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Background: Comminuted subtrochanteric fractures have been a challenge for orthopedic surgeons in terms of appropriate reduction and stable fixation. Numerous methods have been used for the fixation of comminuted subtrochanteric fractures among which some are accompanied with technical difficulties and complications of their own. Regarding the results of previous studies, we decided to evaluate the biological fixation method in comminuted subtrochanteric fractures. Methods: In this prospective study, we evaluated 20 men with comminuted subtrochanteric femoral fractures. The patients underwent indirect reduction with dynamic hip screw (DHS) or dynamic condylar screw (DCS) fixation within one week of injury. The patients were evaluated clinically for pain, hip and knee range of motion, leg-length discrepancy and angular and rotational deformities, in addition the radiographic assessment of the ::::union::::. Results: According to Seinsheimer's classification of subtrochanteric fractures, four patients had type III, nine had type IV and seven had type V fractures. Fracture fixation was performed by DCS in eight and by DHS in 12 cases. The average time of the operations was 79.4 (ranging from 60-125) minutes. Mean blood loss was 634 (ranging from 340-1160) milliliters. Uneventfully, ::::union:::: occurred in all patients with no clinical pain or dysfunction. Conclusion: Submuscular plating with either DCS or DHS is a viable option to treat comminuted subtrochanteric fractures. The results of this study highly suggest use of submuscular plating in the treatment of comminuted subtrochanteric fractures, especially in the third world countries.

To determine the distribution of keratometry and corneal astigmatism (CA) and their association with demographic factors, systemic parameters, anthropometric measures, ocular biometric indices, and refractive errors in people aged 60 years and above. In this cross-sectional study, 160 clusters were randomly selected from Tehran city (Iran) using the multi-stage cluster sampling method. All participants underwent optometric examinations including testing uncorrected and best-corrected distance visual acuity, non-cycloplegic autorefraction, and subjective refraction. Pentacam imaging for all participants was carried out using Pentacam AXL. Keratometry and CA were reported based on Pentacam's data. The average, standard deviation (SD) and 95% confidence interval (CI) of flat keratometry (Kf), steep keratometry (Ks), mean keratometry (mean K), and CA were 44.02 ± 1.58 D (95% CI 43.94-44.1), 44.86 ± 1.67 D (95% CI 44.78-44.94), 44.44 ± 1.58 D (95% CI 44.36-44.52), and 0.84 ± 0.74 D (95% CI 0.81-0.87), respectively. The 95% and 99% percentiles of mean K were 47.1 and 48.6 D, respectively. According to the multiple generalized estimating equation model, the mean K was significantly higher in males, in myopes, and in those with higher systolic blood pressure. Moreover, the mean K was inversely related to the axial length, height, anterior chamber depth (ACD), corneal diameter, and central corneal thickness (CCT). The prevalence of various types of CA based on a cut-off > 0.50 D was as follows; with-the-rule: 32.5% (95% CI 30.6-34.4), against-the-rule: 18.2% (95% CI 16.7-19.7), and oblique: 10.0% (95% CI 9.1-11.0). The present study investigated the normal distribution of keratometry and CA in individuals ≥ 60 years, and results can be used in clinical matters, especially in intraocular lens power calculation. Sex, systolic blood pressure, height, and some biometric components such as ACD, corneal diameter, and CCT were significantly related to keratometry and should be considered., (© 2024. The Author(s).)

Background: Corneal abnormalities are one of the important reasons for visual impairment. There is little evidence of the prevalence of different types of corneal abnormalities. The aim of this study was to assess the prevalence of various corneal abnormalities and identify the key risk factors associated with these abnormalities in an elderly population residing in Tehran., Methods: The Tehran Geriatric Eye Study (TGES) was conducted as a cross-sectional study, utilizing a population-based approach and employing stratified cluster random sampling. The study focused on individuals aged 60 years and above residing in Tehran. An ophthalmologist performed a slit lamp examination to evaluate the eyelid, cornea, and crystalline lens., Results: The prevalence of posterior embryotoxon (PE), punctate epithelial defect (PED), pigment on endothelium (POE), corneal dystrophy (CDys), corneal vascularization (CV), and corneal degeneration (CDeg) were estimated to be 0.08% (95% confidence interval [CI]: 0.02 to 0.40), 8.77% (95% CI: 6.64 to 11.51), 0.57% (95% CI: 0.33 to 0.98), 0.53% (95% CI: 0.33 to 0.82), 0.95% (95% CI: 0.60 to 1.52), and 44.87% (95% CI: 41.80 to 47.98), respectively. Overall, approximately 49.08% of the participants exhibited some form of corneal abnormality in at least one eye. The multiple logistic regression model revealed that increasing age was significantly associated with PED, CV, and CD. Furthermore, illiterate participants had a significantly higher prevalence of PE., Conclusion: The findings of this study indicate that approximately half of the elderly population aged 60 years and above in Tehran have at least one corneal abnormality, with corneal degeneration being the most prevalent. Age was identified as the primary determinant of corneal abnormalities., (© 2024 The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.)

Aim: To determine the prevalence of some retinal pathologies in people over 60y and their association with demographic and ocular factors., Methods: A cross-sectional study was conducted in Tehran using multistage cluster sampling. After selecting subjects aged 60 and over, optometric, and ophthalmic examinations were done. For retinal examination, a 90 D lens was used and indirect ophthalmoscopy was performed after instilling tropicamide drops. Biometry was done using the IOL Master for all participants., Results: Of 3791 people that were invited through cluster sampling, 3310 participated in the study (response rate=82%). The prevalence of retinal pigmented epithelium (RPE) change, drusen, geographic atrophy (GA), hypertensive retinopathy (HTR), nonproliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR), choroidal neovascularization (CNV), central retinal artery occlusion (CRAO), myopic retinopathy (MR), branch retinal vein occlusion (BRVO), and central retinal vein occlusion (CRVO) was 27.42%, 11.08%, 4.52%, 3.03%, 4.05%, 0.54%, 0.82%, 0.39%, 0.20%, 0.49%, and 0.19%, respectively. After removing the effect of age, the odds of NPDR were 1.68 times higher in women compared to men ( P =0.014). After removing the effect of sex, the odds of drusen, RPE change, GA, CNV, BRVO, and CRVO increased with age., Conclusion: There is a higher prevalence of RPE change, drusen, GA, CNV and a lower prevalence of MR and CRAO in the elderly population of Tehran aged over 60y compared to global average values. Considering the correlation of most of the diseases with age and their effects on vision, attention should be paid to these diseases and the related screening programs to prevent vision impairment., Competing Interests: Conflicts of Interest: Mortazavi A, None; Hashemi A, None; Jamali A, None; Hashemi H, None; Aghamirsalim M, None; Khabazkhoob M, None., (International Journal of Ophthalmology Press.)

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., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

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., (International Journal of Ophthalmology Press.)

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., (© 2022. The Author(s), under exclusive licence to The Royal College of Ophthalmologists.)

