Analysis of Alphabet Patterns of Deviations Found in Patients Without Strabismus in Primary Position.

AIM: To detect alphabet patterns in a group of patients without strabismus and to determine whether they induced any convergence insufficiency type symptoms. METHODS: Data on subjective refraction, distance and near heterophoria, distance and near positive fusional vergence (BO), near point of convergence (NPC), measurements of upgaze and downgaze made 45° above and below the primary position with alternate cover test and a prism bar at a distance of 37.5 cm, were collected from participants of two clinics. Symptoms were assessed using the 15-item Convergence Insufficiency Symptoms Survey (CISS) to determine a symptom score. Association between alphabet patterns and the other variables was analyzed using parametric and non-parametric tests. RESULTS: Out of 122 patients, 14 were found to present an alphabet pattern. Defining a V pattern exophoria ≥15-prism dioptre or ≥10-prism dioptre deviation, three patients (2.5%) and 12 patients (9.8%) were identified, respectively. In addition, one case resembled an X pattern and another a diamond pattern. The refraction, distance and near heterophoria, positive fusional vergence and CISS scores were not significantly different in the participants with V pattern compared to those without V pattern. CONCLUSION: Alphabet patterns, especially V type, were demonstrated in approximately 11.5% of a sample of 122 non-strabismus patients. These alphabet patterns were found not to be associated with convergence insufficiency-like symptoms.

Corneal and conjunctival injury seen in urgent care centres in Israel.

PURPOSE: Corneal and conjunctival injuries (CCI) comprise a large portion of the cases presenting to hospital-based emergency departments (ED) with ocular involvement. Urgent Care Centres (UCC) offer community based emergency care at lower cost than hospital-based emergency departments (ED) and with greater temporal convenience than primary care office settings. While CCI prevalence and treatment at hospital-based EDs has been well studied, this is the first report, to our knowledge, on CCI demographics and aetiology presenting to UCCs. METHODS: This retrospective study was approved by the institutional ethics committee. The setting is a UCC system in Israel, modelled on USA urgent care facilities, consisting of 17 branches at the time of the study. Electronic medical record data (between November 1, 2015 and October 31, 2016) of patients diagnosed with corneal disorder, foreign body or eye disorder were retrieved and reviewed for inclusion/exclusion criteria. Data collected included gender, age, chief complaint, diagnosis, treatment and discharge status (sent home or referred to ED). International Classification of Diseases, Ninth Revision (ICD-9) codes were assigned to each record based on a review of all fields. UCC results were compared to all ED patients in Israel using data from a public report. Data were analysed by descriptive statistics and logistic regression analysis. RESULTS: Of the 602 074 charts screened, 4797 patients presented with CCI (0.8%). The average age was 32.6 ± 18.2 years and 71.3% were male. Among these, 26.4% were referred to the ED compared to 6.8% from the entire UCC cohort. ICD-9 code Foreign body (FB) of the eye was the most common cause of CCI (56.5%) followed by the following ICD-9 codes: trauma (18.1%), chemical in the eye (11.1%) and corneal disorder due to a contact lens (5.1%). Logistic regression analyses showed the following risk factors for ED referral: age (22-64), male gender, ICD-9 code FB, work-related injury and the presence of a clinical abrasion in the eye. CONCLUSIONS: The aetiology of ocular injury at UCC is similar to previous studies of ED. Most CCI can be treated at UCC saving ED resources and underscores the importance of this mode of health care delivery in the overall health system.

Effect of uncorrection versus full correction on myopia progression in 12-year-old children.

PURPOSE: To investigate the effects of no correction versus full correction on myopia progression in Chinese children over a period of 2 years. METHODS: Myopia was defined as cycloplegic spherical equivalent (SE) of ≤ -0.50 D. Uncorrection was defined as no spectacles worn, and full correction was defined as when the value of SE subtracted from the dioptric power of the child's current spectacles was less than 0.5 D. Ocular examinations included visual acuity, cycloplegic autorefraction, axial length and vertometer measurements. Questionnaires were completed by parents on behalf of the children. RESULTS: A total of 121 myopic children, with a median age of 12.7 years, were screened from the Anyang Childhood Eye Study, with 65 in the uncorrected group and 56 in the full correction group. At 2-year follow-up, children with no correction had slower myopia progression (-0.75 ± 0.49 D vs. -1.04 ± 0.49 D, P < 0.01) and less axial elongation (0.45 ± 0.18 mm vs. 0.53 ± 0.17 mm, P = 0.02) than children with full correction. In multivariate modeling, adjusting for baseline SE or axial length, age, gender, height, number of myopic parents, age at myopia onset, and time spent in near work and outdoors, children with no correction still had slower myopia progression (-0.76 ± 0.07 vs. -1.03 ± 0.08 D, P < 0.01) and less axial elongation (0.47 ± 0.03 mm vs. 0.51 ± 0.03 mm, P < 0.01). Myopia progression decreased significantly with an increasing amount of undercorrection in all children (r = 0.22, b = 0.16, P = 0.01). CONCLUSION: Our findings suggest that myopic defocus slows the progression of myopia in already myopic children, supporting previous findings from animal studies.

