​Journal of Current Ophthalmology
Year:2004 | Volume:16 | Issue:3|Papers Count:13

Aims: To determine the age and gender specific prevalence of refractive errors in Tehran through a population-based study. Methods: A total of 6497 citizens representing a cross-section of the population of Tehran were sampled from 160 clusters using stratified, randomized, cluster sampling strategy. Eligible individuals were enumerated through a door-to-door household survey in the selected clusters and were invited to participate. All participants were transferred to a clinic for extensive eye examination and interview. Refractive error was determined using manifest and cycloplegic refraction. Myopia was defined as spherical equivalent of -0.5 diopters (D) or more and hyperopia was defined the spherical equivalent of more than +0.5 D. Results: Of those sampled, 4565 (70.3%) people participated in the study. Refraction data for 4354 participants aged five years and over are presented. The age- and gender-standardized prevalence of myopia based on manifest refraction was 21.8% and that for hyperopia was 26.0%. The prevalence based on cycloplegic refraction were 17.2% and 56.6%, respectively. Prevalence of myopia and hyperopia differed significantly among age and gender groups (P<0.001). Astigmatism of 0.75 cylinder diopter or greater was present in 29.6% with manifest refraction and in 30.3% with cycloplegic refraction. Among the study population, 6.1% had anisometropia of 1 D or more. Conclusion: This report has provided details of the refractive status in the population. We have documented prevalence of myopia, hyperopia, astigmatism and anisometropia by age and gender, identifying more severely affected people for prevention programs in the community.  

Purpose: To evaluate the refractive outcome of silicone oil removal and intraocular lens (IOL) implantation using laser interferometry. Methods: Thirteen silicone oil-filled eyes of twelve patients were included in the study. IOL power calculation was performed using laser interferometry (IOL MasterTM V1.1, Carl Zeiss, Jena, Germany). All of these eyes underwent silicone oil removal and cataract extraction with IOL implantation. Post-operative refraction was evaluated. Results: The mean deviation of the final post-operative refraction (spherical equivalent) was -0.30±0.91 D (Range, -1.87 to +1.3) at 12 weeks. The mean axial length of the eyes was 22.99±0.84mm (range, 22.07 to 25.24 mm). No major complications occurred intra or post-operatively. Conclusion: Laser interferometry appears to be a feasible and satisfactorily accurate method to calculate IOL power in some silicone oil-filled eyes. Further studies comparing this technique to others are warranted. .          

Objective: To evaluate surgically induced astigmatism after sutureless superior and temporal clear corneal phacoemulsification with 4.1 mm incision. Setting: Department of Ophthalmology; Rasoul Akram Hospital. Design-Self-Controlled Clinical Trial, and non-randomized interventional case-series. Patients and Methods: 118 eyes of 89 Patients undergoing sutureless phaco surgery were prospectively studied. Superior CCI was used in 33 eyes with> 1 D with-the – rule astigmatism and temporal CCI in eyes with ≤ D with - the - rule (n=49) or against the rule astigmatism (n=36). Corneal Toporgaphy was done preperatively as well as 1, 6 and 12 weeks post-operatively. Results: Mean induced astigmatism after 12 weeks, calculated by Jaffe vector analysis was 1.42 ±0.23 D in sup CCI and 0.68± 0.21 D in temporal CCI group. The Temporal CCI group had significantly less induced astigmatism (P=0.001) and fluctuation over time (P=0.011). Conclusion: Temporal 4.1 mm CCI induces less astigmatism than superior 4.1 mm CCI and remains more stable over time.  

