BINA
Year:2003 | Volume:9 | Issue:1 (33)|Papers Count:14

Purpose: To determine the prevalence of glaucoma in a population-based sample of urban citizens of Tehran older than 40 years in 2002. Methods: The Ophthalmic Research Center of Shaheed Beheshti University of Medical Sciences performed this cross-sectional survey with the collaboration of Shaheed Behesthti, Tehran, and Iran  Universities of Medical Sciences, and the RP Center. Through stratified clustered random-sampling, 4418 eligible individuals were invited for an ophthalmologic examination. After obtaining informed consent and performing a medical history interview, all participants were examined according to standard protocols including refraction, visual acuity testing, slit-lamp biomicroscopy of the anterior segment, tonometry, funduscopy, and gonioscopy. Suspects according to history and examination underwent a threshold visual field test. Glaucoma was diagnosed according to presence of at least two of following findings: glaucomatous visual field defects, abnormal IOP (IOP > 22 mmHg or IOP asymmetry>6 mmHg), or glaucomatous optic disc abnormalities. Results: From 4418 invited subjects, 2184 participated in the survey (50% participation rate). Twenty-four of them were excluded due to incomplete information. The remaining 2160 subjects included 814 males (38%) and 1346 females (62%) with a mean age of 55.1±10.2 years (40-96 years). The overall prevalence of glaucoma was 1.44% (95%CI; 0.94-1.94) including POAG (0.46%; 0.17-0.75), PACG (0.33%; 0.08-0.56), NTG (0.28%; 0.06-0.5), capsular glaucoma (0.23%; 0.03-0.43), and other types of glaucoma (0.14%; 0-0.3). The prevalence of glaucoma among males (2.3%; 1.3-3.3) was 2.3 times that of females (0.97%; 0.45-1.5). The prevalence of glaucoma among adults older than 80 were 4.9% while among the 40-49 years age group was 0.55%. The glaucoma suspect rate was 2.2% (1.6-2.8) including ocular hypertension (1.1%; 0.7-1.5) and glaucomatous disc abnormality (1.1%; 0.7-1.5). There were glaucomatous abnormalities on ophthalmologic examinations in 90.3%, and glaucomatous visual field defects in 83.9% of glaucomatous individuals. More than 10% (223 cases) of the participants needed visual field testing, in which 15.2% had glaucomatous defects and 11.7% had glaucoma. More than 80% of the 31 persons with glaucoma were not aware of their problem before the study. Conclusion: The prevalence of glaucoma in the urban population of Tehran aged more than 40 is significant. The majority of cases are not aware of their condition and the participation rate is low. We suggest this protocol and such a survey at national scale or at least in some other area of Iran.  

Purpose: To compare the visual and anatomical outcomes and complications of primary vitrectomy versus scleral buckling in the management of retinal detachment in patients with history of cataract extraction. Methods: In this multicenter randomized controlled trial, all patients with retinal detachment after cataract surgery were enrolled and randomly assigned to two treatment groups: conventional scleral buckling and standard 3-port pars plana deep vitrectomy. They had follow up visits at 1, 2, 4, and 6 months postoperatively and visual acuity, anatomical status of the retina, and postoperative complications were evaluated and compared. Results: Of 225 eligible eyes, 126 underwent scleral buckling and 99 had deep vitrectomy. Statistically significant different characteristics between the 2 groups included: age, preoperative visual acuity, family history of retinal detachment, vitreous incarceration in cataract wound, history of secondary IOL implantation, history of retinal detachment in the sound eye, and extent of retinal detachment. Time interval between initiation of RD symptoms to RD surgery in the buckle group and vitrectomy group were 20.8 and 22.2 days, respectively. Retinal break detection during surgery in the buckle group and vitrectomy group were 27.1% and 33.5%, respectively. BCVA (log MAR) 6 months after operation in the buckle group and vitrectomy group were 0.96±0.68 and 0.96±0.62, respectively. Anatomical success rate at 6 months postoperatively in eyes with vitreous incarceration in cataract wound was 58.3% and 68.4% in the buckle group and vitrectomy group, respectively and in eyes without that was 78% in buckle group and 74.5% in vitrectomy group, which did not have any statistically significant difference. Six months postoperatively, retinal redetachment rate in the buckle group was 32% and in vitrectomy group was 37.2%. CME rate in buckle group was 6.6% and in vitrectomy group was 9.1%. Macular pucker in buckle group and vitrectomy group were 22% and 22.7%, respectively. IOP>20 mmHg in buckle group was 6.4% and in vitrectomy group was 5.7%. None of the above mentioned characteristics had statistically significant difference. Extraocular muscle dysfunction was the only complication that was significantly different between the 2 groups; 4.1% in buckle group and zero in vitrectomy group. Conclusion: Primary vitrectomy does not seem to be a more reasonable option than scleral buckling in the management of eyes with history of cataract surgery. Therefore selection of these surgical options depends on judgment and experience of the surgeon, feasible facilities, and patient’s situation.    

