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Biomedical subjects

Maureen G Maguire

Publications and source records attributed to Maureen G Maguire.

At least 19 recordsLinked to original sources

Children unable to perform screening tests in vision in preschoolers study: proportion with ocular conditions and impact on measures of test accuracy.

PURPOSE: To examine the relative prevalence of ocular conditions among children who are unable to perform preschool vision screening tests and the impact on measures of screening test performance. METHODS: Trained nurse and lay screeners each administered a Lea Symbols visual acuity (VA) test (Good-Lite, Inc., Steamwood, IL), Stereo Smile II test (Stereo Optical, Inc., Chicago, IL), and Retinomax Autorefractor (Right Manufacturing, Virginia Beach, VA), and SureSight Vision Screener (Welch Allyn, Inc., Skaneateles Falls, NY) examinations to 1475 children who later received a comprehensive eye examination to identify amblyopia, strabismus, significant refractive error, and unexplained reduced VA. The outcomes of the examination for children for whom screeners were unable to obtain results (Unables) were compared to the outcomes of children who passed and children who failed each screening test. When estimating sensitivity, specificity, and positive and negative predictive values (PPV and NPV), Unables were classified as either screening failures or screening passers. RESULTS: Less than 2% of children were classified as Unables for each test. The percentage with an ocular condition was at least two times higher for Unables than for screening passers for six of the eight modes of screening (P < 0.05). Considering Unables as screening failures, rather than screening passers, increased the estimate of sensitivity by 1% to 3% (depending on test) and decreased the estimate of specificity by 0% to 2%; PPV decreased by 0% to 4% for most tests, whereas NPV increased by <1%. CONCLUSIONS: Preschool children who are unable to perform VIP screening tests are more likely to have vision disorders than are children who pass the tests. Because < or =2% of children were unable to do each test, referring these children for an eye examination had little impact on the PPV and NPV of the tests, as administered in VIP.

Allied Health Personnel↗

Validation and test characteristics of a 10-item neuro-ophthalmic supplement to the NEI-VFQ-25.

PURPOSE: To determine whether a 10-Item Neuro-Ophthalmic Supplement increases the capacity of the 25-Item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) to capture self-reported visual dysfunction in patients with neuro-ophthalmologic disorders. DESIGN: A cross-sectional survey to examine the characteristics of a 10-Item Neuro-Ophthalmic Supplement to the 25-Item NEI-VFQ-25 in a cohort of patients with neuro-ophthalmologic disorders. METHODS: The 10-Item Neuro-Ophthalmic Supplement was designed previously by our research group by survey and focus-group methods. In the present study, the NEI-VFQ-25 and 10-Item Supplement were administered concurrently to patients and disease-free control subjects. High-contrast visual acuities with patient usual distance correction were measured with the use of Early Treatment Diabetic Retinopathy Study (ETDRS) charts. RESULTS: Diagnoses for patients (n = 215) included optic neuritis, multiple sclerosis, idiopathic intracranial hypertension, ischemic optic neuropathy, stroke, ocular myasthenia gravis, ocular motor palsies, and thyroid eye disease. Scores for the 10-Item Supplement had a significant capacity to distinguish patients vs disease-free control subjects that was independent of the NEI-VFQ-25 composite score (odds ratio in favor of patient vs control status for 10-point worsening in Supplement scores: 2.7 [95% confidence interval [CI], 1.6, 4.6]; P < .001, logistic regression models that account for NEI-VFQ-25 composite score, age, and gender). Patients with visual dysfunction (binocular Snellen equivalents worse than 20/20) had significantly lower mean scores (9-21 points lower); these differences remained significant after accounting for age and gender (P >or= .001, linear regression). Supplement items and composite scores demonstrated appropriate degrees of internal consistency reliability. CONCLUSION: The 10-Item Neuro-Ophthalmic Supplement demonstrates a capacity to capture self-reported visual dysfunction beyond that of the NEI-VFQ-25 alone, which supports validity for this new scale. The use of the 10-Item Supplement in clinical trials and epidemiologic studies will examine its capacity to demonstrate treatment effects in longitudinal cohorts.

