مجله چشم پزشکی بینا
سال یازدهم شماره 2 (زمستان 1384)

To determine the prevalence and causes of blindness and low vision in Tehran province in 2005. A population-based cross-sectional study was carried out involving all habitants living in Tehran province in 2005. The study design was according to the World Health Organization recommendation methods and also a pilot study preformed among rural and urban areas of Karaj. It was a multi-stage cluster sampling method, and sample size was calculated due to the distribution of the total population of Tehran derived from the national census and estimated rates of blindness. Information was collected using a questionnaire, including the general information and results of the optometrists’ and ophthalmologists’ diagnoses. Initial information gathering was performed at the rural and urban health centres. The categorization of blindness and low vision was according to the International Classification of Diseases version 10 (ICD 10). Overall, 11975 subjects with the average age of 27.8 years participated (response rate 90.4%). The prevalence rate of bilateral blindness was 1.09% (95%CI= 0.90-1.61). There was a positive significant trend with age (P<0.001) and no significant difference by sex and residential area. The prevalence rate of low vision was 4.04% (95% CI= 3.69-4.39). The prevalence rate of bilateral low vision was increasing by age (P<0.001) and was higher among females (OR=1.42, 95%CI= 1.16-1.74). However, there was no significant difference by residential area. The leading causes of visual impairment were from cataract (33.9%), amblyopia due to refractive error and so on (22.7%), and vitreo-retinal diseases (12.3%). It is estimated that there is about 124165 bilateral blinds and 463431 people with low vision in Tehran province. Compared to other similar countries, the prevalence rates of blindness and low vision is in average in this community. This study recommends similar studies over the country and reinforces the needs of the expansion of health programs on prevention and control of visual impairments and their causes. Furthermore, employing of these findings is necessary for appropriate design of Vision 2020 program in Iran.

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 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 as a treatment strategy for refractory diabetic macular edema.

To evaluate the effect of oral prednisolone on visual outcome and complications of scleral buckling (SB) in patients with rhegmatogenous retinal detachment (RRD). In a randomized double-blind placebo-controlled trial, patients with acute RRD who underwent SB were randomly divided into two groups. Oral prednisolone was administered for the treatment group and placebo for the control group. The two groups were compared for visual acuity (VA), retinal detachment (RD), cystoid macular edema (CME), and proliferative vitreoretinopathy (PVR). The trial was performed on 25 patients in the treatment group and 27 patients in the placebo group. Mean preoperative VA (LogMAR) was 1.460.81 overall, including 0.850.62 in the treatment group 0.260.61 in the placebo group (P=0.39). Extent of RD, hypotony and RD location were equal in both groups. Choroidal detachment was seen in 3 eyes in the treatment group and 4 eyes in the placebo group. (P=0.45) Significant PVR was seen in one eye in the treatment group and 3 eyes in the placebo group. (P=0.33) CME was seen in 3 eyes in the treatment group and 5 eyes in the placebo group. (P=0.39) Postoperative oral prednisolone does not seem to affect visual outcomes and complications of scleral buckling in phakic patients.

To assess the efficacy of intrastromal rings for management of keratoconus (KCN). This prospective non comparative case series includes 14 eyes of 11 contact lens intolerant patients with KCN. Corneal thickness of at least 450  at the site of segment insertion was required for enrollment. Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), refraction, pachymetry, endothelial cell count and anterior chamber depth were measured pre and post operatively. Fourteen eyes of 11 patients (7 male and 4 female) with mean age of 32 years (21-40) were operated and followed 3 to 8 months (mean 6.1 months). UCVA increased from 0.76  0.40 LogMAR preoperatively to 0.45  0.30 post operatively and BCVA from 0.29  0.10 to 0.23  0.20 (P= 0.001). Mean preoperative spherical equivalent was -4.19  1.70 D which decreased to -2.102.30 D post-operatively. Mean pre and post operative keratometry was 48.64  3.1 and 45.21 3.0, respectively. Major complications included segment displacement in 3 eyes (21%) with severe vascularization in 2. Lipoid deposition occurred in the tunnel in 4 eyes (29%) and one broken segment was noticed 3 days after the operation. INTACS are effective for the treatment of mild to moderate KCN, however it can not be an alternative to deep lamellar keratoplasty or penetrating keratoplasty.

