Refractive Changes After Horizontal Strabismus Surgery

PURPOSE

To investigate the changes in refractive status after surgery in patients with horizontal strabismus and high refractive error.

METHODS

This was a prospective study of patients with horizontal strabismus and high refractive error. The patients were divided into a horizontal rectus recession group (group 1) and a horizontal rectus recession combined with horizontal rectus resection group (group 2). The postoperative follow-up duration was 3 months. The refractive status of the patients was evaluated at each postoperative examination, and the refractive changes in the two groups were compared.

RESULTS

The spherical equivalent in group 1 changed by -0.26 D at 3 months postoperatively relative to the preoperative value (p = 0.078), indicating gradual progression toward myopia over time, but the difference was not significant; however, the postoperative cylinder in group 1 significantly increased by 0.34 D at 3 months postoperatively relative to the preoperative value (p = 0.03). The spherical equivalent in group 2 also indicated progression toward myopia; compared with the preoperative value, the spherical equivalent significantly decreased by -0.28 D (p = 0.019) at 1 month postoperatively and decreased by -0.21 D at 3 months postoperatively. The regression line drawn among the points also indicated a progression in the spherical equivalent toward myopia. In group 2, the cylinder increased by 0.30 D (p = 0.004) from the preoperative level at 1 month postoperatively, peaked, then decreased by 3 months postoperatively.

CONCLUSIONS

Patients with high refractive error who undergo horizontal strabismus correction will experience myopic shift. Patients who undergo rectus recession surgery should be fully informed of the possibility of changes in astigmatism preoperatively. For patients who undergo horizontal rectus recession combined with horizontal rectus resection, it is not recommended that glasses be changed within 1 month after surgery.

Detection of significant vision conditions in children using QuickSee wavefront autorefractor

PURPOSE

This study evaluated the ability of QuickSee to detect children at risk for significant vision conditions (significant refractive error [RE], amblyopia and strabismus).

METHODS

Non-cycloplegic refraction (using QuickSee without and with +2 dioptre (D) fogging lenses) and unaided binocular near visual acuity (VA) were measured in 4- to 12-year-old children. Eye examination findings (VA, cover testing and cycloplegic retinoscopy) were used to determine the presence of vision conditions. QuickSee performance was summarised by area under the receiver operating characteristic curve (AUC), sensitivity and specificity for various levels of RE. QuickSee referral criteria for each vision condition were chosen to maximise sensitivity at a specificity of approximately 85%-90%. Sensitivity and specificity to detect vision conditions were calculated using multiple criteria. Logistic regression was used to evaluate the benefit of adding near VA (6/12 or worse) for detecting hyperopia. A paired t-test compared QuickSee without and with fogging lenses.

RESULTS

The mean age was 8.2 (±2.5) years (n = 174). RE ranged up to 9.25 D myopia, 8 D hyperopia, 5.25 D astigmatism and 3.5 D anisometropia. The testability of the QuickSee was 94.3%. AUC was ≥0.92 (excellent) for each level of RE. For the detection of any RE, sensitivity and specificity were 84.2% and 87.3%, respectively, using modified Orinda criteria and 94.5% and 78.2%, respectively, using the American Academy for Pediatric Ophthalmology and Strabismus (AAPOS) guidelines. For the detection of any significant vision condition, the sensitivity and specificity of QuickSee were 81.1% and 87.9%, respectively, using modified Orinda criteria and 93% and 78.6%, respectively, using AAPOS criteria. There was no significant benefit of adding near VA to QuickSee for the detection of hyperopia ≥+2.00 (p = 0.34). There was no significant difference between QuickSee measurements of hyperopic refractive error with and without fogging lenses (difference = -0.09 D; p = 0.51).

CONCLUSIONS

QuickSee had high discriminatory power for detecting children with hyperopia, myopia, astigmatism, anisometropia, any significant refractive error or any significant vision condition.

Association between maternal fasting glucose levels throughout pregnancy and preschoolers' refractive errors

PURPOSE

We aimed to investigate the association between maternal fasting plasma glucose (FPG) trajectories during pregnancy and children's refractive errors at 6 years old.

DESIGN

Based on the Ma'anshan Birth Cohort (MABC) in China, a total of 1987 mother-child pairs were included in this study.

