Insight into small eyes: a practical description from phenotypes presentations to the management.

This narrative review aimed to have an algorithmic approach to microphthalmos by a systematic search. The definition can be related to a number of special phenotypes. In the more challenging cases of complex microphthalmos, relative anterior microphthalmos, and nanophthalmos, the surgeon can approach these cases more safely if they have a deep understanding of the anatomical variations and ideal formulae for intraocular lens computation and knows how to avoid intra- and post-operative complications. In this article, we review the criteria by which we recognize and describe pre-, intra-, and post-operative considerations, as well as discuss the ideal intraocular lenses for microphthalmos, given the intricate varieties of small eye phenotypes.

Oral Contraceptive Steroids Promote Papillary Thyroid Cancer Metastasis by Targeting Angiogenesis and Epithelial-Mesenchymal Transition.

Thyroid cancer is the most prevalent type of endocrine malignancy with the highest incidence rate among women under 45 years old. Ethinylestradiol (EE) and levonorgestrel (LNG) are two steroid components of low-dose oral contraceptives used all over the world. In this study, we aimed to examine the possible effects of the combination of these two steroids on metastasis and angiogenic factors in BCPAP papillary thyroid cancer (PTC) cell line. After treatment of BCPAP cells with the combination of 20 nM EE and 90 nM LNG, mRNA expression levels of long noncoding RNAs HOTAIR and MALAT1, angiogenic and antiangiogenic gene markers VEGFA and THBS1, and epithelial-mesenchymal transition (EMT) biomarkers CDH1, CDH2, FN1, and VIM were analyzed by real-time PCR. Additionally, the protein expression of VEGFA was semiquantified by Western blotting. Results showed that the combination of LNG and EE significantly elevated the level of VEGFA protein and mRNA expression of VEGFA, MALAT1, HOTAIR, CDH2, FN1, and VIM genes while decreased CDH1 gene expression but had no marked effect on the expression of THBS1 gene in comparison with the control group. Also, our results suggest that LNG and EE may increase the metastatic and migratory properties of BCPAP cells via modulating angiogenic and EMT biomarkers. These data may highlight the potential of exogenous steroids in the advancement of PTC tumors.

CYP4V2 mutation screening in an Iranian Bietti crystalline dystrophy pedigree and evidence for clustering of CYP4V2 mutations.

PURPOSE: To report the genetic analysis of an Iranian Bietti crystalline dystrophy (BCD)-affected family, and to review previously reported mutations in the gene and assess the distribution of affected amino acids in the encoded protein. METHODS: The eleven exons of CYP4V2 were sequenced in the DNA of the proband of the Iranian BCD family. The putative disease-causing variation was screened in all affected and non-affected members. BCD causing CYP4V2 mutations previously reported in the literature were compiled, and positions of amino acids affected by nonsense and missense mutations were mapped onto the primary structure of the CYP4V2 protein. RESULTS: C.1219G > T in CYP4V2 that causes p.Glu407* was identified as cause of BCD in the Iranian family. The mutation segregated with disease status. Clinical presentations were similar among affected members, except that one patient presented with retinal macular hole. Twelve nonsense and 47 missense mutations in CYP4V2 were compiled. Inspection of distribution of amino acids affected by the mutations suggested non-random distribution and clustering of affected amino acids in nine regions of the protein, including regions that contain the heme binding site, the metal binding site, and a region between these binding sites. The most C-terminus proximal nonsense mutation affected position 482. CONCLUSIONS: This study presents results of the genetic analysis of an Iranian BCD family. Protein regions affected by mutations within the nine mutation clusters include regions well conserved among orthologous proteins and human CYP4 proteins, some of which are associated with known functions. The findings may serve to identify reasonable candidate gene region targets for gene editing therapy approaches.

Modeling a Telemedicine Screening Program for Diabetic Retinopathy in Iran and Implementing a Pilot Project in Tehran Suburb.

