The Effect of Cycloplegia on Ocular Alignment and AC/A Ratio.

Purpose: The present study sets out to investigate the effect of cyclopentolate-induced cycloplegia on distance and near deviation and the accommodative convergence/accommodation (AC/A) ratio. Methods: This prospective study was performed on 30 subjects. The inclusion criteria included a lack of any active ocular pathology and systemic diseases, no history of ocular surgery, and nonuse of various medications. Refraction, near and distance deviation were measured for all subjects, and the same examinations were repeated after the administration of two drops of cyclopentolate 1% to both eyes. Results: The obtained data from 30 subjects, including 19 males, with a mean age of 22.53 ± 1.74 years were analyzed. The mean ± SD of near deviation in dry and cycloplegic conditions were -6.9 ± 8.1 and +6.4 ± 9.1 prism diopters, respectively, which were statistically significant (P < 0.001). Distance deviation in cycloplegic conditions demonstrated an average difference of 0.8 prism diopters, compared to dry conditions (P < 0.001). AC/A ratios were 4.7 ± 2.5 and 9.7 ± 3.9 (Δ/D) in non-cycloplegic and cycloplegic conditions, respectively, which was a statistically significant difference (P < 0.001). The multiple regression indicated that among all under study variables, refraction (B coefficient: -2.4; P < 0.001) and near pre-cycloplegic deviation (B coefficient: 0.56; P < 0.001) were significantly associated with post-cycloplegic near deviation. Conclusion: The results of this study indicated that cycloplegia causes a considerable esophoric shift in near deviation and a negligible esophoric shift in distance deviation. As a result, the AC/A ratio demonstrated a significant increase due to unequal changes in near and distance deviation.

Hypertension prevalence in Iran's elderly according to new criteria: the Tehran Geriatric Eye Study.

Purpose: To determine the prevalence of hypertension in a population above 60 years of age and its relationship with demographic and anthropometric factors. Methods: A cross-sectional population-based study was conducted in 2019. Using a multistage random cluster sampling, 160 clusters were selected from 22 districts of Tehran. All participants were interviewed to collect demographic, anthropometric, and socioeconomic information. Then, systolic (SBP) and diastolic (DBP) blood pressures were measured under standard conditions twice, 10 min apart. A third measurement was performed if the two measurements showed a difference of ≥ 10 mmHg in SBP or ≥ 5 mmHg in DBP. Hypertension was defined as a SBP > 130 mmHg or a DBP > 80 mmHg (new criteria), being a known case of hypertension, or use of blood pressure lowering medications. Results: Of 3791 invitees, 3310 participated in the study (87.3%). The mean age of the participants was 68.25 ± 6.54 years (60-97 years). The prevalence of hypertension was 81.08% (95% CI: 79.57-82.59) in the whole sample; 82.96% (95% CI: 81.02-84.91) in females, and 79.15% (95% CI: 76.6 -81.69) in males. The prevalence of hypertension ranged from 75.47% (95% CI: 72.65-78.29) in the age group 60-64 years to 88.40% (95% CI: 83.71-93.08) in the age group ≥ 80 years. The prevalence of hypertension unawareness was 32.84% (95% CI: 30.82-34.86). The highest and lowest prevalence of hypertension was seen in illiterate subjects (89.41%) and those with a university education (77.14%), respectively. According to the multiple logistic regression analysis, older age, lower education level, obesity and overweight, neck circumference, and diabetes were significantly associated with the prevalence of hypertension. Conclusion: A significant percentage of Iranian elderly have hypertension and one of every 3 affected individuals is unaware of their disease. Considering the population aging in Iran, urgent and special attention should be paid to the elderly population. Caring for the elderly, informing families, and using non-traditional screening methods are recommended by families at the first level and policymakers at the macro level.

The association between ocular biometric components and corneal aberrations.