METHODS

Using the group-based trajectory model, trajectory fitting was performed on fasting blood glucose levels during the first, second, and third trimesters of pregnancy. Children's vision was measured at 6 years of age using the standard logarithmic visual acuity E-chart and cycloplegic refraction examination. Logistic regression models and multi-informant generalized estimating equations were used to analyze the association between maternal blood glucose level and 6-year-old children's visual acuity.

RESULTS

Children born of mothers with high level FPG trajectory had a higher risk of developing refractive error [OR=1.46 (95% CI 1.08 1.97)], hypermetropia [OR=1.64 (95% CI 1.09, 2.46)] and astigmatism [OR=1.60 (95% CI 1.06, 2.41)] at age six compared to those with low level trajectory. Maternal blood glucose level in the first [β=-0.012 (95% CI -0.024, -0.001)] and the second [β=-0.016 (95% CI -0.025, -0.006)] trimesters was associated with 6 year children's distance vision value.

CONCLUSIONS

High level of fasting plasma glucose trajectories during pregnancy has been observed to be associated with 6-year-old children's refractive error, hypermetropia and astigmatism. The first and the second trimesters may be critical periods for the effects of maternal blood glucose on children's vision. The long-term effect of maternal glucose metabolism on children's visual development deserves further study.

Osmosis as nature's method for establishing optical alignment

For eyes to maintain optimal focus, precise coordination is required between lens optics and retina position, a mechanism that in vertebrates is governed by genetics, visual feedback, and possibly intraocular pressure (IOP).1 While the underlying processes have been intensely studied in vertebrates, they remain elusive in arthropods, though visual feedback may be unimportant.2 How do arthropod eyes remain functional while undergoing substantial growth? Here, we test whether a common physiological process, osmoregulation,3 could regulate growth in the sophisticated camera-type eyes of the predatory larvae of Thermonectus marmoratus diving beetles. Upon molting, their eye tubes elongate in less than an hour, and osmotic pressure measurements reveal that this growth is preceded by a transient increase in hemolymph osmotic pressure. Histological evaluation of support cells that determine the lens-to-retina spacing reveals swelling rather than the addition of new cells. In addition, as expected, treating larvae with hyperosmotic media post-molt leads to far-sighted (hyperopic) eyes due to a failure of proper lengthening of the eye tube and results in impaired hunting success. This study suggests that osmoregulation could be of ubiquitous importance for properly focused eyes.

Using Smartphones to Enhance Vision Screening in Rural Areas: Pilot Study

BACKGROUND

While it is treatable, uncorrected refractive error is the number one cause of visual impairment worldwide. This eye condition alone, or together with ocular misalignment, can also cause amblyopia, which is also treatable if detected early but still occurs in about 4% of the population. Mass vision screening is the first and most critical step to address these issues, but due to limited resources, vision screening in many rural areas remains a major challenge.

OBJECTIVE

We aimed to pilot-test the feasibility of using smartphone apps to enhance vision screening in areas where access to eye care is limited.

METHODS

A vision screening program was piggybacked on a charity summer camp program in a rural county in Sichuan, China. A total of 73 fourth and fifth graders were tested for visual acuity using a standard eye chart and were then tested for refractive error and heterophoria using 2 smartphone apps (a refraction app and a strabismus app, respectively) by nonprofessional personnel.

RESULTS

A total of 5 of 73 (6.8%, 95% CI 2.3%-15.3%) students were found to have visual acuity worse than 20/20 (logarithm of minimal angle of resolution [logMAR] 0) in at least one eye. Among the 5 students, 3 primarily had refractive error according to the refraction app. The other 2 students had manifest strabismus (one with 72-prism diopter [PD] esotropia and one with 33-PD exotropia) according to the strabismus app. Students without manifest strabismus were also measured for phoria using the strabismus app in cover/uncover mode. The median phoria was 0.0-PD (IQR 2.9-PD esophoria to 2.2-PD exophoria).

CONCLUSIONS

The results from this vision screening study are consistent with findings from other population-based vision screening studies in which conventional tools were used by ophthalmic professionals. The smartphone apps are promising and have the potential to be used in mass vision screenings for identifying risk factors for amblyopia and for myopia control. The smartphone apps may have significant implications for the future of low-cost vision care, particularly in resource-constrained and geographically remote areas.