Characteristics of Keratoconic Patients Attending a Specialist Contact Lens Clinic in Kenya.

PURPOSE: To describe the characteristics of keratoconus (KC) patients seen in a contact lens clinic of a children's hospital in Kenya. RESULTS: A total of 254 patients' records were analyzed. Mean age at presentation to the clinic was 20.97 ± 11.13 year (range, 6-84 years) with 75% between the ages of 6 and 25 years. There was a preponderance of males (59.8%). Most patients were referred by an ophthalmologist. All patients were Africans. The most common complaints were blurred vision (50%), poor visual acuity with spectacles (33.5%), contact lens intolerance (11.8%), and other (unspecified). Most cases were severe (71%) followed by moderate (22.9%) and mild (6.2%). Mean BCVA was 0.24 ± 0.23 (6/11). An optical correction was provided in 98% of cases; 34.6% with spectacles, 31.1% with gas permeable lenses and the remaining with both. Referral for keratoplasty was warranted in 16.5%. CONCLUSION: This is the first study of KC conducted in Kenya. KC presented at a very early age and tended to be severe. Ophthalmologists were the main source of referral. The main presenting symptom was reduced vision. Optical correction was the most common management and the percentage of patients referred for surgery concurred with other studies.

Chinese Eye Exercises and Myopia Development in School Age Children: A Nested Case-control Study.

Chinese eye exercises have been implemented in China as an intervention for controlling children's myopia for over 50 years. This nested case-control study investigated Chinese eye exercises and their association with myopia development in junior middle school children. Outcome measures were the onset and progression of myopia over a two-year period. Cases were defined as 1. Myopia onset (cycloplegic spherical equivalent ≤ -0.5 diopter in non-myopic children). 2. Myopia progression (myopia shift of ≥1.0 diopter in those who were myopic at baseline). Two independent investigators assessed the quality of Chinese eye exercises performance at the end of the follow-up period. Of 260 children at baseline (mean age was 12.7 ± 0.5 years), 201 were eligible for this study. There was no association between eye exercises and the risk of myopia-onset (OR = 0.73, 95%CI: 0.24-2.21), nor myopia progression (OR = 0.79, 95%CI: 0.41-1.53). The group who performed high quality exercises had a slightly lower myopia progression of 0.15 D than the children who did not perform the exercise over a period of 2 years. However, the limited sample size, low dosage and performance quality of Chinese eye exercises in children did not result in statistical significance and require further studies.

Effect of ageing on keratoconic corneas.

PURPOSE: To explore the potential effect of ageing on the corneal curvature and corrected visual acuity in patients with long-term keratoconus because of the paucity of these patients older than 50 years. METHODS: Records of keratoconic patients, who had initially presented to a specialized contact lens clinic and followed for more than 20 years after disease onset, were reviewed. Collected information included age, gender, date of first and last examination, date of onset of the disease, central corneal curvature, refraction, best corrected visual acuity (BCVA), therapeutic modality and clinical signs. RESULTS: Age of patients at last examination was 53.8 years±7.2 (range 44-67 years). Disease onset was self-reported to be at age 18.4 years±3.8. First examination was at age 25.1 years±9.4 and the mean number of years between first and last examination was 28.7 years. Mean central corneal curvature was 6.87mm (48.77D)±0.65 and 6.56mm (51.09D)±0.74, at first and last examination, respectively, a difference which was significant (p<0.001). However, the last measurement of corneal curvature was found to remain approximately constant over the years from about 20 to 50 years after onset. Mean BCVA was not significantly different between first and last examination and was found to be approximately constant over the years. CONCLUSION: Corneal curvature became steeper possibly within the first 20 years after disease onset but remained approximately unchanged afterwards. Likewise, BCVA remained practically constant over the years indicating relative stability of the disease after 20 years.