Background: Knowledge of predisposing factors for allograft rejection or graft failure and their prevalence in penetrating keratoplasty (PK) is very important. Patients & Methods: In a descriptive study, 800 patient's records of PK were studied. 70 records with high-risk characteristics were selected. Incomplete records were omitted. Demographic data, including sex, age, predisposing factors, visual acuity and graft survival were analyzed. Results: Overall, 40 patients were male (57.1%), average age was 30.9y (1-74 years). The three most prevalent risk factors were multiple allograft rejections, corneal scar & neovascularization & chemical burn. The most common complication of surgery was allograft rejection (P<0.001). Visual acuity significantly increased after PK (P<0.001). Sex and age had no influence on results. Graft survival was 86%at 1 year, 69% at 3 years, 61% at 5 years and 27% at 10 years. The gravest results were for corneal scar & chemical burn. Discussion: Despite the presence of risk factors, penetrating keratoplasty had good results and increased visual acuity. Graft survival was in an acceptable range. Corneal graft survival has increased with using new surgical techniques & supportive measures.    

Purpose: To compare the effect of Dalteparin (Low molecular weight heparin) versus Aspirin on recent-onset central retinal vein occlusion (CRVO). Patients & Methods: A randomized controlled clinical trial was conducted on patients with definite CRVO of less than 21 days duration. Patients in the Dalteparin group received subcutaneous Dalteparin (100 IU/kg bid for 10 days and 100 IU/kg daily for another 10 days); patients in the aspirin group were given Aspirin (100 mg daily). Results: Thirty-eight patients were enrolled, 18 in the Dalteparin group and 20 in the Aspirin group. The duration of follow-up was 6 months. Visual outcome was compared between two groups and no significant difference was found (P=0.74). All 3 patients who received Dalteparin within 7 days of onset of CRVO had dramatic improvement in visual acuity (mean change in logMAR=1.16). NVI occurred significantly less frequently in Dalteparin treated cases as compared with Aspirin (0.55% vs. 30%, P=0.006). Conclusion: Patients treated with Dalteparin within 21 days of onset of CRVO were less likely to develop NVI. There was no significant difference in visual acuity between the two groups at 6 months.  

Background & Purpose: Acute compressive injuries to the head and chest, visual loss with a special form of retinopathy called Purtscher Retinopathy may be followed by this retinopathy is characterized by cotton-wool spots, hemorrhages and retinal edema around the optic disc in one or both eyes. A case of unilateral Purtscher-Like Retinopathy is introduced after blunt trauma to one eye without compression. Patients & Findings: A 16-year-old boy came with history of blunt trauma to his right eye and decreased vision since 2 days prior to presentation. Visual acuity was counting fingers at 1 m in the right eye and 10/10 in the left. Except for chemosis and subjconjunctival hemorrhage no other finding was seen on slit lamp biomicroscopy. Conclusion: According to clinical manifestations, changes like Purtscher Retinopathy seems to occur not only after compressive head and chest injuries, but also following direct injuries to the eye.  

Synergistic divergence is a congenital syndrome of monocular adduction deficit with simultaneous abduction of both eyes on attempted gaze in the field of paretic medial rectus muscles. EMG data showed that it is a neural miswiring disorder related to Duane syndrome. We presented two brothers with typical bilateral adduction palsy and simultaneous divergence. One of them underwent maximal bilateral lateral rectus recession with marked improvement.  

Purpose: To report a case of steroid induced ocular hypertension that caused keratitis and transient myopia after laser in situ keratomileusis (LASIK). Methods: Uncomplicated bilateral LASIK was performed in a healthy 29 year old woman with myopic astigmatism. Her preoperative refractive error was -11.50 -1.25×45° and - 5.25 - 2.5×18° in the right and left eye respectively. The patient had no history of ocular disease. After the procedure, she used topical steroids frequently for 2 weeks when she reported worsening of visual acuity specially in the right eye. Her UCVA was 1/10 in the right eye and 8/10 in the left. IOP by applanation tonometry was 37 mmHg in the right eye and 27 mmHg in the left. Slit lamp examination revealed corneal haze at the interface. Retinoscopy was -7.50 - 2.25×10° in the right eye and -0.50 - 2.00×15° in the left. Results: The topical steroid was discontinued. The patient was started on combined topical timolol and systemic Acetazolamide to lower IOP. After 2 weeks corneal haze disappeared. Retinoscopy showed +0.50-1.00×178° and +1.00-1.25× 119° in the right and left eye respectively. IOP measured by applanation tonometry was 15mmHg in both eye, UCVA was 9/10 in both eye. Conclusion: Pressure induced stromal keratitis (PISK) has not been well recognized. Early detection of this complication of LASIK is very important because the condition may be misdiagnosed as DLK but unlike DLK it would be caused or worsened by frequent topical steroids. Treatment consists of normalizing IOP and discontinuation of topical steroid. Elevated IOP after LASIK may be associated with myopia, prompt diagnosis and treatment would prevent glaucomatous optic neuropathy.  