Determination of Refractive Error Using Direct Ophthalmoscopy in Children

Purpose

Refractive error is a major cause of visual impairment in children and its early detection can prevent ocular morbidity such as amblyopia and strabismus. Brückner test is a comprehensive test which can be easily administered in children using a direct ophthalmoscope. We aimed to determine refractive error in children by analysis of the red reflex using modified Brückner test.

Patients and Methods

This prospective observational study was conducted on 683 undilated eyes of 683 children aged four to 10 years. They were evaluated with a direct ophthalmoscope from one meter in a dimly lit room. The characteristics of the red reflex and crescent obtained were compared with photoscreener refraction value and analyzed.

Results

The presence of superior crescent was associated with hypermetropia (Chi square 37.11, p < 0.001, kappa = 0.15) and inferior crescent with myopia (Chi square 157.29, p < 0.001, kappa = 0.477). Superior crescent was 98.4% sensitive in detecting hypermetropia. Hypermetropia greater than +1.5D, was associated with larger superior crescent crossing horizontal midline of pupil (Chi square = 5.29, p = 0.021).

Conclusion

The modified Brückner test is useful in detection and quantification of refractive error in children. It is easy, simple, quick and can be employed in the community as a screening test to detect potentially amblyogenic refractive errors.

Prevalence of Comprehensive Eye Examination in Preschool Children With Eye Conditions

Introduction

The purpose of this study is to assess the prevalence of comprehensive eye examinations in multiethnic preschool children, including children with visually significant eye conditions, and identify factors associated with comprehensive eye examinations.

Methods

A sample of 9,197 African American, Hispanic, Asian American, and non-Hispanic White children aged 6-72 months was recruited for the Multi-Ethnic Pediatric Eye Disease Study from 2003 to 2011. Logistic regression performed in 2022 identified independent factors associated with parent-reported history of comprehensive eye examinations. The proportion of children with previous comprehensive eye examinations and the proportion with undetected amblyopia or strabismus were measured.

Results

The prevalence of comprehensive eye examinations was 6.3% overall and 38.3%, 24.8%, 19.1%, 15.1%, and 9.8% among children with strabismus, amblyopia, significant anisometropia, hyperopia, and astigmatism, respectively. Children without prior comprehensive eye examinations were more likely to have undetected amblyopia or strabismus than those with comprehensive eye examination history (ps<0.001). The prevalence of comprehensive eye examinations was higher among older children. Prevalence varied by race/ethnicity, with 8.1%, 7.9%, 6.3%, and 4.9% of non-Hispanic White, Asian American, African American, and Hispanic children having had prior comprehensive eye examinations, respectively; however, the differences did not remain after adjusting for other associated factors. Older age, a primary caregiver with a college/university degree or higher, having vision insurance, gestational age <33 weeks, neurodevelopmental disorder diagnosis, strabismus, and ocular disease history were all statistically significantly associated with a relatively higher prevalence of comprehensive eye examinations in multivariable analyses.

Conclusions

Comprehensive eye examinations were uncommon among preschool children, including those with treatable vision disorders. Interventions, such as parent education and vision insurance, are needed to imaprove comprehensive eye examination access and utilization for at-risk preschool children.

Association between hyperglycemia during pregnancy and offspring's refractive error: A focused review

This review article explores the relationship between hyperglycemia during pregnancy and the visual development of offspring, specifically focusing on refractive error. The authors conducted a comprehensive search for relevant articles in various databases and assessed the methodological quality of the included studies. The findings consistently indicate that hyperglycemia during pregnancy can have a detrimental impact on the structural and functional aspects of visual development in offspring. The intrauterine hyperglycemic environment appears to negatively affect the retina and lens, leading to refractive errors. In conclusion, there is likely an association between hyperglycemia during pregnancy and the development of refractive errors in offspring.

Quality of Refractive Error Care in Cambodia: An Unannounced Standardized Patient Study

PURPOSE

Quality-of-care in refractive error services is essential, as it directly affects vision outcomes, wellbeing, educational attainment, and workforce participation. In Cambodia, uncorrected refractive error is a leading cause of mild and moderate vision impairment in adults. We evaluated the quality of refractive error care in Cambodia by estimating the proportion of prescribed and dispensed spectacles appropriate for people's refractive error needs and factors associated with spectacle quality.