To report the prevalence of fungal keratitis as a cause of corneal ulcer in patients refered to Boo-Ali Sina Hospital in Sari and identify the predisposing factors. This prospective study was conducted on patients who presented with corneal ulcers to the ophthalmology ward at Boo-Ali Sina Hospital in Sari, 2004-2005. Using standard techniques, a corneal scraping was performed by an ophthalmologist. Material obtained from the scraping was smeared onto two slides which were stained by Gram stain for bacterial keratitis and 10% potassium hydroxide (KOH) with or without calcofluor white (KOH+CFW) stain for fungal keratitis. Specimens were inoculated directly onto blood agar, Sabouraud's dextrose agar, and potato dextrose agar in C-shaped streaks. A total of 22 patients were examined including 10 female (45.5%) and 12 male (54.5%) subjects. Average age was 61.5 ± 17.7 years (range: 15-83 years). Branching septate hyphae were identified in 7 patients (31.8%) including five male and 2 female subjects; two of these specimens were positive for Aspergillus fumigatus and Fusarium Spp on culture. Average age of patients with fungal keratitis was 60.4 ±12.1 years (range: 39 to 73 years). Three patients with fungal keratitis were farmers. The mean interval between onset of symptoms and diagnosis was 26.4 days with a range of 1 to 93 days. Trauma with plant debris and straws were noted in two patients with fungal keratitis. Five cases of fungal keratits had received topical antibiotics. Analyses using KOH + CFW as the golden standard revealed individual sensitivities for detection of fungi to be 71.4% and 42.9% for KOH and Gram stain, respectively. Infections of the cornea due to filamentous fungi are frequent cause of corneal damage and should always be kept in mind. Direct microscopy is an essential tool in the diagnosis of fungal keratitis. Mounts with KOH+CFW or KOH alone can be relied upon as the single most important method for rapid diagnosis of fungal corneal ulcer.

To evaluate topographic corneal changes in relatives of patients with keratoconus (KCN). This study was performed on 300 eyes of 150 relatives of 45 KCN patients. Complete slit lamp examination, refraction, and corneal topography was performed on all eyes. The topographic indices for diagnosis of keratoconus was based on Rabinowitz criteria. The study included 84 (56%) female and 66 (44%) male subjects. Mean age was 32.4 ± 15 years (range, 16-83). KCN was detected in 14% of the subjects and 7.3% were diagnosed as KCN suspect. The overall prevalence of astigmatism was 58% including in 42.1% in the KCN group, 66.7% in the KCN suspect group, and 49.6% in the normal group. Thirty one eyes had high regular astigmatism (> 1.5 diopters) including, 17 (54.8%) in the KCN group and 14 (45.2%) in the normal group. Oblique astigmatism was seen in 33 eyes (11%) including 34.2% in the KCN group, 47.6% in the KCN suspect group, and 4.6% in the normal group. Relatives of KCN patients have a high prevalence of undiagnosed KCN. Corneal topography is very important for the diagnosis of KCN and KCN suspects in family members of KCN patiens. Therefore, keratorefractive surgery should be considered cautiously in these individuals.

To evaluate the effect of amniotic membrane transplantation in trabeculectomy. The study was conducted on 25 eyes of 25 patients with advanced and medically uncontrolled glaucoma. All patients underwent trabeculectomy with a fornix based conjunctival flap, amniotic membrane was then placed under the scleral flap and fixed using 10-0 nylon suture. Amniotic membrane was retrieved from healthy pregnant women during elective cesarian section. Preoperative intraocular pressure was 33.5±5.0 mmHg (26-50 mmHg) with full medication, which decreased to 12.4±1.8 mmHg (9-15 mmHg) post-operatively (P= 0.0001). Intraocular pressure was less than 21 mmHg after surgery in all eyes, with (8%) or without (92%) use of antiglaucoma medications after six months. The use of amniotic membrane in trabeculectomy can increase the chance of success in terms of maintenance of a functional bleb and prevention of failure. This method may be superior to antimetabolites due to lack of complications.

