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

PURPOSE: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Evaluating distance stereoacuity in children 4-17 years of age with a novel digital application.

Distance stereoacuity measurement enables the evaluation and management of binocular vision disorders. Here, we compare the results obtained using standard tests for distance stereoacuity measurement with the novel STab test. We tested 87 children (4-17 years of age) using different tests for the quantification of stereopsis at distance: Distance Randot Stereotest (DRS), M&S random dots (M&S), and STab. A strong correlation was demonstrated between M&S-DRS (0.8), M&S-STab (0.81), DRS-STab (0.85) (all P < 0.0001). The limit of agreement between M&S and DRS was 0.45; between M&S and STab, 0.47; and between DRS and STab, 0.38. Our results suggest that all three methods can be used interchangeably.

The dynamic optotype (Dyop): a novel visual acuity test for use in children.

PURPOSE: To evaluate the "dynamic optotype" (Dyop), a simple visual acuity test based on a dynamic target that requires minimal knowledge of symbols and letters. METHODS: A total of 160 consecutive, systemically healthy children, 4-17 years of age were prospectively recruited from the Pediatric Ophthalmology Unit of Meir Medical Center. Children were tested with the Dyop visual acuity test and the Early Treatment Diabetic Retinopathy Study (ETDRS) Lea numbers chart. The results of both tests were compared. The eye with the poorest acuity was tested with the new Dyop eye chart and the Lea numbers chart. The order of the testing was reversed between children. The logMAR visual acuity scores for each eye chart were compared. RESULTS: We found a strong linear correlation (r = 0.88) between visual acuity measures. The mean difference in visual acuity was -0.01 (95% CI, -0.02 to 0.01). The 95% limits of agreement were ±1.2 lines. The logMAR equivalent mean difference was about less than 1 letter. The Dyop test underestimated visual acuity relative to the Lea numbers chart. CONCLUSIONS: The results of this study support the Dyop eye chart as a valid measure of visual acuity in children 4-17 years of age, with visual acuity ranging from 20/16 to 20/200.

Diagnosis and Management Practice Patterns among Pediatric Ophthalmology Personnel in Israel.

PURPOSE: To investigate the diagnosis and management practice patterns of different aspects of pediatric ophthalmology among pediatric ophthalmologists and orthoptists in Israel. METHODS: A 21-question survey was delivered to all registered pediatric ophthalmologists and orthoptists in Israel. RESULTS: The response rate was 58.3%. Most pediatric ophthalmology personnel in Israel do not document intermittent exotropia (IXT) with a control scale, do not use modalities other than patching for amblyopia, and do not use distance stereoacuity tests. There was no consensus regarding patching and over minus treatments in IXT. In contrast to frequent use of prism adaptation test (PAT) for evaluating strabismus, most Israeli pediatric ophthalmology personnel do not use postoperation diplopia test (PODT). While most orthoptists use a questionnaire when diagnosing convergence insufficiency (CI), most pediatric ophthalmologists do not. CONCLUSION: This study highlights the current areas of consensus and disagreement regarding pediatric ophthalmology diagnosis and management practices in Israel. Adopting a uniform approach regarding diagnosing CI, including using a questionnaire by pediatric ophthalmologists and orthoptic exercises in the management of IXT, is warranted to enable unified treatment by pediatric ophthalmologist and orthoptists in Israel.