CLINICAL RELEVANCE: Evaluating factors affecting corneal higher-order aberration component has a very important role in interpreting the characteristics of the formed image on the retina. BACKGROUND: To determine the relationship between ocular biometric components and corneal higher-order aberrations in an elderly population. METHODS: This report is related to a subsample of the Tehran Geriatric Eye study (TGES), a population-based cross-sectional study that was conducted on individuals aged 60 years and above in Tehran city, Iran using multistage stratified random cluster sampling. All study participants underwent ocular examinations including visual acuity measurement, refraction and slit-lamp biomicroscopy. Anterior segment imaging and corneal aberrometry were performed using Pentacam AXL. RESULTS: In the present study, 644 eyes of 415 individuals (56.9% female) with mean age of 66.36 ± 4.70 years were evaluated. According to a multiple generalised estimating equation model, the root mean square of total higher-order aberrations was related to age (ß = 0.081, p = 0.002), crystalline lens thickness (ß = 0.08, p < 0.001), and corneal diameter (ß = -0.04, p = 0.014). The root mean square of total coma aberration was directly related to the female sex (ß = 0.02, p = 0.05), and crystalline lens thickness (ß = 0.06, p < 0.001). There was a direct relationship between the root mean square of third- and fourth-order higher-order aberrations and crystalline lens thickness (p < 0.001). Spherical aberration was directly related to the male sex (ß = -0.02, p = 0.004), axial length (ß = 0.05, p < 0.001) and central corneal thickness (ß = 0.001, p = 0.025), and was inversely related to anterior chamber depth (ß = -0.07, p = 0.031) and crystalline lens thickness (ß = -0.25, p < 0.001). CONCLUSION: Ocular biometric components are related to corneal aberrations in the elderly. These factors need to be considered in respect of medical and surgical procedures required for the elderly.

Anterior segment indices in mentally retarded children.

To compare the anterior segment indices between mentally retarded and normal children. The current study was conducted as a cohort. In this study, 73 mentally retarded and 76 normal children were selected from normal school and special schools for mentally retarded children using random cluster sampling method. Mental retardation in children was confirmed by a psychologist. Optometry examinations including visual acuity and refraction were performed for all participants, and ultimately, corneal imaging measurements were taken by Pentacam. The mean age of mentally retarded and normal children was of 13.30 ± 1.83 and 13.05 ± 1.82 years, respectively (P = 0.180). A multiple generalized estimating equations model demonstrated that there is a significant association between central corneal thickness (CCT) (coef = 1.011, P < 0.001), corneal diameter (CD) (coef = 0.444, P = 0.046), anterior chamber depth (ACD) (coef = 0.23), P < 0.001) and index of vertical asymmetry (IVA) (coef = 0.12, P < 0.001) and mental retardation. Cerebral palsy children had higher keratoconus index (KI), central keratoconus index (CKI), index of height asymmetry(IHA), and index of height decentration (IHD) compared to those without cerebral palsy (P < 0.05). Children with moderate mental retardation had higher index of surface variance (ISV), IVA, IHA, and IHD than those with mild mental retardation (P < 0.05). The mean and standard deviation of CCT, CD, ACD and IVA index in mentally retarded children were 535.3 ± 46.68 micron, 11.87 ± 0.42 mm, 3.29 ± 0.24 mm and 0.25 ± 0.18 mm, respectively. These indices in the normal group were 525.53 ± 47.52 micron, 11.84 ± 0.38 mm, 3.15 ± 0.28 mm and 0.17 ± 0.05 mm, respectively. The findings of this study showed that some anterior segment indices were different in mentally retarded compared to normal children. Moreover, some keratoconus indicators were worse in cerebral palsy children and children with higher grade mental retardation. So, it is important to consider keratoconus screening in these children.

Epidemiology of Ocular Trauma in the Elderly: A Population-Based Study.