Purpose: To determine the two-year results of small incision lenticule extraction (SMILE) for correcting post-keratoplasty myopia and myopic astigmatism., Methods: In this case-series study, 10 eyes of 10 patients with a 6- to 10-year history of successful deep lamellar keratoplasty (DALK) underwent SMILE using the VisuMax laser platform. Ophthalmologic examinations and visual acuity and refraction measurement were taken pre- and 1, 3, 6, 12, and 24 months postoperatively. The Pentacam and Sirius imaging were done in the first and last follow-up sessions., Results: The mean age of the patients was 39.60 ± 7.86 years. Six subjects were male. Two years after SMILE, the mean improvement in UDVA and CDVA was 3.60 ± 1.84 (P < 0.001) and 1.60 ± 2.91 (P = 0.231) LogMAR, respectively. The mean decrease in spherical equivalent, spherical error, and cylinder power was 1.92 ± 1.96 diopter (D) (P = 0.013), 0.70 ± 3.05D (P = 0.213), and 2.42 ± 2.91D (P = 0.024), respectively. The vector mean target-induced astigmatism, surgical-induced astigmatism, and difference vector were 1.30D@44˚, 1.11D@24˚, and 0.86D@73˚, respectively. Two years after SMILE, vertical coma, horizontal coma, and spherical aberration increased by 0.44 ± 0.51, 0.23 ± 0.32, and 0.02 ± 0.16 µm, respectively, (all P > 0.05) while trefoil reduced by 0.29 ± 0.75 µm (P = 0.428)., Conclusion: SMILE can be an effective procedure for reducing refraction and astigmatism after DALK in patients with moderate myopia and moderate to severe astigmatism and improves the visual acuity in these patients. Axis rotation during surgery may result in under-correction of astigmatism. Refinement of SMILE treatment nomogram for post-DALK cases seems necessary., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Purpose: To determine the prevalence of cataract and its relationship with some determinants in individuals above 60 years., Methods: 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., Results: 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., Conclusion: 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.

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., (© 2022. Japanese Ophthalmological Society.)

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., (© 2022. The Author(s).)

Corneal disease is one of the most significant causes of blindness around the world. Presently, corneal transplantation is the only way to treat cornea blindness. It should be noted that the amount of cornea that people donate is so much less than that required (1:70). Therefore, scientists have tried to resolve this problem with tissue engineering and regenerative medicine. Fabricating cornea with traditional methods is difficult due to their unique properties, such as transparency and geometry. Bioprinting is a technology based on additive manufacturing that can use different biomaterials as bioink for tissue engineering, and the emergence of 3D bioprinting presents a clear possibility to overcome this problem. This new technology requires special materials for printing scaffolds with acceptable biocompatibility. Hydrogels have received significant attention in the past 50 years, and they have been distinguished from other materials because of their unique and outstanding properties. Therefore, hydrogels could be a good bioink for the bioprinting of different scaffolds for corneal tissue engineering. In this review, we discuss the use of different types of hydrogel for bioink for corneal tissue engineering and various methods that have been used for bioprinting. Furthermore, the properties of hydrogels and different types of hydrogels are described.

Purpose: To determine the repeatability of corneal densitometry measured by the Scheimpflug imaging system., Methods: This cross-sectional study was conducted on photorefractive keratectomy candidates. One eye of each participant underwent imaging using Pentacam HR three times, 10 min apart. The repeatability of densitometry measurements was evaluated in four concentric annuli around the corneal apex and in different corneal depths. The repeatability of the measurements was evaluated using the intraclass correlation coefficient (ICC), repeatability coefficient (RC), and coefficient of variation (CV). The difference of repeatability between layers and zones was tested by tolerance index (TI)., Results: Sixty eyes of sixty patients with a mean age of 27.76 ± 3.93 years were studied. Half of the participants were female ( n = 30, 50%). ICC was above 0.9 in all corneal parts. The posterior layer and central zones showed the least variability of densitometry measurements considering the CV values. The RC was 2.06, 1.17, and 0.92 in anterior, central, and posterior layers, respectively. The RC was 0.88, 0.71, 1.51, and 4.56 in 0-2, 2-6, 6-10, and 10-12 mm circles, respectively. Only the reliability of densitometry in 10-12 mm annulus was statistically lower than the central zone (TI = 0.71)., Conclusions: Corneal densitometry measurements provided by the Pentacam had good repeatability. The repeatability of densitometry measurements decreased from the center to the periphery (with an exception for 0-2 mm and 2-6 mm) and from the posterior to the anterior of the cornea. The reliability of the 10-12 mm zone was markedly less than other zones., Competing Interests: There are no conflicts of interest., (Copyright: © 2022 Journal of Current Ophthalmology.)

Purpose: The purpose of this study was to evaluate the efficacy and safety of implantation of a new continuous corneal ring in keratoconic corneas of an Iranian population., Methods: This study was conducted on 95 contact lens-intolerant keratoconic eyes with clear central corneas. A continuous corneal ring, annular intrastromal corneal inlay (AICI), was inserted using femtosecond laser in all cases. Patients were followed up for 1, 3, and 12 months postsurgery. Visual and subjective refractive outcomes were evaluated in each examination. Besides, keratometry and aberrometric values were recorded before and 12 months after surgery. Finally, vector analysis of refractive astigmatism was performed using the Alpins method., Results: The uncorrected and corrected distance visual acuities improved significantly 12 months after surgery from 0.91 ± 0.39 to 0.38 ± 0.22 (P < 0 0.001) and 0.33 ± 0.21 to 0.13 ± 0.11 logMAR (P < 0.001), respectively. Moreover, spherical and cylindrical refractive components reduced from -2.52 ± 2.62 to -0.76 ± 1.78 D (P < 0.001) and -4.14 ± 1.64 to -1.91 ± 1.18 D (P < 0.001), respectively. The mean anterior keratometry had a significant reduction 12 months after AICI insertion (P< 0.001). Primary coma and spherical aberration values showed a significant increase (both, P < 0.05). Our results showed 100% safety (safety index: 1.8) and 45% efficacy (efficacy index: 1)., Conclusions: AICI implantation seemed to be a safe and effective procedure for improving visual acuity and refractive outcomes in subjects with keratoconus., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: To determine the age-sex-standardized prevalence of uncorrected refractive error and its determinants., Methods: This population-based cross-sectional study was conducted on 3310 people aged≥ 60 years in Tehran, Iran in 2019. Need for spectacles was defined as uncorrected visual acuity worse than 20/40 in better eye that could be corrected to more than 20/40 with suitable spectacles. Met need was defined as proportion of individuals with need for spectacles whose visual acuity was 20/40 or better with current spectacles. Unmet need was defined as proportion of individuals with need for spectacles who needed but did not have spectacles or their visual acuity was worse than 20/40 with current spectacles while suitable spectacles improved their visual acuity to 20/40 or better., Results: The age-sex-standardized prevalence of need for spectacles, met need, and unmet need was 16.67% (95% CI: 15.33-18.09), 7.81% (95% CI: 6.95-8.78), and 8.85% (95% CI: 7.77-10.07), respectively. Myopic subjects had the highest prevalence of need for spectacles (24.06%, 95% CI: 21.47-26.87). The odds ratio of met and unmet need in subjects≥ 80 years versus those aged 60-65 years was 0.36 ( p -value: 0.009) and 2.34 ( p -value: <0.001), respectively. The odds ratio of met and unmet need in subjects with a university education versus illiterate subjects was 1.72 ( p -value: 0.045) and 0.42 ( p -value: 0.007), respectively., Conclusion: The prevalence of uncorrected refractive error was lower in this study compared to previous studies. The met need rate was lower in subjects with older age and lower education levels.