Adult↗

Relation of visual function to retinal nerve fiber layer thickness in multiple sclerosis.

PURPOSE: To examine the relation of visual function to retinal nerve fiber layer (RNFL) thickness as a structural biomarker for axonal loss in multiple sclerosis (MS), and to compare RNFL thickness among MS eyes with a history of acute optic neuritis (MS ON eyes), MS eyes without an optic neuritis history (MS non-ON eyes), and disease-free control eyes. DESIGN: Cross-sectional study. PARTICIPANTS: Patients with MS (n = 90; 180 eyes) and disease-free controls (n = 36; 72 eyes). METHODS: Retinal never fiber layer thickness was measured using optical coherence tomography (OCT; fast RNFL thickness software protocol). Vision testing was performed for each eye and binocularly before OCT scanning using measures previously shown to capture dysfunction in MS patients: (1) low-contrast letter acuity (Sloan charts, 2.5% and 1.25% contrast levels at 2 m) and (2) contrast sensitivity (Pelli-Robson chart at 1 m). Visual acuity (retroilluminated Early Treatment Diabetic Retinopathy charts at 3.2 m) was also measured, and protocol refractions were performed. MAIN OUTCOME MEASURES: Retinal nerve fiber layer thickness measured by OCT, and visual function test results. RESULTS: Although median Snellen acuity equivalents were better than 20/20 in both groups, RNFL thickness was reduced significantly among eyes of MS patients (92 mum) versus controls (105 mum) (P<0.001) and particularly was reduced in MS ON eyes (85 mum; P<0.001; accounting for age and adjusting for within-patient intereye correlations). Lower visual function scores were associated with reduced average overall RNFL thickness in MS eyes; for every 1-line decrease in low-contrast letter acuity or contrast sensitivity score, the mean RNFL thickness decreased by 4 mum. CONCLUSIONS: Scores for low-contrast letter acuity and contrast sensitivity correlate well with RNFL thickness as a structural biomarker, supporting validity for these visual function tests as secondary clinical outcome measures for MS trials. These results also suggest a role for ocular imaging techniques such as OCT in trials that examine neuroprotective and other disease-modifying therapies. Although eyes with a history of acute optic neuritis demonstrate the greatest reductions in RNFL thickness, MS non-ON eyes have less RNFL thickness than controls, suggesting the occurrence of chronic axonal loss separate from acute attacks in MS patients.

Acute Disease↗

Automated combined kinetic and static perimetry: an alternative to standard perimetry in patients with neuro-ophthalmic disease and glaucoma.

OBJECTIVES: To create a fully automated, combined perimetry program consisting of a static examination and a kinetic examination, and to compare the results of this test with standard static and kinetic visual fields (VFs). METHODS: Fifty-six patients (74 eyes) undergoing neuro-ophthalmic or glaucoma evaluation who had standard static or kinetic perimetry examinations underwent the combined perimetry test. This automated, combined test, performed on the Octopus 101 perimeter, consisted of a static tendency-oriented perimetry examination and a preprogrammed kinetic examination. Three masked physician reviewers independently classified all of the VFs. The VF pairs were considered a match if the consensus descriptions of the standard and combined VFs matched. RESULTS: Thirty-seven eyes underwent evaluation for neuro-ophthalmic disease (comparison standard test, 20 static and 17 kinetic) and 37 for glaucoma (comparison standard test, 17 static and 20 kinetic). The VP pairs matched in 32 eyes (86%) in the neuro-ophthalmic group and 28 (76%) in the glaucoma group. On inspection by a fourth reviewer, many of the nonmatching VF pairs were those for which a consensus was not reached, but still conveyed similar information. Two glaucomatous eyes demonstrated central scotomata not delineated by the combined examination findings. Two subtle nasal steps were detected solely by the combined examination. The combined test ranged in time from 6 to 12 minutes per eye. CONCLUSIONS: The Octopus 101 perimeter can be used to create an automated test that combines the advantages of static and kinetic perimetry and produces equivalent results while not requiring examiner expertise.