Background: Deep lamellar keratoplasty (DLKP) is believed to be an effective treatment for eyes in which endothelial cell function is preserved. Patients & Methods: In a prospective, uncontrolled pilot study, Melles' technique was performed on 13 eyes. The main indications were keratoconus with contact lens intolerance and poor visual acuity. Results: Uncorrected visual acuity was 2%0or better in 76.9% of patients and the best spectacle corrected visual acuity was 2%0 or better in 92.3% patients; 60% achieved 20/20 vision. Mean refractive astigmatism was 3.01D and mean spherical equivalent was -1.75D. Intraoperative perforation of Descemet's membrane (DM) did not occur in our patients. There was no interface opacity that compromised visual acuity. Conclusion: DLKP is a safe and effective procedure, especially in bilateral cases, because it avoids endothelial rejection. However, it is technically difficult. Visual results were good and acceptable in our patients with no significant complications.    

Purpose: Defining indications, surgical success rates and visual results of pediatric corneal transplantation. Materials & Methods: In a retrospective study, all records of pediatric (age less than 14 years) corneal transplantation from 1365 to 1373 with a minimum follow-up of six months were reviewed. The corneal opacities were categorized into 3 groups: congenital, acquired non-traumatic and acquired traumatic. The patients were regularly visited. All patients were recalled and completely examined in 1374. Findings: One hundred nineteen grafts in 104 eyes of 81 patients were reviewed. Using Cox regression model, some variables such as age (less than 3, 3 to 7, greater than 7) (P=0.01), associated surgical procedures (P=0.009), regraft (P=0.016), diagnostic categories (congenital, acquired nontraumatic, acquired traumatic) (P=0.001), timing of suture removal (less or more than 3 months) (P=0.016) were significantly related with graft survival. For patients whose visual acuities could be measured with Snellen chart (57 pts), using Wilcoxon test, visual acuity improved (P<0.0001). For patients with a minimum follow-up of one year (86.5%), variables such as age (P=0.001), associated surgery (P=0.095), regraft (P=0.002), diagnostic categories (P<0.001), number of rejections (P=0.13), were significantly related with graft clarity after one year. Conclusion: With appropriate patient selection and regular follow-up for pediatric corneal transplantation, visual acuity improves and graft survival increases.

Aim: To evaluate safety and efficacy of surgical induction of chorioretinal venous anastomosis in the management of ischemic central retinal vein occlusion (CRVO). Materials & Methods: In a comparative clinical trial, 28 patients of ischemic CRVO were included, of whom 18 who declined surgery were considered as controls. The ten surgical cases underwent standard vitrectomy with incisions into the choroids adjacent to the partially cut major retinal veins. Mersilene suture insertion was done to induce chorioretinal venous shunt. Mild endolaser was applied. Patients were followed for 6 to 18 (mean: 10) months. Results: Clinical success in shunt development was 90%. Surgical cases had a significantly better VA improvement in comparison to controls (mean difference: 1.5 Log MAR, P: 0.001) with 80% of them showing improvement (in comparison to 28% of the controls, P: 0.016). Neovascularization developed in 39% of the control group in comparison to 0% of the surgical cases (P: 0.03). In multivariate analysis, surgery remained to be the sole significant predictor of the visual improvement. We had 3 reoperations for vitreous cavity hemorrhage, cataract, and retinal detachment.Conclusion: Surgical induction of chorioretinal venous anastomosis may result in VA improvement and prevent neovascularization in ischemic CRVO. Randomized studies are needed to strictly compare the current study modality with the natural course of CRVO and the emerging procedures like optic neurotomy in the management of ischemic CRVO.