Purpose: To compare the effect of duration of fluorometholone 0.1% treatment on corneal haze after photorefractive keratectomy (PRK) with mitomycin C (MMC) 0.02%., Design: Prospective, randomized, double-blind, clinical trial., Methods: Single-center clinical trial of 252 myopic PRK candidates (252 eyes) aged 21 to 40 years with a mean spherical equivalent (SE) of ≤ 6 diopters (D). Participants were randomized to receive one of the three corticosteroid regimens after PRK: Group A = 1 month followed by 2-month placebo; Group B = 2 months followed by 1-month placebo; and Group C = 3 months. The main outcome measures were corneal haze incidence, subjective SE, uncorrected distance visual acuity (UDVA), and corneal densitometry., Results: The corneal haze incidence (Grade ≥ 1) at 12 months was 1.35% (1/74 eyes) in Group A and 0% in the other two groups. The mean anterior corneal densitometry (grayscale unit) was 21.19 ± 2.07, 21.09 ± 2.19, and 21.31 ± 2.21 in Groups A, B and C, respectively. The mean SE was 0 ± 0.09, 0 ± 0.11, and 0 ± 0.10, and UDVA (decimal) was 1 ± 0, 1 ± 0.01, and 1 ± 0 in Groups A, B and C, respectively. During 1-year follow-up, no statistically significant difference was observed in mean SE (P = .158), UDVA (P = .343), and anterior corneal densitometry (P = .109) at any stage between the study groups., Conclusions: Long-term topical corticosteroids are unnecessary following PRK with MMC for moderate myopia., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: To assess transepithelial photorefractive keratectomy (tPRK) in terms of corneal epithelial healing rate, postoperative pain, postoperative discomfort, and visual and refraction outcomes compared to mechanical epithelial debridement PRK (mPRK) and alcohol-assisted PRK (aaPRK)., Methods: In this double-masked, randomized clinical trial, thirty-nine patients underwent tPRK in one eye and mPRK in the fellow eye (arm A), and 33 patients underwent tPRK in one eye and aaPRK in the contralateral eye (arm B). All surgical procedures were done using the Schwind Amaris excimer laser. The area of corneal epithelial defect in all eyes was captured and analyzed using ImageJ software., Results: Mean epithelial healing time was respectively 3.74 ± 0.82 and 3.59 ± 0.79 days in tPRK versus mPRK (P = 0.21) in arm A, and 3.67 ± 0.92 and 3.67 ± 0.74 days in tPRK versus aaPRK (P = 1.00) in arm B. Accounting for the initial corneal epithelial defect area, the epithelial healing rate was faster in conventional PRK groups compared to tPRK (both P<0.001) in both arms. However, there was no significant difference in safety, efficacy, spherical equivalent refractive accuracy, or corneal haze development between tPRK and conventional PRK groups (all P > 0.05)., Conclusions: All three methods are effective in terms of visual and refractive outcomes. However, although time to complete re-epithelialization was similar with the three methods, the epithelial healing rate was faster in conventional PRK considering the initial corneal epithelial defect area, and the patients experienced less pain and discomfort in the first postoperative day., Trial Registration: IRCT, IRCT20200317046804N1 . Retrospectively registered 5 May 2020., (© 2022. The Author(s).)

Purpose: The aim of the present study was to evaluate the topographic status of the welders' corneas., Methods: In this historical cohort, a group of welders (with at least 5 years' experience in welding) and a control group were assessed and compared. Lack of exposure to welding for 3 months or more was considered an exclusion criterion. In all participants, after taking a complete history of visual and ocular problems, both eyes underwent Pentacam imaging. Then, all subjects received slit lamp biomicroscopy for evaluation of ocular surface diseases., Results: The data of 140 welders (mean age: 46.66 ± 13.01 years) and 172 controls (mean age: 45.05 ± 12.61 years) were analyzed. The welders' corneas had significantly higher eccentricity ( p  < 0.0001), keratometry readings ( p  < 0.0001), and cylinder power ( p  < 0.0001). The central, inferior, and nasal cornea were significantly thinner in the welders than in controls ( p  < 0.0001) while the difference was not significant in the superior and temporal cornea. All indices of corneal irregularity except for the central keratoconus index (CKI) and index of height asymmetry (IHA) were higher in welders compared to the control group ( p  < 0.0001)., Conclusion: According to the results of this study, the welders' corneas are topographically irregular. Welders exhibit characteristics like steeper keratometry readings; higher eccentricity indexes; thinner central, inferior, and nasal corneas; and higher indices of corneal irregularity, especially the CK index. Long-term ultraviolet exposure may be a possible reason for these corneal changes.