Adolescent↗

Quantifying rod photoreceptor-mediated vision in retinal degenerations: dark-adapted thresholds as outcome measures.

Pre-clinical trials of treatment in retinal degenerations have shown progress toward preventing loss or restoring function of rod photoreceptors. In anticipation of human clinical trials, we assessed two psychophysical methods of quantifying rod photoreceptor-mediated function as potential outcome measures. Modified automated perimeters were used to deliver focal or full-field light stimuli and dark-adapted thresholds were measured. Patients with retinal degeneration were studied in two experimental protocols. Experiment 1 (n = 35 patients) studied dark-adapted focal chromatic stimuli in central retinal locations along the horizontal meridian. Experiment 2 (n = 146 patients) studied dark-adapted responses to a full-field stimulus test (FST) using white and chromatic stimuli. Patients in both experimental groups had testing on two different visits to determine inter-visit variability. In Experiment 1, two subgroups of patients were identified: a group with a majority of test loci detected by rod photoreceptors and a group with only cone-mediated detection. Inter-visit variability (95% confidence interval) was +/-3.1 dB for normals, +/-3.0 dB for patients with rod-mediated function and +/-2.8 dB for patients with only cone-mediated function. In Experiment 2, the dynamic range of the FST using white stimuli was sufficient to quantify sensitivity in all patients studied, including those with severe retinal degenerations. Chromatic stimuli in the FST were detectable by 85% of patients and rod- or cone-mediation could be determined. Regional retinal sources of FST were explored by comparing FST and dark-adapted perimetry in the same patients; there was a strong correlation between FST level and the loci with highest sensitivity by perimetry. Inter-visit variability (95% confidence interval) in the patients was +/-3.9 dB compared to +/-3.5 dB in normals. Dark-adapted focal threshold measurements with an abbreviated protocol in retinal degeneration patients with stable fixation may be useful as an outcome measure for therapies that can affect rod vision. FST measurements were feasible and reproducible in a large spectrum of retinal degenerative diseases and will be most applicable as a psychophysical outcome measure for treatment trials of very severe disorders in which fixation is lost and there is need for a large dynamic range of stimulus intensity.

Adolescent↗

Laser prophylaxis for age-related macular degeneration.

BACKGROUND: Age-related macular degeneration (AMD) is the most common cause of severe and irreversible vision loss among people 50 years of age or older in many Western countries. Most of the available treatments for AMD are intended for the late stage, specifically for choroidal neovascularization (CNV). Effective preventive treatments could have an even greater impact on the vision of the millions of people at risk for vision loss from AMD. Drusen are typically the earliest lesions seen in patients with AMD and precede the development of CNV. In 1973, Gass noted the disappearance of drusen in eyes that received laser photocoagulation, which led to the hypothesis that laser-induced drusen reduction could alter the natural course of AMD. METHODS: We reviewed relevant articles found through a search of MEDLINE through February 2005 by means of the following key words, alone or in combination: drusen, laser, photocoagulation, age-related macular degeneration, macula and choroidal neovascularization. RESULTS: Reports ranging from individual cases and case series to randomized controlled pilot studies have described various laser treatment protocols and their effects on eyes with high-risk drusen but no neovascular changes. These reports provide evidence that laser photocoagulation can induce drusen reduction. Although some investigators have reported a corresponding improvement in visual function, others have found no change or even worsening. The results in several of the larger randomized controlled studies suggest that CNV may occur at an increased rate in laser-treated eyes with high-risk drusen in patients who have neovascular AMD in the other eye. The long-term effects of laser treatment in patients with high-risk drusen in both eyes and no neovascular changes have yet to be determined. INTERPRETATION: The outcome of clinical trials such as the Prophylactic Treatment of Age-Related Macular Degeneration and the Complications of Age-Related Macular Degeneration Prevention Trial will help to determine the role of laser prophylaxis in patients with AMD.