METHODS

A cross-sectional protocol was employed with 18 Khmer-speaking adult participants observing testing procedures in 156 optical services across six provinces in 2022. A total of 496 dispensed spectacles were assessed against spectacle quality indicators.

RESULTS

The analysis revealed that 35.1% of dispensed spectacles were of optimal quality. The most common error observed in sub-optimal spectacles was the presence of horizontal prism outside of tolerance limits. The study also found that 44.0% of emmetrope visits involved unnecessary prescription spectacle recommendations, and 18.3% of written prescriptions did not correspond with dispensed spectacles. Sex differences were observed, with men predominantly providing refractive error care and women more likely to be unnecessarily recommended prescription spectacles.

CONCLUSION

The findings highlight the importance of prioritizing quality-of-care in refractive error services. A key recommendation is to consider regulatory mechanisms to ensure optical services employ appropriately qualified staff. Additionally, efforts should be made to eliminate unnecessary prescriptions -- especially for emmetropes and females -- standardize written prescriptions, ensure consistent pupil distance measurements, reduce reliance on autorefraction, and address the gender imbalance in the refractive error workforce.

Manhattan Vision Screening and Follow-up Study (NYC-SIGHT): Vision and refractive error results

CLINICAL RELEVANCE

Optometrists can play a key role in providing access to eye care in underserved populations by organising community-based eye health screenings that include optometric exams to detect vision impairment and uncorrected refractive error.

BACKGROUND

Community-based eye health screenings and optometric exams were conducted in the NYC-SIGHT Study.

METHODS

A sub-analysis of vision impairment and refractive error results within a 5-year prospective, cluster-randomised clinical trial. Eligible individuals (age ≥40 years) were recruited from 10 affordable housing developments in Upper Manhattan. Developments were randomised into usual care (received glasses prescription only) and intervention (free glasses) groups. Participants with 6/12 visual acuity or worse, intraocular pressure 23-29 mmHg, or an unreadable fundus image were scheduled with the study optometrist for refraction and a non-dilated exam. Visual improvement data were obtained by comparing the presenting acuity at screening compared to the best corrected acuity after refraction by the optometrist. Chi-square, two-sample t-tests, and a stepwise multivariate logistic regression model were used to determined factors associated with improvable visual impairment.

RESULTS

Seven hundred and eight participants completed screening, 308 received an optometric exam. Those with improvable vision impairment (n = 251), mean age: 69.8 years, 70.5% female, 53% African American, 39.8% Hispanic, >95% had health insurance. Refractive error diagnosed in 87.8% of the participants; lines of improvement: 2 lines (n = 59), 3 to 5 lines (n = 120), and ≥6 lines (n = 72). Stepwise multivariate logistic regression analysis showed that participants with visual acuity 6/12 or worse (odds ratio 16.041, 95% confidence interval 6.009 to 42.822, p = 0.000) or a normal fundus image (odds ratio 2.783, 95% confidence interval 1.001 to 7.740, p = 0.05) had significantly higher odds of improvable vision impairment.

CONCLUSION

This innovative, targeted community-based study included an optometrist who detected high rates of refractive error and improvable vision impairment in an underserved population living in New York City.

Understanding accommodative control in the clinic: Modeling latency and amplitude for uncorrected refractive error, presbyopia and cycloplegia

Accommodation is the process of adjusting the eye's optical power so as to focus at different distances. Uncorrected refractive error and/or functional presbyopia mean that sharp focus may not be achievable for some distances, so observers experience sustained defocus. Here, we identify a problem with current models of accommodative control: They predict excessive internal responses to stimuli outside accommodative range, leading to unrealistic adaptation effects. Specifically, after prolonged exposure to stimuli outside range, current models predict long latencies in the accommodative response to stimuli within range, as well as unrealistic dynamics and amplitudes of accommodative vergence innervation driven by the accommodative neural controller. These behaviors are not observed empirically. To solve this issue, we propose that the input to blur-driven accommodation is not retinal defocus, but correctable defocus. Predictive models of accommodative control already estimate demand from sensed defocus, using a realistic "virtual plant" to estimate accommodation. Correctable defocus can be obtained by restricting this demand to values physically attainable by the eye. If we further postulate that correctable defocus is computed using an idealized virtual plant that retains a young accommodative range, we can explain why accommodative-convergence responses are observed for stimuli that are too near-but not too far-to focus on. We model cycloplegia as a change in gain, and postulate a form of neural myopia to explain the additional relaxation of accommodation often seen with cycloplegia. This model produces plausible predictions for the accommodative response and accommodative convergence signal in a wide range of clinically relevant situations.