Purpose: To determine the prevalence of different types of ocular trauma and their relationship with some factors in the elderly population. Methods: The present population-based cross-sectional study was conducted on the elderly population aged 60 years and above in Tehran, Iran, using multi-stage stratified random cluster sampling in 2019. After selecting the samples and their participation in the study, demographic information and history of ocular trauma were obtained through an interview. Psychological evaluation was performed using the Goldberg's 28-question General Health Questionnaire. All study participants underwent optometric and ophthalmological examinations. Results: Three thousand three hundred and ten people participated in the study (response rate: 87.3%). Of these, 1912 individuals (57.8%) were female and the mean age of individuals was 68.25 ± 6.55 (from 60 to 97) years. 7.46% (95% confidence interval [CI]: 6.51-8.41) of the study participants reported a history of ocular trauma. Blunt and chemical traumas were the most and the least common types of ocular trauma, respectively (5.72% and 0.16%). 3.93% of cases visited an ophthalmologist for ocular trauma, 1.67% reported a history of hospitalization, and 1.47% underwent surgery. The prevalence of visual impairment in individuals with a history of ocular trauma was 12.53%. Visual impairment was more prevalent in people with a history of ocular trauma than those without a history of ocular trauma (P < 0.05). History of ocular trauma was only significantly related to low education level (odds ratio = 0.63, 95% CI = 0.40-0.99). Participants with a history of ocular trauma had more anxiety and higher mean psychological distress score than those without a history of ocular trauma (P = 0.035). Conclusions: The development of preventive programs against the occurrence of ocular trauma can play an important role in reducing the psychological damage of affected patients while reducing visual disorders. These interventions should be especially considered in groups with a lower education level.

Epidemiological aspect of retinoblastoma in the world: a review of recent advance studies.

AIM: To collect and present updated evidence about epidemiological aspects of retinoblastoma (Rb) in the world. METHODS: A comprehensive search without the time and language restrictions was conducted in international databases, including MEDLINE, Scopus, Web of Science, and PubMed. The search keywords were "retinoblastoma" OR "retinal Neuroblastoma" OR "retinal glioma" OR "retinoblastoma eye cancer" OR "retinal glioblastoma". RESULTS: The worldwide incidence of Rb is 1 in 16 000-28 000 live births, but was higher in developing compared to developed countries. Several attempts for improving early detection and treatment had increased the Rb survival rate from 5% to 90% in developed countries over the past decade, but its survival was lower in developing countries (about 40% in low-income countries) and the majority of mortalities occurred in developing countries. The etiology of Rb could be viewed as genetics in the heritable form and environmental and lifestyle factors in the sporadic form. Some environmental risk factors such as in vitro fertilization; insect sprays; father's occupational exposure to oil mists in metal working, and poor living conditions might play a role in the occurrence of the disease. Although ethnicity might affect Rb incidence, sex has no documented effect and the best treatment approaches were now ophthalmic artery chemosurgery and intravitreal chemotherapy. CONCLUSION: Determining the role of genetics and environmental factors helps to accurately predict the prognosis and identify the mechanism of the disease, which can reduce the risk of tumor development.

P100 Wave Latency and Amplitude in Visual Evoked Potential Records in Different Visual Quadrants of Normal Individuals.

Purpose: Assessment of the pattern visual evoked potential (PVEP) responses in different areas of visual fields in individuals with normal vision. Methods: This study was conducted on 80 eyes of normal subjects aged 18-35 years. All participants underwent refraction and visual acuity examination. Visual evoked potential (VEP) responses were recorded in different areas of field. The repeated measure test was used to compare the P100 latency and amplitude of PVEP among different areas. Results: The repeated measures analysis of variance showed a statistically significant difference among different areas in terms of amplitude and latency of P100 (P = 0.002 and P < 0.001, respectively). According to the results, the highest and lowest amplitude of P100 was observed in inferior-nasal and superior areas, respectively. The highest and lowest latency of P100 was related to the temporal and inferior-nasal areas, respectively. Conclusion: This study partially revealed the details of local PVEP distribution in the visual field and there was a significant difference in the amplitude and latency of PVEP wave in different areas of the visual field.

Distribution and associated factors of intraocular pressure in the older population: Tehran Geriatric Eye Study.

