Greater Myopia Research Articles

Quantifying refractive error in companion dogs with and without nuclear sclerosis: 229 eyes from 118 dogs.

To evaluate the relationship between nuclear sclerosis (NS) and refractive error in companion dogs. One hundred and eighteen companion dogs. Dogs were examined and found to be free of significant ocular abnormalities aside from NS. NS was graded from 0 (absent) to 3 (severe) using a scale developed by the investigators. Manual refraction was performed. The effect of NS grade on refractive error was measured using a linear mixed effects analysis adjusted for age. The proportion of eyes with >1.5 D myopia in each NS grade was evaluated using a chi-square test. Visual impairment score (VIS) was obtained for a subset of dogs and compared against age, refractive error, and NS grade. Age was strongly correlated with NS grade (p < .0001). Age-adjusted analysis of NS grade relative to refraction showed a mild but not statistically significant increase in myopia with increasing NS grade, with eyes with grade 3 NS averaging 0.58-0.88 D greater myopia than eyes without NS. However, the myopia of >1.5 D was documented in 4/58 (6.9%) eyes with grade 0 NS, 12/91 (13.2%) eyes with grade 1 NS, 13/57 (22.8%) eyes with grade 2 NS, and 7/23 (30.4%) eyes with grade 3 NS. Risk of myopia >1.5 D was significantly associated with increasing NS grade (p = .02). VIS was associated weakly with refractive error, moderately with age, and significantly with NS grade. NS is associated with visual deficits in some dogs but is only weakly associated with myopia. More work is needed to characterize vision in aging dogs.

Vision degrading myodesopsia assessed with optos ultra-widefield scanning laser ophthalmoscope

BackgroundTo investigate the diagnostic sensitivity of Optos imaging for vision degrading myodesopsia (VDM).MethodsA total of 420 eyes from 345 patients with VDM were collected in this cross-sectional study. All eyes were classified as having posterior vitreous detachment (PVD) or not having PVD. The sensitivity of Optos imaging for the visibility of vitreous floaters was evaluated. The associated factors with the visibility of vitreous floaters on Optos images were analyzed in univariate and multivariate logistic regression analyses.ResultsThe mean age of all patients was 56.19 ± 13.89 years old, and 66.67% of patients were female. The vitreous floaters were visible on the ultrasound B scan in all eyes, but only in 47.62% of Optos images (55.29% in eyes with PVD and 15% in eyes without PVD). In the multiple binary logistic regression analysis, age (OR = 1.094, 95%CI = 1.063–1.125, P < 0.001), spherical equivalent (OR = 0.869, 95%CI = 0.791–0.955, P = 0.004) and the distance of the floaters from the retina (OR = 1.191, 95%CI = 1.059–1.339, P = 0.003) were significantly correlated with the visibility of vitreous floaters on Optos images. On Optos images, 25.71% of VDM eyes presented additional retinal abnormalities.ConclusionsOptos imaging has a low sensitivity for vitreous floaters, particularly in eyes without PVD. On Optos imaging, floaters were more visible in older patients, eyes with greater myopia, and floaters that were further from the retina.

Usher Syndrome on the Island of Ireland: A Genotype-Phenotype Review.

Usher syndrome (USH) is a genetically heterogeneous group of autosomal recessive (AR) syndromic inherited retinal degenerations (IRDs) representing 50% of deaf-blindness. All subtypes include retinitis pigmentosa, sensorineural hearing loss, and vestibular abnormalities. Thorough phenotyping may facilitate genetic diagnosis and intervention. Here we report the clinical/genetic features of an Irish USH cohort. USH patients were selected from the Irish IRD registry (Target 5000). Patients were examined clinically (deep-phenotyping) and genetically using a 254 IRD-associated gene target capture sequencing panel, USH2A exon, and whole genome sequencing. The study identified 145 patients (24.1% USH1 [n = 35], 73.8% USH2 [n = 107], 1.4% USH3 [n = 2], and 0.7% USH4 [n = 1]). A genetic diagnosis was reached in 82.1%, the majority (80.7%) being MYO7A or USH2A genotypes. Mean visual acuity and visual field (VF) were 0.47 ± 0.58 LogMAR and 31.3° ± 32.8°, respectively, at a mean age of 43 years. Legal blindness criteria were met in 40.7%. Cataract was present in 77.4%. ADGRV1 genotypes had the most VF loss, whereas USH2A patients had greater myopia and CDH23 had the most astigmatism. Variants absent from gnomAD non-Finnish Europeans and ClinVar represented more than 20% of the variants identified and were detected in ADGRV1, ARSG, CDH23, MYO7A, and USH2A. USH is a genetically diverse group of AR IRDs that have a profound impact on affected individuals and their families. The prevalence and phenotype/genotype characteristics of USH in Ireland have, as yet, gone unreported. Understanding the genotype of Irish USH patients may guide clinical and genetic characterization facilitating access to existing/novel therapeutics.