Refractive outcome in combined phacovitrectomy: Anterior segment changes and corrective factor for IOL power calculation improvement

PURPOSE

To analyze differences in refractive outcome Δ (difference between postoperative and expected refractive error) and in anterior segment changes between cataract surgery patients and combined phacovitrectomy patients. We also aimed to provide a corrective formula allowing to minimise the refractive outcome Δ in combined surgery patients.

METHODS

Candidates for phacoemulsification and combined phacovitrectomy (respectively PHACO and COMBINED groups) were prospectively enrolled in two specialised centres. Patients underwent best corrected visual acuity (BCVA) assessment, ultra-high speed anterior segment optical coherence tomography (OCT), gonioscopy, retinal OCT, slit lamp examination and biometry at baseline, 6 weeks postoperatively and 3 months postoperatively.

RESULTS

No differences in refractive Δ, refractive error and anterior segment parameters were noted between PHACO and COMBINED group (109 and 110 patients respectively) at 6 weeks. At 3 months, COMBINED group showed a spherical equivalent of -0.29 ± 0.10 D versus -0.03 ± 0.15 D in PHACO group (p = 0.023). COMBINED group showed a significantly higher Crystalline Lens Rise (CLR), angle-to-angle (ATA) and anterior chamber width (ACW) and a significantly lower anterior chamber depth (ACD) and refractive Δ with all 4 considered formulas at 3 months. For IOL power lower than 15, a hyperopic shift was observed instead.

CONCLUSIONS

Anterior segment OCT suggests anterior displacement of the effective lens position in patients undergoing phacovitrectomy. A corrective formula can be applied to IOL power calculation to minimize undesired refractive error.

Childhood vision impairment and blindness in West Africa: public health measures and implications for systemic health

Childhood blindness is an issue of global health impact, affecting approximately 2 million children worldwide. Vision 2020 and the United Nations Sustainable Development Goals previously identified childhood blindness as a key issue in the twentieth century, and while public health measures are underway, the precise etiologies and management require ongoing investigation and care, particularly within resource-limited settings such as sub-Saharan Africa. We systematically reviewed the literature on childhood blindness in West Africa to identify the anatomic classification and etiologies, particularly those causes of childhood blindness with systemic health implications. Treatable causes included cataract, refractive error, and corneal disease. Systemic etiologies identified included measles, rubella, vitamin A deficiency, and Ebola virus disease. While prior public health measures including vitamin A supplementation and vaccination programs have been deployed in most countries with reported data, multiple studies reported preventable or reversible etiologies of blindness and vision impairment. Ongoing research is necessary to standardize reporting for anatomies and/or etiologies of childhood blindness to determine the necessity of further development and implementation of public health measures that would ameliorate childhood blindness and vision impairment.

Two different autorefractors for vision screening in children and adolescents

AIM

To compare the consistency of two autorefractors (Tianle RM-9000 and Topcon KR-800) for school-age myopia children, and to provide a basis for largescale data analysis and comparison.

METHODS

The refractive error in 909 subjects (age 4-18y) were measured using both autorefractors without cycloplegia. The data were analyzed using Fourier decomposition and the correlation coefficients, intraclass correlation coefficients (ICC), and Bland-Altman limits of agreement (LoA) for each parameter were calculated.

