The effect of intraoperative retinal manipulation on the underlying retinal pigment epithelium: an experimental study

PURPOSE: Retinal pigment epithelial changes described after vitreoretinal surgery may result from localized compression injury caused by intentional or inadvertent contact with vitreoretinal instruments. The authors evaluated these changes resulting from manipulation of the retina without frank retinal injury. METHODS: One eye each of six pigmented rabbits underwent surgery during which the inner retinal surface was touched at several points with a 20-gauge silicone-tipped subretinal fluid cannula without causing a retinal break or subretinal hemorrhage. The rabbits were followed-up with indirect ophthalmoscopy, fundus photography, and fluorescein angiography, and were killed at 1 hour, 1 week, or 2 weeks. Light microscopy was used for histopathologic evaluation. RESULTS: On fluorescein angiography, diffuse leakage noted at the injury sites significantly decreased by the fourth day and almost completely disappeared by the second week. Disruption of photoreceptor outer segments and retinal pigment epithelium in the early specimens, and irregular pigmentation, proliferation, and migration of the retinal pigment epithelium at 1 and 2 weeks were the prominent features on histopathologic examination. CONCLUSIONS: Intraoperative manipulation of the attached retina may cause significant pigment epithelium displacement and proliferation and varying degrees of disorganization of normal retinal architecture in the absence of clinically evident retinal breaks and subretinal hemorrhages.     

Toxicity of the photosensitizer NPe6 following intravitreal injection

BACKGROUND AND OBJECTIVE: To determine the retinal toxicity of mono-L-aspartyl chlorin e6 (NPe6) following intravitreal injection. METHODS: Twelve Dutch-belted rabbits divided into 5 experimental groups (n=2 each) were injected intravitreally with 6.25, 12.5, 25, 50, or 100 microg of NPe6; one control group (n=2) was injected with intravitreal normal saline. One eye in each rabbit was sutured shut to test the effect of light exposure. Fundus photography and electroretinograms were performed before treatment and 2 days, 1 week, and 2 weeks after injection. Animals were euthanized and the eyes enucleated for histopathologic analysis. RESULTS: After 1 week, 4 uncovered eyes given 50 and 100 microg had central retinal vein occlusion and varying degrees of retinal hemorrhage. RPE proliferation was seen in the covered eyes given 50 or 100 microg. Electroretinograms revealed absent retinal response at 100 microg and mild toxicity at 50 microg, but no change from normal at doses of < or = 25 microg of NPe6. CONCLUSIONS: Intravitreal doses of < or = 25 microg NPe6 caused little or no apparent toxicity; however, toxicity was significant at doses of 50 microg and 100 microg.     

Joint replacement and human immunodeficiency virus

The incidence of human immunodeficiency virus(HIV)-infected cases that need total joint replacement(TJR) is generally rising. On the other hand, modern management of HIV-infected cases has enabled them to achieve longevity while increasing the need for arthroplasty procedures due to the augmented degenerative joint disease and fragility fractures, and the risk of osteonecrosis. Although initial investigations on joint replacement in HIV-infected cases showed a high risk of complications, the rec...     

Complication of lengthening and the role of post-operative care,physical and psychological rehabilitation among fibula hemimelia

There is a clear clinical need for efficient physiotherapy and rehabilitation programs during and after bone lengthening and reconstruction for gaining the optimal effect and also prevention or treatment of lengthening side effects. Pin tract infection is the most prevalent side effect during lengthening which could be prevented and treated initially via proper wound care. Muscle contractures are typically a consequence of the generated tension on the distracted muscle. It can be managed by physiotherapy initially and surgically in later severe stages. Furthermore, it is essential to avoid muscle contracture development, which is the demonstration of the imbalanced muscle appeals on the joint to inhibit the following subluxation. The knee is the furthermost affected joint by the aforementioned problem due to the inherent lack of ligamentous and bony stability. Joint stiffness is the other possible unfavorable effect of lengthening. It happens because of extensive muscle contractures or may possibly be attributed to rigidity of the joint following the amplified pressure on the joint surface during the process of lengthening. Physiotherapy and occupational therapy including endurance and strength exercise as well as stretching play an important role during the rehabilitation periods for the prevention and also the treatment of muscle contracture and the following deformity and also joint stiffness. Likewise, the effect of mental and physical rehabilitation programs should not be overlooked.     