The effect of refractive error on the accommodative response gradient: a summary and update.

PURPOSE: To give a summary of the original paper 'The effect of refractive error on the accommodative response gradient' published in 1986 and to present a brief overview of the most salient, subsequent findings which have appeared since then. RECENT FINDINGS: Intensive and prolonged near work as a precursor to myopia has been substantiated since the original paper and is thought to contribute to the remarkable increase in the prevalence of myopia in the world which has occurred in the last 30 years, consistent with the emergence of compulsory education, computers and urbanisation. Increased accommodation has not been found to be essential in the development of myopia, but inaccurate accommodation during near work in the form of accommodative lag with its consequent hyperopic defocus has been confirmed as an association with myopia, although it is not clear whether that association is causal or merely a consequence of myopia. SUMMARY: The premise of the original paper that near work engenders lower accommodation in myopes compared to emmetropes and hyperopes has been corroborated over the years, particularly in progressing myopes as distinct from stable adult myopes. Inaccurate accommodation resulting in accommodative lag has been amply confirmed in subsequent studies.

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.

Effect of undercorrection on myopia progression in 12-year-old children.

BACKGROUND: To prospectively observe the effects of undercorrection of myopia on myopia progression and axial elongation in a population of 12-year-old Chinese children. METHODS: A total of 2,267 children in the Anyang Childhood Eye Study were examined at baseline, and 1,769 were followed for 1 year. Ocular examinations included cycloplegic autorefraction, axial length, visual acuity, vertometry, and accommodative lag. Questionnaires were completed by children and parents. Undercorrection of myopia was determined at baseline if presenting visual acuity could be improved by at least 2 lines with subjective refraction. RESULTS: Of 253 myopic children with spectacles and available information, 120 (47.4 %) were undercorrected (-4.63D to -0.50D) and 133 (52.6 %) were fully corrected. In a multivariate model adjusting for age, gender, number of myopic parents, time spent on near work and outdoor activities per day, usage and time for wearing spectacles per day, children with undercorrection had significantly more baseline myopia (P < 0.01) and longer axial length (P = 0.03) than children with full correction. However, there were no significant differences in myopia progression (P = 0.46) and axial elongation (P = 0.96) at 1 year between the two groups of children. The regression analysis showed that myopia progression significantly decreased with increasing amount of undercorrection (r (2) = 0.02, P = 0.02) in all children. Accommodative lag significantly decreased with increasing amounts of undercorrection (P < 0.01). CONCLUSIONS: Based on this 1-year study in Chinese children, undercorrection or full correction of myopia by wearing spectacles did not show any differences in myopia progression or axial elongation.

The genetic and environmental factors for keratoconus.

Keratoconus (KC) is the most common cornea ectatic disorder. It is characterized by a cone-shaped thin cornea leading to myopia, irregular astigmatism, and vision impairment. It affects all ethnic groups and both genders. Both environmental and genetic factors may contribute to its pathogenesis. This review is to summarize the current research development in KC epidemiology and genetic etiology. Environmental factors include but are not limited to eye rubbing, atopy, sun exposure, and geography. Genetic discoveries have been reviewed with evidence from family-based linkage analysis and fine mapping in linkage region, genome-wide association studies, and candidate genes analyses. A number of genes have been discovered at a relatively rapid pace. The detailed molecular mechanism underlying KC pathogenesis will significantly advance our understanding of KC and promote the development of potential therapies.

Efficacy of Chinese eye exercises on reducing accommodative lag in school-aged children: a randomized controlled trial.

PURPOSE: To evaluate the efficacy of Chinese eye exercises on reducing accommodative lag in children by a randomized, double-blinded controlled trial. METHODS: A total of 190 children aged 10 to 14 years with emmetropia to moderate myopia were included. They were randomly allocated to three groups: standard Chinese eye exercises group (trained for eye exercises by doctors of traditional Chinese medicine); sham point eye exercises group (instructed to massage on non-acupoints); and eyes closed group (asked to close their eyes without massage). Primary outcome was change in accommodative lag immediately after intervention. Secondary outcomes included changes in corrected near and distant visual acuity, and visual discomfort score. RESULTS: Children in the standard Chinese eye exercises group had significantly greater alleviation of accommodative lag (-0.10 D) than those in sham point eye exercises group (-0.03 D) and eyes closed group (0.07 D) (P = 0.04). The proportion of children with alleviation of accommodative lag was significantly higher in the standard Chinese eye exercises group (54.0%) than in the sham point eye exercises group (32.8%) and the eyes closed group (34.9%) (P = 0.03). No significant differences were found in secondary outcomes. CONCLUSION: Chinese eye exercises as performed daily in primary and middle schools in China have statistically but probably clinically insignificant effect in reducing accommodative lag of school-aged children in the short-term. Considering the higher amounts of near work load of Chinese children, the efficacy of eye exercises may be insufficient in preventing myopia progression in the long-term. TRIAL REGISTRATION: ClinicalTrials.gov NCT01756287.