AIM: To determine the distribution and associated factors of intraocular pressure (IOP) in an Iranian elderly population 60 years of age and above. METHODS: The present report is part of the Tehran Geriatric Eye study (TGES), a population-based cross-sectional study that was conducted on the residents of Tehran 60 years of age and above. The sampling was performed using multistage stratified random cluster sampling methods from 22 districts of Tehran, Iran. Demographic and history information, blood samples, and blood pressure were collected from all participants. Ocular examinations included measurement of uncorrected and best-corrected visual acuity, objective and subjective refraction, and slit-lamp biomicroscopy. The IOP was measured using Goldmann applanation tonometry (GAT). Corneal imaging and ocular biometry were performed using Pentacam AXL. RESULTS: The data of 3892 eyes of 2124 individuals were analyzed for this report. The mean age of the study participants was 66.49±5.31y (range: 60 to 95y). The mean IOP was 15.2 mm Hg (95%CI: 15.1 to 15.4), 15.3 mm Hg (95%CI: 15.1 to 15.5) and 15.1 mm Hg (95%CI: 15.0 to 15.3) in all participants, males, and females, respectively. Of the study participants, 1.3% had an IOP of ≥20 mm Hg. The mean IOP increased from 15.1 mm Hg in the age group 60-64y to 16.3 mm Hg in the age group ≥80y. According to the final multiple GEE model, the IOP was statistically significantly higher in men than in women. All the studied age groups, except for the 75-79-year-old age group, had significantly higher IOP compared to the 60-64-year-old age group. The IOP was significantly higher in underweight compared to other body mass index groups. Moreover, the IOP had a statistically significant direct relationship with the mean corneal power (mean CP), central corneal thickness (CCT), and systolic blood pressure. CONCLUSION: The present study presents the distribution of IOP in an Iranian elderly population. A higher IOP (within the range 14 to 17 mm Hg) is significantly associated with older age, male sex, high systolic blood pressure, increased mean CP, and CCT. These factors should be considered in the clinical interpretation of IOP.

Distribution of Corneal Volume and Its Associated Factors in an Elderly Population: Tehran Geriatric Eye Study.

PURPOSE: The aim of this study was to determine the distribution of corneal volume (CV) using Pentacam and its relationship with demographic and ocular factors in an elderly population older than 60 years. METHODS: The present report is a part of the Tehran Geriatric Eye Study. The sampling was performed using the multistage stratified random cluster sampling method. The preliminary ocular examinations were performed for all individuals including visual acuity measurement, objective and subjective refraction, and slit-lamp biomicroscopy. Finally, study participants underwent anterior segment imaging and ocular biometry using Pentacam AXL. RESULTS: The mean CV was 57.92 mm 3 [95% confidence interval (CI): 57.76-58.08] in the whole sample. The mean CV was 57.69 mm 3 (95% CI: 57.52-57.87) after excluding diabetic patients. The mean CV was 57.79 mm 3 (95% CI: 57.57-58.01) and 58.04 mm 3 (95% CI: 57.83-58.26) in men and women, respectively. The mean CV was 57.96 mm 3 (95% CI: 57.71-58.21), 57.84 mm 3 (95% CI: 57.49-58.19), and 57.92 mm 3 (95% CI: 57.7-58.13) in individuals with emmetropia, myopia, and hyperopia, respectively. The CV decreased significantly with advancing age. Moreover, the anterior chamber depth, central corneal thickness, mean keratometry, anterior corneal asphericity (Q value), and posterior corneal astigmatism were significantly directly related to CV, whereas axial length and white-to-white distance had a statistically significant inverse association with the CV. CONCLUSIONS: Aging is one of the important factors in reducing CV that should be considered. Some other topographic and biometric indices also have a significant relationship with CV.

Central corneal thickness and its determinants in a geriatric population: a population-based study.