To determine any possible correlation between delayed ocular complications with late-onset complications of mustard gas poisoning in other systems including skin, respiratory tract, and immunohematologic system. The study was conducted on 40 chemical war victims in Khorasan province, Iran. Ophthalmologic and dermatologic examinations and spirometry were performed for all patients. The severity of ocular, cutaneous, and respiratory complications were classified into four grades from mild to severe. Blood cell counts, flow-cytometric analyses, serum immunoglobulins and complement measurements were performed for all patients and for 35 healthy male controls. Hematological and immunological parameters were compared between the patients and the controls, using Mann-Whitney test. The correlation between these parameters and the severity of ocular complications in patients were determined, using Spearman's rank correlation test. Forty male patients (aged 43.8±9.8 years) with confirmed mustard gas poisoning 16 to 20 years after exposure were studied. Main ocular complications were found as vascular tortuosity (15%), limbal ischemia (12.5%), corneal opacity (10%), corneal vascularization (7.5%), and corneal epithelial defect (5%). The values for WBC, RBC, HCT, IgM, and C3, as well as for the percentage of monocytes and CD3+ lymphocytes were significantly higher (p<0.042) and the percentage of CD16+56+ cells was significantly lower in patients than controls (P=0.006). No significant correlation was found between the immunological parameters and the severity of ocular complications. The comparison of clinical complications in the skin, eyes, and respiratory system revealed a significant positive correlation between the respiratory and ocular complications (r=0.322, P=0.043). Although sulfur mustard is known to cause long lasting systemic toxicity such as hematological and immunological complications, its adverse effects on the skin, eyes and the respiratory system are mainly due to its local irritant effects and do not have any relationship with immunohematological complications

To compare the Tono-pen and Schiotz tonometers in measurement of intraocular pressure (IOP) in patients with primary congenital glaucoma.

This study was conducted on 38 eyes of 20 patients with primary congenital glaucoma. All measurements were performed under general anesthesia. One minute after receiving Halothane 3% IOP was determined by Tono-pen and then by Schiotz tonometers. Data were analyzed by regression analysis and Bland-Altman bias plot.

Mean age of patients was 19.4±14.5 months and 15 (75%) of them were male. Glaucoma was bilateral in 18 (90%) and unilateral in 2 (10%) subjects. Mean IOP measured by Tono-pen and Schiotz tonometers was 19.39±8.51 and 18.84±8.9 mmHg, respectively. These tonometers had good concordance in determination of IOP in primary congenital glaucoma according to the results of regression analysis and Bland-Altman bias plot.

Considering the sample size of this study, the Tono-pen and Schiotz tonometers are highly concordant regarding intraocular pressure measurement in children with primary congenital glaucoma.

To assess the histopathological and immunohistochemical features of orbital spindle cell tumors. A descriptive, retrospective study was performed on 63 pathology reports on all types of orbital spindle cell tumors at the pathology department of Farabi hospital between 1995 and 2005. Immunohistochemistry studies for different markers, such as smooth muscle actin, Desmin, S100 protein, CD31, Factor VIII, CD 68 and CD34, were carried out in cases with indeterminate origin on routine histopathologic study to achieve a definitive diagnosis. Our study included 63 cases with average age of 30 years including 62% female and 38% male subjects. The leading types of orbital spindle cell tumor in our study in order of frequency included: benign nerve sheath tumors (46.0), rhabdomyosarcoma (11.1%), hemangiopericytoma (7.9%), fibrous dysplasia (7.9%), ossifying fibroma (4.8%), fibrous histiocytoma (3.2%), and other types (19.1%). From 29 cases with benign nerve sheath tumor, 16 cases (25.4%) were neurofibroma and 13 cases (20.6%) were schwannoma. The orbital tumors were benign in 74.7% and malignant in 25.3%. The most common type of orbital spindle cell tumor in this study was benign nerve sheath tumor. Immunohistochemical studies for different markers are required for definitive diagnosis of cases with indeterminate origin on routine histopathological study.

