Risk Factors For Keratoconus Research Articles

Social determinants of health as risk factors for keratoconus in the All of Us database

Background/aimsClinical risk factors for keratoconus (KCN) have previously been established. While the impact of the social determinants of health on the epidemiology and pathophysiology of KCN has been explored, further...

Children with high astigmatism: tomographic and refractive characteristics and the ability of current indices to rule out keratoconus

PurposeTo assess corneal tomographic, topographic, and refractive changes in children with high astigmatism and their ability to exclude keratoconus. MethodsIn this longitudinal observational study, the medical records of children with high regular cylindrical refraction of ≥3.50 D referred to the Hospital for Sick Children, Toronto, to exclude keratoconus between January 2009 and June 2020 were reviewed retrospectively. Corneal tomography records (Scheimpflug imaging) were reviewed for subjects with total astigmatism of ≥ +3.50 D by retinoscopy. Children with abnormal anterior segment examination and/or other risk factors for corneal disease or ectasia and those with unreliable corneal tomography were excluded. Baseline demographic, longitudinal tomographic, topographic, and refractive data were analyzed. ResultsA total of 67 eyes of 37 children (mean age, 9.1 ± 3.5 years) were included. Mean cylindrical refraction at presentation was 5.10 ± 1.30 D. Mean follow-up was 2.3 ± 1.8 years. Twenty-nine eyes had Kmax ≥47.20 D at baseline, with no change at last follow-up. Ksteep, Kmax, and thinnest pachymetry were 46.44 ± 2.33 D, 47.06 ± 2.57 D, and 525.86 ± 35.45 μm, respectively, at baseline compared with 46.40 ± 2.28 D, 46.98 ± 2.40 D, and 527.61 ± 37.67 μm at last follow-up (P > 0.05). All eyes were predicted as not having keratoconus using inferior-superior dioptric asymmetry ratio (I-S ratio), and the keratometry, inferior-superior, and astigmatism index (KISA%), which also incorporates skew percentage. The other tomographic indices predicted keratoconus or subclinical keratoconus in at least 22.4% of eyes. All parameters did not significantly change during follow-up. ConclusionsIn the absence of other risk factors for keratoconus, children with high regular astigmatism demonstrated clinical and tomographic stability over time. Based on our results, we recommend that I-S ratio and KISA% be primarily used when monitoring normal children with high astigmatism to rule out keratoconus-related changes.

The association between keratoconus and allergic eye diseases: A systematic review and meta-analysis.

To investigate the association between keratoconus (KC) and allergic eye diseases, eye rubbing, and atopy. PubMed, Web of Science, Scopus, and Cochrane databases were searched for studies investigating eye allergy, atopy, and eye rubbing as risk factors for KC up to April 2021. Two authors independently screened all titles and abstracts against the predefined inclusion and exclusion criteria. The study analysed the prevalence of KC and its risk factors, including eye rubbing, family history of KC, atopy, and allergic eye diseases. The National Institutes of Health Study Quality Assessment Tool was used. Pooled data are presented as odds ratios (OR) and 95% confidence intervals (CI). The analysis was conducted using RevMan version 5.4 software. The initial search yielded 573 articles. After screening, 21 studies were identified for qualitative analysis and 15 for quantitative synthesis. A significant association was found between KC and eye rubbing (OR=5.22, 95% CI [2.80, 9.75], p < 0.00001), family history of KC (OR=6.67, 95% CI [4.77, 9.33], p < 0.00001), and allergies (OR=2.21, 95% CI [1.57, 3.13], p < 0.00001). However, no significant association was found between KC and allergic eye disease (OR=1.82, 95% CI [0.37, 8.97], p=0.46), atopy (OR=1.54, 95% CI [0.58, 4.09], p=0.39), allergic rhinitis (OR=0.85, 95% CI [0.54, 1.33], p=0.47), smoking (OR=0.96, 95% CI [0.76, 1.21], p=0.73), and asthma (OR=1.58, 95% CI [0.99, 2.53], p=0.05). Significant associations were observed between KC and eye rubbing, family history, and allergy, but not with allergic eye disease, atopy, asthma, and allergic rhinitis.

