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To determine the prevalence of myopia and hyperopia in Shahroud schoolchildren and their risk factors Optometric examinations including the measurement of uncorrected and corrected visual acuity as well as non-cycloplegic and cycloplegic refraction using retinoscopy were done for students. Generalized Structural Equation Modeling (GSEM) was used to determine direct and indirect effects of independent variables on myopia and hyperopia. The data of 5581 students with a mean age of 9.24 ± 1.7 years were used in this study. The prevalence of myopia was 5.0% (95%CI: 4.3–5.7) and the prevalence of hyperopia was 4.8% (95%CI: 4.0 − 5.5) in all schoolchildren. According to the GSEM results, the odds of myopia in rural areas were 0.55 compared to urban areas. A one-unit increase in the ocular AL increased the odds of myopia by 4.91 times. The interaction of sex and age on myopia was significant such that in girls, the odds of myopia increased by 20% for every one-year increase in age while no significant change was seen in boys. A one-unit increase in the ocular AL decreased the odds of hyperopia by 0.49 times. Moreover, the interaction of outdoor activity hours and sex on the prevalence of hyperopia was significant such that increased outdoor activity reduced the odds of hyperopia in girls while no significant correlation was found in boys. Myopia and hyperopia had moderate prevalence. Axial Length had the largest direct association on myopia and hyperopia. Age and outdoor activity had weak associations on refractive errors. [ABSTRACT FROM AUTHOR]

To evaluate the effect of dry eye disease (DED) on the central corneal thickness and anterior corneal surface irregularity parameters using Scheimpflug tomography. In this study, the central corneal thickness and topometric indices of the anterior corneal surface were compared between the right eyes of 43 subjects with dry eye (DE group) and the right eyes of 35 non-dry eye individuals (NDE group). The central corneal thickness (CCT) and the topometric indices of the anterior corneal surface, including IVA, IHA, ISV, and IHD, were measured using the Pentacam HR (Pentacam-HR, Oculus, Wetzlar, Germany). Dry eye was diagnosed using a symptom questionnaire, TBUT, and Schirmer’s test without anesthesia. The mean ISV, IVA, IHA, and IHD were 17.02 ± 3.43, 0.114 ± 0.04, 5.82 ± 4.82, and 0.011 ± 0.01 in the DE group and 14.65 ± 3.10, 0.086 ± 0.03, 3.70 ± 3.23, and 0.007 ± 0.00 in the NDE group, respectively. All of the above corneal irregularity indices were significantly higher in the DE group (P<0.05). The mean CCT was 531.19 μ (±34.88 μ) and 540.66 μ (±27.13 μ) in the DE and NDE group, respectively. Based on linear regression analysis, ISV, IVA, IHA, and IHD had a significant association with DED (P<0.05), while CCT had no significant association with DED (P=0.148). DED significantly increases corneal surface irregularity, but it has no significant effects on CCT measured by the Pentacam. [ABSTRACT FROM AUTHOR]

To investigate the prevalence of Meibomian gland dysfunction (MGD) and its relationship with some determinants in underserved villages of Iran. This population-based cross-sectional study was conducted on 3850 subjects that were randomly selected from the villages of two underserved districts in the north and southwest of Iran using multistage cluster sampling. All participants underwent complete ophthalmic examinations, including visual acuity and refraction measurement. Then, slit-lamp biomicroscopy was done by an ophthalmologist to investigate MGD. Of 3850 subjects that were invited, 3314 participated in the study (participation rate=86.07%), of whom 1834 (55.34%) were women. The mean age of the participants was 37.7±21.4 years (range=2-93 years). The prevalence (95% CI) of MGD in at least one eye was 29.20% (27.35 to 31.06). According to the results of multiple regression analysis, MGD had a positive association with the male sex (OR: 1.75; CI 95%: 1.44 to 2.13), age 61-70 years (OR: 7.15; CI 95%: 3.65 to 14.01), and living in southern villages (OR: 1.82; CI 95%: 1.48 to 2.22) and an inverse association with education level (OR: 0.89; CI 95%: 0.80 to 0.98). The results of this study showed a lower prevalence of MGD even in Iranian rural regions compared to other Asian countries. This study found that older age, male sex, and low education level served as MGD risk factors. It seems that improved health conditions are an important factor in preventing MGD. [ABSTRACT FROM AUTHOR]

To determine the prevalence of cataract and its relationship with some determinants in individuals above 60 years. Of 3792 subjects that were invited, 3310 participated in the study (response rate = 87.31%). All subjects underwent full optometric, slit lamp, and fundoscopic examinations. Then, their lenses were evaluated according to the World Health Organization cataract grading system after pupil dilation. Age- and sex-standardized prevalence with 95% confidence interval (CI) of nuclear, cortical, posterior subcapsular cataracts (PSC), any type cataract, and all lens change was 53.09% (49.80 to 56.35), 23.02% (20.87 to 25.32), 5.57% (4.62 to 6.70), 58.78% (55.65 to 61.83), and 72.49% (70.14 to 74.71), respectively. Any type, nuclear, cortical, and PSC cataracts, had a positive association with age and an inverse association with education. Moreover, the prevalence of cortical and PSC cataract had an inverse association with economic status. Among all variables, age was the strongest determinant for cataract and its subtype. This study found a higher prevalence of cataract compared to some previous studies such that about two-thirds of the geriatric population had cataract in the past or at the time of the study. Considering the association of cataract with variables such as economic status and education level, it seems that training and increased awareness and knowledge of the elderly population regarding the importance of eye care by physicians plays an important role in reducing the burden of cataract. [ABSTRACT FROM AUTHOR]