Prescribing patterns of myopia control contact lenses among optometrists in Ireland.

This retrospective analysis of electronic medical record (EMR) data investigated the prescribing patterns of soft myopia control contact lens (MCCL) treatments since their introduction in Ireland in 2017. Anonymised EMR data were sourced from 33 optometry practices in Ireland from 2017 to 2021 to determine the number of practices prescribing MCCLs to myopic children 5-18 years old. In MCCL-prescribing practices, the proportion of contact lens wearing children fitted with MCCLs and the proportion of progressive (≤-0.25 D/year) myopic children fitted with MCCLs were determined. Logistic regression was used to determine which factors influenced the likelihood of being prescribed a MCCL. Overall, just 10 practices were found to prescribe MCCLs of any type. The Coopervision MiSight contact lens was used in 85% of all MCCL fittings with most other fits being off-label multifocals. The use of MCCLs rose from 3% of contact lens fits in 2017 to 27% in 2021. Children fitted with MCCLs were on average younger (12.2± 2.3 years vs. 15.4± 2.1 years) but more myopic (-3.46 ± 1.84 D vs. -3.03 ± 1.69 D) than those fitted with standard contact lenses. The most predictive factors for being fitted with MCCLs were year of examination (OR: 2.54, 95% CI: 2.13, 3.03), younger age (OR: 1.52, 95% CI: 1.39, 1.64) and greater myopia (OR: 1.25, 95% CI: 1.11, 1.39). Clinician engagement in myopia management has increased in Ireland since the formal introduction of MCCLs, but more than two-thirds of practices included are yet to offer this form of myopia management. The proportion of children with progressive myopia that has been prescribed MCCLs has increased, but the majority of children are still managed for vision correction only. There is significant scope for improving the uptake of evidence-based myopia control treatments and for optimising the age and degree of myopia at which such interventions are initiated.

Clinical Effects of Myopia Correction on the Angle of Exodeviation in Patients with Intermittent Exotropia

Purpose: To evaluate the extent to which myopia correction decreases distant exodeviation in patients with intermittent exotropia (IXT) and myopia.Methods: The medical records of patients with IXT who underwent myopia correction without surgical intervention were retrospectively reviewed. No patient evidenced anisometropia or amblyopia; all exhibited distant angles of deviation greater than 10 prism diopters (PD). The refractive errors of the eye with greater myopia were analyzed. Patients who underwent at least 3 months of follow-up were included. We recorded age, sex, the angle of deviation, the stereoacuity, and suppression status. Patients who did and did not evidence improvement were analyzed at 9 months in terms of change in the distant angle of deviation.Results: A total of 30 patients were analyzed. The average age was 8.27 ± 2.59 years. There were 18 (60%) males and 12 (40%) females. Twenty-four (80%) exhibited statistically significant decreases in the distant angle of deviation after wearing glasses for 3 months; the average value was 5.54 ± 3.59 PD (range 2-16 PD) (&lt;i&gt;p&lt;/i&gt; &lt; 0.001). We found no significant decrease from 3 months to &gt; 9 months (1.17 ± 3.63 PD) (&lt;i&gt;p&lt;/i&gt; = 0.129). In patients evidencing no improvement at 3 months, we found no significant change in the distant angle of deviation at either 3 months (3.00 ± 4.56 PD) (&lt;i&gt;p&lt;/i&gt; = 0.102) or 9 months (-3.66 ± 4.41 PD) (&lt;i&gt;p&lt;/i&gt; = 0.132).Conclusions: Eighty percent of IXT patients with myopia exhibited significant decreases in the distant angle of deviation after wearing glasses for 3 months, and this was well-maintained after 9 months.

