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Introduction: Cataract is a common cause of vision loss and blindness in humans. After surgical management of cataract, all efforts should be focused on reducing postoperative astigmatism thus providing an excellent vision to patients. Aim: To determine the relationship between corneal incision and refraction changes before and after phacoemulsification surgery in 300 patients undergoing cataract surgery in Khatam hospital in Mashhad, Iran from January 2017 to April 2018. Materials and methods: Three hundred patients (144 women and 156 men) with cataract undergoing phacoemulsification surgery were recruited in this cross-sectional study. Refraction, keratometry and visual acuity measurement were performed before surgery. Then, a steep-based incision in the cornea was made without stitches. A 3.2 mm corneal incision was made at two supratemporal and temporal sites. The patients were followed-up for one and six months, and one year after surgery monitoring their vision and refraction, and performing keratometric measurements. Results: The mean age of the patients was 65.7±9.54 years (age range, 42–84 years). No major complications were observed. The greatest mean of changes in corneal power was in the supratemporal incision (1.28±0.6). Keratometry had a significant relation with the incision (p Conclusions: An incision made along the steepest meridian leads to flatness of this meridian, this effect being more pronounced at the supratemporal incision. A temporal incision is recommended in cases where there is little difference in the keratometry of the two axes.

Purpose: To evaluate the long-term outcomes of collagen crosslinking in early keratoconus. Methods: Thirty eyes of twenty patients with early keratoconus were enrolled. Uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), objective refraction, subjective refraction, corneal topography and pachymetry were assessed before and 3, 6, 12 months and 9 years after performing collagen crosslinking surgery. Results: The patients' mean age was 31.2 ± 5.59 years at nine-year follow-up (range, 25–44 years). The means of preoperative UCVA and BSCVA were 0.57 ± 0.34 and 0.15 ± 0.12 logMAR, respectively, and these values remained stable at the final follow-up (P = 0.990 and P = 0.227, respectively). The mean objective spherical equivalent decreased considerably from –6.00 ± 4.05 D preoperatively to –5.22 ± 3.71 D at the final follow-up (P < 0.05). The mean subjective spherical equivalent was –4.25 ± 2.87 D preoperatively and this value was stable at the last follow-up (P = 0.92). No considerable difference was found between the post- and preoperative mean objective cylinder values (P = 0.34). The mean subjective cylinder value changed significantly from –4.05 ± 1.85 D preoperatively to –3.1 ± 1.42 D at the final follow-up (P < 0.05). The mean central corneal thickness was 496.97 ± 45.95 µm preoperatively and this value was stable at nine-year follow-up (P = 0.183). No significant difference was found between the pre- and postoperative mean maximum and mean minimum corneal curvature values (P = 0.429 and P = 0.248, respectively). There were no significant postoperative complications. Conclusion: Corneal crosslinking in early keratoconus seems to be a safe procedure that can effectively stabilize UCVA, BSCVA, subjective SE and CCT, while improving objective spherical equivalent.

Purpose To determine the normal range of intraocular pressure (IOP) in the young and its association with certain corneal parameters using a non-contact device. Methods Subjects were selected from students of Mashhad University of Medical Sciences through stratified sampling. All participants had visual acuity testing, corneal imaging, a comprehensive slit-lamp examination by an ophthalmologist, and IOP measurement using a non-contact air-puff tonometer. Results Of the 1280 invitees, 1073 (83.8%) participated, and 1027 were eligible. Mean IOP was 16.38 mmHg [95% confidence interval (CI): 16.22–16.53] in the total sample, 16.14 mmHg (95% CI: 15.84–16.45) in men, and 16.48 mmHg (95% CI: 16.31–16.66) in women. There was a significant IOP difference between myopes and emmetropes (P = 0.031). Based on the multiple linear regression model, IOP associated directly with age and central corneal thickness (CCT), and inversely with corneal diameter, spherical equivalent (SE), and keratoconus. Based on standardized coefficients of the regression model, CCT and SE had the strongest association with IOP. Conclusions In the present study, we demonstrated the IOP distribution in a young population using a non-contact method. CCT and SE were strongly associated with IOP.