Atopic triad (allergic rhinitis, eczema, and asthma) and eye rubbing as risk factors for keratoconus: a systematic review and meta-analysis

Keratoconus (KN), is an eye disorder, characterized by progressive thinning and protrusion of central cornea. A number of conditions such as such as allergy, asthma, eczema, and eye rubbing has been shown to be associated with the development of KN. However, there is a disagreement regarding some of risk factors and their strength so we conducted systematic review and meta-analysis to determine how strongly risk factors such as eye rubbing, and atopic triad associate with KN development and progression. We systematically searched the literature for related studies using specific keywords and key phrases. The studies were scrutinized based on inclusion and exclusion criteria. Finally, we extracted relevant qualitative and quantitate information from studies. For meta-analysis we used odds ratio (OR) and their 95% CI were used to draw forest plots. 35 studies were selected in final meta-analysis. Our meta-analysis yielded the combined effect of risk factors with OR of 2.20 and a 95% CI of 1.84–2.64. Furthermore, we found that eye rubbing-related studies had effect size of OR 2.09 with a 95% CI of 1.76–2.49 and a p value of 0.00001. For atopic triad (allergic rhinits, asthma and eczema) related studies, the meta-analysis yielded overall effect size of OR 2.34 with 95% CI of 2.06-2.66. Eye rubbing and atopic triad (allergic rhinitis, eczema, and asthma) are important risk factors for KC development with statistically strong association.

Prevalence and risk factors for keratoconus in a university-based population in Turkey.

To determine the prevalence of keratoconus (KC) in the students and faculty members (aged ≥18 and ≤30 years) studying/working at the Medical and Health Sciences faculties of Eskişehir Osmangazi University. Eskişehir Osmangazi University, Eskişehir, Turkey. Prevalence study. Subjects were randomly selected to undergo KC screening using a proportional stratified sampling method. Of the 648 invited subjects, 585 (90.3%) responded to the invitation. The demographic data, medical/family history, and habits of the subjects were collected using a standardized questionnaire. Subjects were classified as KC, ectasia susceptibility, and normal based on the corneal tomography. The chi-square and Kruskal-Wallis tests were used for the analysis of categorical variables and parametric values, respectively. Risk factors for KC were determined using logistic regression analysis. Of the enrolled 585 subjects, the prevalence of KC was 2393/100 000 (2.4%, 95% CI: 1.3% to 4%), whereas that of ectasia susceptibility was 1538/100 000 (1.5%, 95% CI: 0.7% to 2.9%). Although the prevalence was much higher in males (4%, 95% CI: 1.7% to 7.7%) than in females (1.6%, 95% CI: 1.1% to 4.4%), the difference was not statistically significant (P = .09). Most (78.6%, n = 11) patients with KC were unaware of their disease. Eye rubbing (odds ratio [OR]: 3.53, P = .024) and consanguineous marriage (OR: 12.87, P = .032) were independent risk factors for KC. To the authors' knowledge, this is the first population-based KC prevalence study in a randomized sample conducted in Turkey. The prevalence of KC in Turkey was much higher than in European countries but similar to neighboring countries in the Middle East. Eye rubbing and history of consanguineous marriage were significant risk factors.

Correlation between Keratoconus and Pollution

ABSTRACT Introduction: Keratoconus is a corneal ectasia with multifactorial origin. Three risk factors for keratoconus are currently recognized: ultraviolet rays (UV), eye rubbing and atopy. In the current literature, other factors are evoked such as pollution, whose role in the physiopathology of keratoconus is unclear. The effects of particles matter (PM) 2.5 and 10 are the most studied and questioned in the scientific literature. Material and method: A correlation study was carried out to determine the influence of pollution on keratoconus. Fine particulate matter levels were measured according to available WHO data and were correlated with the prevalences of epidemiological studies. These measures were included in the study according to strict selection criteria. Results: The mean pollution rate of the selected studies was 29.1 ± 24.3 μg/m3 for PM2.5 and 57.2 ± 56.2 μg/m3 for PM10. The Pearson test shows a moderate correlation between the prevalence of keratoconus and the levels of PM2.5 (R = 0.51; p = .022) and a strong correlation with the levels of PM10 (R = 0.71; p < .001). Discussion: Fine particulate matter appears to be an emerging risk factor for keratoconus. They are thought to act indirectly by exacerbating known risk factors such as atopy and eye rubbing. And could have a direct action on the cornea by increasing the apoptosis of epithelial cells and interacting directly with the structure of collagen of the stroma.

