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.

Convergence Insufficiency in the Geriatric Population.

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.

Corneal asphericity and related factors in the geriatric population: A population-based study.

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.

Dermatochalasis Through Decades: A Histopathologic Study.

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.

Revisiting Anchor Epicanthoplasty in Mild to Moderate Asian Epicanthal Folds: A Clinicopathological Study.

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 .

Meibomian gland dysfunction in geriatric population: tehran geriatric eye study.

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.

The prevalence of refractive errors in the Middle East: a systematic review and meta-analysis.

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.

Pentacam Accuracy in Discriminating Keratoconus From Normal Corneas: A Diagnostic Evaluation Study.

OBJECTIVES: This study aims to determine the diagnostic ability of Pentacam indices for keratoconus and identifying the best index for differentiating diseased from normal cases. METHOD: In this study, 150 keratoconus patients and 150 refractive surgery candidates with a definitive diagnosis of normal healthy corneas were enrolled. Initially, the placido disk topography imaging was performed. The keratoconus and normal corneas were defined based on placido disk topographic data from Rabinowitz-McDonnell. After complete eye examinations for all participants, they underwent Pentacam imaging, and corneal surface topographic indices were extracted. Multiple logistic regression was used to determine the best indices for differentiating diseased from healthy corneas, and the receiver operating curve was calculated to determine the diagnostic capability of each index. RESULTS: Among the studied indices, the keratoconus index (KI), index of vertical asymmetry (IVA), thinnest point (TP), and maximum keratometry (Kmax) were found capable of detecting keratoconus. Among these, IVA was the best index, with an area under curve (AUC) of 95.24%. The best cutoff point for IVA was 0.20 µm, and its sensitivity and specificity were 87.50% and 96.30%, respectively. Comparison of the AUC of different indices showed that only TP and IVA significantly differed (P=0.002). The combination of KI, IVA, Kmax, and TP indices leads to correct detection in 78% of cases. CONCLUSION: Measuring corneal topographic indices using Pentacam can be helpful in the diagnosis of keratoconus. According to the results of this study, IVA is the best diagnostic index for keratoconus. However, it is recommended to use a combination of Pentacam indices for more accurate differentiation of keratoconus from normal cases.

Intrasubject Repeatability and Interdevice Agreement of Anterior Chamber Depth Measurements by Orbscan and Pentacam in Different Grades of Keratoconus.

OBJECTIVES: To evaluate the repeatability of anterior chamber depth (ACD) measurements by Orbscan and Pentacam imaging devices in different grades of keratoconus. METHODS: One examiner performed 3 consecutive ACD measurements with both devices on 74 eyes of 42 keratoconus patient. Repeatability was assessed using intrasession test-retest variability. Within-subject SD was determined for repeatability, and the coefficient of variation was calculated for each measurement. The intraclass correlation coefficient (ICC) was also determined to assess the variance of repeated data. RESULTS: Overall, the three ACD measurements were not significantly different either with Pentacam or Orbscan. The ICC index values were greater than 90% with both devices, and it significantly reduced at higher grades of keratoconus with Pentacam. Interdevice differences were statistically significant. The interdevice agreement with ACD measurements was 0.981, and the agreement was lower at higher grades of keratoconus. The 95% limits of agreement between the 2 devices for ACD was from -0.19 to 0.04. CONCLUSIONS: Our results indicate acceptable repeatability for ACD measurements with both Orbscan and Pentacam in keratoconus patients. The progression of keratoconus has no significant effect on repeatability results of these devices. The good agreement between them allows their interchangeable use.

Anterior chamber indices in a population-based study using the Pentacam.