Purpose: To determine the age and sex-standardized prevalence and risk factors of anterior blepharitis in a geriatric population in "…"., Methods: This population-based study was conducted on the elderly population (over 60 years of age) of Tehran, the capital of "…" in 2019. Examinations included visual acuity assessment, refraction, and complete slit lamp examination. After the diagnosis of anterior blepharitis, its type (staphylococcal vs. seborrheic) was also determined. Multiple logistic regression was used to determine the risk factors of the disease., Results: 3310 individuals participated in this study. The data of 3284 participants were available for this report. The mean age of the participants was 68.6 ± 24.5 years, and (57.8 %) were female. Age and sex-standardized prevalence of anterior blepharitis was 33.5 % (95 % CI: 30.6-36.5%) of which 96.5 % were bilateral. The prevalence of seborrheic and staphylococcal types was 22.4 % (95 % CI: 19.9-25.2%) and 11.3 % (95 % CI: 9.2-13.5%), respectively. According to the multiple logistic regression, the prevalence of anterior blepharitis was positively related to age over 80 years (P < 0.001) and male gender (P < 0.001), and inversely related to education level (P = 0.033). No significant relationship was found between anterior blepharitis and other variables including systemic hypertension, diabetes mellitus, hyperlipidemia, smoking, socioeconomic status, and history of the previous eye examination. Sex had the greatest effect on developing anterior blepharitis (standardized coefficient: 0.325)., Conclusion: The results of this study showed a relatively high prevalence of anterior blepharitis in the elderly population which requires special attention of the health system to inform and control this disease through continuous training of the media and regional health centers., (Copyright © 2021 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Background: To determine the distribution of the near point of convergence (NPC) and its related factors in an elderly population in Tehran, Iran., Methods: This population-based cross-sectional study was conducted on the elderly population (60 years of age and over) of Tehran, Iran in 2019. The samples were selected using stratified random cluster sampling. The examinations included the measurement of uncorrected and best-corrected visual acuity, objective and subjective refraction, unilateral and alternate cover test, ocular health examination, and NPC measurement., Results: The mean age of the participants was 65.90 ± 4.56 years and 59.6% of them were females. The mean (95% CI) NPC in the total sample was 7.84 cm (95% CI: 7.65-8.03). The mean (95% CI) NPC in males and females was 7.92 cm (7.63-8.21) and 7.75 cm (7.54-7.97) (P = 0.338), respectively. The mean NPC increased from 7.8 cm (95% CI: 7.55-8.05) in the age group 60-64 years to 8.83 cm (95% CI: 7.47-10.2) in the age group ≥ 80 years (P > 0.05). The mean (95% CI) NPC in emmetropic, myopic, and hyperopic individuals was 7.67 cm (95% CI: 7.33-8.02), 7.96 cm (7.56-8.37), and 7.87 cm (7.63-8.11), respectively (P = 0.378). There was no statistically significant relationship between NPC with education level, smoking, diabetes mellitus (DM), and hypertension (HT)., Conclusions: The NPC values found in this study were significantly lower (less remote) than the values reported in previous studies in similar age groups. The NPC had no significant relationship with age, sex, education level, smoking, DM, and HT., (© 2021. The Author(s), under exclusive licence to The Royal College of Ophthalmologists.)

Purpose: This study was conducted to determine economic inequality in Eye Care Services Utilization (ECSU) and its determinants in the underserved rural population of Iran., Methods: In this population-based study, two underserved regions in the north and southwest of Iran were randomly selected and 3850 individuals living in these regions were invited to participate in the study. ESCU was defined as a history of at least one optometric or ophthalmologic visit during the lifetime. Concentration index (C) was used to evaluate economic inequality and the Oaxaca- Blinder decomposition was applied to decompose the gap between the rich and poor., Results: Of 3851 individuals, 3314 participated in the study (response rate: 86%). The data of 3094 participants were analyzed. The concentration index was 0.139 (95% CI: 0.218 - 0.590), indicating a pro-rich inequality in the ECSU. The ECSU was 12.38% (10.46 to 14.31) in the poor and 21.15% (18.38 to 23.92) in the rich, and the gap between them was about 90% in favor of the rich ( p < 00.001). A marked percentage of the gap was due to the explained portion (b: -11.49; p < .001). The unexplained portion coefficient was b: 2.72 (p: 0.020). In the explained portion, economic status (b: -12.37; p < .001) and age (b: 0.90; p: 0.021) caused inequality in favor of the rich and poor respectively while only economic status (b:-21.1; p < .001) had a significant effect on inequality in favor of the rich in the unexplained portion., Conclusion: There is a significant pro-rich inequality in ECSU in the rural areas of Iran. A major portion of this inequality is related to differences in age and economic status between the two groups. Economic status has direct and indirect effects on inequality in ECSU; therefore, health policymakers should focus on economic improvement to remove the gap.

Purpose: To determine the prevalence of fusional vergence dysfunction (FVD) and its relationship with age, sex, and refractive errors in a population-based study., Methods: In this cross-sectional study, all residents of Mashhad, northeast of Iran, aged >1 year were subjected to random stratified cluster sampling. After selecting the participants, they all underwent complete optometric examinations including the measurement of visual acuity and refraction, assessment of binocular vision and accommodative status, and slit-lamp biomicroscopy., Results: Of 4453 invited individuals, 3132 participated in the study. After applying the exclusion criteria, statistical analysis was performed on the data of 1683 participants. The prevalence of FVD was 3.2% in all participants, 4.0% in men, and 2.9% in women ( P = 0.234). The prevalence of FVD increased linearly with aging from 2.3% in the age group of 10-19 years to 5.4% in the age group of 40-49 years ( P = 0.034). The prevalence of myopia, hyperopia, and emmetropia was 11.1%, 29.6%, and 59.3% in participants with FVD and 16.7%, 26.4%, and 57% in participants without FVD, respectively ( P = 0.570). Multiple logistic regression analysis only showed a significant association between age and FVD (odds ratio =1.03 95% confidence interval: 1.02-1.05, P = 0.031)., Conclusion: The prevalence of FVD in this study was higher than most previous reports and increased significantly with aging. FVD had no significant association with sex and refractive errors., Competing Interests: There are no conflicts of interest., (Copyright: © 2021 Journal of Current Ophthalmology.)

Purpose: To determine the distribution of the corneal asphericity coefficient (Q value) and related factors in an Iranian geriatric population., Methods: This population-based study was conducted in 2019 in Tehran, using stratified multistage random cluster sampling. The study population was ≥60 years of age. Participants underwent corneal imaging using a Pentacam HR. Mean keratometry, corneal astigmatism, central corneal thickness, anterior chamber depth and the overall anterior and posterior Q values (for 8 mm chord diameter) were recorded. Axial length measurements were performed using the IOL Master 500., Results: 2457 eyes of 2457 individuals were analysed. The mean age was 67.3 ± 5.82 years and 1479 (60.2%) were female. The mean Q value for the anterior corneal surface was -0.35 ± 0.17 (95% CI: -0.35 to -0.34). The anterior Q value showed a statistically significant inverse relationship with axial length and mean keratometry, and a significant direct association with anterior chamber depth and corneal astigmatism. The mean posterior Q value was -0.41 ± 0.15 (95% CI: -0.42 to -0.40). The posterior Q value had a significant direct relationship with age, anterior chamber depth, mean keratometry and corneal astigmatism., Conclusion: The corneal Q values in this geriatric Iranian population were more negative than the values reported in most previous studies. Corneal asphericity was greater affected by ocular biometry and corneal curvature than demographic factors and refractive status., (© 2021 The Authors Ophthalmic and Physiological Optics © 2021 The College of Optometrists.)

Clinical relevance : The findings of this study can be useful in the process of patient selection as well as in optimising the prescription of the prism in patients with convergence insufficiency. Background : To determine the relationship between the demographic variables and baseline clinical characteristics with the prism effectiveness in young adults with convergence insufficiency. Methods : Sixty-four young adults with convergence insufficiency entered a randomised clinical trial and were randomly assigned to either treatment or placebo groups. For participants in the treatment group, the near optical correction containing base-in prism was determined based on the Sheard's criterion. Participants in the placebo group received near optical correction. After three months of using the assigned correction, the outcome examinations were performed. Results : In the univariate analysis, a remote near point of convergence, a higher baseline symptoms score, and a higher prescribed prism power showed a significant relationship with the increase in prism effectiveness. A significant inverse relationship was found between the near positive fusional vergence, vergence facility, and prism adaptation rate with the prism effectiveness. Based on the results of the multiple regression, the prism adaptation rate was the only independent predictor factor of prism effectiveness, so that the prism effectiveness increased by 0.60 for each per cent reduction in prism adaptation rate. Conclusion : Prism adaptation is the only independent predictive factor of prism effectiveness in young adults with convergence insufficiency. Based on the findings of the present study, it is recommended that careful assessment of prism adaptation be considered before considering prism prescription.

