BINA
Year:2013 | Volume:18 | Issue:4 (73)|Papers Count:19

Purpose: To describe the prevalence and risk factors of diabetic retinopathy (DR) in adults aged 40-80 years in Yazd province in 2011.Methods: This is a population-based survey on 2,320 urban and rural residents of Yazd province. Random multi-stage cluster sampling was employed in the survey. Diagnosis of diabetes was made upon past medical history and drug history or insulin injection and in cases without history of diabetes upon two fasting blood sugar exceeding 126 mg/dl. A detailed interview, eye examination and stereoscopic fundus photography were conducted for each eligible participant. DR definition and grading were based on ETDRS definition and the International Clinical Diabetic Retinopathy Disease Severity Scale.Results: Out of the eligible individuals, 2,098 cases (90.1%) participated in the study. The standardized prevalence of diabetes was 24.5% (95% confidence interval, 22.5-26.8%), 29.6% (25-34.3) of diabetics were diagnosed with DR. The prevalence of mild, moderate and severe forms of nonproliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR) was 12.7% (95%CI, 9.5-15.8%), 11.8% (95%CI, 9-14.7%), 9.9% (95%CI, 6.6-13.3%), and 3.9% (2-5.8%), respectively. The prevalence of clinically significant macular edema (CSME) was 4.9% (2.7-7.2%) and vision-threatening diabetic retinopathy including severe NDPR, PDR and CSME was present in 11.1% (7.9-14.3%) of cases.Conclusion: This study showed that out of every four people above 40, one had diabetes and out of every three diabetic patients one had DR. The high prevalence rates of diabetes and DR indicate the need for adequate prevention and management strategies in the study population.

Purpose: To compare success rates of external dacryocystorhinostomy (DCR) with and without bicanalicular silicone intubation for management of primary acquired nasolacrimal duct obstruction.Methods: In a randomized clinical trial study, 52 patients with primary acquired nasolacrimal duct obstruction underwent external DCR. Patients were randomly enrolled into two groups. In the 1st group, external DCR was performed without intubation and in the 2nd one, monocanalicular intubation was used. All patients were followed for at least 3 months. Subjective and objective signs were evaluated by Munk score and irrigation & aspiration respectively. Demographic data such as age, gender, subjective and objective success were collected and analyzed.Results: Overall, 26 eyes were enrolled in each group. Mean age of patients was 44.5±18.5 years in the monocanalicular silicone intubation group and 48.3±21.2 years in the group without intubation, (P=0.502). Success in group one (without intubation) was achieved objectively in 24 of 26 eyes (92.3%) and subjectively in 25 of 26 eyes (96.1%) compared to 22 of 26 eyes (84.6%) and 24 of 26 eyes (92.3%) in the monocanalicular silicone intubation group (P=0.5). Mean follow-up was 7.2±2.5 in group one and 7±2.2 in group two (P=0.76).Conclusion: Although external dacryocystorhinostomy without intubation had marginally higher success rates, this difference is not statistically significant. It seems that surgeon’s experience and surgical techniques play the main role irrespective of performing intubation.

Purpose: To compare recurrence rates and complications of 2 surgical methods for primary pterygium excision: subconjunctival injection of mitomycin C (MMC) 1 month before bare scleral excision and conjunctival rotational flap with intraoperative MMC application.Methods: Eighty-two eyes of 82 patients participated in the study and were allocated randomly into two groups. Group A received subconjunctival injection of MMC 1 month before bare scleral excision, and group B underwent conjunctival rotational flap with intraoperative MMC application for 2 minutes. Exclusion criteria consisted of pregnancy and lactation, history of ocular surgery, glaucoma, herpetic keratitis, trachoma and any autoimmune disease. The main outcome measure was recurrence and complications rate in each group.Results: Mean age of the patients was 48.48±13.67 years and 51.1% of cases were female. Follow up visits were performed at 1, 3, 6, 9 and 12 months after the operation. Two cases of clinical recurrence occurred in group B (4.3%). However there was no statistically significant difference between groups in terms of recurrence rate (P=0.31).Conclusion: Subconjunctival injection of MMC 1 month before bare scleral excision is a quick, easy, and safe surgical procedure for pterygium excision and is at least as effective as conjunctival rotational flap with intraoperative MMC application.

