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IMPORTANCE: Myopia (nearsightedness) has its onset in childhood and affects about one-third of adults in the United States. Along with its high prevalence, myopia is expensive to correct and is associated with ocular diseases that include glaucoma and retinal detachment. OBJECTIVE: To determine the best set of predictors for myopia onset in school-aged children. DESIGN, SETTING, AND PARTICIPANTS: The Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study was an observational cohort study of ocular development and myopia onset conducted at 5 clinical sites from September 1, 1989, through May 22, 2010. Data were collected from 4512 ethnically diverse, nonmyopic school-aged children from grades 1 through 8 (baseline grades 1 through 6) (ages 6 through 13 years [baseline, 6 through 11 years]). MAIN OUTCOMES AND MEASURES: We evaluated 13 candidate risk factors for their ability to predict the onset of myopia. Myopia onset was defined as −0.75 diopters or more of myopia in each principal meridian in the right eye as measured by cycloplegic autorefraction at any visit after baseline until grade 8 (age 13 years). We evaluated risk factors using odds ratios from discrete time survival analysis, the area under the curve, and cross validation. RESULTS: A total of 414 children became myopic from grades 2 through 8 (ages 7 through 13 years). Of the 13 factors evaluated, 10 were associated with the risk for myopia onset (P < .05). Of these 10 factors, 8 retained their association in multivariate models: spherical equivalent refractive error at baseline, parental myopia, axial length, corneal power, crystalline lens power, ratio of accommodative convergence to accommodation (AC/A ratio), horizontal/vertical astigmatism magnitude, and visual activity. A less hyperopic/more myopic baseline refractive error was consistently associated with risk of myopia onset in multivariate models (odds ratios from 0.02 to 0.13, P < .001), while near work, time outdoors, and having myopic parents were not. Spherical equivalent refractive error was the single best predictive factor that performed as well as all 8 factors together, with an area under the curve (C statistic) ranging from 0.87 to 0.93 (95% CI, 0.79-0.99). CONCLUSIONS AND RELEVANCE: Future myopia can be predicted in a nonmyopic child using a simple, single measure of refractive error. Future trials for prevention of myopia should target the child with low hyperopia as the child at risk.

OBJECTIVE To report the percentage of new cases of myopia in 4927 children aged 5 to 16 years who participated in the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error Study between 1989 and 2009. DESIGN A multicenter, longitudinal, observational, volunteer study of refractive error and ocular development in children from 5 racial/ethnic groups in which the participants were children who were not myopic (right eye cycloplegic autorefraction of less myopia/more hyperopia than −0.75 diopters [D] in both principal meridians) at study entry. A new case was a diagnosis of myopia (right eye cycloplegic autorefraction of −0.75 D or more myopia in both principal meridians) after study entry. RESULTS Of the 4556 children entering the study who were not myopic, 749 (16.4%) received a diagnosis of myopia after study entry. Among these 749 children, the ages of the participants at diagnosis varied from 7 to 16 years, with the largest number diagnosed at age 11 years (136 participants [18.2%]). New cases of myopia occurred in 27.3% of Asians, 21.4% of Hispanics, 14.5% of Native Americans, 13.9% of African Americans, and 11% of whites. Female participants had more new cases than did male participants (18.5% vs 14.5%). Normal-birth-weight children had more new cases than did low-birth-weight children (16.9% vs 15.5%). CONCLUSIONS Sixteen percent of children enrolled in the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error Study developed myopia during their school-aged years. The percentage increased yearly until age 11 years, after which it decreased. New cases of myopia varied by ethnic/racial group.

To determine whether compliance with referral 1 year after vision screening failure was associated with care model, demographic, or ocular factors.

To describe corneal and crystalline lens dimensions before, during, and after myopia onset compared with age-matched emmetropic values.

The ethnically diverse Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study cohort provides a unique opportunity to explore associations among intraocular pressure (IOP), ethnicity, and refractive error while adjusting for potential confounding variables.

This cross-sectional report includes ocular component data as a function of age, gender, and ethnicity from the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study.

The C677T polymorphism of methylene tetrahydrofolate reductase (MTHFR) lowers the activity of this enzyme, producing moderate elevation of blood levels of homocysteine (Hcy) and lowering the levels of 5-methyl-tetrahydro-folic acid (5-MeTHFA), methionine (Meth), and S-adenosylmethionine (SAM). In this study we examined 100 apparently normal subjects of both sexes (average age 25.6 ± 4.25) for the genotypic presence of the T allele and its association with accommodative amplitude (AA).