PURPOSE: To determine the distribution of anterior chamber depth (ACD), anterior chamber volume (ACV), and anterior chamber angle (ACA) values in a rural population over 5 years of age using the Pentacam. METHODS: In this cross-sectional study, samples were selected from over 1-year-old inhabitants of two villages in Iran using a multistage cluster sampling approach. All participants underwent the measurement of uncorrected and corrected visual acuity and auto-refraction, retinoscopy, subjective refraction, and slit lamp examination. Finally, corneal imaging was done for all subjects over 5 years of age using the Pentacam. RESULTS: Of 3851 selected individuals, 3314 participated in the study, of whom 2681 met the inclusion criteria. The mean age of the sample was 36.03 ± 18.5 years (range 6-90 years). The mean ACD, ACA, and ACV values were 3.37 mm (95% CI: 3.37-3.39), 34.82° (95% CI: 34.45-35.2), and 159.17 µL (95% CI: 156-161.36), respectively. The results of multiple linear regression models showed that ACD, ACA, and ACV values reduced with age, and ACD and ACV values were significantly higher in males. ACA and ACV values correlated inversely with central corneal thickness, while the ACA value correlated directly with keratometry and inversely with the ACV value. CONCLUSION: This study is one of the few studies in the world showing changes in ACD values in different age groups using the Pentacam. According to the results, aging was associated with a decline in the mean ACD, ACA, and ACV values. These parameters were the largest in patients with emmetropia and smallest in hyperopic subjects.

High prevalence and familial aggregation of keratoconus in an Iranian rural population: a population-based study.

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

Distribution and associated factors of keratometry and corneal astigmatism in an elderly population.

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.

A supplemental video teaching tool enhances splinting skills.

BACKGROUND: The ability to apply casts and splints is a technical skill that requires practice and understanding of basic principles of musculoskeletal medicine. A video in which a given procedure is simulated on a dummy can represent reality under controlled conditions. A decrease in physician competency in musculoskeletal medicine is the result of educational deficiencies at the medical school level. QUESTIONS/PURPOSES: We asked whether (1) a supplemental video educational program enhances performance of medical students' musculoskeletal clinical skills and (2) factors such as the proportion of orthopaedic professors to students, sex, age, and previous scores of medical students affected the clinical skills of medical students. METHODS: We allocated 474 medical students into one of two groups: all participants received 90 minutes of lecture instruction on how to splint and cast but one group viewed the supplemental instructional video and the other did not. There were no differences in terms of sex, age, basic science exam scores, or grade point average of the groups. Thirteen specific skills in splinting an injured limb were evaluated. We recorded grade point averages. We developed a 10-point scoring system and graded each student on their splinting skills 6 months after the lectures. RESULTS: The medical students who watched the video had an average score of 7.6, whereas the control group's average score was 2.0. We observed a positive association between watching the educational video and clinical exam score. A higher professor-to-student ratio was associated with lower student Objective Structured Clinical Examination score. CONCLUSIONS: Our observations suggest a supplemental video instructional program improved the performance of musculoskeletal clinical skills in comparison to only a traditional lecture series.

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.

Effectiveness of educational intervention on undermanagement of osteoporosis in fragility fractures.

PURPOSE: Fragility fractures are characterized by a low energy trauma and should be considered as potentially osteoporosis-related fractures. This study aimed to determine whether the orthopedic surgeons' awareness could increase the osteoporosis management rate in patients with fragility fractures. METHOD: This study was undertaken in three phases: evaluation of existing practice patterns, educational intervention and evaluation of the effect of the training. During the study period, orthopedic surgeons who worked at academic hospitals attended five educational sessions and were provided with posters and brochures. Patients were interviewed at sixth and twelfth months after discharge using an evaluation questionnaire regarding their perceptions of the barriers to osteoporosis treatment. RESULTS: Seventy-two orthopedic surgeons volunteered to participate in the study between June 2008 and December 2011. The patients were followed for a minimum of 1 year. Rate of calcium and vitamin D prescriptions increased from 10 to 91 %. The rate of bisphosphonate administration reached to 73 %. The number of follow-up evaluations did not differ significantly. CONCLUSION: The detection and medication rates for osteoporosis in patients with fragility fractures increased more than tenfold after the intervention program.

Clinical Outcomes of a New Type of Continuous Intrastromal Corneal Ring for Treatment of Keratoconus.

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.

3D Printed Hydrogels for Ocular Wound Healing.

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.

Repeatability of Corneal Densitometry Measurements using a Scheimpflug Camera in Healthy Normal Corneas.

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.

Effect of Short Versus Long-Term Steroid on Corneal Haze After Photorefractive Keratectomy: A Randomized, Double-Masked Clinical Trial.

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.

Prevalence of Uncorrected Refractive Error and Its Risk Factors; Tehran Geriatric Eye Study (TGES).

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.