Accurate measurement of the anterior chamber depth is very important. There is no report regarding the agreement between rotating Scheimpflug imaging (Pentacam HR) and biograph (Lenstar LS 900) in children. This study therefore explores the agreement between Pentacam and Biograph in measuring anterior chamber depth in children. This study aims to determine the agreement between Pentacam and Biograph in measuring anterior chamber depth in children. The participants were students living in urban and rural areas of Shahroud, Iran, selected through cluster sampling. The students were transported to the examination site to undergo imaging and optometric tests. Pentacam imaging was then conducted, and biograph was used to measure biometric components. In this report, the anterior chamber depth was calculated from the corneal endothelium. Of 6624 students selected randomly, 5620 participated in the study. After applying the exclusion criteria, 4882 eyes were included in the final analysis. The mean anterior chamber depth measured by the Pentacam (3.09 ± 0.26 mm) was higher than that of biograph (3.04 ± 0.24 mm) (p < 0.001). The 95% limit of agreement (LOA) between the two devices was −0.19 to 0.09 mm. The variation of the difference between the two devices decreased, LOA became narrower, and the correlation coefficient of the devices increased with ageing. The highest intraclass correlation coefficient was seen among myopic (0.974) participants. The 95% LOA was −0.20 to 0.12 mm in hyperopic, −0.17 to 0.07 mm in myopic and −0.19 to 0.09 mm in emmetropic participants. The Pentacam and Biograph can be used interchangeably for measuring the anterior chamber depth in children. [ABSTRACT FROM AUTHOR]

Considering the significant relationship between opioid abuse and some accommodative and convergence disorders, opioid use should be considered in the differential diagnosis and will directly affect the management plan. To determine the prevalence of accommodative and convergence anomalies and their related factors in a population of male young adults with opioid use disorder (OUD). This cross-sectional study was conducted using a convenience sampling method in 2019. The study sample included male young adults with OUD who had been referred to a specialised drug-dependence rehabilitation centre in Mashhad, Iran. The diagnosis of OUD was made by a psychologist based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria. All patients underwent complete optometric examinations. Eighty male young adults with OUD were included in this study. The mean age of participants was 30.5 ± 3.9 years (age range 19 to 35 years). The prevalence of accommodative and convergence disorders was 33.75% (95% CI: 23.55-45.19) and 25.00 (95% CI: 15.99-35.94), respectively. Accommodative insufficiency (22.5%, 95% CI: 13.91-33.21) had a higher prevalence than accommodative excess (3.75%, 95% CI: 0.78-10.57) and accommodative infacility (7.50%, 95% CI: 2.80-15.61). Convergence insufficiency (18.75%, 95% CI: 10.89-29.03) had a higher prevalence compared to convergence excess (3.75%, 95% CI: 0.78-10.57) and basic exophoria (2.50%, 95% CI: 0.30-8.74). According to the multiple logistic regression, a significant inverse relationship was observed between pupil size with accommodative insufficiency (OR = 0.45), accommodative infacility (OR = 0.67), and convergence insufficiency (OR = 0.55). The results of the present study showed a higher prevalence of some accommodative and convergence disorders in OUD patients compared to the prevalence reported in previous studies conducted on the normal populations with a similar age range. [ABSTRACT FROM AUTHOR]

To evaluate and compare posterior corneal elevation data and anterior segment parameters in different grades of keratoconus by Pentacam. 114 eyes of 114 keratoconic patients (85 men and 56 women) with a mean age of 31.6±4.7 years were evaluated with a Pentacam Scheimpflug camera. Keratoconic eyes were divided into 3 groups or grades according to the maximum keratometry reading: mild or grade I (K=50 or less than 50 diopters [D]), moderate or grade II (K=50.0 to 55.0 D), and severe or grade III (K=55.0 D or higher). The posterior corneal parameters were obtained posterior. There were no statistically significant differences between keratoconus grades in terms of sex (P=0.661). Also, there were no statistically significant differences between 3 grades in terms of age (P=0.214). There were statistically significant differences in anterior keratometry readings (K), anterior chamber depth (ACD), anterior chamber angle (ACA), and all pachymetric corneal measurements between all groups. With the progression of the disease, posterior K readings and all posterior elevation measurements were statistically different between the three grades. However, there were no significant differences in pupil diameter, anterior chamber volume (ACV), and corneal volume (CV) between the three grades of keratoconus. According to the results of this study, height data of posterior elevation, when combined with corneal anterior segment parameter, could provide a useful keratoconus severity classification tool. [ABSTRACT FROM AUTHOR]