Purpose: To evaluate tear film status and refractive conditions during and one month after treatment of acne vulgaris with isotretinoin (Accutane).Methods: This prospective study was performed on 26 eyes of 13 known cases of acne vulgaris. All cases were referred by a dermatologist and were candidates for low dose isotretinoin (0.5 mg/kg). Full anterior and posterior segment examination and objective and subjective refraction were conducted. Tear film function was assessed by the anesthetized Schirmer test, tear breakup time (TBUT) and tear osmolarity test before, during and after treatment with systemic isotretinoin. Collected data were analyzed using paired t-test.Results: No significant difference was observed in BCVA and refractive conditions in patients before, during, or after systemic isotretinoin prescription. Increased TBUT results were observed in 2 and 3 patients during and one month after use of the medication, respectively which was not significant. Anesthetized Schirmer test showed a significant decrease during treatment (P=0.01). However this trend did not remain significant after drug cessation (p=0.78). On the other hand, tear film osmolarity showed a significant increase during (303.91±15.71osm/L) (p<0.05) and even one month after drug discontinuation (312.75±28.39osm/L) (p=0.01).Conclusion: Although after 2 months of low dose isotretinoin consumption and one month after drug cessation significant alterations in basal tear secretion were not observed, this study showed that such can lead to therapy alterations in tear film osmolarity persisting for at least one month after drug cessation. Therefore both patients and practitioners should be aware of these changes is important before isotretinoin prescription.

Purpose: To compare visual and refractive outcomes as well as graft survival after penetrating keratoplasty (PK) in keratoconic patients with or without acute hydrops.Methods: In this comparative interventional case series, 14 eyes of 14 keratoconic patients with acute hydrops (group 1) and 37 eyes of 37 keratoconic patients with no history of acute hydrops (group 2) underwent PK. Visual acuity, refractive status, keratometry, intraoperative and postoperative complications, and rejectionfree graft survival were compared between the study groups.Results: Mean patient age was 27.6±11.7 years in group 1 and 30.5±10.1 years in group 2 (P=0.37). Time interval from the occurrence of acute hydrops to PK in group 1 was 32.0±29.0 days, ranging from 5 to 58 days. Mean follow-up period after keratoplasty was 30.5±15.5 months and 28.2±11.4 months in groups 1 and 2, respectively (P=0.9). Suture removal was initiated after 7.8±5.7 months in group 1 and after 11.6±7.4 months in group 2 (P=0.17) and was completed after 16.3±13.2 and 16.7±6.2 months in the same order (P=0.13). At final follow-up, mean BCVA was 0.23±0.10 and 0.15±0.10 logMAR (P=0.08), mean spherical equivalent refractive error was -3.57±1.73 and -2.32±2.31 D (P=0.25), and mean keratometric astigmatism was 3.55±1.54 and 4.36±1.78 D (P=0.26) in group 1 and 2, respectively. The two study groups were comparable in terms of rejection-free graft survival.Conclusion: PK can be performed successfully in keratoconus complicated by acute hydrops involving more than half corneal surface, which provides clinical outcomes and graft clarity comparable to those without hydrops.

Purpose: To determine changes in streoacuity in anisometropic myopic eyes after photorefractive keratectomy (PRK).Methods: This quasi-experimental clinical trial was performed in myopic patients with at least 1 D of in anisometropia spherical, astigmatic or spherical equivalent who underwent photorefractive keratectomy (PRK) using the Technolas 217 Z excimer laser machine. Changes in streoacuity were evaluated. TNO and butterfly stereoacuity tests before PRK and at 2 weeks, 1 month and 3 months after PRK.Results: Overall, 98 eyes of 49 patients (71.4% male and 28.6% female subjects) with mean age of 28±5.5 years and mean myopia of -3.32±1.74D and mean astigmatism of 1.3±1.3 D were enrolled in study. Preoperative mean stereoacuity values were 102±103.44 sec/arc and 56.8±41 sec/arc by TNO and butterfly stereoacuity tests which changed to 90±110.52 sec/arc (P=0.009), and 56.5±41.3 sec/arc (P=0.80) respectively 3 months after PRK. Total proportion of improvement in stereoacuity values was 10.2% and 6.12% by TNO and Butterfly Stereoacuity tests respectively.Conclusion: Stereoacuity improves after photorefractive keratectomy in anisometropic myopic patients. This improvement is more significant with TNO test than the Butterfly Stereoacuity test.