PURPOSE: To model a community-based telescreening program for diabetic retinopathy (DR) in Iran and to implement a pilot project at the Iranian Diabetes Society (IDS) branch in a Tehran suburb. METHODS: In this mixed model study, a web application called the "Iranian Retinopathy Teleophthalmology Screening (IRTOS)" was launched. The educational course for DR screening was established for general practitioners (GPs). Registered patients in IDS branch were recalled for fundus photography; images were transferred to the reading center via IRTOS to be graded by GPs, and patients were informed about the results via mobile messaging. All images were independently reviewed by a retina specialist as the gold standard. Patients who required further assessment were referred to an eye hospital. RESULTS: Overall, 604 subjects with diabetes were screened; of these, 50% required referral. The sensitivity and specificity for diagnosis of any stage of DR by trained GPs were 82.8% and 86.2%, respectively, in comparison to the gold standard. The corresponding values for detecting any stage of diabetic macular edema (DME) were 63.5% and 96.6%, respectively. CONCLUSIONS: Telescreening was an effective method for detecting DR in a Tehran suburb. This screening model demonstrated its capacity for promoting diabetic eye care services at the national level. However, the sensitivity for detecting DME needs to be improved by modifying the referral pathway and promoting the skill of GPs.

The roles and role-players in thyroid cancer angiogenesis.

Thyroid cancer is the most prevalent endocrine cancer worldwide. Angiogenesis, the formation of new blood vessels, plays a pivotal role in the development and progression of tumors. Over the past years, cancer research has focused on the ability of tumors to induce newly formed blood vessel, because tumor growth and the process of cancer metastasis mainly depends on angiogenesis. Tumor neovascularization occurs following the imbalance between pro-angiogenic and anti-angiogenic factors until the tumor switches to an angiogenic phenotype. A number of signaling factors and receptors that are implicated in the regulation of angiogenesis have been identified and characterized; most notably, the vascular endothelial growth factors (VEGFs) family and their receptors, which are the main pro-angiogenic molecules during early development and in pathological conditions such as cancer. Although thyroid is a highly vascularized organ, angiogenic switch in tumors of this organ leads to the formation of a vast network of blood vessels that favors the dissemination of tumor cells to distant organs and results in deterioration of patient conditions. Accordingly, the identification of key angiogenic biomarkers for thyroid cancer can facilitate diagnosis, prognosis and clinical decision-making and also may help to discover targeting factors for effective cancer therapy as well as monitoring response to therapy. Hence, the main purposes of this review are to summarize the types and mechanisms of angiogenesis emphasizing the prominent factors implicated in thyroid cancer angiogenesis.

Intravitreal Injection of Anti-vascular Endothelial Growth Factor Agents for Ocular Vascular Diseases: Clinical Practice Guideline.

PURPOSE: To provide the clinical recommendations for the administration of intravitreal anti-vascular endothelial growth factor (VEGF) drugs especially bavacizumab for ocular vascular diseases including diabetic macular edema, neovascular age-related macular degeneration, myopic choroidal neovascularization, retinal vein occlusion and central serous chorioretinopathy. METHODS: Twenty clinical questions were developed by the guideline technical committee. Relevant websites and databases were searched to find out the pertinent clinical practice guidelines to answer the questions. The technical committee provided possible answers (scenarios) according to the available evidences for each question. All scenarios along with their levels of evidence and the supported articles were sent to the experts for external review. If the experts did not agree on any of the scenarios for one particular clinical question, the technical committee reviewed all scenarios and their pertinent evidences and made the necessary decision. After that, the experts were asked to score them again. All confirmed scenarios were gathered as the final recommendations. RESULTS: All the experts agreed on at least one of the scenarios. The technical committee extracted the agreed scenario for each clinical question as the final recommendation. Finally, 56 recommendations were developed for the procedure of intravitreal anti-VEGF injection and their applications in the management of ocular vascular diseases. CONCLUSION: The implementation of this guideline can standardize the management of the common ocular vascular diseases by intravitreal injection of anti-VEGF agents. It can lead to better policy-making and evidence-based clinical decision by ophthalmologists and optimal evidence based eye care for patients.