The Sociodemographic and Risk Factors for Keratoconus: Nationwide Matched Case-Control Study in Taiwan, 1998-2015

PurposeThe aim of this study was to determine the sociodemographic and risk factors for keratoconus (KC) patients with a nationwide Asian database. DesignPopulation-based matched case-control study. MethodsWe performed a secondary data analysis of the Taiwan National Health Insurance Research Database (NHIRD). Cases were patients with newly diagnosed KC in 1998-2015. Controls were patients without KC and matched 4:1 with the KC cases by age, sex, and index date. Comorbidities diagnosed before KC included diabetes mellitus (DM), asthma, allergic rhinitis, mitral valve prolapse, collagen vascular disease, aortic aneurysm, Down syndrome, sleep apnea, depression, hyperlipidemia, astigmatism, and myopia. Conditional logistic regression with forward selection were used to obtain risk factors for KC. ResultsA total of 5,055 patients with KC were matched with 20,220 controls. The average age at KC first diagnosis was 29.76 years. Individuals who lived in suburban and rural area had lower odds ratio of KC (adjusted odds ratio [OR] 0.86, 95% confidence interval [CI] 0.80-0.94; and 0.73, 95% CI 0.67-0.79; respectively) when comparing with those who lived in urban area. Multivariate analysis revealed that Down syndrome, astigmatism, myopia, allergic rhinitis, and asthma were positively associated with KC with adjusted odds ratios (adjusted OR 8.69, 95% CI 3.74-20.19; 6.23, 95% CI 5.35-7.24; 2.99, 95% CI 2.70-3.32; 1.22, 95% CI 1.14-1.32; and 1.18, 95% CI 1.07-1.30, respectively). On the other hand, hyperlipidemia, depression, and DM (uncomplicated and complicated) were negatively associated with KC (adjusted OR 0.67, 95% CI 0.59-0.77; 0.58, 95% CI 0.48-0.71; 0.77, 95% CI 0.64-0.93; and 0.61, 95% CI 0.44-0.86, respectively). ConclusionsOur study found that patients with hyperlipidemia, depression, or DM were less likely to have KC, and patients with asthma, allergic rhinitis, astigmatism, myopia, or Down syndrome had higher odds ratio of KC.

The Prevalence and Risk Factors for Keratoconus: A Systematic Review and Meta-Analysis.

This study was conducted to determine the prevalence and risk factors for keratoconus worldwide. In this meta-analysis, using a structured search strategy from 2 sources, 4 electronic databases (PubMed, Web of Science, Google Scholar, and Scopus) and the reference lists of the selected articles were searched from inception to June 2018 with no restrictions and filters. The outcome of the study was the prevalence of keratoconus and its risk factors, including eye rubbing, family history of keratoconus, atopy, allergy, asthma, eczema, diabetes type I and type II, and sex. In this study, 3996 articles were retrieved, of which 29 were analyzed. These 29 articles included 7,158,241 participants from 15 countries. The prevalence of keratoconus in the whole population was 1.38 per 1000 population [95% confidence interval (CI): 1.14-1.62 per 1000]. The prevalence of keratoconus was 20.6 per 1000 (95% CI: 11.68-28.44 per 1000) in men and 18.33 per 1000 (95% CI: 8.66-28.00 per 1000) in women in studies reporting sex. The odds ratio of eye rubbing, family history of keratoconus, allergy, asthma, and eczema was 3.09 (95% CI: 2.17-4.00), 6.42 (95% CI: 2.59-10.24), 1.42 (95% CI: 1.06-1.79), 1.94 (95% CI: 1.30-2.58), and 2.95 (95% CI: 1.30-4.59), respectively. The results of this study, as the most comprehensive meta-analysis of keratoconus prevalence and risk factors, showed that keratoconus had a low prevalence in the world and eye rubbing, family history of keratoconus, allergy, asthma, and eczema were the most important risk factors for keratoconus according to the available evidence.

Risk factors for keratoconus in Israel: a case-control study.