Purpose: To evaluate the role of transvitreal optic neurotomy in the treatment of nonarteritic anterior ischemic optic neuropathy. Methods: Seven eyes of seven selected patients with severe visual loss (<20/800) from nonarteritic anterior ischemic optic neuropathy underwent transvitreal nasal radial optic neurotomy. The study was not masked and not randomized. Visual acuity and visual fields, when possible, were measured and fluorescein angiography was performed both preoperatively and postoperatively. Results: Four male and three female patients had mean age of 52.4 years; five had bilateral disease. Mean follow-up was 13±7 weeks. Mean preoperative visual acuity was 20/2400; mean postoperative visual acuity reached 20/250, with an average of 10 lines of improvement. Six of seven patients showed visual improvement. One patient had peripapillary choroidal neovascularization. In two patients with sufficient visual acuity, preoperative visual fields could be obtained; these patients showed significant improvement on postoperative perimetry. Five patients had some loss of vision which made it impossible to obtain preoperative visual fields. Conclusion: Relaxation of the scleral ring in the prelaminar and laminar regions of the optic nerve head reduces constriction and may prevent necrosis of salvageable but underperfused nerve fibers. Despite improvement of visual acuity in our patients, transvitreal optic neurotomy should be considered experimental. More definitive statement requires a randomized clinical trial.  

Purpose: To identify the clinical features in eyes with non-metallic and non-magnetic metallic intraocular foreign bodies (IOFBs) and evaluate the results of surgical management in such patients referred to Labbafinejad Medical Center from 1987 to 2002. Methods: We reviewed the hospital records of a consecutive series of patients who had undergone vitrectomy due to IOFB extraction. Results: Thirty two eyes of twenty eight patients underwent vitrectomy and IOFB extraction. All IOFBs were removed with intraocular forceps, either through pars plana vitrectomy in 30 eyes (93.9%) or through a limbal groove in 2 eyes (6.1%). Average follow-up period was 7.5 months. The IOFBs were non-metallic in 22 eyes (68.75%) including stone in 9 eyes (40.90%), glass in 7 eyes (31.81%), wood in 2 eyes (9.0.9%), and undetermined in 4 eyes (18.18%). Non-magnetic IOFBs were encountered non-magnetic metallic in 10 eyes (31.25%) including copper in 7 eyes (70%), lead in 2 eyes (20%), and aluminum in 1 eye (10%). Of seven eyes with retained copper foreign bodies, 6 (85.7%) had signs of ocular chalcosis. Final visual acuity was 20/40 in 10 eyes (31.3%) and 5/200- 20/50 in 10 eyes (31.3%). In 7 eyes (21.7%), a retinal break was seen posterior to the sclerotomy at the final follow up examination. Preoperative retinal detachment was seen in 4 eyes (12.5%) and postoperative retinal detachment was observed in 2 cases. There was no significant relationship between final visual acuity of 20/200 or better and the type or size of non-metallic and non-magnetic metallic IOFBs. Conclusion: Performance of a meticulous vitrectomy is mandatory and an attempt should be made to minimize the rate of iatrogenic peripheral retinal breaks. The results of vitreous surgery for IOFB extraction are remarkably good.    