Glaucoma is the second cause of irreversible blindness, and the Primary Open Angle Glaucoma (POAG) subtype is the most common type of glaucoma. It has been shown that genetic mutations increase the risk of POAG used for early detection. The aim of the current study was to determine the association between genetic variations of Myocilin (MYOC) gene and susceptibility to POAG in the Iranian population. This case-control study was conducted on patients with POAG, referred to Khatam-al Anbia Eye Hospital, Mashhad, Iran. The control group was selected from healthy patients with a refractive disorder, who had referred to this hospital. After extracting the DNA from the whole blood sample, the Polymerase Chain Reaction-Single-Strand Conformation Polymorphisms (PCR-SSCP) method was used to discriminate variability in sequences in three exons of MYOC gene locus, known as GLC1A. Clinical characteristics of the subjects, comprised of visual acuity, Cup to Disc Ratio (CDR), and Intra-Ocular Pressure (IOP) were statistically compared between the wild and mutant type of the MYOC gene using independent samples t-test, Chi-square, and logistic regression test with SPSS version 15.0 software. P-values of < 0.05 were considered significant. One hundred and forty participants (75.1% males) were studied in two groups of case (n = 70) and control (n = 70). The frequency of mutant alleles in patients and healthy groups was statistically significant (40% versus 11.5%, Odd’s Ratio (OR): 5.1, CI 95% for OR: 2.1 to 12.4, P-value < 0.001). Also, the detected mutation in the case group was significantly higher in exon 1 and 3 (15.7% versus 0%, P-value = 0.001, and 11.5% versus 2.8%, P-value = 0.049, respectively). Based on the result of the current study, it seems that the MYOC gene polymorphisms increased the risk of POAG in the Iranian population.

BACKGROUND: Glaucoma is a common cause of irreversible blindness. Transforming growth factor beta-1(TGF-β1) is the main isoform of TGF-β superfamily in the eye. Overexpression of TGF-β1 is shown to be related with the glaucoma. Studies have shown that the presence of mutant T allele of TGF-β1 -509C>T polymorphism (rs1800469) is associated with increased gene expression. So, in present study, association of the TGF-β1-509C>T gene polymorphism and primary open angle glaucoma (POAG) in patients from north east of Iran was investigated. METHODS: A case-control study was conducted on 112 POAG patients and 112 control participants. TGF-β1- 509C>T genotyping was done by PCR-restriction fragment length polymorphism (PCR-RFLP) method using Bsu36I restriction enzyme. Moreover, cup to disk ratio(CDR), intraocular pressure (IOP) and visual acuity (VA) were measured. The obtained results were statistically analyzed. RESULTS: The highest frequency of genotype in the control group was related to CC genotype (44.6%), but the heterozygous CT genotype (45.6%) was observed as the highest frequency of genotypes in patient group (P value: 0.022, OR for TT genotype: 2.54 CI95% for OR: 1.22, 5.27). Also, the frequency of the T mutant allele showed a significant difference between case and control groups (P value: 0.005, OR: 1.73 CI95% for OR: 1.18, 2.53). CONCLUSION: In conclusion, a significant association was seen between TGF-β1 -509C>T gene polymorphism and POAG disease and inheritance of mutant T allele is considered to be a risk factor for glaucoma in patients living in North Eastern part of Iran.