Purpose: To investigate the biomechanical features of transplanted corneas after penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), and Descemet stripping automated endothelial keratoplasty (DSAEK) and compare these measurements with those of a normal group.Methods: Forty-five eyes of 36 patients underwent PK, 23 eyes of 21 patients received DALK using Anwar’s big bubble technique, and 17 eyes of 17 patients had DSAEK. Thirty-three right eyes of 33 normal subjects served as controls. Corneal hysteresis (CH) and corneal resistance factor (CRF) were measured at least 3 months after complete suture removal using the Ocular Response Analyzer. These parameters were compared between the study groups using the one-way ANOVA test.Results: The mean age was 26.9±5.0 years in the control group, 28.8±4.2 years in the PK group, 27.2±6.5 years in the DALK group, and 62.5±1.8 in the DSAEK group (P<0.001). Central corneal thickness was 539.0±24.8, 567.5±38.8, 547.0±42.6, and 631.1±84.8 m, respectively (P<0.001). CH and CRF were significantly lower in the DSAEK group (7.79±2.0 and 7.88±1.74 mmHg, respectively) than in the PK (10.23±2.07 and 10.13±2.22 mmHg, respectively) and DALK (9.64±2.07 and 9.36±2.09 mmHg, respectively) groups. The two latter groups demonstrated results comparable to the normal subjects (9.84±1.59 and 9.89±1.73 mmHg, respectively).Conclusion: The graft biomechanics after DSAEK are lower than those after PK and DALK. Both PK and DALK can increase these metrics in keratoconic eyes to normal values. These differences should be considered when interpreting intraocular pressure or planning grafts refractive surgery after keratoplasty.

Purpose: To evaluate changes in anterior chamber (AC) parameters before and one month after Nd: YAG capsulotomy.Methods: A total of 30 eyes from 27 patients with posterior capsule opacification graded 2-4 with surgical history of uneventful phacoemulsification and acrylic foldable IOL implantation were included in this study. Before capsulotomy and one month later, anterior chamber depth, volume and angle were measured by Scheimpflug imaging.Results: All patients showed a significant increase in best corrected visual acuity. A significant anterior IOL shift and therefore myopic change was detected. Anterior chamber volume and angle showed an increasing trend which was not significant statistically. Anterior chamber depth showed a significant reduction one month after Nd: YAG capsulotomy (P=0.001).Conclusion: In our study we found a significant forward displacement of the one piece acrylic IOL one month after capsulotomy which led to a decrease in AC depth and myopic shift in patients. The post-focus mode of modern Nd: YAG lasers and its anteriorly propagated shock wave can be the cause of the IOL displacement. Although Nd: YAG capsulotomy is a safe treatment for PCO but anterior displacement of IOL can lead to a myopic change in refraction. Therefore glass prescription should be withheld until this change has stabilized.

Purpose: To determine agreement between peripapillary retinal nerve fiber layer (RNFL) thickness measurements by two different spectral domain optical coherence tomography (SD-OCT) machines.Methods: Both eyes of 89 subjects were evaluated using Cirrus OCT (Carl Zeiss Meditec, Inc. Dublin, CA, USA) and Topcon OCT (3D OCT 1000, Topcon Corporation, Tokyo, Japan). One eye was randomly selected in each subject and peripapillary RNFL thickness measurements were compared. Bland-Altman plots were used to assess the level of agreement.Results: Forty-four healthy subjects (mean age, 47±15 years) and 45 patients with glaucoma (mean age, 55±14 years) were selected. Average peripapillary RNFL thickness measurements were significantly larger with Topcon OCT as compared to Cirrus OCT both in normal (101±12 vs 91±8mm, P<0.001) and glaucomatous eyes (89±18 vs 76±16mm, P<0.001). The limits of agreement (LOA) for average peripapillary RNFL thickness measurements were poor, -11 to 32mm in normal and -4 to 30 mm in glaucomatous eyes.Conclusion: Peripapillary RNFL thickness values measured by Topcon OCT are greater than those measured by Cirrus OCT in both normal and glaucomatous eyes. Clinicians should be aware of this difference when monitoring patients imaged by different OCT machiness.