Effect of Atropine 0.01% Eye Drops on the Difference in Refraction and Axial Length between Right and Left Eyes

Introduction: This study sought to determine whether the application of 0.01% atropine eye drops could impact the disparity in refraction and axial length (AL) between the right and left eyes in Chinese children. Methods: The study was designed as a double-blind, placebo-controlled randomized trial. A total of 220 children aged 6–12 years were recruited from the Beijing Tongren Hospital in Beijing, China. Participants were randomized in a 1:1 ratio and were prescribed 0.01% atropine or placebo eye drops to be administered once a night to both eyes for the duration of 1 year. The cycloplegic refraction and AL were recorded including baseline, 6 months, and again at the 12 months. Results: After 1-year follow-up period, 76 (69%) and 83 (75%) subjects of the initial 220 participants were identified as the 0.01% atropine and placebo groups, respectively. The inter-ocular difference in spherical equivalent refraction (SER) and AL demonstrated stable values in the 0.01% atropine treatment group (SER: p = 0.590; AL: p = 0.322) analyzed after 1 year, but found a significant increase (SER: p < 0.001; AL: p = 0.001) in the placebo group. Furthermore, over 1 year, eyes with greater myopia in the atropine group exhibited slower myopia progression (0.45 ± 0.44 D) than the lesser myopic eye (0.56 ± 0.44 D) (p = 0.003). Conclusion: This study demonstrated that 0.01% atropine could maintain the inter-ocular SER and AL difference. And 0.01% atropine appeared to be more effective in delaying the progression of myopia in eyes with more myopia than in the less myopic eyes.

The Limited Value of Prior Change in Predicting Future Progression of Juvenile-onset Myopia.

Identifying children at highest risk for rapid myopia progression and/or rapid axial elongation could help prioritize who should receive clinical treatment or be enrolled in randomized clinical trials. Our models suggest that these goals are difficult to accomplish. This study aimed to develop models predicting future refractive error and axial length using children's baseline data and history of myopia progression and axial elongation. Models predicting refractive error and axial length were created using randomly assigned training and test data sets from 916 myopic participants in the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error Study. Subjects were 7 to 14 years of age at study entry with three consecutive annual visits that included cycloplegic A-scan ultrasound and autorefraction. The effect of adding prior change in axial length and refractive error was evaluated for each model. Age, ethnicity, and greater myopia were significant predictors of future refractive error and axial length, whereas prior progression or elongation, near work, time outdoors, and parental myopia were not. The 95% limits for the difference between actual and predicted change were ±0.22 D and ±0.14 mm without prior change data compared with ±0.26 D and ±0.16 mm with prior change data. Sensitivity and specificity for identifying fast progressors were between 60.8 and 63.2%, respectively, when the cut points were close to the sample average. Positive predictive value and sample yield were even lower when the cut points were more extreme. Young, more myopic Asian American children in the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error Study were the most likely to progress rapidly. Clinical trials should expect average progression rates that reflect sample demographics and may have difficulty recruiting generalizable samples that progress faster than that average. Knowing progression or elongation history does not seem to help the clinical decision regarding initiating myopia control.

Peripheral refraction in Japanese schoolchildren with low to moderate myopia.