Purpose: To determine the prevalence of Meibomian gland dysfunction (MGD) and its risk factors in an elderly Iranian population METHODS: This cross-sectional study was conducted in 2019. The target population was the subjects aged 60 and over living in Tehran. Multistage cluster sampling was done to select the subjects from all Tehran districts. After an initial interview, all subjects underwent complete ophthalmic examinations including the measurement of visual acuity and refraction as well as slit lamp biomicroscopy to evaluate Meibomian glands., Results: Of 3791 selected subjects, 3310 participated in the study. The data of 3284 participants were analyzed. The mean age of the subjects was 68.24 ± 6.53 years (range: 60-97 years) and 57.8% of them were female. The total prevalence of MGD was 71.2% (68.3-74.1), and 38.1% (8.35-40.4), 30.3% (27.4-33.2), and 2.8% (2-3.6) of the subjects had MGD stage 2, 3, and 4, respectively. The prevalence of MGD was significantly higher in men (p < 0.001) and increased with age from 64.4% in the age group 60-64 years to 82.4% in subjects aged 80 years and over. There was no significant difference in the prevalence of MGD between smokers and nonsmokers; however, severe MGD was more common in smokers. The prevalence of MGD was 76.3% and 68.52% in subjects with and without a history of ocular surgery, respectively. The prevalence of MGD stage 3 and 4 was higher in subjects with a history of ocular surgery., Conclusions: In line with the results of other studies in Asian countries, this study found a high prevalence of MGD in an elderly population of Iran. It was found that male gender and advanced age were risk factors of MGD and smoking and history of ocular surgery might worsen this disease in MGD patients.

Significance: The present study is the first population-based study to examine the prevalence of convergence insufficiency and its associations specifically in the geriatric population. Knowledge of the population-based determination of prevalence of this disorder in the elderly is necessary to support proper clinical diagnosis and management., Purpose: This study aimed to determine the prevalence of convergence insufficiency and its associated factors in a geriatric population., Methods: In this study, all residents older than 60 years in Tehran city were selected through random stratified cluster sampling. All participants underwent a complete ocular examination including the measurement of uncorrected and best-corrected visual acuity, objective and subjective refraction, binocular vision assessments including unilateral and alternating cover tests, measurement of the near point of convergence, the positive fusional vergence, and finally ocular health examination., Results: In this population-based sample of 1793 participants, the overall prevalences of two-sign and three-sign convergence insufficiency were 29.6% (95% confidence interval, 27.2 to 32.0%) and 21.5% (95% confidence interval, 19.5 to 23.6%), respectively. There were no statistically significant differences in the prevalence of both two-sign (P = .19) and three-sign (P = .41) convergence insufficiency between men and women. The highest and lowest prevalences of two-sign and three-sign convergence insufficiency were in the age groups 70 to 74 and 75 to 79 years, respectively. The prevalence showed no significant trend with age (P = .26 for two-sign convergence insufficiency, P = .33 for three-sign convergence insufficiency). In the multiple logistic regression model, none of the variables, including age, sex, and refractive errors, showed a significant relationship with convergence insufficiency (all, P > .05)., Conclusions: The results of the present study showed a high prevalence of convergence insufficiency in the geriatric population. Clinicians should give special attention to this binocular vision disorder in this age group., Competing Interests: Conflict of Interest Disclosure: No conflicting relationship exists for any author., (Copyright © 2021 American Academy of Optometry.)

Background: The refractive surgeries induce corneal higher order aberrations (C-HOAs). In this study, change of C-HOAs after small-incision lenticule extraction (SMILE) compared to femtosecond assisted laser in situ keratomileusis (femto-LASIK), and to photorefractive keratectomy with mitomycin-C (PRK) under photopic and mesopic conditions., Methods: In this prospective study, age, gender, and apical corneal thickness (ACT) matched cases with moderate myopia [spherical equivalent (SE) 3.00 to 6.00D) to high myopia (SE > 6.00D)] were enrolled. In addition to visual acuity and refraction, total C-HOA, coma, spherical aberration (SA), and trefoil in the 3- and 6-mm zones were measured before and 3 and 6 months after surgery., Results: Overall, 372 moderate myopia cases (124 eyes of 124 individuals in each surgical group) and 171 high myopia cases (57 eyes of 57 individuals in each surgical group) were enrolled. At baseline, the differences in age, gender, ACT, uncorrected and corrected visual acuity, and SE were not statistically significant between subgroups of surgical methods within each myopia group (all P > 0.05). At 12 months, in the moderate myopia group, there was less increase in 6-mm zone total C-HOA, coma, and SA with SMILE compared to the other groups (all P < 0.05). In the high myopia group, there was greater increase in photopic total C-HOA and trefoil and less increase in mesopic SA with SMILE (all P < 0.05)., Conclusions: In correction of moderate myopia, SMILE has better results in mesopic condition. In high myopia correction, femto-LASIK and PRK have better results in photopic and SMILE in mesopic condition.

Purpose: To determine the distribution of keratometry values in a wide age range of 6-90 years., Methods: In this cross-sectional study, samples were selected from two villages in Iran using multi-stage random cluster sampling. After completing optometry and ophthalmic examinations for all cases, corneal imaging was done using Pentacam, and keratometry values were determined., Results: Of the 3851 selected people, 3314 people participated in the study, and after applying the exclusion criteria, analyses were done on data from 2672 people. Mean age of the participants was 36.30 ± 18.51 years (from 6 to 90 years). Mean keratometry (mean-K) in flat and steep meridians was 42.98 (42.9-43.06) diopters (D) and 43.98 (43.91-44.07) D, respectively. Average of mean-K was 43.48 (43.41-43.56) D. Mean-K increased linearly up to the age of 70 years, and the cornea became slightly flat afterwards (coefficient = 0.01; P < 0.001). Mean-K was significantly higher in females ( P < 0.001). Myopic cases had the highest mean-K ( P < 0.001). The correlation of mean-K with age, gender, central corneal thickness, anterior chamber depth, pupil diameter, and spherical equivalent was investigated in a multiple regression model. Only older age and female gender showed a statistically significant association with mean-K. Overall, 31.62% (29.14-34.09) of the sample in this study had at least 1.0 D of corneal astigmatism., Conclusions: This is one of the few studies worldwide that demonstrates changes in keratometry in a wide age range from childhood to old age. Results indicated that age and gender are variables associated with keratometry., Competing Interests: There are no conflicts of interest., (Copyright: © 2021 Journal of Current Ophthalmology.)