Catalyst Behavior Analyzed via General Regression Model with the Parameters Depending on a Covariate.

In this work, the catalytic activity of modified glassy carbon electrodes with xPd-yLaNi0.5Fe0.5O3-chitosan as an anodic catalyst for the polymeric fuel cell was investigated with cyclic voltammetry and controlled potential coulometry techniques; x and y are the mass loading of noble metal and mixed oxide, respectively. For the first time, the statistical regression mixed models were used to compare the electrocatalytic ability of nanocomposites in a fuel cell. The nonlinear regression model of y i,j = f(x i , (s j )) + ε i was considered and simulated, where X i is a random variable, s j is a covariate value, ε i is a normal random error variable, and θ is a P-dimensional vector of parameters of the mentioned model. A strategy to make a mixed model was proposed by using the maximum likelihood or mean square error methods. Then, the appropriate linear and nonlinear models were applied to the electrochemical results. The equations of current density vs time were obtained via the fitting and simulation of experimental data at different potentials and mass loadings of components. The amounts of transferred charge during the methanol oxidation were calculated vs time through the integration of mentioned equations at different potentials and mass loadings of components.

Outcome of Macular Hole Surgery in Bietti Crystalline Dystrophy.

PURPOSE: To describe a 42-year-old man, a known case of Bietti crystalline dystrophy who underwent surgery for unilateral full thickness macular hole. CASE REPORT: Clinical features, color fundus photographs, and optical coherence tomography, electroretinography, and electrooculography findings of the patient are reported. His visual acuity improved from counting fingers to 20/50 after pars plana deep vitrectomy with internal limiting membrane (ILM) peeling and gas injection. CONCLUSION: Macular hole can occur in Bietti crystalline dystrophy and the post-surgical outcome is good.

Two Doses of Intravitreal Ziv-Aflibercept versus Bevacizumab in Treatment of Diabetic Macular Edema: A Three-Armed, Double-Blind Randomized Trial.

PURPOSE: To compare the efficacy of 2 doses of intravitreal ziv-aflibercept (IVZ) with intravitreal bevacizumab (IVB) in the treatment of center-involved diabetic macular edema (DME) at 12 weeks. DESIGN: Three-armed, double-blind, randomized clinical trial. PARTICIPANTS: Eyes with center-involved DME. METHODS: In this trial, 123 eyes with DME were randomly assigned to 3 injections of 1.25 mg IVZ, 2.5 mg IVZ, and 1.25 mg IVB every 4 weeks. Complete ophthalmologic examination and central macular thickness (CMT) measurement by optical coherence tomography were performed every 4 weeks up to 12 weeks. MAIN OUTCOME MEASURES: Change in best-corrected visual acuity (BCVA) at 12 weeks. RESULTS: Although no significant difference was evident between the 2 ziv-aflibercept groups at 12 weeks, the BCVA change was significantly better in the ziv-aflibercept 1.25 mg group than in the IVB group at the 12-week visit (P = 0.021). In regard to CMT changes, there was no significant difference between the 2 ziv-aflibercept groups; however, a significantly greater reduction in CMT was observed in the ziv-aflibercept 2.5 mg group compared with the IVB group at 12 weeks (P = 0.037). Subgroup analysis disclosed no difference in BCVA outcomes at 12 weeks among the groups in the eyes with baseline BCVA ≥20/50. In the eyes with baseline BCVA <20/50, the improvement was significantly better at 12 weeks in the ziv-aflibercept 1.25 mg group compared with the IVB group (P = 0.011). CONCLUSIONS: The 12-week results of this trial disclosed that both 1.25 mg and 2.5 mg doses of IVZ and IVB demonstrated BCVA improvement over baseline in the treatment of center-involved DME. However, a stronger effect of IVZ compared with IVB in terms of both visual acuity improvement and macular thickness reduction was detected in the eyes with initial BCVA <20/50. Longer-term efficacy and safety data will be needed to understand the role for this drug in practice.