Introduction:Bevacizumab (Avastin), as an effectiveness treatment modality, is currently used in patients with various ocular disease. However the results have been promising, the use of bevacizumab in the treatment of ocular disease is an off-label application. Hence, the aim of this study was to systematically review the effectiveness of intravitreal injection of bevacizumab on various ocular tissues, especially corneal endothelial cells. Methods: The articles related to the effect of application of Avastin in the treatment of ophthalmic diseases and especially its effect on corneal endothelial cells were collected and reviewed. We searched PubMed, Google scholar, and Scopus databases and used Avastin, ocular diseases and corneal endothelial cells as search keywords.Result: Of all 55 articles found in all databases, only 10 were relevant to the purpose of this study, and 45 articles were excluded in several step by step process of article selection according to the inclusion/exclusion criteria. The results revealed that intracameral bevacizumab injection caused no changes in specular microscopy and corneal pachymetry. Moreover, it had no significant toxicity on corneal endothelial cells.Discussion: Effectiveness of bevacizumab as a new modality in the treatment of different ophthalmic diseases have been suggested. Recent data on both human and animal models showed that intravitreal injection of bevacizumab resulted in no significant toxicity on various ocular cells, and it could be considered as a suitable therapeutic approach in clinical use.Conclusion: According to the results of included documents, bevacizumab was not toxic to corneal endothelial cells at various clinically relevant doses.

Purpose The objective of this study was to determine the prevalence of keratoconus and the potential effect of genetic and environmental factors on its prevalence in households living in rural areas of Iran in a large population-based study. Methods The present cross-sectional study was performed in two Iranian rural populations. Two rural areas were randomly selected in the southwest and north of Iran. All individuals over one year of age were invited to participate in the study. The study population underwent a thorough eye examination, including visual acuity measurement, refraction, slit lamp biomicroscopy, and Scheimpflug imaging. The diagnosis of keratoconus was made based on Pentacam-specific criteria, tomographic maps, and clinical findings. After detecting keratoconus cases, its prevalence in the study population was reported as a percentage with a 95% confidence interval (CI). For familial aggregation analysis, the odds ratios of keratoconus and its more severe types were calculated in different family relationships (siblings, parents-offspring, spouses) using second order generalised estimating equation. Results Of the 3851 eligible individuals, 3314 subjects participated in the study. After applying the exclusion criteria, data from 2667 subjects was used in the analysis. The prevalence of keratoconus in the present population was 4% (95% CI: 3-4). The odds of keratoconus were significantly higher in males (OR = 2.30, p = 0.032). To investigate the familial aggregation of keratoconus, we only evaluated families from which at least two members participated in the study. So, 403 families (1452 participants) were evaluated. Our results showed a higher odds ratio for the sibling pairs compare to parent-offspring pairs and as reported, the odds ratio of the spouses was less than 1.0. Conclusion Our findings showed a relatively high prevalence and familial aggregation of keratoconus in rural areas of Iran, independent of age, sex, and place of residence. This aggregation may be due to heredity or the effect of undetermined shared environmental factors.

To evaluate the effects of propofol, etomidate, and thiopental administered during phacoemulsification (PE) cataract extraction on intraocular pressure (IOP) and hemodynamic responses with insertion of laryngeal mask airway (LMA).In a randomized double-blind clinical trial, patients scheduled for PE with general anesthesia were included. Patients were allocated randomly to 3 groups: group 1 (n=34): 0.3 mg/kg etomidate; group 2 (n=33): 2 mg/kg propofol; and group 3 (n=34): 4 mg/kg thiopental. IOP, systolic blood pressure, and heart rate (HR) were measured before induction as a baseline, 2 min after induction (immediately before insertion of LMA), and 1 and 3 min after LMA insertion. Blood pressure (BP) and HR of patients during the surgery were monitored and registered before and after induction and intubation.In 3 groups, IOP decreased significantly after injection of drugs and insertion of LMA in comparison to basic values, although IOP after LMA insertion was more than before LMA insertion. In case of propofol, the changes in IOP between 2 min after induction and the baseline were higher than others, especially thiopental (P=0.031). BP declined remarkably after induction (P0.001) and rose significantly after LMA insertion in all groups, except in the propofol group. The HR was decreased significantly after induction, except in thiopental.Propofol prevented IOP increase after induction compared with other drugs. Decrease in BP and HR after induction and LMA insertion was remarkable. Thiopental seemed to be the best drug for controlling cardiovascular parameters, especially HR, and it also prevents IOP rise.