Purpose: To determine the survival time and risk factors for bilateral corneal graft rejection for keratoconus. Methods: Records of 119 patients who underwent bilateral corneal graft due to keratoconus between 1981-2002 were reviewed. For bilateral grafts, many recipient-related and environmental factors are common for both grafts, so we expect survival times for each subject’s graft to be correlated. For considering correlation, Cox frailty model was used for analysis and survival time was calculated by Kaplan-Meier survival curve. Results: We studied 119 patients (238 eyes), including 72 men (60.5%) and 47 women (39.5). Mean age at first transplantation was 25.5 years and at the second was 28.8 years. The period between the first and second graft was from 3.8 to 204 months with a mean of 44.6 months. During the study period, there were 54 rejections (22.7%). The survival time (time lapsed between surgery and rejection) ranged from 1.1 months to 95 months with a mean of 12.5 months and median of 6.9 months. There were 4.2% vernal keratoconjunctivitis (VKC) and 4.6% corneal vascularization. The recipient age at surgery, VKC, and corneal vascularization were significant rejection risk factors. But sex, donor size, recipient size, freshness of donor cornea, and regraft were not significant risk factors. There was no significant difference between the first and second survival times of corneal graft, but a shorter interval between two grafts resulted in increase of rejection risk for the second one. R square was 33% by fitting the Cox frailty model and 7.5% by fitting the Cox model. Conclusion: Increasing the time between two transplantations improves the survival for the second graft. The Cox frailty model considers correlation between the survival times of bilateral corneal grafts, obtains more correct parameter estimates and improves the model to fit the data and is preferred for analysing such data.  

Purpose: To study the effect of prophylactic application of mitomycin-C on regression and corneal haze after photorefractive keratectomy (PRK) for high myopia. Methods: Fifty-four eyes of 28 high myopic patients were enrolled in this prospective study. All eyes underwent PRK followed by 0.02% mitomycin-C application for two minutes, washed with 15 to 20 ml of normal saline afterwards. All eyes were examined thoroughly on the first 7 days and one month after surgery, 48 eyes (88.9%) were evaluated at 3 and 6 months postoperatively. Hanna grading (in the scale of 0 to 4+) was used for assessment of corneal haze. Results: Mean spherical equivalent refraction (SE) was –7.08±1.11 diopters (D), preoperatively. Six months after surgery, 37 eyes (77.1%) achieved uncorrected visual acuity (UCVA) of 20/20 or better and all eyes had an UCVA of 20/40 or better. At 6 months postoperatively, 45 (93.7%) of eyes had SE within ± 1.00D of emmetropia. One month postoperatively, 2 eyes (3.7%) had grade 0.5+ of haze, while at 3 and 6 months after surgery no visited eye had haze at all. There was no decrease in bestcorrected visual acuity after 6 months. In spatial frequencies of 6 and 12 cycle per degree contrast sensitivity decreased immediately after PRK and increased 1.5 lines by the 6th postoperative month compared to preoperative data. Conclusions: Mitomycin-C can prevent corneal haze in treating high myopia with PRK. PRK+ mitomycin-C can be considered as an alternative method for treatment of myopic patients in whom corneal thickness is inadequate for laser in situ keratomileusis (LASIK). However, the results should be confirmed in longer follow-ups.  

Purpose: To report the familial occurrence of congenital superior oblique palsy. Methods: Eight patients from 3 families (A, B, C) with congenital superior oblique palsy were studied. One patient of each family came to the clinic due to ocular deviation and head tilt. Considering the history of similar disease in the family, all available family members had thorough eye examinations. Congenital superior oblique palsy was diagnosed according to “alternate prism cover” and “Bielschowsky head tilt” test results and presence of symptoms since childhood and no incidence of blows to the head. Results: In family “A”, the father and his two children had congenital superior oblique palsy on the left side. One of the father’s sisters also had a history of tilting her head to the right, but was not available for examination. In family “B”, three patients of 2 consecutive generations suffered from unilateral congenital superior oblique palsy. The grandfather and another man from this family also had a history of tilting the head, but were not available for examination. In family “C”, the mother and her daughter had congenital superior oblique palsy on the left side. Four of these patients were operated on by the authors. None of them showed signs of marked laxity or absence of superior oblique tendon. In families “A” and “B”, the transmission of the disease by autosomal dominant was seen. Conclusions: It is necessary to consider genetic transfer in any patient suffering from congenital superior oblique palsy and therefore family members need to be examined.  