Diabetic Retinopathy Clinical Practice Guidelines: Customized for Iranian Population.

PURPOSE: To customize clinical practice guidelines (CPGs) for management of diabetic retinopathy (DR) in the Iranian population. METHODS: Three DR CPGs (The Royal College of Ophthalmologists 2013, American Academy of Ophthalmology [Preferred Practice Pattern 2012], and Australian Diabetes Society 2008) were selected from the literature using the AGREE tool. Clinical questions were designed and summarized into four tables by the customization team. The components of the clinical questions along with pertinent recommendations extracted from the above-mentioned CPGs; details of the supporting articles and their levels of evidence; clinical recommendations considering clinical benefits, cost and side effects; and revised recommendations based on customization capability (applicability, acceptability, external validity) were recorded in 4 tables, respectively. Customized recommendations were sent to the faculty members of all universities across the country to score the recommendations from 1 to 9. RESULTS: Agreed recommendations were accepted as the final recommendations while the non-agreed ones were approved after revision. Eventually, 29 customized recommendations under three major categories consisting of screening, diagnosis and treatment of DR were developed along with their sources and levels of evidence. CONCLUSION: This customized CPGs for management of DR can be used to standardize the referral pathway, diagnosis and treatment of patients with diabetic retinopathy.

Inhibitory effect of curcumin on angiogenesis in a streptozotocin-induced diabetic rat model: An aortic ring assay.

BACKGROUND: Curcumin (diferuloylmethane) has been associated with the inhibition of angiogenesis, as well as the prevention of cancers and inflammatory processes. The aim of this study was to assess the efficacy of curcumin in suppressing angiogenesis in the cultured endothelial cells of rat aortic rings. METHODS: Eight-week-old male Wistar rats were randomized into five groups each with a different treatment and cell culturing paradigm: controls cultured in the absence of VEGF (vascular endothelial growth factor) (C), controls cultured in the presence of VEGF (C-V), controls treated with curcumin and then cultured in media lacking VEGF (C-TC), diabetics cultured in media supplemented with VEGF (D-V) and diabetics treated with curcumin and then cultured in media supplemented with VEGF (D-V-TC). Each group consisted of 8 animals. Diabetes was induced in by streptozotocin (STZ; 60 mg/kg body weight, IV). After 8 weeks, animals were sacrificed and their aortas were excised. Ring-shaped explants were embedded in a 96-well culture plate. Angiogenesis response was measured by counting the number of primary microtubules in each well. RESULTS: Optic microscopy revealed that the D-V group had the highest number of microvessels, while angiogenesis was not observed in the C or C-TC groups. The number of primary microtubules was significantly lower in the D-V-TC group compared to the D-V group (P < 0.05). The D-V-TC group had a significantly higher number of microvessels compared to the C-TC group (P < 0.05). CONCLUSION: Curcumin attenuates angiogenesis response in stertozotocin-induced diabetic rats.

Intraretinal foreign bodies: surgical techniques and outcomes.

PURPOSE: To report the clinical features of eyes with intraretinal foreign bodies (IRFBs) and to evaluate the results of surgical management in these eyes. METHODS: Hospital records of 34 eyes of 33 patients with IRFBs were reviewed. All eyes underwent pars plana vitrectomy to remove the foreign bodies using intraocular forceps or by magnetic extraction. RESULTS: All patients were male with mean age of 28±12.3 years and were followed for a mean period of 24.5±2.3 months. The IRFBs were ferromagnetic in 29 (85.3%) cases and were removed using an external magnet in 13 eyes (38.4%) or intraocular forceps in 21 eyes (61.6%). Laser photocoagulation was performed around the IRFB prior to surgery in 7 (20.6%) eyes. Macular pucker and scars developed in 8 (23.5%) eyes and retinal breaks posterior to the sclerotomy were formed in 12 eyes (35.3%) postoperatively. Final visual acuity was 20/40 or better in 12 (35.3%) eyes and 20/200 or better in 23 (67.7%) eyes. Final visual acuity of 20/200 or better had no significant relationship with the site, size, or type of the IRFB or with the interval from trauma to surgery. CONCLUSION: Despite the complexity of surgical management of IRFBs, anatomic and visual outcomes of vitreoretinal surgery in these cases are generally good. The appropriate route of removal may be determined by the type, size, and site of the IRFB. Removal of magnetic IRFBs using external magnets versus intraocular forceps seems to entail comparable results.