Atropine slows myopia progression more in Asian than white children by meta-analysis.

PURPOSE: To conduct a meta-analysis on the effects of atropine in slowing myopia progression and to compare Asian and white children and randomized controlled trials (RCTs) and observational studies. METHODS: Randomized controlled trials and observational studies that assessed the effects of all concentrations of atropine in slowing myopia progression in children were searched from MEDLINE, EMBASE, and the Cochrane Library up to April 2013. Jadad scoring was used to evaluate the quality of RCTs, and the Newcastle-Ottawa Scale was used for observational studies. RESULTS: Four RCTs and seven cohort studies (a kind of observational study) with 1815 children aged 5 to 15 years were included. The children had a baseline refraction of -0.50 to -9.75 diopters (D) and were followed up for 22.0 months (range, 12.0 to 36.5 months). The weighted mean differences in myopia progression in RCTs and cohort studies of Asian children were 0.55 D per year (p < 0.01) and 0.54 D per year (p < 0.001), respectively, and 0.35 D per year (p = 0.01) in cohort studies of white children. Compared with placebo, the risk of fast myopia progression (>1.0 D per year) using atropine was significantly decreased in both RCTs (odds ratio [OR], 0.14; p < 0.01) and cohort studies (OR, 0.08; p < 0.01), and the benefit of slow myopia progression (<0.50 D per year) using atropine was significantly increased in both RCTs (OR, 6.73; p < 0.01) and cohort studies (OR, 22.10; p < 0.01). CONCLUSIONS: Atropine could significantly slow myopia progression in children, with greater effects in Asian than in white children. Randomized controlled trials and cohort studies provided comparable effects.

Prevalence of choroidal naevi using scanning laser ophthalmoscope.

PURPOSE: To determine the prevalence of choroidal naevi in a healthy population using an ultra-wide scanning laser ophthalmoscope which can capture up to a 200° field of view of the retina, without pupil dilation. METHODS: Subjects were recruited from a college population. Each subject underwent an eye examination that included retinal and choroidal imaging using the Optos scanning laser ophthalmoscope and completed a self-administered questionnaire. Univariate and multivariate regression analysis were performed to identify associated factors with choroidal naevi. RESULTS: The Optomap images of 406 participants (mean age 23.5 ± 4.4) were analysed. Thirty-nine subjects (10%) presented with at least one naevus in one eye, and multiple naevi were observed unilaterally in eight subjects. Drusen were noted in only one eye. The mean naevus diameter was 2.38 mm (± 2.07). Prevalence was not associated with either eye colour, time spent outdoors, visual impairment, or ethnic group, but was significantly associated with male gender (OR 2.41, p = 0.009), blond/red hair colour (OR 2.42, p = 0.037), skin that neither burns nor tans (OR 2.8, p = 0.02) and habitual sunglasses use (OR 0.33, p = 0.002). CONCLUSIONS: A higher prevalence of choroidal naevi was detected in this college population compared to other population-based studies. This is likely due to the use of an ultra-wide field scanning laser ophthalmoscope which provides up to 200° of the fundus. The naevi were associated with several factors.

Is consanguinity a risk factor for keratoconus?

PURPOSE: To determine whether consanguinity is a risk factor for keratoconus (KC). METHODS: A questionnaire was distributed to all patients presenting to St. John Eye Hospital, Jerusalem, Israel. Questionnaire included data on demographic characteristics and potential risk factors. Patients were divided into two groups: cases with KC, in at least one eye, who were diagnosed by the attending ophthalmologist on the basis of abnormal corneal topography and at least one of the common signs of the disease; and controls presenting for problems other than KC and free of systemic and ocular conditions associated with KC. Multivariate logistic analyses were performed to identify risk factors for KC. RESULTS: Seventy cases and 140 controls participated in the study. Groups were similar with respect to sex and age. Univariate analyses found a significant association between KC and parental first-cousin consanguinity, eye rubbing, allergy, positive family history, education (>12 years), and sunglass wear, whereas asthma, eczema, smoking, and second-cousin consanguinity were not. Multivariate analyses showed that total consanguinity (first-cousin and second-cousin) (adjusted odds ratio, 3.96; p = 0.001), eye rubbing and absence of sunglass wear were significant risk factors. Education was also associated with KC, but family history was not so in the multivariate analysis. CONCLUSIONS: This study supports the hypothesis that consanguinity is a significant risk factor for KC and provides strong support for a genetic contribution to the disease. Wearing sunglasses in this environment is beneficial, and the study confirmed that eye rubbing, allergy, and education are also significantly associated with KC after adjusting for other predictors.