Purpose: To determine vision and ocular problems in public vehicle drivers in Kerman province, Iran. Methods: In this cross-sectional study, 1500 public vehicle drivers in goods and passenger transportation department were evaluated. The cases were randomly selected by transportation organization and referred for ocular examination. They were examined by an ophthalmologist. All public vehicle drivers were included. Visual acuity ≥8/10 was considered sufficient.Results: Mean age of drivers was 38±10.5 years. With increasing age, vision worsened and the worst condition was in drivers 55 years or older. Spectacles were used in 14.2% and 25.1% needed spectacles. Visual acuity was less than 8/10 in 13% of the right eyes and 13.2% of the left eyes. After correction of refractive errors to obtain best corrected vision these figures reduced to 3.9% and 3.7%, respectively (P< 0.0001). Among eyes with visual acuity less than 10/10, mean visual acuity (Log MAR) was 0.47 in right eyes and 0.4 in left eyes before correction. The mean reached 0.16 in right eyes and 0.14 in left eyes after correction of refractive errors (P=0.0002). Vision was insufficient for driving public vehicles in 9.1% of drivers and reached 1.9% after correction of refractive errors (P<0.0001). In 70.3% of cases, the main cause of visual deficits was refractive errors. The subsequent causes were macular diseases, amblyopia, cataract, corneal diseases, and retinal diseases. Conclusion: Many drivers have insufficient vision for driving. The most prevalent cause of visual deficits among drivers is refractive errors. Older drivers have worse condition of vision. Repeated examinations by ophthalmologists are recommended at shorter intervals in order to change  driving license especially for older drivers and drivers with visual problems.  

Purpose: To evaluate the outcomes of distance telescope in persons with low vision. Method: Sixteen patients with low vision were supplied with distance telescopes and were followed for 8 months. The type of telescope was Galilean system (Eschenbach model) with 3X magnification. The patients received adequate training for use of the devices. We designed a low vision questionnaire (LVQ) for evaluating the usefulness of telescopes. This questionnaire addressed process measures (frequency of use, length of continuous use, ease of use, rated importance, satisfaction,..). We also used magnification efficiency factor (MEF) for evaluating visual acuity. The MEF measures the effectiveness of a telescope in improving visual acuity. The ideal MEF is equal to one, higher and lower values indicate worse results. Result: Patients (13 male and 3 female) were between 15-40 (62.5%) and 41-80 (37.5%) years of age. The main ocular disorders were maculopathy (31.25%), AMD (25 %), diabetic retinopathy (12.5%), and others (25%). The patients in this study had no additional impairments. These patients were supplied with binocular (68.75%) and monocular (31.25%) telescopes. This study showed MEF>1 in 75% and MEF<1 in 25% of the cases, which shows that the telescopes were efficient. Patient satisfaction was expressed as high (37.5%), intermediate (50%), and low (12.5%). Ease of use was reported as difficulty at all (37.5%), a little bit of difficulty (50%), much difficulty (6.25%), and inability to use (6.25%). Frequency of use was several times each day (56.25%), weekly (37.5%), and never (6.25%). Length of continuous use included 15 minutes or longer (31.25%), 5-15 minutes (56.25%), and less than 5 minutes (12.5%). Rated importance consisted of extremely important (25%), quite a bit important (56.25%), slightly important (12.5%), and not at all important (6.25%). Conclusion: Telescope is an effective means of improving far acuity in people with impaired vision. Low vision patients usually need low power magnification for far viewing for their task and activities. The proposed 3X telescope could be appropriate for them. This telescope offers good image quality and good visual field.    