Causes of visual impairment among patients referred to a visual rehabilitation clinic in Iran.

PURPOSE: Epidemiologic evaluation and investigating the causes of visual impairment in any society is a matter of concern and has a direct effect on the country's health care planning. In this study we describe causes of low vision and blindness in Iranian patients referred to rehabilitation clinics for taking vision aids. METHODS: In this cross-sectional study, visual acuity was classified based on best-corrected visual acuity in the better eye according to the World Health Organization definition (blindness, visual acuity [VA] < 20 / 400; severe visual impairment, VA < 20 / 200-20 / 400; mild to moderate visual impairment, VA < 20 / 60-20 / 200). The causes of blindness and low vision were determined using the 10th version of International Classification of Diseases based on the main cause in both eyes. To describe data, we used mean ± SD and frequency. RESULTS: The study included 432 patients, 65% male, with a mean age of 43.6 ± 25.5 years (range, 3 to 92 years). Mild to moderate visual impairment, severe visual impairment and blindness were present in 122 (28.8%), 196 (46.4%) and 105 (24.8%) of the patients, respectively. The main causes of visual impairment were retinal and choroidal diseases (74.5%), optic nerve and optic tract diseases (9.8%), vitreous and globe disorders (5.3%), congenital cataract (3.1%), and glaucoma (2.6%). The distribution pattern of the causes was similar in all age subgroups. CONCLUSIONS: Diseases of the retina and choroid are the main cause of visual impairment among patients referred to an academic visual rehabilitation clinic in Iran.

Intravitreal bevacizumab vs. sham treatment in acute branch retinal vein occlusion with macular edema: results at 3 months (Report 1).

BACKGROUND: The goal of this work is to compare the visual and anatomical (central macular thickness; CMT) outcomes of intravitreal bevacizumab (IVB) injections relative to sham treatment in eyes with acute (less than 3 months in duration) branch retinal vein occlusion (BRVO). METHODS: In a double-masked randomized clinical trial (RCT), patients with acute BRVO were randomly assigned to one of two treatment groups: IVB (two injections of 1.25 mg IVB 6 weeks apart) or sham treatment. Primary outcome measures included changes in best-corrected visual acuity (BCVA) and CMT in optical coherence tomography (OCT) during follow-up (FU) examinations. Any complications secondary to injections were considered secondary outcomes. FU results after 6 and 12 weeks are reported. RESULTS: Eighty-one eyes (43 OD) of 81 patients (47 females) were enrolled in the study. Forty-two patients were enrolled in the IVB group, and 39 patients were enrolled in the sham group. Visual acuity and CMT improved in the IVB group after week 6 (two Snellen lines and 262 µm, respectively) and week 12 (three Snellen lines and 287 µm, respectively). After week 6, visual improvements in the IVB group were significantly increased relative to that of the sham group. However, visual improvements at week 12 were not significantly different between the two groups (1.5 Snellen lines visual improvement in the sham group at week 12). CONCLUSIONS: In acute BRVO, two IVB injections resulted in significant improvement of vision and CMT at 6 weeks relative to the sham group. However, the visual improvements in the IVB group were not significantly different from those in the sham group at 12 weeks. IVB injections accelerate an initial improvement of visual acuity but do not have any significant effects on vision after 12 weeks.