To report the profile of peripheral refraction in Japanese children with mild to moderate myopia and compare it with reported data from other countries. Cross-sectional study. Subjects were 76 Japanese children with myopia (mean± SD [range] spherical equivalent, -3.04±0.98 [-0.50 to -4.50] D; mean age, 10.0±1.5 [6-12] years). We performed cycloplegic refraction using an open-field autorefractor FR-5000 (Grand Seiko) while the subject looked at external fixation targets located at 0, ±15, ±30 degrees from the center along the horizontal meridian. Only the right eye data were analyzed after converting the readings to the power vector of M (spherical equivalent), J180, and J45. The profile showed a clear hyperopic shift of M from the fovea to the peripheral retina, although a wide inter-subject variation existed. At the gaze positions of ±30 degrees, the mean relative M were +1.16±0.89 D and +1.64±1.02 D (nasal and temporal retina, respectively). Those for J180 were -0.94±0.30 D and -0.70±0.30 D (nasal and temporal retina, respectively). The mean J45 remained small (≦ 0.17 D) within this range of eccentricity. There was no correlation between the relative M at the gaze position of -30 degrees and on-axis refraction, axial length, or children's age (p > 0.05). The profile of peripheral refraction was similar to that reported in children with moderate to high myopia in other East Asian countries. In this cohort, we did not find evidence supporting a hypothesis that greater myopia and longer axial length are associated with a greater peripheral hyperopic shift of the refraction.

Baseline vision results from the Baltimore Reading and Eye Disease Study

ObjectiveWe describe the Baltimore Reading and Eye Disease Study, report baseline ocular findings, and explore the feasibility of eye examinations in the school setting. DesignProspective, school-based cohort study. ParticipantsStudents in second and third grades. MethodsBaseline eye examinations, including near and distance presenting visual acuity (VA), stereopsis, ocular alignment, dilated retinal examination, and cycloplegic refraction, were performed in 12 Baltimore public schools during the 2014–15 school year. Main outcome measuresPresenting VA, prevalence of refractive error, and other ocular findings. ResultsAmong the 1054 eligible students, 321 participated. There were 271 (84.4%) African American and 186 (57.9%) female students; mean age was 7.9 ± 0.8 years. Cycloplegia was achieved in 308. The mean presenting distance and near VA was 0.1 ± 0.2 logMAR (range −0.1 to 1.5) and 0.1 ± 0.2 logMAR (range 0.0–1.6) in the better-seeing eye, respectively. The most common ocular findings were +1.00 diopter (D) or greater hyperopia (34.7%), −0.50 D or greater myopia (29.5%), 1.00 D or greater astigmatism (23.4%), and convergence insufficiency (7.2%). Thirty-seven (11.5%) children needed referral to an eye care provider; 10% of students required glasses full-time. ConclusionsWhereas the majority of second and third grade students in this study have good VA and minimal refractive error, 1 in 9 have an ocular finding necessitating further evaluation. It was feasible to conduct cycloplegic eye examinations in the school setting.

Orthokeratology lens for management of myopia in anisometropic children: A contralateral study

PurposeTo investigate the effect of overnight orthokeratology (OK) lens wear on axial growth in anisometropic children. MethodsThe study involved 17 males and 12 females with an average age of 11.4 ± 2.9 years. Cycloplegic spherical equivalent error (SER) was −0.50D to −6.00D, and anisometropia ≥1.00D. The eyes with greater myopia were assigned to the G eye group and the fellow eyes with less myopia to the L eye group. All eyes were fitted with OK lenses. Axial length (AL) was measured at the beginning of the study and at 6-, 12-, 18-, and 24-month follow-up visits. Refractive error was measured at the beginning and at the 24-month visit. Linear mixed model analysis was used to evaluate the effect of time, group, and time*group on axial growth. Paired t test was used to compare the myopia increase over 24 months between the two groups.Results:The mean baseline AL was 25.06 ± 0.61 mm for the G eyes and 24.48 ± 0.61 mm for the L eyes. After 24 months, AL had increased by 0.31 ± 0.23 mm in the G eye group and by 0.41 ± 0.31 mm in the L eye group. Axial growth of the L eyes was significantly greater than that of the G eyes (p = 0.006). The mean baseline myopia of the G eye and the L eye was −3.62 ± 1.27D [−5.75D to −1.75D] and −1.93 ± 1.02D [−4.00D to −0.50D] respectively. At 24 months, the increase in myopia in the G eyes was significantly less than that in the L eyes (−0.84 ± 0.63D vs, −1.21 ± 0.89D, p < 0.001).Conclusions: In anisometropic children who wore OK lenses, axial growth was greater in the eye with less baseline myopia than in the fellow eye with greater baseline myopia after 2 years.