Blindness↗

The association of astigmatism and spherical refractive error in a high myopia cohort.

PURPOSE: The purposes of this study were to determine whether the degree of myopia influences the presence and degree of total astigmatism, and to assess risk factors of astigmatism in patients with familial nonsyndromic severe myopia. METHODS: We performed a retrospective study of 217 subjects from families with two or more subjects from successive generations with a myopic spherical refractive error of at least -5 D or greater in one eye. Mean myopic spherical equivalent was -10 D and the mean age of myopia onset was 7 years. Refractive error measurements were obtained and the association between the degree of myopia and cylinder power was examined by correlation analysis. RESULTS: The prevalence of astigmatism (1.0 D of cylinder) was 36.1%. With-the-rule astigmatism was most common (55.8%), and the majority of astigmats had between 1.0 and 2.5 D of cylinder (77.6%). Statistically significant associations were found between the presence of astigmatism and risk factors of age and the age of myopia onset. In those patients with astigmatism, however, there was a moderate correlation between the degree of spherical equivalent and cylinder power (r = -0.34, p < 0.0001). Younger age (<16 years) (p = 0.03) was associated with higher cylinder power. CONCLUSIONS: In severely myopic patients, there is a high prevalence of astigmatism that is predominantly with-the-rule. The degree of myopic spherical refractive error is correlated with astigmatism severity but is not a risk factor for the presence of astigmatism.

Adolescent↗

Reduced foveolar choroidal blood flow in eyes with increasing AMD severity.

PURPOSE: In an earlier study, the authors reported that foveolar choroidal blood flow (ChBFlow) decreases in patients with AMD and drusen. To explore further the choroidal circulatory changes in patients with AMD, the relationship between ChBFlow and fundus features associated with increased risk of choroidal neovascularization (CNV) were investigated. METHODS: The study included 26 control eyes of 17 normal subjects and 163 eyes with early AMD characteristics of 123 patients with AMD. The AMD study eyes were divided into three groups according to increasing risk for development of CNV: (1) drusen > or =63 microm, no RPE hyperpigmentary changes in the study eye, and no CNV in the fellow eye; (2) drusen > or =63 microm, RPE hyperpigmentary changes in the study eye, and no CNV in the fellow eye; and (3) eyes with CNV in the fellow eye. Laser Doppler flowmetry was used to assess relative foveolar choroidal blood velocity (ChBVel), volume (ChBVol), and flow (ChBFlow). Differences in the mean circulatory parameters were assessed by analysis of variance (ANOVA) and test of linear trend. RESULTS: Mean ChBVel, ChBVol, and ChBFlow decreased with increased risk for CNV (linear trend, P < 0.05). The lowest circulatory parameters were observed in the eyes with the highest risk for CNV development. Trends for ChBVel and ChBFlow were still significant after adjustment for multiple factors. CONCLUSIONS: There is a systematic decrease in choroidal circulatory parameters with an increase in the severity of AMD features associated with risk for the development of CNV, suggesting a role for ischemia in the development of CNV.

Aged↗

Highly precise eye length measurements in children aged 3 through 12 years.