A generalization of Turnbull's estimator for nonparametric estimation of the conditional survival function with interval-censored data.

Simple nonparametric estimates of the conditional distribution of a response variable given a covariate are often useful for data exploration purposes or to help with the specification or validation of a parametric or semi-parametric regression model. In this paper we propose such an estimator in the case where the response variable is interval-censored and the covariate is continuous. Our approach consists in adding weights that depend on the covariate value in the self-consistency equation proposed by Turnbull (J R Stat Soc Ser B 38:290-295, 1976), which results in an estimator that is no more difficult to implement than Turnbull's estimator itself. We show the convergence of our algorithm and that our estimator reduces to the generalized Kaplan-Meier estimator (Beran, Nonparametric regression with randomly censored survival data, 1981) when the data are either complete or right-censored. We demonstrate by simulation that the estimator, bootstrap variance estimation and bandwidth selection (by rule of thumb or cross-validation) all perform well in finite samples. We illustrate the method by applying it to a dataset from a study on the incidence of HIV in a group of female sex workers from Kinshasa.

Childhood pars planitis; clinical features and outcomes.

PURPOSE: To evaluate the demographic and clinical features of childhood pars planitis, and to determine the therapeutic and visual outcomes of the disease. METHODS: Medical records of pediatric patients (less than 16 years of age at diagnosis) with pars planitis and at least 6 months of follow-up who were referred to Labbafinejad Medical Center, Tehran, Iran over a 22 year period were reviewed. RESULTS: Overall, 117 eyes of 61 patients including 51 (83.6%) male subjects were included. Mean age at the time of diagnosis was 7.8±3.2 (range, 3-16) years. Mean best corrected visual acuity (BCVA) was 0.88±0.76 logMAR at presentation which improved to 0.39±0.51 logMAR at final visit (P<0.001). Endotheliitis was present in 23 (19.6%) eyes and was significantly more prevalent in subjects younger than 9 years (P=0.025). Cataract formation (41.9%) and cystoid macular edema (19.7%) were the most prevalent complications. Univariate regression analysis showed that better baseline visual acuity (OR=0.38, 95%CI 0.21-0.70, P=0.002), age older than 5 years at disease onset (OR=0.36, 95%CI 0.14-0.9, P=0.029), absence of endotheliitis (OR=0.39, 95%CI 0.15-0.99, P=0.047) and female gender (OR=3.77, 95%CI 1.03-13.93, P=0.046) were significantly associated with final BCVA of 20/40 or better. CONCLUSION: Childhood pars planitis was much more common among male subjects. Endotheliitis may be a sign of inflammation spillover and is more prevalent in younger patients. Visual prognosis is favorable in most patients with appropriate treatment.

Pars plana vitrectomy with internal limiting membrane peeling for refractory diffuse diabetic macular edema.

PURPOSE: To evaluate the effect of pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling for management of refractory diffuse diabetic macular edema (DME). METHODS: In this prospective interventional case series, eyes with refractory diffuse DME unresponsive to macular photocoagulation and/or intravitreal bevacizumab, and best corrected visual acuity (BCVA) ≥ 20/200 and ≤ 20/60 underwent triamcinolone-assisted PPV with ILM peeling. Pre- and postoperative evaluations included a complete ophthalmologic examination, fluorescein angiography and optical coherence tomography (OCT). Main outcome measures were BCVA and central macular thickness (CMT). RESULTS: Twelve eyes of 12 patients with mean age of 59.6±3.9 (range, 55-68) years were operated and followed for a mean period of 4.9±1.0 (range, 4-6) months. Mean BCVA at final examination was 0.82 ± 0.18 logMAR which was not significantly better than its preoperative value of 1.00 ± 0.80 logMAR (P=0.959). Visual acuity improved by at least 2 lines in 3 eyes (25%), remained stable in 7 eyes (58%) and decreased by at least 2 lines in 2 eyes (17%). Mean CMT at final examination was 315±95 µm, which was significantly less than its preoperative value of 467±107 µm (P=0.004). Complications included vitreous hemorrhage in 2 and cataract progression in 5 eyes. CONCLUSION: PPV with ILM peeling for refractory diffuse DME seems to reduce macular thickness, but does not significantly improve visual acuity as observed after an intermediate-term follow up of about 6 months.

