​Journal of Current Ophthalmology
Year:2008 | Volume:20 | Issue:3|Papers Count:11

In this issue of IrJO Movassat et al (P: 33-38) present a case series of leber's congenital amaurosis (LCA). LCA is the most severe form of inherited retinal dystrophy responsible for congenital blindness with an early age of onset and accounts for at least 5% of all inherited retinal diseases which affect about one in 3500 individuals in the world.Usually degenerative anomalies of the retina initially affect the rods which cause night-blindness and regression of the visual fields, but progressively the cones, retinal vessels and other cells get involved in this degenerative process.

Purpose: To determine the prevalence of refractive condition and its risk factors among students in Mashhad.Methods: A total of 2510 students representing a cross-sectional of the population of Mashhad were sampled using random cluster sampling strategy. Primary and middle school students underwent cycloplegic refraction. The refractive errors of high school students were measured using non-cycloplegic autorefraction. Myopia was defined as spherical equivalent (SE) of -0.5 diopter (D) or more, and hyperopia was defined as SE of+0.5 diopter (D) or more, and astigmatism of 0.75 cylinder diopter or greater. Examination was carried out in the school using standardized testing protocols.Results: 2150 students (group 1: 1163 primary and middle school, group 2: 947 high school students and 13 missed data) participated. The prevalence of refractive errors in the 1st group was: myopia=2.4%, hyperopia=87.9%, astigmatism=9.8% and anisometropia=3.0% (SE difference at least 1.00 D), and in the 2nd group myopia=24.1%, hyperopia=8.4%, astigmatism=11.8% and anisometropia=5.6%. There was significant difference in refractive errors between girls and boys (P<0.001). In primary and middle school prevalence of myopia increased with age (OR=1.3 95% CI: 1.03 to 1.7 and P=0.013). Conclusion: The prevalence of refractive errors among students in Mashhad is high. Effective detection and treatment of these refractive errors is expected to reduce the incidence of amblyopia and strabismus and also can prevent substantive effects on academic performance.

Purpose: Recession is the main surgical procedure in correction of eye deviation in Duane’s syndrome. We evaluate the efficacy of botulinum toxin injection in the treatment of this type of strabismus instead of surgery or before it.Methods: Three patients with Duane’s syndrome type I and one patient with Type II were selected at Poostchi eye clinic from patients who diagnosed primarily and had not any eye surgery before. Botulinum toxin (Dysport™, 10 IU) was injected into medial or lateral rectus muscles under general (2 patients) or local (2 others) anesthesia. Amount of deviation, leash phenomenon and limitation of movements were measured pre injection and 72 hours, 1, 4, 12 and 24 weeks postinjections and the results were compared.Results: The amount of deviation was decreased between 8-35 PD at 24 weeks postinjection. No significant change was observed in limitation of movement but leash phenomenon improved in 3 patients.Conclusion: Injection of botulinum toxin in Duane’s syndrome will decrease the amount of deviation and leash phenomenon; however, surgical intervention maybe necessary for residual deviation or globe retraction.

Purpose: To investigate the penetration of cefixime and ciprofloxacin to the rabbit eye on the basis of microbial inhibition of aqueous and vitreous humour after oral administration.Methods: In this experimental study, 36 rabbits (72 eyes) were randomly divided into two groups; group A consisted of 20 rabbits and group B 16 rabbits. Each group was divided into four equal subgroups. The rabbits in each subgroup of group A received 4, 8, 12, and 20 mg/kg of syrup of cefixime every 12 hr respectively and the rabbits in each subgroup of group B received 20, 40, 60, and 80 mg/kg tablet of ciprofloxacin respectively every 12 hr. Immediately after the first dose of the drugs, the anterior chamber of one eye was irrigated randomly by 30-40 cc of ringer lactate solution alongside with mild traumatization of iris. Then by 4, 8, 12, 24 and 72 hr intervals after the 3rd dose, 0.1 cc of aqueous, 0.2-0.5 cc of vitreous, 3 cc of blood and one standard disk of the used antibiotic was placed on culture media of a known bacteria which was completely sensitive to the respective antibiotic. Forty eight hours later, the microbial inhibition zone of each sample and the standard disk of antibiotic were compared.Results: No microbial inhibition was seen by sample of aqueous and vitreous, although very large zone of inhibition was seen by blood sample and standard disk of antibiotic.Conclusion: It seems that oral cefixime and ciprofloxacin do not produce an effective dose for microbial inhibition in rabbit eye.