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Quantitative OCT Angiography of the Retinal Microvasculature and the Choriocapillaris in Myopic Eyes.

To study the retinal capillary microvasculature and the choriocapillaris (CC) in myopic eyes using quantitative optical coherence tomography angiography (OCTA) analysis. Macular OCTA images of 3 × 3 mm were obtained using the RTVue-XR Avanti with AngioVue. Quantitative measurements of the retinal capillary microvascular layers and the CC were analyzed using en face projection images. Vessel density and fractal dimension of the superficial and deep retinal capillary plexus, and area and density of flow reduction in the CC were analyzed, quantified, and compared with an age-matched control group. Fifty eyes with myopia and 34 age-matched healthy eyes were included in this study. The vessel density and the vessel branching complexity using fractal dimension of the retinal capillary microvasculature were significantly lower in myopic eyes (P < 0.001 and P = 0.001). The total number of flow voids in the CC was lower (108.93 vs. 138.63, P = 0.001) but the total and average flow void area was significantly higher (total area 3.715 ± 0.257 vs. 3.596 ± 0.194 mm2, P = 0.026; average area 0.044 ± 0.029 vs. 0.028 ± 0.010 mm2, P = 0.002) compared with the healthy control group. Average choroidal thickness was lower in the myopic group versus the normal control cohort (123.538 ± 73.477 vs. 246.97 ± 41.745 μm, P < 0.05) and significantly reduced in eyes with lacquer cracks (LC) compared with myopic eyes without LC formation (P = 0.003). There was no correlation between choroidal thickness and quantitative parameters of the CC in the myopic eyes. The density of the retinal capillary microvasculature is reduced and the area of flow deficit in the CC is increased in eyes with greater myopia. The relevance of microvascular alterations in the setting of myopia warrants further study.

A Prospective Study of Anterior Segment Ocular Parameters in Anisometropia.

PurposeThe aim of this study was to investigate the differences in anterior segment ocular parameters in anisometropia >1 D.MethodsThis study included 202 eyes of 101 subjects ranging from 10 to 40 years of age with anisometropia of 1 D or more. The subjects were divided into groups according to anisomyopia, anisoastigmatism, and anisohypermetropia. After providing informed consent, each patient underwent a detailed ophthalmological examination including cycloplegic refraction, best-corrected visual acuity, cover test, axial length (AL) measurement using A-scan ultrasound biometer, keratometry, anterior chamber depth, and central corneal thickness measurement. For each participant, the eye with greater refractive error was compared to the fellow eye via paired t-tests. Correlations between parameters were studied using the Pearson correlation coefficient.ResultsThe average age of subjects was 21.7 ± 9.3 years. Of 101 subjects, 31 had anisomyopia; 42 had anisohypermetropia; and 28 had anisoastigmatism. A predisposition toward greater myopia in right eyes was noted in anisomyopia (24 of 31 subjects, 77%). The inter-ocular acuity difference was significant in all three groups (p < 0.01). As the degree of anisometropia increased, there was significant positive correlation in the difference in AL in myopes (r = 0.863, p < 0.01) and hypermetropes (r = 0.669, p < 0.01) and the difference in corneal curvature in anisoastigmatism (r = 0.564, p = 0.002) and hypermetropes (r = 0.376, p = 0.014). A significant positive correlation was also present between the anterior chamber depth difference and refractive difference in hypermetropes (r = 0.359, p = 0.020).ConclusionsThis study showed that anisomyopia is correlated only with anterior chamber differences. Anisohypermetropia is correlated with AL differences as well as corneal curvature difference and anterior chamber depth difference. The amount of anisoastigmatism correlates only with corneal curvature difference.

Age-Specific Prevalence of Visual Impairment and Refractive Error in Children Aged 3-10 Years in Shanghai, China.