Outcomes of retinal detachment surgery in eyes with chorioretinal coloboma.

PURPOSE: To report the anatomical and functional outcomes of surgery for retinal detachment associated with chorioretinal colobomas. METHODS: In this retrospective interventional case series, 28 eyes of 28 patients (including 18 male subjects) who had undergone surgery for retinal detachment associated with chorioretinal colobomas were evaluated regarding the type of intervention, final visual acuity and anatomical outcomes, as well as complications. Cases with less than 3 months of follow-up were excluded. RESULTS: Primary surgery included vitrectomy in 25 (89.3%) and scleral buckling in 3 (10.7%) eyes. The internal tamponade used in eyes undergoing vitrectomy was silicone oil in 23 (92%) eyes and 20% sulfur hexafluoride (SF6) in 2 (8%) eyes. Silicone oil was removed in 11 eyes (45.8%). The mean number of operations per eye was 1.57±0.74, mean follow-up was 40±36 months, and the retina remained attached in 26 eyes (92.9%) at final follow-up. Mean preoperative visual acuity was 2.33±0.55 (range, 1.15-2.9) logMAR which significantly improved to 1.72±0.9 (range, 0.09-3.1) logMAR postoperatively (P < 0.001), however, final median visual acuity was counting fingers at 2 m. The most common complications were cataracts (100%) and ocular hypertension (46.4%). CONCLUSION: The most prevalent surgical procedure for treatment of retinal detachment associated with chorioretinal coloboma was pars plana vitrectomy and the most frequently used tamponade was silicone oil. Although anatomical success was satisfactory, functional outcomes were not encouraging which reflects the complexity of the condition and associated abnormalities.

Prevalence of diabetic retinopathy in Tehran province: a population-based study.

BACKGROUND: To determine the prevalence and characteristics of diabetic retinopathy (DR) among Iranian patients with diabetes. DESIGN: population-based cross-sectional study. PARTICIPANTS: patients with diabetes aged 25 to 64 years in Tehran province, Iran. This survey was conducted from April to October 2007. The study sample was derived from the first national survey of risk factors for non-communicable disease. Diabetes mellitus was defined as a fasting plasma glucose of >or= 7.0 mmol/l (126 mg/dl) or more, use of diabetic medications, or a physician's diagnosis of diabetes. All patients known to have diabetes underwent an eye examination by bio-microscope and indirect ophthalmoscope to check for any signs of DR through dilated pupils by + 78 lens. Participants were also interviewed and examined to determine their demographic characteristics, medical conditions and the regularity of their eye visits. RESULTS: Among 7989 screened patients, 759 (9.5%) had diabetes. Of them, 639 patients (84.2%) underwent eye examination. Five patients (0.7%) with media opacity were excluded. Of 634 examined patients with diabetes, 240 had some degree of diabetic retinopathy, and the overall standardized prevalence of any retinopathy was 37.0% (95% CI: 33.2-40.8), including 27.3% (95% CI: 23.7-30.8) (n = 175) with non-proliferative and 9.6% (95% CI: 7.3-11.9) (n = 65) with proliferative diabetic retinopathy. Clinically significant macular edema and vision-threatening retinopathy were detected in 5.8% (95% CI: 4.0-7.7) (n = 38) and 14.0% (95% CI: 11.3-16.7) (n = 95) of patients, respectively. Only 143 patients (22.6%) with diabetes had a history of regular eye examination. CONCLUSION: This study demonstrated a high prevalence and poor control of DR in Tehran province. This suggests the need for adequate prevention and treatment in patients with diabetes.