Purpose: To assess the results of brachytherapy in patients with recurrent or incomplete excised conjunctival squamous cell carcinoma (SCC) and malignant melanoma.Methods: Three patients underwent brachytherapy of one eye and one patient underwent brachytherapy of both eyes with ruthenium-106 (RU-106) plaques, all of them had a history of incomplete resection or recurrence of the tumor after surgery. All patients were male with an average age at diagnosis of 54 years (range, 34-76 years).The shape and the size of plaques were determined based on location and size of the suspected area. The plaque was inserted to deliver a target dose of 80-100 Gy in the region of conjunctival malignancy. The diagnosis was squamous cell carcinoma in three eyes and conjunctival melanoma in two eyes. All patients had surgical history of one to three previous excisions with or without cryotherapy before brachytherapy. There were microscopic residual tumors after excision in 2 eyes and recurrent lesion was evident in 3 other eyes. A mean dose of 95 Gy was delivered to the tumor bed.Results: Complete tumor regression without any evidence of recurrent lesion was obtained in all five eyes. The patients were followed for 32 months on average (range, 18-42 months). No radiation related complication was detected, with an exception of a dry eye in the last follow up.Conclusion: Brachytherapy with RU-106 plaque is an alternative method for treatment of selected patients with recurrent or residual conjunctival SCC and melanoma.

Purpose: To evaluate the visual results of amblyopic therapy in pediatric patients with monocular abnormalities.Methods: The hospital records of visually immature patients with unilateral organic ocular abnormalities and decreased visual acuity, who presented to the pediatric ophthalmology clinic over a one year period, were reviewed. Those who had 8 years old of age or less and underwent amblyopic treatment included in the study. Amblyopia was defined as visual acuity difference of more than 2 lines between the two eyes, absence of central fixation or fixation with inability to maintenance. Amblyopic treatment had been performed using full time occlusion method for one month and then reevaluation of the patient.Results: Twenty patients (8 males and 12 females) with the mean age of 4±3.12 years (range: 1 to 8 years) were included in the study and were followed for a mean of 6 years (range: 2 to 8 years). No patient was excluded from the study due to loss of follow-up. Among those who were able to read the chart (16 patients), the visual acuity increased from 3 meters counting fingers (range: 1 to 5 meters counting fingers) before treatment to 4/10 (range: 2/10 to 6/10) in last visit (P<0.01). In 4 remaining eyes visual acuity increased from central to steady or steady and maintenance.Conclusion: A trial of full-time occlusion for visually immature patients with decreased visual acuity associated with unilateral organic ocular abnormalities specially traumatic or surgical injuries is recommended.

Purpose: To investigate intraocular pressure (IOP) changes due to different serum level heights by using Ton open in acquired globes from the Iran Eye Bank (IEB).Methods: In this interventional prospective case series, serum were infused into 18 normal globes acquired from IEB by using 21G needle inserted in vitreal space through optic nerve head to change the IOP by different fluid level heights from the globe surface. IOP of globes were measured and recorded by Ton open over the sclera and over the cornea at different serum level heights.Results: Twelve globes were acquired from male donors and 6 globes were from female donors. Mean age of donors were 57 year old. Mean measured pressures by Ton open of the 18 globes at the serum level heights of 13.6, 27.2, 40.8, 54.4 and 68 cm from the globe surface were 14, 23.6, 34.8, 44 and 52.8 mmHg over the sclera and 13.1, 22.8, 34.8, 44.1 and 52.8 mmHg over the cornea respectively.Conclusion: Using a Ton open is a proper method to measure the acquired globes IOP, except in serum level height of 13.6 cm (10 mmHg) from the globe surface. In addition, if tonometry over the cornea is not available, it can be done by using Ton open over the sclera.