We assessed changes in age-specific prevalence of refractive error at the time of starting school, by comparing preschool and school age cohorts in Shanghai, China. A cross-sectional study was done in Jiading District, Shanghai during November and December 2013. We randomly selected 7 kindergartens and 7 primary schools, with probability proportionate to size. Chinese children (n = 8398) aged 3 to 10 years were enumerated, and 8267 (98.4%) were included. Children underwent distance visual acuity assessment and refraction measurement by cycloplegic autorefraction and subjective refraction. The prevalence of uncorrected visual acuity (UCVA), presenting visual acuity, and best-corrected visual acuity in the better eye of ≤20/40 was 19.8%, 15.5%, and 1.7%, respectively. Among those with UCVA ≤ 20/40, 93.2% could achieve visual acuity of ≥20/32 with refraction. Only 28.7% (n = 465) of children with UCVA in the better eye of ≤20/40 wore glasses. Prevalence of myopia (spherical equivalent ≤-0.5 diopters [D] in at least one eye) increased from 1.78% in 3-year-olds to 52.2% in 10-year-olds, while prevalence of hyperopia (spherical equivalent ≥+2.0 D) decreased from 17.8% among 3-year-olds to 2.6% by 10 years of age. After adjusting for age, attending elite "high-level" school was statistically associated with greater myopia prevalence. The prevalence of myopia was lower or comparable to that reported in other populations from age 3 to 5 years, but increased dramatically after 6 years, consistent with a strong environmental role of schooling on myopia development.

Associations with Intraocular Pressure in a Large Cohort: Results from the UK Biobank

PurposeTo describe the associations of physical and demographic factors with Goldmann-correlated intraocular pressure (IOPg) and corneal-compensated intraocular pressure (IOPcc) in a British cohort.DesignCross-sectional study within the UK Biobank, a large-scale multisite cohort study in the United Kingdom.ParticipantsWe included 110 573 participants from the UK Biobank with intraocular pressure (IOP) measurements available. Their mean age was 57 years (range, 40–69 years); 54% were women, and 90% were white.MethodsParticipants had 1 IOP measurement made on each eye using the Ocular Response Analyzer noncontact tonometer. Linear regression models were used to assess the associations of IOP with physical and demographic factors.Main Outcome MeasuresThe IOPg and IOPcc.ResultsThe mean IOPg was 15.72 mmHg (95% confidence interval [CI], 15.70–15.74 mmHg), and the mean IOPcc was 15.95 mmHg (15.92–15.97 mmHg). After adjusting for covariates, IOPg and IOPcc were both significantly associated with older age, male sex, higher systolic blood pressure (SBP), faster heart rate, greater myopia, self-reported glaucoma, and colder season (all P < 0.001). The strongest determinants of both IOPg and IOPcc were SBP (partial R2: IOPg 2.30%, IOPcc 2.26%), followed by refractive error (IOPg 0.60%, IOPcc 1.04%). The following variables had different directions of association with IOPg and IOPcc: height (−0.77 mmHg/m IOPg; 1.03 mmHg/m IOPcc), smoking (0.19 mmHg IOPg, −0.35 mmHg IOPcc), self-reported diabetes (0.41 mmHg IOPg, −0.05 mmHg IOPcc), and black ethnicity (−0.80 mmHg IOPg, 0.77 mmHg IOPcc). This suggests that height, smoking, diabetes, and ethnicity are related to corneal biomechanical properties. The increase in both IOPg and IOPcc with age was greatest among those of mixed ethnicities, followed by blacks and whites. The same set of covariates explained 7.4% of the variability of IOPcc but only 5.3% of the variability of IOPg.ConclusionsThis analysis of associations with IOP in a large cohort demonstrated that some variables clearly have different associations with IOPg and IOPcc, and that these 2 measurements may reflect different biological characteristics.