OBJECTIVE: To determine the feasibility, reliability, and validity of using partial coherence interferometry, a noncontact method that detects interference patterns from various layers of the eye, to measure axial length in young children. METHODS: The right eye of 64 subjects (mean age, 8.4 y; age range, 3.4-12.9 y; best-corrected visual acuity >or=20/30) was measured. Subjects fixated monocularly on the collimated light pattern from a laser diode (the alignment beam) and the operator used a video monitor to align the corneal reflection in the optical path. Axial length was measured during an 0.8-second scan using interference patterns from a collimated short coherence superluminescence diode aligned coaxially with the laser diode. Five series of 16 readings each were obtained. The average axial length for each of the 5 series of readings was calculated. Main Outcome Measure Axial length. RESULTS: Within-subject precision of axial length measurements was high, with an overall SE of measurement of 8 micro m for individual subjects across the 5 sessions (95% confidence interval, +/-16 micro m). Subgroup analysis showed that sex, age, spherical equivalent, and refractive error exerted statistically significant effects on precision, but all of the differences among subgroups were 3 micro m or less and likely to be insignificant clinically. Axial length measured by partial coherence interferometry varied systematically, with factors known to influence eye length (ie, age and refractive error), further validating the measurement method. CONCLUSION: The partial coherence interferometry technique provides reproducible, extraordinarily precise eye length measurements in young children and should enable novel approaches to study eye growth and refractive development.

Body Weights and Measures↗

Incidence of exudative age-related macular degeneration among elderly Americans.

PURPOSE: To estimate the 3-year incidence of exudative age-related macular degeneration (AMD) and its treatment by laser photocoagulation in elderly Americans. DESIGN: Population-based cohort study using insurance claims data. PARTICIPANTS: A random 5% sample of Medicare beneficiaries, age 65 and older. METHODS: Incidence of exudative AMD and of laser photocoagulation for this condition was assessed based on four categories of ascertainment criteria that included procedure and diagnosis codes associated with exudative AMD, choroidal neovascularization, and its treatment. MAIN OUTCOME MEASURES: Incidence of AMD and of associated laser photocoagulation. RESULTS: Overall, the 3-year incidence of exudative AMD is estimated to be between 9.4 per 1000 and 11.4 per 1000 Americans age 65 and older (depending on ascertainment criteria), based on those diagnosed and treated by ophthalmologists for the condition. These estimates bracket the measured incidence of exudative AMD in the Beaver Dam Eye Study and lie within its 95% confidence interval. The 3-year incidence of exudative AMD with attendant laser photocoagulation was 2.3 per 1000. Women were found to have a slightly higher incidence of AMD than men using all ascertainment criteria (P < 0.001), and white Americans were found to have a fivefold-to-sixfold higher ascertainment criteria than black Americans (P < 0.001). CONCLUSIONS: The reported incidence of exudative AMD identified in the population of Medicare beneficiaries suggests that measurements on incidence for this condition derived from the Beaver Dam Eye Study can be generalized to the U.S. population.

Age Distribution↗

Myopia and natural lighting extremes: risk factors in Finnish army conscripts.

PURPOSE: To establish whether features of environmental lighting in far northern latitudes might be associated with prevalence of myopia. METHODS: Using both questionnaires and military medical examinations, this cross-sectional survey of Finnish conscripts assessed both light exposure and conventional risk factors for myopia. RESULTS: While myopia was not associated with the month of birth, there was a trend towards a higher prevalence of myopia among conscripts living above the Arctic Circle, consistent with the hypothesis that ambient lighting might influence refractive development. Other novel associations with myopia were decreased sunglasses use and brown iris colour. As indicated by other reports, myopia was found to be associated with family history, education and nearwork. CONCLUSION: Although constraints inherent in surveying this military population may have limited our ability to detect associations, the positive findings suggest that studying northern populations may prove useful in clarifying any potential role of the light/dark cycle in refractive development.

Adolescent↗

Testability of preschoolers on stereotests used to screen vision disorders.