To determine the prevalence of amblyopia and its determinants in underserved rural villages of Iran. This population-based cross-sectional study was conducted in 3850 subjects selected from two underserved districts in the north (Kojur District, Nowshahr County, Mazandaran Province) and southwest (Shahyun District, Dezful County, Khuzestan Province) of Iran using multi-stage cluster sampling. The subjects underwent complete ophthalmic examinations including the measurement of uncorrected (UCVA) and best-corrected (BCVA) visual acuity, objective and subjective refraction, unilateral and alternate cover tests and ocular health examination. Amblyopia was defined as a reduction of BCVA to 20/30 or less in one eye or a 2-line interocular optotype acuity difference in the absence of any pathological factors. Of 3850 selected subjects, 3314 participated in the study (response rate = 86.08%). The mean age of the participants was 36.90 ± 20.21 years (range: 3-93 years). The prevalence and 95% confidence interval of total, bilateral, and unilateral amblyopia were 2.73% (2.17 to 3.38), 0.50% (0.28 to 0.83), and 2.23% (1.73 to 2.83), respectively. The most common type of amblyopia was anisometropic followed by strabismic and mixed. The lowest and highest prevalence was seen in the age group 6-20 years (1.36%; 0.65 to 2.49) and above 70 years (5.97%; 3.02 to 10.44), respectively. According to the results of multiple logistic regression analysis, compared to illiterate subjects, the odds ratio of amblyopia was 0.321 ( P = .033) in subjects with High school education, 0.181 ( P = .030) in subjects with secondary School education, and 0.486 ( P = .041) in subjects with primary school education. The odds ratio of amblyopia for north villages residence vs southwest villages residence was 2.105 ( P = .012). The odds ratio of amblyopia was 2.765 for age group>70 years vs. 6-20 years ( P = .033). The prevalence of amblyopia was higher in north region, in participants with lower education level and older individuals. The high prevalence of amblyopia in older people may be due to the lack of screening programs in previous generations and consequently the lack of timely diagnosis and treatment.

Objectives: Three prior studies (2008, 2011, 2018) histopathologically compared the eyelid specimens of patients with dermatochalasis (DC, undergoing blepharoplasty) with a control group and proposed that DC may begin with subclinical inflammation leading to elastolysis and lymphostasis. With growing number of younger patients consulting for blepharoplasty, the unanswered question is whether histopathologic changes of DC differ between the younger and the older., Patients and Methods: In this prospective case series, 20 right upper eyelid skin of 20 nonsmoker, class 3 Fitzpatrik skin type women (30-68 years old) were histopathologically examined. Patients were divided into 2 age groups of 50 years or older and older than 50 years. Upper eyelid skin was preoperatively marked, intraoperatively removed, postoperatively divided into 3 sections: lateral (lateral limbus to lateral canthus), central (between medial and lateral limbi), and medial (medial limbus to medial canthus), and separately (totally 60 specimens) sent for histopathological examination. A masked pathologist recorded skin thickness in all specimens (60) as well as lymphatic vessels diameter and density, elastic fiber density, macrophage number, collagen intrafibril edema, and depth of collagen stromal bed in central sections (20 specimens)., Results: There were 10 patients at each age group. Histopathological measurements were not significantly different between the 2 age groups except mean lymphatic vessel diameter (P = 0.034) that was larger in the second group (>50 years). A significant positive correlation was also observed between the age and lymphatic vessel diameter (rs = 0.3, P = 0.009)., Conclusions: Lymphangiectasia progresses significantly by age. Histopathological characteristics of DC are the same in the 2 age groups., Competing Interests: Conflicts of interest and sources of funding: The study was funded by Iran University Eye Research Center, which did not have any role in the design, execution, and presentation of results. The authors declare no conflict of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Background: To assess the epicanthal fold (EF), eyelid, eyebrow, scar, and patients' satisfaction after anchor epicanthoplasty and upper blepharoplasty and histopathologically compare Asian epicanthal fold skin with non-Asian counterpart., Methods: Asian Iranians with grade 2 and 3 EF were included. Photographs were taken before and at least 12 months after the surgery. Photoanalysis included EF grade, inter-canthal distance (ICD), margin reflex distance 1 (MRD1), tarsal plate show (TPS), brow fat span (BFS), and eyebrow height. Manchester scar scale score (5-28) and patients' satisfaction score (0-100) were documented. The most medial skin of 5 Asian and 5 non-Asian subjects was histologically compared for the thickness and elastic fiber density and morphology., Results: Included were 89 patients (178 eyelids) with a mean age of 31.6 years and follow-up of 13.1 months. Mean ICD significantly decreased by 3.5 mm (shortening ratio of 9.7%). All grade 2 and almost half of the grade 3 EF disappeared. Significant postoperative increase in mean MRD1 (0.3 mm) and TPS (1.1-1.4 mm) and decrease in BFS (3.3-3.6 mm) and eyebrow height (1.7-3.4 mm) were observed. Revision rate of epicanthoplasty was 7.3%. Mean satisfaction and scar scores were 97.1 and 5.4, respectively. Histopathologically, Asian and non-Asian medial upper eyelid skin was not significantly different., Conclusion: Anchor epicanthoplasty eliminated grade 2 and improved grade 3 EF with a high satisfaction and negligible scar. Simultaneous upper blepharoplasty significantly increased MRD1 and TPS and decreased eyebrow height. EF skin was not histologically different from non-Asians., Level of Evidence Iv: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Purpose: To evaluate level of flare in aqueous humor of dry eye disease (DED) and compare it with normal controls., Methods: In this cross-sectional study, we compared the anterior chamber flare between 28 patients with DED (the DED group) and 27 normal age- and gender-matched controls (the control group). DED group was divided in Sjӧgren's syndrome dry eye (SDE, n = 10) and non- Sjӧgren's syndrome dry eye (non-SDE, n = 18) groups., Results: This study enrolled 55 participants including 28 patients with DED and 27 normal controls. The mean age was 53.4 ± 14.7 years in the DED group and 48.5 ± 14.7 years in the control group (P = 0.086). Mean flare was significantly higher in DED group (12.1 ± 10.2 ph/ms, range 2.7-68.3) compared to the control group (5.0 ± 3.9 ph/ms, range 1.30-30.0, P < 0.001). There was no statistically significant difference in the flare intensity between the Sjӧgren syndrome dry eye (SDE) group (14.5 ± 14.4 ph/ms) and the non-Sjӧgren dry eye (non-SDE) group (10.8 ± 6.9 ph/ms, P = 0.330). A significant correlation was observed between the flare intensity and the ocular surface staining in the SDE group (r = 0.62, P = 0.018)., Conclusion: There is a significant increase in aqueous humor flare in patients with DED. Such finding, which is a marker of disruption of blood-aqueous barrier, demonstrates deeper tissue involvement than ocular surface in these patients., (Copyright © 2020. Published by Elsevier Inc.)