Spectral-Domain Optical Coherence Tomography Imaging in 67 321 Adults: Associations with Macular Thickness in the UK Biobank Study

To derive macular thickness measures and their associations by performing rapid, automated segmentation of spectral-domain optical coherence tomography (SD OCT) images collected and stored as part of the UK Biobank (UKBB) study. Large, multisite cohort study in the United Kingdom. Analysis of cross-sectional data. Adults from the United Kingdom aged 40 to 69 years. Participants had nonmydriatic SD OCT (Topcon 3D OCT-1000 Mark II; Topcon GB, Newberry, Berkshire, UK) performed as part of the ocular assessment module. Rapid, remote, automated segmentation of the images was performed using custom optical coherence tomography (OCT) image analysis software (Topcon Advanced Boundary Segmentation [TABS]; Topcon GB) to generate macular thickness values. We excluded people with a history of ocular or systemic disease (diabetes or neurodegenerative diseases) and eyes with reduced vision (<0.1 logarithm of the minimum angle of resolution) or with low SD OCT signal-to-noise ratio and low segmentation success certainty. Macular thickness values across 9 Early Treatment of Diabetic Retinopathy Study (ETDRS) subfields. The SD OCT scans of 67 321 subjects were available for analysis, with 32 062 people with at least 1 eye meeting the inclusion criteria. There were 17 274 women and 14 788 men, with a mean (standard deviation [SD]) age of 55.2 (8.2) years. The mean (SD) logarithm of the minimum angle of resolution visual acuity was -0.075 (0.087), and the refractive error was -0.071 (+1.91) diopters (D). The mean (SD) central macular thickness (CMT) in the central 1-mm ETDRS subfield was 264.5 (22.9) μm, with 95% confidence limits of 220.8 and 311.5 μm. After adjusting for covariates, CMT was positively correlated with older age, female gender, greater myopia, smoking, body mass index (BMI), and white ethnicity (all P < 0.001). Of note, macular thickness in other subfields was negatively correlated with older age and greater myopia. We report macular thickness data derived from SD OCT images collected as part of the UKBB study and found novel associations among older age, ethnicity, BMI, smoking, and macular thickness.

Analysis of physical activity in emmetropic and myopic university students during semester and holiday periods: a pilot study

BackgroundPrevious studies (mostly questionnaire‐based in children) suggest that outdoor activity is protective against myopia. There are few studies on young adults investigating both the impact of simply being outdoors versus performing physical activity. The aim was to study the relationship between the refractive error of young adults and their physical activity patterns.MethodsTwenty‐seven university students, aged 18 to 25 years, wore a pedometer (Omron HJ720ITE) for seven days both during the semester and holiday periods. They simultaneously recorded the type of activity performed, its duration, the number of steps taken (from the pedometer) and their location (indoors/outdoors) in a logbook. Mean spherical refractive error was used to divide participants into three groups (emmetropes: +1.00 to ‐0.50 D, low myopes: ‐0.62 to ‐3.00 D, higher myopes: ‐3.12 D or greater myopia).ResultsThere were no significant differences between the refractive groups during the semester or holiday periods; the average daily times spent outdoors, the duration of physical activity, the ratio of physical activity performed outdoors to indoors and amount of near work performed were similar. The peak exercise intensity was similar across all groups: approximately 100 steps per minute, a brisk walk. Up to one‐third of all physical activity was performed outdoors. There were some significant differences in activities performed during semester and holiday times. For example, low myopes spent significantly less time outside (49 ± 47 versus 74 ± 41 minutes, p = 0.005) and performed less physical activity (6,388 ± 1,747 versus 6,779 ± 2,746 steps per day; p = 0.03) during the holidays compared to during semester.ConclusionsThe fact that all groups had similar low exercise intensity but many were not myopic suggests that physical activity levels are not critical. There were differences in the activity patterns of low myopes during semester and holiday periods. This study highlights the need for a larger longitudinal‐based study with particular emphasis on how discretionary time is spent.

Near Work Related Parameters and Myopia in Chinese Children: the Anyang Childhood Eye Study.