Optometrists, like all health care providers, should emphasize primary or preventive care. To provide this care optometrists must be aware of the risk factors for major causes of mortality. As an example, the risk profile for a white male age 45 to 49 years is given and discussed. Suggestions for primary vision care and detection of major risk factors by optometrists are also presented.

The psychometric function for the detection of a foveal luminance increment was studied in human observers. The signal to be detected was a modulation of a 1300 cd/m^2 6′ circular red target. For an ideal photodetector, the theory of signal detectability predicts that d′, the index of detectability, should rise linearly with the luminance, E, of the luminance increment unless the observer has some uncertainty concerning the parameters of the signal to be detected. Uncertainty is expressed by the parameter M that indicates the number of orthogonal signals possible. If M is greater than 1.0, (d′)^2 = ln {1 − 1/M +(1/M) exp(E^2/N^2)} where N^2 is the variance of the noise that obscures the signal. In addition, the theory predicts that the slope of the receiver operating characteristic (ROC curve) should decrease with increasing M. In one experiment, in which E was varied, a nonlinear psychometric function and an ROC curve of relatively low slope were found. In another experiment that included a pulsed background (pedestal) whether or not the signal was presented, the predicted linear M = 1 psychometric function was found. Finally, the ROC slope that was measured in rating experiments increased when the pedestal was used. Presumably, the pedestal provides the signal-parameter information that the observer could not remember. We conclude that the human observer acts like an ideal photodetector that has imperfect memory concerning the signal to be detected.

The psychometric function for the detection of a foveal luminance increment was studied in human observers. The signal to be detected was a modulation of a 1300 cd/m^2 6′ circular red target. For an ideal photodetector, the theory of signal detectability predicts that d′, the index of detectability, should rise linearly with the luminance, E, of the luminance increment unless the observer has some uncertainty concerning the parameters of the signal to be detected. Uncertainty is expressed by the parameter M that indicates the number of orthogonal signals possible. If M is greater than 1.0, (d′)^2 = In{1-1/M +(1/M) exp(E^2/N^2)} where N^2 is the variance of the noise that obscures the signal. In addition, the theory predicts that the slope of the receiver operating characteristic (ROC curve) should decrease with increasing M. In one experiment, in which E was varied, a nonlinear psychometric function and an ROC curve of relatively low slope were found. In another experiment that included a pulsed background (pedestal) whether or not the signal was presented, the predicted linear M = 1 psychometric function was found. Finally, the ROC slope that was measured in rating experiments increased when the pedestal was used. Presumably, the pedestal provides the signal-parameter information that the observer could not remember. We conclude that the human observer acts like an ideal photodetector that has imperfect memory concerning the signal to be detected.

Several animal and human investigations have indicated that intraocular pressure (IOP) levels may be associated with extreme drug-induced changes in the extraocular muscles. Further, recent data suggest that, among individuals with normal IOP level, moderate increases in facial muscle (EMG) activity around the eye while the eye is open are associated with increases in IOP. To investigate further the relationship between facial EMG activity and IOP levels and to examine a group of individuals with elevated IOP levels, subjects were recruited from outpatients at an optometry clinic. Three groups of subjects were selected: a group of ocular hypertensive subjects who showed elevated pressures at the optometry clinic and upon the day of testing, a group of labile ocular hypertensive subjects who evinced elevated pressures during their visit to the optometry clinic but lower pressures on the day of testing, and a group of normal IOP subjects who showed normal pressures both during their optometry clinic visit and on the day of testing. To investigate anxiety differences, subjects were administered the State-Trait Anxiety Inventory, but subsequent analysis revealed no group differences. To evaluate the role of stress upon muscle (EMG) functioning around the eye, subjects were subjected to imagery and standardized mental arithmetic stressors; analyses of these results also revealed no significant group differences. Finally, subjects were given EMG biofeedback for muscle activity around the eye while IOP was assessed during five alternating periods in which they made decreases and increases in EMG activity. Results revealed significant group, period, and group by period interaction effects. The pattern of results is interpreted as implicating EMG activity in IOP fluctuations; the implications of these data for potential biofeedback and stress management treatments are discussed.