During recent decades, researchers all around the world have focused on the characteristic pros and cons of the different drug delivery systems for cornea tissue change for sense organs. The delivery of various drugs for cornea tissue is one of the most attractive and challenging activities for researchers in biomaterials, pharmacology, and ophthalmology. This method is so important for cornea wound healing because of the controllable release rate and enhancement in drug bioavailability. It should be noted that the delivery of various kinds of drugs into the different parts of the eye, especially the cornea, is so difficult because of the unique anatomy and various barriers in the eye. Nanoparticles are investigated to improve drug delivery systems for corneal disease. Biodegradable nanocarriers for repeated corneal drug delivery is one of the most attractive and challenging methods for corneal drug delivery because they have shown acceptable ability for this purpose. On the other hand, by using these kinds of nanoparticles, a drug could reside in various part of the cornea for longer. In this review, we summarized all approaches for corneal drug delivery with emphasis on the biodegradable nanoparticles, such as liposomes, dendrimers, polymeric nanoparticles, niosomes, microemulsions, nanosuspensions, and hydrogels. Moreover, we discuss the anatomy of the cornea at first and gene therapy at the end.

Purpose: To describe the normative data of corneal densitometry in photorefractive Keratectomy (PRK) candidates by using a Scheimpflug camera., Methods: Five hundred twenty-two eyes of 261 PRK candidates that underwent comprehensive optometric and ophthalmic examinations were enrolled in this study. Corneal densitometry values were obtained using a Scheimpflug camera (Pentacam HR; Oculus Optikgeräte GmbH, Wetzlar, Germany) and displayed in grayscale units (GSU)., Results: Of 261 participants, 187 (71.6%) were women. The mean age of the participants was 28.79 ± 5.02 years (range: 21-40 years). The mean entire corneal densitometry was 14.86 ± 2.37 GSU. According to corneal depth, maximum and minimum densitometry values were seen in the anterior (30.28 ± 7.42 GSU) and posterior (9.86 ± 2.08 GSU) layers, respectively (P < 0.001). Based on the annulus over the cornea, the highest and lowest densitometry values were seen in the 10- to 12-mm (21.31 ± 4.26 GSU) and 2- to 6-mm zones (13.26 ± 2.34 GSU), respectively. However, this difference was not seen after 35 years of age. Individuals aged 30 to 35 years showed higher corneal densitometry values compared with subjects aged 20 to 25 years old (P < 0.001). In generalized linear models, the corneal thickness was associated with the densitometry value in the central and posterior corneal layers. There were no significant differences in sex and refractive errors among participants., Conclusions: This study provided normal corneal densitometry data in PRK candidates. Corneal densitometry increased with age until 35 years of age and then decreased thereafter. This finding should be considered in patient selection for PRK and their postoperative examinations.

Background: To assess the diagnostic ability of Pentacam HR (Oculus Optikgeräte, GmbH, Wetzlar, Germany) tomographic indices in discriminating keratoconus (KC) and KC suspect (KCS) in 10- to 30-year-old patients with Down syndrome (DS)., Methods: In this study, DS patients were enrolled through special needs schools, the National Down Syndrome Society, and relevant non-profit organizations. Diagnoses were made independently by two experienced specialists. Forty Pentacam indices related to corneal thickness, volume, density, keratometry, power, shape, aberration, and elevation were extracted. For each index, the accuracy for KC and KCS diagnosis was evaluated using discriminant analysis and the area under receiver operating characteristic curve (AUROC). From each enrolled case, data from only one eye was entered in the analyses., Results: Analyses were performed on data from 25 KC, 46 KCS, and 154 non-ectatic DS eyes. The best discriminants for KC were anterior higher order aberrations (HOA) (cutoff > 0.643, AUROC = 0.879), posterior vertical coma (cutoff > 0.0702 μm, AUROC = 0.875), anterior vertical coma (cutoff > 0.4124 μm, AUROC = 0.868), and total HOA (cutoff > 0.608, AUROC = 0.867). The difference between AUROCs were not statistically significant (all P  > 0.05). For KCS, the best discriminants were minimum corneal thickness (cutoff ≤ 480.0 μm, AUROC = 0.775), corneal volume (cutoff ≤ 55.3 μm, AUROC = 0.727) and Belin Ambrosio display-total deviation (BAD-D) (cutoff > 2.23, AUROC = 0.718) with no significant difference between AUROCs (all P  > 0.05)., Conclusions: In this sample of DS patients, best KC discriminators were HOA and coma which showed good diagnostic ability. For KCS, best predictors were minimum corneal thickness, corneal volume, and BAD-D with relatively good diagnostic ability. Defining a new set of KC diagnostic criteria for DS patients is suggested., Competing Interests: Competing interestsThe authors declare that they have no competing interests., (© The Author(s) 2020.)

The aim of our study was to estimate regional and global cataract prevalence, its prevalence in different age groups, and the determinants of heterogeneity and its prevalence. For that, we used international databases such as PubMed, Web of Science, Scopus, Embase, and other sources of information to conduct a systematic search for all articles concerning the prevalence of age-related cataract and its types in different age groups. Of the 9922 identified articles, 45 studies with a sample size of 161,947 were included in the analysis, and most of them were from the Office for the Western Pacific Region (19 studies). Age- standardized pooled prevalence estimate (ASPPE) and 95% confidence interval (95% CI) of any cataract, cortical cataract, nuclear cataract, and posterior subcapsular (PSC) cataract were 17.20% (13.39-21.01), 8.05% (4.79-11.31), 8.22% (4.93-11.52), and 2.24% (1.41-3.07), respectively. Significant effects on heterogeneity were observed for the WHO region in the prevalence of any cataract (b: 6.30; p: 0.005) and study year in the prevalence of nuclear cataract (b: -0.66, p: 0.042). In general, the prevalence of cataract not only varies by region but also by age group, and most cases are over the age of 60 years. We examined the sources of variance in the prevalence of cataract and its different types, and identified age as a responsible factor in the prevalence of any cataract, cortical cataract, nuclear cataract, and PSC of cataract, WHO region in the prevalence of any cataract, and study year in the prevalence of nuclear cataract.

Purpose: To review current non-surgical management methods of intermittent exotropia (IXT) which is one of the most common types of childhood-onset exotropia., Methods: A search strategy was developed using a combination of the words IXT, divergence excess, non-surgical management, observation, overcorrecting minus lens therapy, patch/occlusion therapy, orthoptics/binocular vision therapy, and prism therapy to identify all articles in four electronic databases (PubMed, Web of Science, Google Scholar, and Scopus). To find more articles and to ensure that the databases were thoroughly searched, the reference lists of the selected articles were also reviewed from inception to June 2018 with no restrictions and filters., Results: IXT is treated when binocular vision is impaired, or the patient is symptomatic. There are different surgical and non-surgical management strategies. Non-surgical treatment of IXT includes patch therapy, prism therapy, orthoptic sessions, and overcorrecting minus lens therapy. The objective of these treatments is to reduce the symptoms and the frequency of manifest deviation by decreasing the angle of deviation or enhancing the ability to control it., Conclusions: Evidence of the efficacy of non-surgical management options for IXT is not compelling. More comprehensive randomized controlled trial studies are required to evaluate the effectiveness of these procedures and detect the most effective strategy., Competing Interests: There are no conflicts of interest., (Copyright: © 2020 Journal of Current Ophthalmology.)