PurposeTo examine the associations of near work related parameters with spherical equivalent refraction and axial length in Chinese children.MethodsA total of 1770 grade 7 students with mean age of 12.7 years were examined with cycloplegic autorefraction and axial length. Questions were asked regarding time spent in near work and outdoors per day, and near work related parameters.ResultsMultivariate models revealed the following associations with greater odds of myopia: continuous reading (> 45min), odds ratio [OR], 1.4; 95% confidence interval [CI], 1.1-1.8; close television viewing distance (≤ 3m), OR, 1.7; 95% CI, 1.2-2.3; head tilt when writing, OR, 1.3; 95% CI, 1.1-1.7, and desk lighting using fluorescent vs. incandescent lamp, OR, 1.5; 95% CI, 1.2-2.0. These factors, together with close reading distance and close nib-to-fingertip distance were significantly associated with greater myopia (P<0.01). Among near work activities, only reading more books for pleasure was significantly associated with greater myopia (P=0.03). Television viewing distance (≤ 3 m), fluorescent desk light, close reading distance (≤20 cm) and close nib-to-fingertip distance (≤ 2 cm) were significantly associated with longer axial length (P<0.01). Reading distance, desk light, and reading books for pleasure had significant interaction effects with parental myopia.ConclusionsContinuous reading, close distances of reading, television viewing and nib-to-fingertip, head tilt when writing, reading more books for pleasure and use of fluorescent desk light were significantly associated with myopia in 12-year-old Chinese children, which indicates that visual behaviors and environments may be important factors mediating the effects of near work on myopia.

A hierarchical cluster analysis of normal-tension glaucoma using spectral-domain optical coherence tomography parameters.

Normal-tension glaucoma (NTG) is a heterogenous disease, and there is still controversy about subclassifications of this disorder. On the basis of spectral-domain optical coherence tomography (SD-OCT), we subdivided NTG with hierarchical cluster analysis using optic nerve head (ONH) parameters and retinal nerve fiber layer (RNFL) thicknesses. A total of 200 eyes of 200 NTG patients between March 2011 and June 2012 underwent SD-OCT scans to measure ONH parameters and RNFL thicknesses. We classified NTG into homogenous subgroups based on these variables using a hierarchical cluster analysis, and compared clusters to evaluate diverse NTG characteristics. Three clusters were found after hierarchical cluster analysis. Cluster 1 (62 eyes) had the thickest RNFL and widest rim area, and showed early glaucoma features. Cluster 2 (60 eyes) was characterized by the largest cup/disc ratio and cup volume, and showed advanced glaucomatous damage. Cluster 3 (78 eyes) had small disc areas in SD-OCT and were comprised of patients with significantly younger age, longer axial length, and greater myopia than the other 2 groups. A hierarchical cluster analysis of SD-OCT scans divided NTG patients into 3 groups based upon ONH parameters and RNFL thicknesses. It is anticipated that the small disc area group comprised of younger and more myopic patients may show unique features unlike the other 2 groups.

Risk factors for glaucoma suspicion in healthy young asian and caucasian americans.

Purpose. To determine the prevalence of certain risk factors for glaucoma in a healthy, young population and to compare these risk factors between Asian Americans and Caucasians. Methods. 120 healthy graduate students (mean age 24.8 ± 3.0 years) underwent a comprehensive ophthalmic examination. Regression analyses controlling for age, sex, and refraction, comparing glaucoma risk factors in Asians (n = 54) and Caucasians (n = 41), were performed. Outcome variables included family history, intraocular pressure (IOP), spherical equivalent, central corneal thickness (CCT), mean deviation (MD) and pattern standard deviation (PSD), and disc and retinal nerve fiber layer (RNFL) parameters. Results. 61% of subjects were female; the mean spherical equivalent was −3.81 ± 3.2 D; and the mean axial length (AL) was 25.1 ± 1.7 mm. Regression analysis showed race affected spherical equivalent (P < 0.001), AL (P = 0.0073), IOP (P < 0.001), and cup to disc area ratio (CDAR) (P = 0.012). Family history, CCT, MD, and PSD did not vary between Asians and Caucasians (P > 0.05). In this study, we found Asian Americans, compared to Caucasians, had 2.95 ± 0.64 D greater myopia; greater IOP by 2.74 ± 0.62 mmHg; and larger CDAR by 0.12 ± 0.046. Conclusions. In our study population, young, healthy Asian Americans had greater myopia, IOP, and CDAR as compared to Caucasians, suggesting that racial variations can be important when diagnosing glaucoma.