Purpose To determine the prevalence of keratoconus and some associated factors in the students of Mashhad University of Medical Sciences, Iran. Method In this cross sectional study, multistage cluster sampling was used to select the participants. All participants underwent retinoscopy, slit lamp examination, topography with the TMS-4 and corneal assessment with the Orbscan II. The diagnosis of keratoconus was based on both clinical evidence and the results of corneal imaging. Results Of 1280 selected students, 1073 agreed to participate in the study, and of those who agreed, 1027 fulfilled the inclusion criteria. 42.5% of the study population was male with a mean age of 26.1 ± 2.3 years. The prevalence of keratoconus was 2.5% (n = 26) (95% confidence interval, CI 1.6–3.5). Eighteen students (69%) had bilateral keratoconus. Imaging of the cornea revealed that 70% of the keratoconics had nipple cones and the remaining had asymmetric bow-tie patterns. The prevalence of keratoconus was not significantly associated with age or gender (p > 0.05). In a multiple logistic regression model, family history (OR = 11.4, 95% CI: 2.5–51.3) and eye rubbing (OR = 6.3, 95% CI: 1.6–24.3) were significantly correlated with keratoconus. Conclusions These results taken together with recent studies in the area suggest that keratoconus may have a higher prevalence in the Middle East and Asia than in Western Countries.

PURPOSE To determine the prevalence of amblyopia, anisometropia, and strabismus in schoolchildren of Shiraz, Iran. MATERIALS AND METHODS A random cluster sampling was used in a cross-sectional study on schoolchildren in Shiraz. Cycloplegic refraction was performed in elementary and middle school children and high school students had non-cylcoplegic refraction. Uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) were recorded for each participant. Anisometropia was defined as spherical equivalent (SE) refraction difference 1.00D or more between two eyes. Amblyopia was distinguished as a reduction of BCVA to 20/30 or less in one eye or 2-line interocular optotype acuity differences in the absence of pathological causes. Cover test was performed for investigating of strabismus. RESULTS Mean age of 2638 schoolchildren was 12.5 years (response rate = 86.06%). Prevalence of anisometropia was 2.31% (95% confidence interval [CI], 1.45 to 3.16). 2.29% of schoolchildren (95% CI, 1.46 to 3.14) were amblyopic. The prevalence of amblyopia in boys and girls was 2.32% and 2.26%, respectively (p = 0.945). Anisometropic amblyopia was found in 58.1% of the amblyopic subjects. The strabismus prevalence was 2.02% (95% CI, 1.18 to 2.85). The prevalence of exotropia and esotropia was 1.30% and 0.59%, respectively. CONCLUSIONS Results of this study showed that the prevalence of anisometropia, amblyopia, and strabismus are in the mid range. The etiology of amblyopia was often refractive, mostly astigmatic, and non-strabismic. Exotropia prevalence increased with age and was the most common strabismus type.

Purpose To determine the prevalence and risk factors of refractive errors among schoolchildren in Bojnourd, Iran. Methods In a cross-sectional study using random cluster sampling, 2020 schoolchildren 6 to 17 years of age were selected in this study. The participants totaled 1551; 643 boys and 908 girls of the elementary and middle schoolchildren of Bojnourd, northeast of Iran. Mean age of the participants was 11.2 years (response rate=76.7%). Refractive errors were measured under cycloplegia. Myopia defined as spherical equivalent (SE) refraction - 0.5 dioptre (D) or worse, hyperopia as SE +2.00 D or more, and astigmatism as cylinder -0.75 D or worse. Results The prevalence of myopia, hyperopia and astigmatism were 4.3%, 5.4% and 11.5% respectively and were not related to the gender. The prevalence of myopia and against-the-rule astigmatism increased with age (p