Keratoconus (KC) is a progressive corneal thinning disorder with an uncertain aetiology. Environmental and genetic factors, including consanguinity, eye rubbing and possibly sun exposure, play a role in the aetiology of KC. Here we test for risk factors for KC in an Israeli population with particular emphasis on sun exposure. This case-control study included KC patients who were diagnosed at Care Laser Medical Group, a refractive surgery clinic with branches throughout Israel. The control group included age, sex and ethnicity matched individuals who were randomly selected from patients presenting at the clinic for refractive surgery, but without KC. Study subjects were asked to fill out a self-administered questionnaire that included demographic and geographic details, questions on ocular and general health and sun exposure. Conditional logistic regression was used to analyse univariable and multivariable data to identify risk factors for KC. Seventy-three KC patients and 146 controls participated in the study. Univariable analyses demonstrated that eye rubbing [odds ratio (OR) = 3.76], positive family history of KC (OR = 6.10) and parents' education (<12 years, OR = 0.27, 0.23 for father's and mother's education respectively) were significant risk factors for KC. Univariable analyses of sun exposure behaviour during teenage years proved equivocal with some behaviours emerging as protective for KC (wearing a hat outdoors, OR = 3.13) or as risk factors (spending time in the shade, OR = 0.45), while others showed no association [limiting time in the sun (p = 0.51), and wearing sunglasses (p = 0.20)]. Most of the factors that were significant in the univariable analyses, also emerged as statistically significant in the multivariable model (OR = 3.37, 9.68, 0.35, 5.51 for eye rubbing, family history, parental education, wearing a hat outdoors, with the exception of spending time in the shade (p = 0.88). Eye rubbing, parents' education (as a measure of socio-economic status) and having family members with KC emerged as significant risk factors for KC. The role of sun exposure in KC remains equivocal and warrants further research.

Prevalence of Keratoconus among Young Arab students in Israel

ABSTRACT Purpose To determine the prevalence of keratoconus (KC) in an Arab population in Israel. Materials and methods Videokeratography was performed on volunteer students from the Academic Arab College of Education, in Haifa, Israel. All participants filled out a self-administered questionnaire to evaluate possible risk factors for KC. Univariate and multivariate analysis were performed. Results Data of 314 participants were analyzed and a prevalence of (N = 10), 3.18% (95% CI, 1.2 to 5.1%) was found. The only significant factor (both in univariate and multivariate analysis) that was associated with KC was parental consanguinity (OR 5.10, p = 0.02). Druzes and Bedouins had a higher prevalence than Muslims and Christians. However, the differences were not significant possibly due to the small size of the sample. Conclusion The result of this study was similar to other studies conducted in the Middle East, which indicate a higher prevalence of KC than in western countries. It is also recommended that people who have consanguinity in their family should be topographically tested to detect the early stages of KC. How to cite this article Shneor E, Millodot M, Gordon-Shaag A, Essa M, Anton M, Barbara R, Barbara A. Prevalence of Keratoconus among Young Arab Students in Israel. Int J Kerat Ect Cor Dis 2014;3(1):9-14.

Keratoconus associated with Williams–Beuren syndrome: First case reports

Purpose: To report two memorable clinical comorbid cases of Williams–Beuren syndrome (WBS) associated with keratoconus (KC). WBS is known to be an abnormal systemic development caused by a microdeletion of contiguous genes in chromosome 7q11.23, which includes the elastin gene. KC is currently suspected to have a genetic origin but the responsible gene has not been clearly identified.Methods: KC and WBS is described for two cases. Risk factors for KC were investigated by interviewing parents, and WBS was confirmed by fluorescence in-situ hybridization (FISH). Histological analysis with Orcein (coloring specific to elastin) on the receiver corneal button of patient 1 was carried out.Results: Because of the rarity of both pathologies and the absence of other risk factors for developing keratoconus, we considered a possible genetic link. The association had never been reported in the literature. The first histological investigation could not confirm the presence of abnormal elastin in the cornea, but another gene could be responsible.Conclusion: This report highlights the first cases of this association. Further histological and cytogenetic investigation on the deletion should be interesting in order to argue a possible physiopathological or genomic link.

A profile of keratoconus in New Zealand.

To examine the characteristics and risk factors for keratoconus in a New Zealand population. A one-page questionnaire was designed and sent to optometrists and ophthalmologists in New Zealand. Eye care practitioners then issued questionnaires to their keratoconic patients over a 6-month period. A total of 673 completed questionnaires were received from patients with keratoconus. A male bias (59%) was apparent in the sample. In line with previous work, a high proportion of the keratoconic cohort rubbed their eyes and suffered from atopy. A familial rate of 23.5% was evident, with several families reporting multiple keratoconus cases. Eleven pairs of twins were identified with at least one keratoconic sibling. Multivariate statistical analysis revealed significant independent correlations between the early development of keratoconus and gender, allergy, asthma, and latitude of childhood domicile. Results from the survey concur with a previous local report that keratoconus affects males more frequently and earlier in life than females in New Zealand. The concurrence of atopic disease and eye rubbing with keratoconus was as expected, and an association between the early development of the disease and latitude of the childhood domicile emerged. A strong familial component, exceeding previously reported figures, was evident in the cohort.