OBJECTIVE: The purpose was to determine whether preschool children aged 3 years 0 months through 3 years 6 months could be tested with the Random Dot E, Stereo Smile, and Randot Preschool stereoacuity tests, which are random dot stereotests marketed for use with preschoolers. METHODS: A total of 118 children from five Vision In Preschoolers Study Clinical Centers participated. Strabismic children, as determined by the cover test at distance and near, were excluded from this study. Stereopsis was tested on each child using each of the three tests in a variable, balanced order. A child's testability for each test was determined by the ability to complete the nonstereo task (pretest) and the gross stereo task for each stereotest. Proportions of children able to perform each test were compared using statistical methods accommodating multiple measurements per child. RESULTS: Testability of children on the pretest was greater for the Stereo Smile test (91%) than for the Random Dot E test (81%; p = 0.007) or the Randot Preschool test (71%; p < 0.0001) and greater for the Random Dot E test than for the Randot Preschool test (p = 0.02). For all children, testability on the gross stereo task was greater for the Stereo Smile (77%; p < 0.0001) and Random Dot E (74%; p = 0.005) tests than for the Randot Preschool test (56%) but did not differ significantly between the Stereo Smile and Random Dot E tests (p = 0.19). There were no significant differences among the proportion of children able to complete the gross stereo task among those who were testable on the pretest (p > 0.12, all comparisons). CONCLUSIONS: Among preschoolers aged 3 years 0 months through 3 years 6 months, testability differs significantly across the three commercially available random dot stereotests evaluated. The results suggest that two-choice procedures increase testability of young preschoolers.

Amblyopia↗

Risk factors for choroidal neovascularization and vision loss in the fellow eye study of CNVPT.

PURPOSE: To identify risk factors for the development of choroidal neovascularization (CNV) and vision loss in the Fellow Eye Study of the Choroidal Neovascularization Prevention Trial. METHODS: Retrospective review of 121 patients enrolled in a multicentered, randomized, controlled trial. Patients had neovascular age-related macular degeneration in one eye and more than 10 large drusen in the other eye. Records of patients randomly assigned to laser treatment or observation were reviewed through 4 years of follow-up. Three candidate risk factors for the development of CNV and vision loss were evaluated. RESULTS: Eyes with hyperfluorescent drusen on fluorescein angiography at 3 minutes appeared to have a decreased risk of CNV. Patchy choroidal filling was seen in 14% of patients. Eyes with patchy choroidal perfusion showed a higher risk of developing CNV that was not statistically significant, and the increased risk was present only in treated eyes. Reticular pseudodrusen were present in only three eyes. CONCLUSIONS: Reticular pseudodrusen were rare. Late drusen fluorescence may protect against the development of CNV.

Aged↗

Macular pigment and lutein supplementation in choroideremia.

Choroideremia is an incurable X-linked retinal degeneration caused by mutations in the gene encoding Rab escort protein-1. A group of clinically defined and genotyped patients were studied to determine: (1) the degree of rod and cone dysfunction and structural abnormality in the central retina and the level of macular pigment; and (2) the response of macular pigment and foveal vision to a 6 month trial of supplementation with oral lutein (at 20 mg per day). Rod and cone-mediated function was measured with dark-adapted static perimetry; in vivo retinal structure was determined with optical coherence tomography; and macular pigment optical density was measured with heterochromatic flicker photometry. In this cohort of patients (ages 15-65 years), both rod- and cone-mediated central function declined with age as did central retinal thickness. Macular pigment levels did not differ between patients and male control subjects. Supplementation of oral lutein in a subset of patients led to an increase in serum lutein and macular pigment levels; absolute foveal sensitivity did not change. It is concluded that macular pigment density can be augmented by oral intake of lutein in patients with choroideremia. There was no short-term change in the central vision of the patients on the supplement, but long-term influences of lutein supplementation on disease natural history warrant further study.

Adolescent↗

Self-reported visual dysfunction in multiple sclerosis: new data from the VFQ-25 and development of an MS-specific vision questionnaire.