Although microvascular dysfunction is a major component in diabetic retinopathy, recent observations have proved that alteration of macroglial, neuronal, and microglial cells in diabetes mellitus may have a major impact on breakdown of blood-retinal barrier that can lead to loss of vision. In addition, the effect of systemic pathophysiologic influences including metabolic control, blood pressure, and fluid volume in the formation of diabetic macular edema are well known. Furthermore, the role of inflammatory mechanisms in the retina in diabetes has been proposed. Scatter and focal photocoagulation have been shown to be effective in reducing visual loss but may not always prevent it. Medical treatment has led to another  revolution in the treatment of diabetic retinopathy. In very near future, there will be significant advances in the pharmacologic treatment of diabetic retinopathy. Treatment with antioxidants, agents inhibiting  hyperglycemia-induced protein kinase activity and other agents will likely prevent the development and progression of diabetic retinopathy and macular edema. Availability of safe long-acting intravitreal steroids like fluocinolone acetonide and also use of vitrectomy for eyes with a tight posterior hyaloid face may further help reducing diabetic macular edema and preserve vision in patients with diabetic retinopathy.    

Purpose: To report a case of cerebrospinal fluid (CSF) leakage during dacryocystorhinostomy (DCR) in a patient with Mobius syndrome and history of meningoencephalocele. Patient and findings: This 12-year-old girl had undergone an operation for meningoencephalocele at infancy by a neurosurgeon and was referred because of nasolacrimal drainage obstruction. She underwent DCR surgery at age 10 and 12 years. CSF leakage was detected during surgery. The authors describe the course and management of this patient. Conclusion: In patients with any history of surgery or trauma in the periorbital region, the ophthalmologist should be ready to manage CSF leakage during DCR.  

Purpose: To report an unusual manifestation of retinoblastoma in a 12-year-old boy. Patient and findings: A 12-year-old boy was referred to an ophthalmologist with redness and decreased visual acuity in his right eye. On examination, visual acuity was 2/10 and 2+ cell in the anterior chamber with 3+ cell in the vitreous were detected. Intraocular pressure (IOP) was within normal limits and the retina seemed normal. Topical, oral, and subtenon steroid therapy was started. After 10 weeks, vitreous opacity increased, lens opacity (posterior subcapsular cataract) developed, and IOP was elevated in spite of antiglaucoma medications. Deep vitrectomy with lensectomy was performed. No malignant cell was seen in vitreous aspirate. After operation, vitreous inflammation increased, IOP rised, and visual acuity decreased to light perception. Six months later, the patient referred with no light perception, proptosis, corneal ulcer, and limitation of eye movement, and enucleation was done. Pathological examination of specimens showed presence of a small cell tumor with rosette formation in favor of retinoblastoma with involvement of the optic nerve at the cut end. The patient received one course of chemotherapy. Conclusion: Diffuse infiltrating retinoblastoma is a rare type of tumor which usually presents late and should be considered in any atypical uveitis in children. If vitrectomy is performed before diagnosis, radiotherapy with or without adjunctive chemotherapy is recommended after enucleation to prevent metastasis.    

Purpose: To report a case of major β-Thalassemia with angioid streaks complicated by CNV. Patient and finding: A 41-year-old woman presented with decreased visual acuity in the right eye 2 months following a mild head trauma. The patient was a known case of major β-thalassemia and clinical examination and F/A disclosed angioid streaks complicated by subfoveal CNV in her right eye. Conclusion: β-thalassemia patients have been shown to present a high prevalence of angioid streaks, and ocular examination must be one of the major parts of the evaluation of these patients. Arterial calcifications are common in β-thalassemia patients and consequently vascular events complicating this anemia should be expected and evaluated by physicians.  

Purpose: To report a case of peripheral retinal neovascularization in a patient with hyperprolactinemia and neurological manifestations. Patients and findings: A 35-year-old woman presented with low vision. On examination, vitreous hemorrhage in the left eye and peripheral retinal neovascularization in both eyes were detected. She had history of vestibuloauditory and neurological problems. Systemic evaluations were all negative except for high serum prolactin, for which she had been treated for many years. Conclusion: Although this case confirms the association of peripheral retinal neovascularization with vestibuloauditory and neurological manifestation, but more importantly, for the first time suggests the possible relationship of this type of neovascularization with hyperprolactinemia.