examined ears in the case group vs 89 of 166 [53.6%] ears in the control group [P<0.001; odds ratio [OR] = 6.69; 95% confidence interval [CI], 3.49-11.79]. Overall 78 subjects [94.0%] in the case group vs 58 subjects [69.9%] in the control group had hearing loss in one or both ears [P< 0.001; OR=6.72; 95%CI, 2.42-18.62]. Hearing thresholds at each of the examined frequencies and the HTL-1, 2, 3 were also significantly higher in individuals with PXF. Although glaucoma was significantly more common in subjects with PXF [51.8% vs 22.9%, P<0.001], it was not associated with hearing loss in any of the study groups. Hearing thresholds at frequencies which are important for speech comprehension are significantly worse in individuals with ocular PXF as compared to matched controls. This finding may support the multi-organ nature of PXF syndrome

Results of post-trabeculectomy bleb revision using conjunctiva

To evaluate and compare the results of different surgical methods for post-trabeculectomy bleb revision at Labbafinejad Medical Center, Tehran-Iran, from 1999 to 2003. This study was conducted on all patients who underwent post-trabeculectomy bleb revision due to hypotony [intraocular pressure [IOP] less than 6 mmHg] or bleb leakage. Surgical methods were: conjunctival advancement, rotational conjunctival flap and free conjunctival graft. Bleb revision was performed in the cases of bleb leakage if the bleb hole was greater than 1 mm or leakage could not be controlled within 1 to 2 weeks of conservative treatment. Bleb revision was performed in eyes with hypotony in cases with cataract development or progression or hypotony maculopathy or iridocorneal adhesion. Surgical success was defined as IOP between 6-21 mmHg with a maximum of 2 topical antiglaucoma medications and discontinuation of leakage. Twenty-seven eyes of 27 patients [17 male, 10 female] with mean age of 37.8 +/- 15.2 years [9-37 years] were studied. Indication for surgery was bleb leakage in 22 cases [81.5%] and hypotonous maculopathy in 5 cases [18.5%]. Mean IOP was 4.4 +/- 1.04 mmHg preoperatively and 13.00 +/- 1.29 mmHg postoperatively. [P< 0.001] Mean visual acuity was 0.9 LogMAR [20/160] before surgery and reached 0.6 LogMAR [20/80] after bleb revision. [P<0.002] Mean cup/disc ratio was 0.7 preoperatively which remained unchanged postoperatively. Conjunctival advancement was performed in 18 cases [success rate = 72.2%], rotational conjunctival flap in 6 cases [success rate= 66.7%] and free conjunctival graft in 3 cases [success rate= 66.7%]. [P=0.73] Bleb revision was repeated in 2 cases due to continuous leakage. Mitomycin-C [MMC] and 5-fluorouracil had been used during primary trabeculectomy in 62% and 7.6% of cases, respectively. In 19.6% of cases surgery was done without using antimetabolites and usage of antimetabolites was unknown in 11%. The average time between primary trabeculectomy and bleb leakage or hypotonia was 17 months in cases with prior use of MMC and 52 months in the cases with no antimetabolite usage. [P<0.05] Post-trabeculectomy bleb revision using conjunctiva seems to be a successful method for control of leakage and prevention of complications of hypotony

Mitomycin-C Trabeculectomy versus Ahmed Glaucoma Implant for treatment Pediatric Aphakic Glaucoma

To compare the outcomes and complications of mitomycin-C [MMC] trabeculectomy and Ahmed glaucoma implant [AGI] for treatment of aphakic glaucoma following congenital cataract surgery in children

[Confounding factors on the effect of Intravitreal triamcinolone for refractory diabetic macular edema]