RESULTS

There was a strong correlation between the spherical equivalent (SE), sphere diopter (DS), and cylinder diopter (DC) readings of the Tianle RM-9000 and those of the Topcon KR-800, with correlation coefficient values of 0.98, 0.98 and 0.83 and ICC values of 0.99, 0.99 and 0.93, respectively. However, the correlation coefficients and ICC values of J0 and J45 were unreliable (R=-0.004, -0.034; both ICC<0.10). Bland-Altman analysis revealed that SE, DS, and DC measured by the Tianle RM-9000 were significantly biased toward myopia compared with the Topcon KR-800, and the mean differences were -0.072, -0.026, -0.091 D, respectively (all P<0.01). The minimum absolute value of the difference within the 95% LoA for SE, DS, and DC was 0.63 D, 0.50 D, 0.62 D, respectively; all these values were in the clinically acceptable range. For J0 and J45, the mean differences were close to zero (P=0.43, 0.84); however, the 95% LoA were relatively wide (J0 SD: 0.53; 95%CI: -1.00, 1.10; J45 SD: 0.52; 95%CI: -1.00, 1.00).

CONCLUSION

The two autorefractors are consistent with each other, as the differences in SE, DS, and DC were within the clinically acceptable range. Readers can compare the data measured by either device in different studies and use the two devices in the same study to generate a dataset that can be analyzed together. However, the J0 and J45 vectors are unreliable and should not be used to assess astigmatism.

Influence of Lens Thickness on Accuracy of Kane, Hill-RBF 3.0, Barrett Universal II, Emmetropia Verifying Optical, and Pearl-DGS Formulas in Eyes with Nonhigh Myopia and High Myopia

PURPOSE

To investigate the influence of lens thickness (LT) on accuracy of Kane, Hill-RBF 3.0 Barrett Universal II (BUII), Emmetropia Verifying Optical (EVO), and Pearl-DGS formulas in eyes with different axial lengths (AL).

METHODS

The prospective cohort study was conducted at Eye and ENT Hospital of Fudan University. Patients who had uneventful cataract surgery between March 2021 and July 2023 were recruited. Manifest refraction was conducted two-month post-surgery. Eyes were divided into 4 groups based on AL: short (<22mm), medium (22-24.5 mm), medium long (24.5-26mm) and very long (≥26mm). In each AL group, eyes were then divided into 3 subgroups based on the LT measured with IOLmaster700: thin (<4.5 mm), medium (4.5-5.0 mm), and thick (≥ 5 mm). The influence of LT on accuracy of Kane, Hill-RBF 3.0, BUII, EVO, and Pearl-DGS formulas were investigated in each AL group.

RESULTS

A total of 327 eyes from 327 patients were analyzed, with 64, 102, 73 and 88 eyes in each AL group, respectively. In eyes with AL < 24.5 mm, myopic PE was significantly associated with greater LT using all the 5 formulas (all p < 0.05). Backward stepwise multivariate regression analyses revealed that LT was an important influencing factor for PE in all 5 formulas, particularly in eyes with AL <24.5 mm. In eyes with AL <24.5 mm and LT > 5.0 mm, PE of all 5 formulas calculated with the optional parameter LT were more myopic than those calculated without LT.

CONCLUSIONS

Thicker LT was associated with more myopic PE among eyes with AL <24.5 mm when using all 5 formulas. Further optimization of current formulas is necessary, especially for eyes with short AL and thick LT.

Association of sleep timings, duration, consistency, and chronotype with premyopia and myopia among Indian children

BACKGROUND

To explore the association of sleep timings, duration, consistency, and chronotype with premyopia and myopia among Indian children.

METHODS

This hospital-based cross-sectional study included 453 children, aged 6-12 years. Two myopia participants were selected for each individual with the corresponding premyopia or emmetropia. All children underwent cycloplegic autorefraction and ocular biometric tests. The Children's Sleep Habits Questionnaire (CSHQ) and parental information on behavioral habits were used to assess the association of sleep parameters with myopia and premyopia using logistic regression models.

RESULTS

Both myopia and premyopia exhibited significant late bedtime, short sleep duration, early wakeup time on only weekdays, and longer weekend catch-up sleep than emmetropia children (p < 0.05). In multivariate analysis, late bedtime (more than 24:00 a.m.) on weekdays (Odds ratio, OR = 3.63, 95% CI [0.74, 8.68]) as well as on free days (OR = 1.04, 95% CI [0.02, 8.08]); and early wake-up time only on weekdays (5:00-6:00 a.m., OR = 2.16, 95% CI [0.24, 6.76] and 06:00-07:00 a.m., OR = 2.42, 95% CI [0.51, 8.44]) were associated with increased risk of myopia (all p < 0.05) but not premyopia. After adjusting the confounding factors, when each of the eight CSHQ subscale components was analyzed, only bedtime resistance, night waking, and daytime sleepiness scores were significantly associated with a higher risk for premyopia and myopia (p < 0.05).