PURPOSE: To determine the distribution of central corneal thickness (CCT) and its determinants in an Iranian geriatric population. METHODS: This population-based study was conducted in 2019 in Tehran, the capital of Iran, using stratified multistage random cluster sampling. The study population was all residents ≥60 years of age. First, preliminary optometric and ocular health examinations were performed including the measurement of uncorrected and best-corrected visual acuity, objective and subjective refraction, anterior and posterior segment examination. The study participants then underwent corneal imaging using Pentacam HR. RESULTS: Out of 3791 invitees, 3310 participated in this study (response rate: 87.3%). The mean CCT and apex corneal thicknesses were 528 µ (95% CI: 526-529) and 529 µ (95% CI: 527-530), respectively. The highest and lowest mean corneal thickness was related to the superior (620 µ: 95% CI: 618-622) and the temporal (591 µ: 95% CI: 590-592) paracentral points, respectively. According to the multiple linear regression model, the CCT was significantly inversely related to keratometry readings (K1 and K2) and had a statistically significant direct relationship with intraocular pressure (IOP), corneal eccentricity (ECC), and corneal volume (CV) (all p values <0.05). The CCT was significantly higher in diabetic patients (p = 0.043). CONCLUSION: The CCT values in the geriatric Iranian population were lower than the values reported in most previous studies. The CCT is mostly influenced by IOP and corneal parameters (curvature, shape factor, and volume) and is not affected by demographic factors, refractive error, and ocular biometric components.

Anterior and posterior corneal higher-order aberrations in early diagnosis and grading of keratoconus.

CLINICAL RELEVANCE: Evaluation of corneal higher-order aberrations can be used clinically to diagnose early cases of keratoconus as well as to classify the severity of keratoconus. BACKGROUND: To investigate the anterior and posterior corneal higher-order aberrations (HOAs) up to the sixth order and their ability to identify early keratoconus (KCN) as well as differentiate different severities of KCN using cross-validation analysis. METHODS: This prospective cross-sectional comparative study was performed at a tertiary eye hospital in Tehran, Iran, in 2019. The study sample consisted of 95 eyes of 95 patients with KCN and 53 eyes of 53 normal individuals. The eyes with KCN were classified into three groups based on the Amsler-Krumeich classification system: group 1 (mild KCN), group 2 (moderate KCN), and group 3 (severe KCN). Corneal wavefront analysis was performed using Pentacam HR. RESULTS: Based on the magnitude of AUC, posterior vertical secondary coma (Z5-1) had an excellent discriminant ability (AUC: 0.91) and anterior vertical coma (Z3-1) and anterior vertical secondary coma (Z5-1) had a good discriminant ability (0.8 < AUC < 0.89) for differentiating eyes with mild KCN from normal eyes. The anterior and posterior primary spherical aberrations (Z4°) had an excellent ability (AUC > 0.9), and anterior secondary spherical aberration (Z6°) had a good ability (AUC: 0.83) for differentiating moderate from mild KCN. In the differentiation of severe from moderate KCN, anterior and posterior primary aspherical aberrations (Z4°) had a good AUC value (AUC > 0.8). CONCLUSION: Coma-like aberrations had a good discriminant ability between normal eyes and eyes with mild KCN. Spherical aberrations showed a good ability for differentiating between different stages of KCN. The cut-off values reported in this study can be used for early detection of KCN as well as classification of KCN severity.

Refractive Errors and Their Associated Factors in Schoolchildren: A Structural Equation Modeling.

PURPOSE: To determine the prevalence of myopia and hyperopia in Shahroud schoolchildren and their risk factors. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Prevalence and Causes of Visual Impairment and Blindness in Elderly Population; an Urgent Geriatric Health Issue: Tehran Geriatric Eye Study (TGES).