To determine the correlation between hand dominancy and eye dominancy with visual acuity and refraction in subjects with refractive errors. This cross-sectional study includes 620 patients undergoing LASIK. Their refractive error (dry and cycloplegic), hand dominancy, eye dominancy (by hole-in-the-hand method) and visual acuity were determined. Exclusion criteria were monocularity, patient's inability to perform hole-in-the-hand test, and amblyopia. Overall, 585 patients met the inclusion criteria for this study. Age range was 21-43 years (mean= 33.7 years), 58% were female and 42% were male. The right hand was dominant in 90.9% and the right eye was dominant in 77.9% of the subjects. Right eye dominancy was observed in 79.1% of right handed individuals and in 66.1% of left handed patients. Cross eye-hand dominancy was observed in 38.3% and uncrossed eye-hand dominancy in 61.7%. Visual acuity was better in dominant eyes in 68.2% (P=0.03, t=0.89). The non dominant eyes had higher refractive errors than dominant eyes (P=0.01, t=0.88). In both groups of right handed and left handed individuals, the right eye was more often dominant and uncrossed dominancy was more prevalent than crossed dominancy. Better visual acuity or smaller refractive error may influence eye dominancy.

To determine the indications for penetrating keratoplasty (PK) in Iran over an 11-year period. All eye bank records of patients who underwent PK from 1994 to 2004 at ophthalmologic centers throughout Iran were reviewed. During this 11-year period, a total of 19,668 cases were operated. The most common indication for penetrating keratoplasty was keratoconus (34.5%), followed by corneal opacity and scar (18.7%), pseudophakic bullous keratopathy (9.2%), corneal dystrophies (6.5%), aphakic bullous keratopathy (6.1%), and regraft (5.3%). There was an increasing trend in rates of keratoconus and pseudophakic bullous keratopathy and a decreasing trend in aphakic bullous keratopathy during this period. (P<0.001) No significant change of trend was noted in the corneal opacity and scar, regraft, and corneal dystrophy groups. Keratoconus is the most common indication for penetrating keratoplasty in Iran.

To report two cases of secondary epithelial iris cyst (SEIC) with pus-like precepitates in the cyst. Patients and Two young men with history of penetrating trauma to the eye and primary repair developed secondary epithelial iris cyst several years later. Slit-lamp biomicroscopy revealed a large cyst originating from the site of the laceration. The cyst was filled with pus-like precipitates inferiorly and clear fluid superiorly. Contents of the cyst were aspirated and the cysts were treated successfully by chemical cautery with 98% ethanol irrigation. Aspirated fluid culture and smear was negative and cytology revealed lymphocysts and epithelial cells. Pus-like precipitate within iris cyst is a rare presentation which seems to be sterile. Treatment with intracystic ethanol irragation is successful in such cases.

To report multiple astrocytic hamartomas in a patient with tuberous sclerosis (TS).Patient and A 16-year-old girl with TS without any ocular complaint was referred for ophthalmologic examination. She had papular rash on her face and other skin lesions elsewhere in the body which were specific for TS. Multiple well-circumscribed elevated lesions characteristic of astrocytic hamartoma were seen in the retina of both eyes. Two larger nodular and calcified masses, one in inferotemporal retina of the left eye and another in superotemporal retina of the right eye were also detected. One of these lesions was located in far periphery. One of the retinal masses in our patient was located in the far periphery of the retina which is in contrast to previous reports that mention a maximum of 2 disc diameter distance from the optic disc for such lesions. Because of high probability of eye involvement, all cases of TS should undergo a thorough ocular examination.

To report a relatively rare case of familial exudative vitreoretinopathy (FEVR).Patient and A 13-year-old boy referred with decreased visual acuity of both eyes, specially right eye from 6 years ago. He had several ophthalmologist and optometrist visits and spectacle prescription without any improvement of vision. Best corrected visual acuity (BCVA) was 25 cm of count finger in right eye and 10/10 in left eye. Right eye had +2 APD without positive finding on slit-lamp examination. Blurred optic disk margin with large and diffuse exudate involing macular region and avascular zone, especially on temporal side with fibrovascular tissue between avascular zone were detected on funduscopy in the right eye. Following several laboratory examination, diagnosis of FEVR was determined and patient underwent full panretinal photocoagulation. Early detection of FEVR plays an important role on preventing the progression of the diseases and improving the vision of patient and his/her family.

To report a case of periocular dirofilariasis.Patient and A 27-year-old female referred with history of edema and redness in left eye for two days. On slit-lamp examination, a moving threadlike worm was seen in subconjunctival area. Two days later a live filaria worm measuring 12 cm in length was extracted from lower lid subcutaneous tissue. The worm was diagnosed dirofilaria immitis on microscopic examination. Dirofilaria immitis can cause periocular infection.