PURPOSE: To examine vision-specific health-related quality of life in a cohort of patients with multiple sclerosis (MS) using the 25-Item National Eye Institute Visual Function Questionnaire (VFQ-25), and to identify content areas for a brief MS-specific vision questionnaire. DESIGN: Cross-sectional survey. METHODS: The VFQ-25 and a modified version of the Optic Neuritis Treatment Trial (ONTT) Patient Questionnaire were administered by in-person interview to 80 patients at the University of Pennsylvania MS Center. Binocular visual acuities were obtained following a standard protocol using retroilluminated Early Treatment Diabetic Retinopathy Study charts. RESULTS: Despite a median binocular visual acuity of 20/16 (20/12.5-20/250), VFQ-25 subscale scores in the MS cohort were significantly lower (worse) compared with those of a published reference group of eye disease-free patients (P =.0001-0.009, two-tailed t tests). Rank-correlations of VFQ-25 composite (overall) scores with visual acuity were modest, but significant (r(s) = 0.33, P =.003), supporting construct validity for VFQ-25 scores in MS populations. Seven additional aspects of self-reported visual dysfunction in MS were also identified. CONCLUSIONS: Patients with MS have a high degree of self-reported visual dysfunction that is not entirely captured by visual acuity. The VFQ-25 is an effective measure of self-reported visual loss in MS. A brief MS-specific vision questionnaire may provide additional useful information when administered concurrently with the VFQ-25 in future investigations of MS and other neuroophthalmologic disorders.

Adult↗

Darkness and near work: myopia and its progression in third-year law students.

PURPOSE: To evaluate myopia prevalence, myopia progression, and various potential myopia risk factors in third-year law students. DESIGN: Cross-sectional study and survey. PARTICIPANTS: One hundred seventy-nine third-year law students at the University of Pennsylvania. METHODS: We administered a questionnaire to assess the prevalence of myopia, myopia progression, and risk factors, including near work, family history, and daily light/dark exposure. We conducted a screening eye examination to ascertain myopia status. Myopia was defined as the mean spherical equivalent of the two eyes of </=-0.5 diopters; myopia progression was defined by the self-reported need for a stronger eyeglass prescription during law school. MAIN OUTCOME MEASURES: (1) prevalence of myopia, (2) progression of myopia. RESULTS: Seventy-nine percent of the class participated (n = 179, two were excluded for amblyopia leaving 177 students). Fifty-eight percent were male, 75% were Caucasian, and the mean age was 27 years. Seventy-nine percent reported parental myopia. The mean amount of near work was 7.4 hours/day; mean sleep was 7.9 hours/day; mean darkness was 5.3 hours/day. Sixty-six percent of the students were myopic. Of 96 participants myopic before law school, myopia increased in 83 (86%) during law school. Among 75 students not myopic at the beginning of law school, 14 (19%) became myopic. The onset of myopia could not be determined for 6 patients. There were trends for higher myopia prevalence among those with a parental myopia history (P = 0.14) and for increased myopia progression among those reporting more daily near work (P = 0.18). Students with </=5.6 hours of daily darkness were more likely to report myopia progression than those with >5.6 hours of darkness per day (95% vs. 80%, P = 0.07). To account for possible confounding effects of risk factors with myopia progression, logistic regression with categorization of the continuous exposure variables (hours of near work, sleep, and darkness) above or below median values weakened the near work association (odds ratio 1.8, 95% confidence interval 0.5-6.7, P = 0.35) but continued to identify darkness association with daily hours of darkness (odds ratio 4.8, 95% confidence interval 1.0 >/= 23.3, P < 0.05). Among the 77 students with myopia onset before college, those with </=5.6 hours of daily darkness were more likely to progress than those with more hours of daily darkness (97% vs. 76%, P = 0.01). CONCLUSIONS: This study confirms high rates of myopia prevalence and myopia progression among law students. The strongest association, especially in those with myopia onset before college, was a relation of myopia progression during law school with less daily exposure to darkness, a potential risk factor previously identified in childhood myopia. The role of exposure to darkness in refractive development warrants additional study.

Adult↗