To evaluate the influence of different confounding factors on the effect of intravitreal triamcinolone acetonide injection for refractory diabetic macular edema. In a prospective placebo-controlled randomized clinical trial, 88 eyes with refractory diabetic macular edema were randomly assigned into two groups including 45 in the treatment group [4 mg intravitreal triamcinolone acetonide] and 43 in the placebo group. Multivariate analysis was performed for three main outcomes, including visual acuity, central macular thickness, and the amount of hard exudates. Confounding factors that showed some effect on the main outcomes were used for building multivariate models. It was revealed that blood urea nitrogen, fasting blood sugar, serum cholesterol, initial visual acuity, presence of cystoid macular edema, amount of hard exudates, and size of foveal avascular zone had some influence on visual acuity outcome; previous macular photocoagulation, serum cholesterol, baseline central macular thickness, initial intraocular pressure, amount of hard exudates, and size of foveal avascular zone had some influence on visual acuity outcome; previous macular photocoagulation, serum cholesterol, baseline central macular thickness, initial intraocular pressure, amount of hard exudates, and size of foveal avascular zone had some influence on central macular thickness changes; and serum cholesterol, baseline central macular thickness, and amount of hard exudates had some influence on hard exudates in both groups. Size of foveal avascular zone, initial intraocular pressure, amount of hard exudates, and baseline central macular thickness also had an additive effect on the outcomes in the treatment group. Many confounding factors may influence the effect of intravitreal triamcinolone. These factors should be considered when adopting intravitreal triamcinolone. These factors should be considered when adopting intravitreal triamcinolone as a treatment strategy for refractory diabetic macular edema

[Chronic and delayed onset mustard gas keratitis: report of 48 patients]

Purpose: to report the clinical features of 93 eyes with chronic and delayed onset mustard gas keratitis in 48 patients

Methods: forty-eight Iranian survivors of Iraqi chemical warfare with chronic or delayed onset mustard gas keratitis were enrolled. We reviewed the symptoms, signs, clinical course, and treatment of our patients. In 5 cases, histopathologic features of corneal and conjunctival specimens are presented

Results: of 48 patients, 3 1 [64.6%] had chronic symptomatology whereas 17 [3 5.4%] experienced delayed onset lesions. Visual acuity at referral ranged from hand motions to 20120. Ocular surface changes included chronic blepharitis and decreased tear meniscus in all, limbal ischemia [81.3%] and conjunctival vascular abnormalities [50%]. Corneal signs in order of frequency were: scar/opacity [87.5%], neovascularization [70.8%], thinning [58.3%], lipoid deposits [52. I%], amyloid deposits [43.8%], and epithelial defects and irregularity [3 1.3%]. Twenty patients received conservative treatment; others underwent allograft stem cell transplantation [20 eyes of 17 patients], penetrating keratoplasty [12 eyes of 12 patients], and lamellar keratoplasty [4 eyes of 3 patients]. Conjunctival specimens were evaluated by light microscopy. Decreased goblet cell density, attenuated or thickened epithelium, scarring in the substantia propria associated with plasmacytic and lymphocytic infiltration, and dilated lymphatic vessels were noted. Excised corneal buttons disclosed absence of epithelium and Bowman's layer, firbrovascular pannus, stromal scarring, and vascularization

Conclusion: mustard gas may cause chronic and delayed destructive lesions in the ocular surface and cornea leading to progressive visual deterioration and ocular irritation. The pathophysiology of these changes is not clearly identified. Excised conjunctival and corneal specimens revealed a mixed inflammatory response without any specific features. Based on the clinical appearance of the lesions and histopathologic findings, an immune-mediated component seems possible

[Transvitreal optic neurotomy: a new treatment option for centra1 retinal vein occlusion]

Central retinal vein occlusion [CRVO] occurs at the scleral outlet where the optic nerve, central retinal artery, and central retinal vein enter the eye; therefore it may be considered a "compartment syndrome" which is defined as a neurovascular compression within this confined space of scleral outlet resulting in tissue ischemia and dysfunction. Transvitreal optic neurotomy [TON] is a new surgical technique advocated for treatment of CRVO. By this procedure and providing surgical relaxation of the scleral outlet, clearing of macular edema and interaretinal hemorrhage and improved retinal blood flow may reestablish. TON may be a beneficial surgical procedure for patients with sever CRVO via decompressing the scleral outlet and by that affecting the optic nerve and the blood supply. In addition to scleral ring relaxation, other postulated mechanisms of effect in TON include development of opticociliary vessels and increased perfusion into pre-existing opticociliary vessels. Preliminary results of TON for CRVO have demonstrated encouraging results; however these results need to be reconfirmed in a randomized clinical trial