Incidence of obesity,overweight and hypertension in children and adolescents in Ahvaz southwest of IRAN: Five-years study

ObjectiveThe purpose of this study was to investigate the incidence of obesity, overweight and hypertension in children and adolescents aged 10–15 in Ahvaz.MethodsThis is a epidemiologic study performed on 176 people aged 10–15 in Ahvaz. In 2009, 300 people underwent weight, height and blood pressure measurements. Five years later, the same people were reassessed for obesity, overweight and hypertension, of whom a total of 176 people agreed to repeat the procedure.ResultsThe study included 100 (57%) males and 76 (43%) females. Mean BMI was 22.1 ± 4.3 kg / m2 in year 2014, without any significant difference between the two sexes (P = 0.518). In the same year, the prevalence of obesity and overweight was 26 (14.8%) and 13 (7.4%), respectively. After 5years, BMI increased significantly (P < 0.001). Of the 150 norma participants with normal BMI in 2009, 15 (10%) and 6 (4%) became overweight and obese in 2014 respectively. The mean systolic and diastolic blood pressures increased significantly over 5 years P = 0.042 and P < 0.001.ConclusionsThis study shows an increase in mean BMI and mean systolic and diastolic blood pressures after 5 years among people aged 10–15 in Ahvaz.     

An Unusually Frequent β-Thalassemia Mutation in an Iranian Province

Iran, a country located on the “thalassemia belt”, is an area with an unusually high prevalence of β-thalassemia (thal). The gene frequency of thalassemia shows great variation within Iran from one area to another. The purpose of this study was to determine the spectrum of β-thal mutations in Sistan-Baluchestan (S-B), a southeastern province of Iran which has a high mutation frequency of about 10%, and to compare this with neighboring provinces and countries. A total of 400 carriers (200 pre-marriage young couples selected at centers conducting prenatal diagnosis programs) with an established diagnosis of β-thal minor, were enrolled into the study. Mutations in the β-globin gene were detected using amplification refractory mutation system (ARMS) and restriction fraction length polymorphism (RFLP). Three hundred and sixty mutant chromosomes (13 different mutations) were detected with the two most common mutations accounting for about 80% of all detected β-thal alleles in this region. The most common mutation by far was IVS-I-5 (G>C) (72.3%), followed by frameshift codons (FSC) 8/9 (+G) (5.8%) and codon 44 (?C) (2.5%). In conclusion, IVS-I-5 and FSC 8/9 (+G) account for about 80% of all mutations in S-B. Sistan-Baluchestan may be regarded as the ‘hot zone’ for the IVS-I-5 mutation.     

Tissue plasminogen activator in the treatment of experimental retinal vein occlusion

The thrombolytic effect of recombinant tissue plasminogen activator was studied in 28 randomly selected rabbit eyes to lyse photochemically induced retinal vein occlusion. Occlusion was confirmed histologically and assessed by fluorescein angiography. Sixteen eyes were treated with recombinant tissue plasminogen activator given intravenously and 12 control eyes were given similar volumes of normal saline solution. Fluorescein angiography was performed before and at various intervals after treatment. Four hours after treatment, the retinal vein was patent in 16 eyes (100%) treated with recombinant tissue plasminogen activator, as opposed to one eye (8.3%) treated with normal saline. The results indicate that tissue plasminogen activator is effective in lysing experimentally induced retinal vein thrombi.     

A preliminary study of corneal penetration of 125I-labelled idoxuridine liposome

We compared corneal penetration of idoxuridine (IDU) to liposome-encapsulated IDU. Liposomes of phosphatidic acid, phosphatidyl choline, and alpha-tocopherol in a molar ratio 1:8:1 were prepared using the reverse phase evaporation method. New Zealand albino rabbits received either 0.1% solution of I125-labelled aqueous IDU or liposome-encapsulated IDU topically every 2 min for 6 min. Corneal, aqueous, and vitreous samples were assayed for I125 radioactivity at 15 min and at 1, 2, 3, and 6 h following drug application. Our results indicated that corneal penetration of liposomal IDU was significantly increased over the regular form of the drug for a time interval of 6 h.     

Contact Nd:YAG laser for use in oculoplastic surgery

We used a contact Nd:YAG laser with a sapphire tip to perform blepharoplasties in rabbits, and to cut bone in the orbital rim. All procedures were performed easily and without intraoperative hemorrhage.     

Retinal and choroidal detachments: role of magnetic resonance imaging and computed tomography

This article presents MR and CT images of certain inflammatory and neoplastic choroidal and retinal disorders that are associated with retinal and choroidal detachment. The characteristic MR and CT features of retinal and choroidal detachments in many cases can assist ophthalmologists and radiologists in arriving at correct diagnoses of ocular diseases.