Characteristics of 244 patients with keratoconus seen in an optometric contact lens practice.

BACKGROUND: The purpose of this study was to describe the characteristics of keratoconic patients seen in a specialised contact lens practice from a general population with a high prevalence of the disease. METHODS: Patients attending a contact lens practice for management of keratoconus were asked to complete a questionnaire. Data were collected on demographic characteristics, general health, family history, eye rubbing, allergy, asthma, eczema, education level, history of keratoplasty and smoking. RESULTS: Two hundred and forty-four patients completed the questionnaire. There was a male bias (54.5 per cent). The majority of the patients (78.7 per cent) wore contact lenses, of whom 67.7 per cent wore hard, 13 per cent soft and 4.2 per cent scleral contact lenses. Some of the patients (21.3 per cent) had undergone corneal graft surgery. Eighteen per cent had an associated systemic disease, the most common of which was type 2 diabetes, although this disease was less prevalent, but not significantly, in the keratoconic sample than in the general population (p = 0.19). The prevalence of eye rubbing (65.6 per cent) was similar to other studies. Compared to the general population, asthma (13.2 per cent) was slightly, but not significantly, less prevalent (p = 0.17), eczema (6.6 per cent) was significantly less (p < 0.001) and allergy (34.4 per cent) was more prevalent (p < 0.001). A high proportion of patients reported a family history of the disease (27.9 per cent) and most were better educated than the general population. CONCLUSION: The results of this survey concur with those of other studies with regard to most known characteristics of keratoconus; however, the proportion of asthma and eczema tended to be less than in other surveys and may be linked to the environmental influence of a hot and sunny country. The high prevalence of positive family history of the disease in this cohort suggests a genetic influence.

Full correction and Undercorrection of Myopia Evaluation Trial: design and baseline data of a randomized, controlled, double-blind trial.

BACKGROUND: To determine the difference in the rate of myopic progression between children wearing single vision lenses with undercorrection of +0.50 D and children whose myopia is fully corrected, and to explore the factors that may influence the process. DESIGN: Randomized, controlled, double-blind trial. PARTICIPANTS: Two hundred children aged 7-15 years with low-to-moderate myopia (-1.5 D to -6.0 D), astigmatism <-1.5 D and anisometropia <1.0 D. METHODS: The children were randomly allocated to wear single vision lenses with full correction or undercorrection by +0.50 D. Ocular examinations and questionnaire surveys for myopia-related factors will be performed every 6 months. MAIN OUTCOME MEASURES: Cycloplegic autorefraction and axial length. RESULTS: Of 200 children, 100 (50%) were girls, 41 (21%) esophoric and 82 (42%) exophoric at near. The characteristics of gender, age, age of myopia onset, phoria, eye dominance, parental myopia, refractive error, axial length, corneal curvature, mean time spent in near work and outdoor activities between the two groups were not significantly different. The accommodative responses at 33 cm, the accommodative demands and lags at infinity were significantly different in the two groups as they were measured with full correction in one group and undercorrection in the other. CONCLUSION: Full correction and Undercorrection of Myopia Evaluation Trial is a clinical trial designed to determine the effectiveness of undercorrection of myopia by +0.5 D on myopic progression in a population of school-aged children known to be susceptible to myopia and to identify the factors influencing the process.

Aberrations and topography in normal, keratoconus-suspect, and keratoconic eyes.