PURPOSE: To determine the prevalence of vision impairment (VI) and blindness and their determinants in the elderly population of Tehran. METHODS: In a cross-sectional study, multi-stage cluster sampling was used to select a sample of over 60 year population of Tehran. Optometric examinations included the measurement of uncorrected visual acuity, objective and subjective refraction, presenting and best corrected visual acuity. Vision impairment is reported according to the WHO definition. Visual acuity worse than 20/60 and 20/400 in the better eye was regarded as low vision and blindness, respectively. RESULTS: According to presenting visual acuity, VI was found in 14.8% (95%CI: 13.1-16.5) of the participants, including low vision in 13.8% (95%CI: 12.2-15.4) and blindness in 1.1% (95%CI: 0.5-1.6). The prevalence of VI ranged between 7.8% (95%CI: 6.0-9.5) in subjects aged 60-64 years and 40.0% (95%CI: 33.0-47.0) in participants over 80 years (p < .001). Multivariable logistic regression analysis showed that older age (OR = 1.07(per year)), lower education level (illiterate versus college: OR = 3.55), and lower economic status (middle versus rich: OR = 1.30 and poor versus rich; OR = 1.72) had a significant relationship with an increase in the prevalence of VI, and older age (OR = 1.14(Per year increase)) and diabetes (OR = 2.62) had a significant relationship with blindness. Refractive errors (63.1%) was the leading cause of VI followed by cataract (22.5%). However, cataract (48.3%) was the leading cause of blindness. CONCLUSION: Many older adults suffer from VI. Correction of refractive errors and cataract reduces a large percentage of VI. Age, education level, and economic status are other determinants of VI.

Does Long-Term Night Shift Work Cause Dry Eye in Hospital Nurses?

Purpose: To determine the long-term effects of night shift work on dry eye in hospital nurses. Methods: Each participant was evaluated four times, including at the beginning of the day shift (8 am), at the end of the day shift (2 pm), at the beginning of the night shift (8 pm), and at the end of the night shift (8 am), using the tear break-up time (TBUT) test and ocular surface disease index (OSDI) questionnaire. Results: The results showed significant differences in the TBUT and OSDI between the end of the day shift (2 pm) (10.26, 16.61) and the end of the night shift (8 am) (6.89, 38.59) relative to each other and relative to the beginning of the day and night shifts. As for the correlation between TBUT and OSDI, a significant correlation was found at all measurement times (correlation coefficient: -0.478, -0.707, -0.556, and -0.365, respectively) (p < 0.05). Conclusion: The results showed that the severity of dry eye increased after the night shift with variation over a 24-hr period. Moreover, a significant correlation was observed between TBUT and OSDI results at the beginning and at the end of the day and night shifts.

Governmental support for achieving "VISION 2020: the Right to Sight" in Iran: the cataract surgical rates.

PURPOSE: The aim of this study was evaluate the effect of governmental support in the form of Health Transformation Plan (HTP) on increasing the cataract surgical rate. METHODS: The number of cataract surgeries was collected from Iranian cataract surgery clinics during 2019. HTP was implemented in 2014. Forty-seven major and forty-five minor surgery centers were selected from all provinces. In each center, sampling was done from 2012, 2013, 2015, and 2016. RESULTS: On average, 6202 and 7134 cataract surgery rate were performed before and after HTP, respectively. The cataract surgical rate rose by 15.03% after the HTP. After HTP, the proportion of cataract surgery increased by 21.32% in governmental centers and decreased by 17.56%, 24.45%, and 14.89% in private, insurance, and charity centers, respectively. The cataract surgical rate was 4093 and 6026 in the first economic quartile (the poorest), 3669 and 4595 in the second quartile, 5884 and 5928 in the third quartile, and 8427 and 9681 in the fourth quartile (the richest) before and after HTP, respectively. The highest growth in the cataract surgical rate was seen in the first quartile (47.24%) followed by the second (25.26%), fourth (14.88%), and third quartiles (0.74%). CONCLUSION: The Health Transformation Plan has been successful in increasing the cataract surgical rate in the low-income group and identifying differences in the services as well as the economic groups within the population.

Astigmatism profile in the elderly population: Tehran Geriatric Eye Study.