Aim: To investigate the heritability of corneal thickness at the apex, entrance pupil centre, thinnest point, pachymetric progression index (PPI) and maximum Ambrósio relational thickness (ART max ) using Pentacam., Methods: The present cross-sectional and population-based study was conducted in two rural districts that were selected randomly. Individuals 5 years and older and data from households where one of the parents and at least one child participated in the study were considered for this analysis. All subjects were examined for visual acuity, refraction, biomicroscopy and, finally, Pentacam imaging. The heritability estimate was used to calculate familial aggregation of pachymetric indices., Results: Of the 3851 selected individuals, 3314 participated in the study. After applying the exclusion criteria, a total of 1383 individuals from 382 households were included in the analysis; of these, 754 (54.52%) were female. The mean age of the subjects was 37.23±19.35 years (from 6 to 93 years). The highest heritability was observed for corneal thickness at the apex (85%), and the lowest was for ART max (27.62%). The heritability of other studied parameters, including corneal thickness at the entrance pupil centre, thinnest point and average PPI, was 82.0%, 77.0% and 31.49%, respectively., Conclusion: The high heritability of the mentioned pachymetric parameters confirms the high correlation between these phenotypes and genetic factors and calls for genetic and molecular research to find related genes and to understand the aetiology of associated diseases, especially glaucoma and keratoconus., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: This study sought to determine the diagnostic ability of anterior, posterior and total keratometric indices in discriminating keratoconus (KCN) stages 1 to 4 from normal corneas., Methods: Anterior and posterior simulated keratometry (sim-Ksteep and sim-Kflat), maximum keratometry (Kmax), Kmax y co-ordinate, anterior and posterior radii of curvature centred on the thinnest point (ARC-3 mm and PRC-3 mm), and anterior, posterior, and total asphericity (Q-value) measured by Pentacam were extracted from electronic medical records of 200 KCN and 200 normal cases. Stepwise leave-one-out cross-validation and areas under receiver operating characteristic curves (AUROC) were used to detect the best set of indices for differentiating normal from low-grade (stages 1-2, Kmax ≤ 53.00 D) and high-grade (stages 3-4, Kmax > 53.00 D) KCN., Results: Mean age in KCN and normal groups was 33.10 ± 7.48 and 32.24 ± 9.00 years (p = 0.332), respectively. In the low-grade KCN group, PRC-3 mm (AUROC = 0.986), Kmax (AUROC = 0.979), and Kmax y co-ordinate (AUROC = 0.824) performed best, and the difference in AUROC between PRC-3 mm and Kmax was not significant (p = 0.153). In the high-grade KCN group, Kmax (AUROC = 1.000), PRC-3 mm (AUROC = 0.998), posterior Ksteep (AUROC = 0.970), posterior Q-value (AUROC = 0.940), and posterior Kflat (AUROC = 0.894) performed best, and there was no significant difference in AUROC values between Kmax and PRC-3 mm (p = 0.307) or between posterior Ksteep and posterior Q-value (p = 0.113)., Conclusions: Among the studied keratometric indices, PRC-3 mm and Kmax appear to have the best ability for detecting mild to severe KCN. The next best factors which showed good discrimination ability were Kmax y co-ordinate in low-grade cases and posterior Ksteep and Q-value in high-grade cases., (© 2019 Optometry Australia.)

Keratoconus (KCN) and Down syndrome affect the corneal density and volume. In this study included Down syndrome patients with and without KCN (24 Down-KCN and 204 Down-nonKCN eyes) and normal age- and gender-matched individuals (184 eyes). Studied parameters were the corneal density measured with Pentacam HR in 5 concentric zones and annuli (0-2 mm, 2-6 mm, 6-10 mm, 10-12 mm, and 0-12 mm) in 4 different depth layers (anterior 120 µm, posterior 60 µm, middle layer, and the full thickness of the cornea), and the 10 mm zone corneal volume. In Down-KCN, Down-nonKCN, and control groups, respectively, mean full thickness density in the 0-12 mm zone was 19.35 ± 2.92, 17.85 ± 2.55, and 15.78 ± 2.67 GSU, and mean corneal volume was 57.45 ± 4.37, 56.99 ± 3.46, and 61.43 ± 3.42mm 3 . All density readings were significantly different between the three studied groups (all P < 0.01) except full thickness density in 0-2 mm and 2-6 mm (P > 0.05) and corneal volume (P = 0.519) between Down-KCN and Down-nonKCN groups; these inter-group densitometry differences within the 6 mm zone were only in the middle layer, and not the anterior or posterior thickness layers (all P > 0.05). Corneal density increased with age and corneal thickness, but there was no significant relationship with gender. Overall, Down syndrome is associated with increased density and light scatter in all corneal layers up to the 12 mm diameter. In Down patients with KCN, the increased light scatter and density in the 6 mm zone is only in the middle thickness layer. Corneal volume is reduced in Down syndrome irrespective of the presence or absence of KCN.

Purpose: The purpose of the present study was to evaluate the prevalence of refractive errors in the Middle East region., Methods: In this meta-analysis, a structured strategy was applied to search databases PubMed, Web of Science, Scopus, and Google Scholar, databases as well as the reference lists of the selected articles to identify cross-sectional studies assessing the prevalence of refractive errors in the Middle East region until September 2019. The outcome measure was the prevalence of refractive errors, including myopia, hyperopia, and astigmatism, in two age groups of ≤ 15 years and > 15 years. The study results were combined using a random effects model at a confidence level of 95%., Results: The prevalence of myopia, hyperopia, and astigmatism was 4% (95% CI 4, 5), 8% (95% CI 6, 10), and 15% (95% CI 10, 19) in people less than or equal to 15 years and 30% (95% CI 25, 34), 21% (95% CI 15, 28), and 24% (95% CI 16, 31) in subjects over 15 years, respectively. The prevalence of myopia, hyperopia, and astigmatism was 3.5%, 12.4%, and 9.0% in male and 4.2%, 13.1%, and 9.9% in female subjects aged ≤ 15 years, respectively. In subjects aged > 15 years, the prevalence was 31.7%, 14.5%, and 31.5% in males and 31.9%, 11.2%, and 31% in females, respectively., Conclusion: The prevalence of hyperopia is relatively high in Middle Eastern children, while the prevalence of myopia is higher in adults in this region. It seems that astigmatism is not a serious refractive problem in this region compared to the rest of the world.