PURPOSE: This study was designed to compare higher order aberrations of the cornea and of the eye with inferior-superior (I-S) corneal topographic values in keratoconic eyes. METHODS: We studied 92 eyes from 78 subjects: 21 eyes of 14 subjects with suspected keratoconus, 23 eyes of 16 subjects with manifest keratoconus, and 48 eyes of 48 subjects without keratoconus using the L80 wave+, an instrument which can measure corneal topography and aberrations simultaneously with a large dynamic range making it possible to evaluate higher order aberrations to the seventh order of the Zernike polynomial function series. RESULTS: All ocular and corneal higher order aberrations were found to be significantly higher for keratoconic than normal eyes, but for suspected keratoconus the results were mixed. Corneal aberrations were higher than ocular aberrations due to compensation from the internal aberrations. For manifest keratoconus, the corneal and ocular vertical coma displayed the largest difference being 38.6 and 78.5 times higher, respectively, than normal eyes, while the largest differences for suspected keratoconus were only 5.3 and 4.0 times higher, respectively. On the other hand, inferior-superior dioptric asymmetry was 9.4 and 37.3 times higher for suspected keratoconus and keratoconic eyes, respectively, than normal eyes. The separation of normality curves between suspected keratoconus and normal eyes was 28.6% for I-S and 14.3% for both corneal vertical coma and corneal total coma. CONCLUSIONS: Although corneal vertical coma and, to a lesser extent, ocular vertical coma were found to be good indicators for the detection of keratoconic eyes, the traditional corneal topographic value such as the inferior-superior dioptric asymmetry remains an important predictor for identifying suspected keratoconus. However, ocular vertical coma and ocular higher order total root mean square also represent a good means of identifying suspected keratoconus.

Clinical evaluation of the L80 autorefractometer.

BACKGROUND: A clinical evaluation of the L80 wave+ autorefractometer (Visionix Luneau, Chartres, France) was performed to evaluate its validity and repeatability compared with non-cycloplegic subjective refraction. The L80 wave+ autorefractometer is a new instrument based on the Hartmann-Shack principle that has a specific autorefraction function using the wavefront device and can also measure keratometry, topography of the cornea and higher-order aberrations. METHODS: Refractive error measurements were obtained from 100 eyes of 50 subjects (age, 25 ± 2.71 years) subjectively by one masked practitioner and objectively with the L80 wave+ autorefractometer (with a 3.0 mm pupil) by a second practitioner. Intra-test and inter-test (within a week after the initial objective measures) variability was assessed on 28 new subjects (56 eyes). RESULTS: The results of the objective and subjective measurements of refractive error were very similar (mean difference 0.03 ± 0.47 D, p = 0.49 for sphere; 0.05 ± 0.27 D, p = 0.06 for cylinder; 0.06 ± 0.44 D, p = 0.20 for spherical equivalent; 0.01 ± 0.13 D, p = 0.37 for J(0) and -0.005 ± 0.12 D, p = 0.69 for J(45) ). High intra-test and inter-test repeatability were demonstrated for all parameters measured and found comparable with other clinical autorefractors. CONCLUSION: The L80 wave+ autorefractometer represents a reliable and valid objective refractive tool for general optometric practice.

Prevalence and associated factors of keratoconus in Jerusalem: a cross-sectional study.

PURPOSE: To determine the prevalence and associated factors for keratoconus in a college student population sample in Jerusalem. METHODS: Volunteers participated in this cross-sectional study. Videokeratography was performed on both eyes of each subject who also completed an anonymous questionnaire. Keratoconus was defined by cone apex ≥ 50D, inferior-superior dioptric difference ≥ 3.5 diopters, as well as positive results from the software indices KISA, KCI and KSI. The association between independent predictors and keratoconus was analyzed using multivariate logistic regression analysis. RESULTS: Of a total of 987 volunteers, 981 (mean age 24.4) were included. The prevalence of keratoconus among all subjects was 2.34% (95% confidence interval [CI] 1.4-3.3). It was significantly higher in men (4.91%, CI 2.6-7.3) than women (1.07%, CI 0.3-1.9) but not between Israeli Arabs (3.0%, CI 0.6-5.4) and Israeli Jews (2.2%, CI 1.2-3.3). Keratoconus was significantly associated with positive family history of the disease (Odds Ratio [OR] 17.1, CI 5.0-57.8, P<0.001), male gender (OR 5.4, CI 2.1-14.3, P=0.001) and atopy (OR 3.0, CI 1.2-7.6, P=0.02), but not with eye rubbing. CONCLUSIONS: The prevalence of keratoconus in Jerusalem was found to be much higher than that seen in other parts of the world, except India. This may be related to a combination of genetic and environmental factors. Positive family history, male gender and atopy were shown to be significant predictors. The results of this study signal a need for public health outreach and intervention for keratoconus.