PURPOSE: To determine the prevalence of astigmatism and its associated factors and examine astigmatism symmetry patterns in an elderly population. STUDY DESIGN: Population based cross-sectional study. METHODS: The present population-based cross-sectional study was conducted on an elderly population above 60 years of age in Tehran, Iran in 2019. The sampling was done using the stratified multistage random cluster sampling method. All study participants underwent a complete optometric examination and slit-lamp biomicroscopy. RESULTS: The prevalence of astigmatism higher than -0.50, -1.00, and -2.00 D was 83% (95% CI: 81 -84), 52 % (95% CI: 50 -54), and 19% (95% CI: 17-20), respectively. These prevalence was 79%(95% CI: 77-81), 46(95% CI: 44-49) and 14(95% CI: 13-16) in subjects without a history of ocular surgery, respectively. Based on cylinder power worse than -1.00 D, 10% (95% CI: 9-12), 20% (95% CI: 18-22), and 21% (95% CI:19-23) of study participants had with the rule, against the rule, and oblique astigmatism, respectively. According to the results of the multiple regression model, male gender, older age, low education level, pure posterior subcapsular cataract, pseudophakia, and myopia were independent factors associated with astigmatism. The prevalence of anisorule astigmatism was 57 % (95% CI: 56-59), the most common anisorule astigmatism was against the rule-oblique type with a prevalence of 36% (95% CI: 34-38). CONCLUSION: The prevalence of astigmatism was high in the elderly population of Tehran. More than half of the participants in this study had anisorule astigmatism, and against the rule-oblique combination was more prevalent than other types. A posterior subcapsular cataract, a history of cataract surgery, and myopia were the associated factors of astigmatism in this study.

Prevalence and associated factors of corneal arcus in the geriatric population; Tehran geriatric eye study.

PURPOSE: To determine the age and sex-standardized prevalence of corneal arcus and its associated factors in a geriatric population. METHODS: This population-based cross-sectional study was conducted in 2019 in Tehran; the capital of Iran, using a multi-stage stratified random cluster sampling method. All participants underwent a detailed interview, blood pressure measurement, laboratory blood tests, and a complete ocular examination. RESULTS: Three thousand three hundred ten of 3791 invitees participated in the study (response rate: 87.31%). The mean age of the participants was 69.35 ± 7.62 years (60-97 years) and 1912 (57.76%) were female. Overall, the age and sex-standardized prevalence (95% CI) of corneal arcus was 44.28% (41.21-47.39). Based on the multiple logistic regression, the odds of corneal arcus were higher in men than in women (OR: 1.51; 95% CI: 1.14-2.00); in the age group ≥ 80 years compared to the age group 60-64 years (OR: 2.44; 95% CI: 1.68-3.53), and in retired people compared to employed individuals (OR: 2.05; 95% CI: 1.31-3.21). CONCLUSION: The present study showed a high prevalence of corneal arcus in the geriatric population. Although various studies have reported a significant relationship between corneal arcus with blood lipid and glucose levels as well as blood pressure, these relationships were not found in the present study.

Age and Sex Standardized Prevalence of Corneal Opacity and Its Determinants; Tehran Geriatric Eye Study (TGES).

Background: We aimed to determine the age and sex standardized prevalence of corneal opacity and its determinants. Methods: The Tehran Geriatric Eye Study (TGES) is a population-based cross-sectional study conducted on 3791 subjects aged above 60 yr in Tehran, Iran (2019) selected using stratified random cluster sampling. After sampling, all subjects underwent complete ophthalmic, optometric, and eye examinations. Results: The 3310 participated in the study, of whom the data of 3284 were analyzed. The age and sex standardized prevalence with 95% confidence interval (CI) of corneal opacity in at least one eye, both eyes, and one eye was 9.58% (95% CI: 8.50 to 10.79), 5.52% (95% CI: 4.71 to 6.45), and 4.07% (95% CI: 3.35 to 4.94), respectively. The mean uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA) according to LogMar were worse in subjects with corneal opacity (both P<0.001). According to multiple logistic regression analysis, male sex (OR: 1.98; P: 0.003), age>80 yr (OR: 2.05; P: 0.004), and lack of insurance coverage (OR: 1.87; P: 0.004) increased the odds and high school education (OR: 0.68; P: 0.003) reduced the odds of corneal opacity. Among the study variables, sex was the most important determinant of corneal opacity (standardized beta: 0.126). Conclusion: This study found a high prevalence of corneal opacity in the geriatric population. Considering the increasing trend of population aging in Iran, attention should be paid to prioritizing public health policies to estimate resources required for providing comprehensive corneal services and improving geriatric eye health.