Purpose To determine the prevalence of anisometropia, amblyopia and starbimus in schoolchildren of Bojnourd, Iran. Methods A random cluster sampling was used in a cross-sectional study on 2020 schoolchildren in Bojnourd, northeast of Iran. The participants totaled 1551;643 boys and 908 girls. Mean age of the partipiciants was 11.12 years (respose rate=76.7%). Examinations included: uncorrected and best corrected visual acuity (UCVA and BCVA) measurements, cycloplegic refraction and cover test. Anisometropia defined as spherical equivalent (SE) refraction difference 1.00 D and more between two eyes. Amblyopia was defined as a reduction of BCVA to 20/30 or less in one eye or two lines introcular optotype acuity difference in the absence of pathological causes. Strabismus was characterized as a heterotropia at distance or near fixation. Results The prevalence of anisometropia, amblyopia and strabismus were 2.7%, 2.2 and 2% respectively and were not related to the gender. The prevalence of exotropia, esotropia and hypertropia were 1.37%, 0.51% and 0.12% respectively. Conclusion Prevalence of anisometropia, amblyopia and strabismus among the schoolchildren of Bojnourd were in the mid range and similar to that in most places of the world. Exotropia was the most common strabismus type and comparable to the other Asian countries.

PURPOSE To determine the prevalence of refractive errors in Shiraz schoolchildren by age and gender. METHODS For this cross-sectional study, random cluster sampling was carried out from students of the 2008-2009 academic year. After the initial interview, ophthalmic examinations including tests of visual acuity, non-cycloplegic and cycloplegic refraction and binocular vision were performed. Myopia was defined as a spherical equivalent or =+2.0 D, and astigmatism as a cylinder refraction > or =0.75 D. All values for school grade and gender were directly standardized based on the total student population in the 2008-2009 school year. RESULTS A total of 2130 students were sampled, of which 1872 participated in the study (response rate = 87.88%). The prevalence of uncorrected, best-corrected, presenting and spectacle corrected visual acuity of 6/12 or worse in the better eye was 6.46%, 0%, 1.49% and 0.9%, respectively. The prevalence rates of myopia, hyperopia and astigmatism were 4.35% (95% confidence interval [CI]: 2.89-5.82%), 5.04% (95% CI: 3.50-6.58%), and 11.27% (95% CI: 9.81-12.74%), respectively. Anisometropia was detected in 2.58% of schoolchildren. The prevalence of hyperopia significantly decreased with age (P = 0.021). CONCLUSIONS Compared with other reported rates, the prevalence of myopia in the schoolchildren of Shiraz is similar to that in most places excluding East Asian countries, and that of hyperopia is in the mid range.

To evaluate and compare central corneal thickness measurements using rotating Scheimpflug camera, scanning-slit topography, and ultrasound pachymetry in virgin, healthy corneas.Prospective, observational, cross-sectional study.Central corneal thickness in 157 healthy eyes of 157 patients without ocular abnormalities other than refractive errors was measured, in a sequential order, once with rotating Scheimpflug camera and scanning-slit topography and 3 times with ultrasound pachymetry as the last part of examination. All measurements were performed by a single experienced examiner. The results from scanning-slit topography are given with and without correction for "acoustic correction factor" of 0.92.The average measurements of central corneal thickness by rotating Scheimpflug imaging, scanning-slit pachymetry, and ultrasound were 537.15 ± 32.98 μm, 542.06 ± 39.04 μm, and 544.07 ± 34.75 μm, respectively. The mean differences between modalities were 6.92 μm between rotating Scheimpflug and ultrasound (P.0001), 2.01 μm between corrected scanning-slit and ultrasound (P = .204), and 4.91 μm between corrected scanning-slit and rotating Scheimpflug imaging (P = .001). According to Bland-Altman analysis, highest agreement was between ultrasonic and rotating Scheimpflug pachymetry.In the assessment of normal corneas, rotating Scheimpflug topography measures central corneal thickness values with higher agreement to ultrasound pachymetry.