Purpose: To evaluate the incidence of Leber’s Congenital Amaurosis (LCA) in low vision children referred to electrophysiology ward of Farabi Eye Hospital, and review the clinical features of disease and Electroretiongraphy (ERG) test values to confirm the diagnosis and severity of the disease in Iran.Design: Prospective observational case series.Methods: Two-hundred and fifteen cases of low vision infants and young children were referred to electrophysiology ward of Farabi Eye Hospital during 18 months. Clinical LCA diagnosis was made and ERG tests were done and LCA diagnosis was confirmed. The symptoms, signs and the results of eye examination and ERG findings were recorded.Results: The mean age of the patients was 27.43 (range, 1-120 months). Among low vision patients fourteen percent of patients had LCA. Fifty-four percent of the patients were female. Nystagmus and low vision were the two most common clinical manifestations of these patients. Hyperopia was the main refractive error (54.80%) and mild abnormalities in fundus examinations were found in 67.70% of cases. In nearly 90% of cases consanguinity was found. ERG was flat or unrecordable in more than 90% of cases, but in less than 10% of cases with recordable curves, severe decrease in amplitude of waves was encountered. ERG confirmed LCA diagnosis in 31 out of 37 patients (positive predictive value of 83.7%).Conclusion: The incidence of LCA in low vision children is similar to other studies. ERG helped in confirmation of presence or absence of overall retinal dysfunction in the majority 31/37 (83.7%) of LCA patients. It can differentiate these cases from other cases with poor vision in infantile age but genetic testing is recommended.

Purpose: Evaluation of efficacy of Memantine (N-Methyl-D-Aspartate Receptor Antagonist) on visual function of patients with acute non-arteritic ischemic optic neuropathy (NAION).Methods: The study was conducted as interventional case series from November 2005 through November 2006 in Farabi Eye Hospital. Twenty-two patients with acute NAION of less than 8 weeks duration entered the study. Memantine was prescribed with a dose of 5 mg per day for the first week and 10 mg per day for the following two weeks. Baseline best corrected visual acuity (BCVA); visual evoked potential (VEP) and visual field was done for all patients. BCVA recording repeated 3 weeks, 3 and 6 months later. VEP and perimetry repeated 3 months after treatment.Results: After 3 weeks, 3 and 6 months, BCVA improved -0.32±0.40 LogMAR, -0.51±0.49 and -0.51±0.49, respectively (P=0.005, P=0.001 and P=0.001, respectively). VEP recordings after 3 months, demonstrated -8.61±14.51 db mean decrease in implicit time (P=0.019). Amplitude of voltage did not show significant difference with baseline (P=0.10). Perimetry results after 3 months showed that mean deviation (MD) improved 2.77±3.94 db (P=0.016).Conclusion: Memantine resulted in significant improvement of BCVA 3 weeks, 3 and 6 months after treatment of acute NAION. Memantine also resulted in significant decrease of implicit time and significant improvement of mean deviation in VEP and perimetry after 3 months.

Purpose: To introduce a small incision technique of fascia lata (FL) harvesting for frontalis suspension blepharoptosis procedure.Methods: A skin incision was made in a line between the lateral condyle of the tibia and the anterior superior iliac crest, starting 4-5 cm above the knee and extending upward 2-2.5 cm. Approximately 8 cm superior to the first incision, a second skin incision was made with the same length. The FL was dissected from subcutaneous tissue from 1 cm superior to superior border of upper incision to 1 cm inferior to inferior border of lower incision. A 15 mm x 5-10 mm strip of FL was excised. The fascial defect was left open. Subcutaneous and deep layers were closed with three 4-0 plain catgut sutures and the skin with subcuticular 5-0 prolene sutures.Results: The technique was used in 22 patients from 4 to 47 years of age (Mean: 18.29±14.20) for 34 frontalis sling procedures. Mean follow-up time was 6.17±3.21 (3-16) months. Wound hematoma (1/22, 4.5%), wound discharge (2/22, 9%), pain at rest (100%, up to 4 days), pain on walking (20/22, 90%; up to 3 weeks), limping (13/22, 59.1%; up to 7 days) were the main postoperative complications. No significant skin scar was observed and none of the patients needed scar revision.Conclusion: Small incision FL harvesting procedure is a good alternative method when the FL stripper is not available.

Purpose: To describe a case of acute angle-closure glaucoma associated with oral topiramate (Topamax, Aria Daroo) therapy.Case report: Two weeks after initiation of oral topiramate therapy for epilepsy, a 35-year-old woman presented with blurred vision and headache. Intraocular pressure in both eyes was significantly elevated and her visual acuity was 20/30 Ocular Uterque (OU). Bilateral conjunctival chemosis, shallow anterior chamber and mild corneal edema were observed. Topiramate therapy was discontinued. Topical therapy was initiated in both eyes with betamethasone, atropine and timolol.Results: Symptoms and signs including vision accuracy, refraction and intraocular pressure resolved over the next 2 weeks.Conclusion: Topiramate therapy may be associated with ciliochoroidal effusion resulting in angle-closure glaucoma; therefore, patients on such therapy should be carefully monitored.