Diabetic retinopathy is the leading cause of blindness in the world. Strict control of blood sugar, blood pressure, laser therapy, pharmacotherapy and vitrectomy are of among common diabetic retinopathy treatments. Further studies to investigate the effect of protein kinase C inhibitors, angiotensin converting enzyme inhibitors, growth hormone and other proposed treatments for diabetic retinopathy are ongoing. Diabetic retinopathy is the most common micro-vascular complications of diabetes. Two important causes of visual loss in diabetic retinopathy are diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR). Diabetic macular edema due to retinal blood barrier breakdown is caused by increased vascular permeability leading to increased thickness of the macula and fatty deposits. To avoid the mentioned complications, some standardized and approved treatment and also some new treatments which require further complementary investigation are proposed that they will be discussed in this article.

Computers are used everywhere from home to work these days, thus the effects on the visual system will be more noticeable every day. Problems associated with computer usage are generally known as the computer vision syndrome (CVS).These problems include eye fatigue, irritation, redness, blurred vision and dry eye. All of these problems have adverse effects on individuals in the long term and reduce the efficiency and quality of workers. CVS is due to various display characteristics such as screen brightness, high brightness in the workplace, screen refresh rate, radiation, reduced rate of blinking, large eye surface prone to dryness and accommodation effort for close work. Treatment requires a multidirectional approach such as adjustment of the workstation. Proper lighting, anti-glare filters, ergonomic positioning of the monitor and regular work breaks may help improve visual comfort. Lubricating eye drops and special computer glasses help relieve ocular surface related symptoms. Also the treatment of this syndrome especially in the early stages has successful result, but users that do not know about this problems, tolerate a lot of complications.

Purpose: To report a case of cystinosis and idiopathic intracranial hypertention associated with Duane syndrome type I.Case Report: A 15 years old girl and a known case of nephrotic cystinosis presented to eye clinic with complaints of lid fissure changes on horizontal gaze and headache since 6 months ago. She was obese and had short stature. She had history of kidney transplantation 6 years ago. On physical examination both eyes were orthophoric in primary position but limitation of movements in abduction, globe retraction and narrowing of the palpebral fissure in adduction was present slit lamp examination revealed deposition of cystine crystals in the conjunctiva and corneal stroma of both eyes. On fundus examination both optic discs had blurred margin and were edematous. In lumbar puncture (LP) intracranial pressure was high. One month after starting acetazolamide, the papilledema was decreased significantly and her headache improved. After 3 months the patient passed away because of metabolic problems in neurologic ward.Conclusion: Herein we report a rare case of concurrent cystinosis, bilateral Duane syndrome type I and idiopathic intra cranial hypertention.

Purpose: A 12 year-old boy and a known case of Job’s syndrome presented with a large conjunctival mass which represented coexistence of HPV and HSV infections.Case Report: The presence of HPV virus within these lesions was confirmed by biopsy and DNA analysis. The mass lesions did not respond to anti-HPV therapy with topical interferon-2b, oral cimetidine and oral acyclovir, but improved promptly with antiviral therapy with intravenous acyclovir administered for cutaneous herpetic lesions. HSV infection was diagnosed clinically by the typical extensive epithelial dendritic lesion over the conjunctival mass and its dramatic response to IV acyclovir.Conclusion: Based on our results and on the relevant literature we propose an immunological mechanism for this unique manifestation of coexisting herpes simplex virus and human papilloma virus infections in hyper-IgE syndrome.

Purpose: To present a case of bilateral idiopathic central serous chorioretinopthy (ICSC) complicated by bullous serous retinal detachment (RD).Case Report: A 26-year old female suffered from acute loss of vision in the both eyes. Best spectacle-corrected visual acuity was 1/10 OU. The examination of anterior segment was unremarkable and a mild vitreous reaction was noted. Dilated fundus examination revealed bullous exudative retinal detachment in both eyes. Fundus fluorescein angiography (FFA) demonstrated multiple hyperfluorescent spots at the level of retinal pigment epithelium. The initial diagnosis Harada's disease (VKH) and oral corticosteroid was started which led to worsening of the condition. Therefore, systemic corticosteroid was discontinued and indocyanine green angiography (ICG) and ocular coherent tomography (OCT) were performed. ICG showed extensive choriodopathy and OCT showed multiple sensory retinal detachments. On the basis of the abovementioned findings, bullous variant of ICSC was diagnosed and the patient was followed up periodically. The lesion resolved spontaneously and completely within 4 months.Conclusion: A severe variant of ICSC characterized by multiple posterior exudation and bullous RD may affect otherwise a healthy young female. Recognition of this atypical presentation is important to avoid inappropriate treatment.