CONCLUSIONS

The sleep quality components, including bedtime resistance, night waking, and daytime sleepiness, equally involve a higher risk for myopia as well as premyopia.

Prevalence, Associated Factors, and Inter-Eye Differences of Refractive Errors in a Population-Based Japanese Cohort: The Tohoku Medical Megabank Eye Study

PURPOSE

To investigate the prevalence, associated factors, and inter-eye differences of myopia and astigmatism in an adult Japanese population-based cohort.

METHODS

A total of 4282 participants from the Tohoku Medical Megabank Organization Eye Study (ToMMo Eye Study) underwent comprehensive ocular examinations as well as extensive physiological tests and a lifestyle questionnaire. The spherical equivalent (SE) and cylinder power were obtained as refractive parameters. The age- and gender-stratified prevalences of high myopia (SE < -5D), myopia (SE < -0.5D), hyperopia (SE > 0.5D), astigmatism (cylinder power < -0.5D), and anisometropia (SE difference >1D) were calculated. Multivariable analyses were performed to identify associated factors for refractive error (RE). Distribution and associated factors of the inter-eye difference in RE were also investigated.

RESULTS

The age-adjusted prevalence of high myopia, myopia, hyperopia, astigmatism, and anisometropia was 15.9%, 63.5%, 14.7%, 51.1%, and 14.7%, respectively. Both myopia and high myopia were more prevalent in the younger age group, while astigmatism was more prevalent in the older age group. Age, education, blood pressure, intraocular pressure, and corneal thickness are significantly associated with myopic refraction. Age, gender, intraocular pressure, and corneal thickness are correlated with astigmatism. Older age was associated with against-the-rule astigmatism. Older age, myopia, and longer education showed a significant correlation with large inter-eye differences in SERE.

CONCLUSIONS

This study demonstrated the high prevalence of myopia in young Japanese, which may be caused by a generational shift. This study also confirmed the influence of age and education on both the prevalence and inter-eye differences of RE.

Headache Attributed to Refractive Error: Improvement after Topography-Guided Photorefractive Keratectomy with Corneal Cross-Linking in Patients with Keratoconus

PURPOSE

To investigate if topography-guided photorefractive keratectomy (TGPRK) alleviates headache, particularly headache attributed to refractive errors (HARE) in keratoconus.

METHODS

Patients diagnosed with keratoconus undergoing TGPRK for refractive correction were included. Best spectacle corrected visual acuity (BSCVA) using the logMAR scale and refractive error were measured. Patients answered a questionnaire exploring headaches, characteristics, treatment, and the Headache Impact Test (HIT-6) before and 6 months after the surgery.

RESULTS

40 patients were included. Preoperatively, 24 patients (60%) met criteria for headaches: five for migraine, 14 for HARE, and five for tension-type headache (TTH). Patients with headaches preoperatively were more likely to require bilateral TGPRK, and the mean sphere and cylindrical power were higher. Postoperatively, 15 out of the 24 patients of the headache group experienced complete resolution of headaches, and only nine patients met diagnostic criteria for headaches: two for migraine, six for HARE, and one for TTH. The number of headaches reduced from 4.4 ± 2.4 to 0.5 ± 0.7 days/week (p < 0.001). Headache duration decreased from 108.5 ± 100.7 min to 34.4 ± 63.5 min (p = 0.002). Postoperatively, the consumption of analgesia decreased. The HIT-6 revealed an improvement in the quality-of-life post-procedure (p < 0.001).

CONCLUSIONS

Surgical correction of irregular astigmatism in patients with keratoconus can alleviate or resolve headaches in a large proportion of patients, resulting in an improvement in their quality of life. Physicians should consider keratoconus in patients fitting criteria for HARE not alleviated by spectacle correction and suboptimal vision in glasses.

Relationship between dynamic visual acuity and static visual acuity, refractive error, and binocular vision in elite soccer players

CLINICAL RELEVANCE

In many sports, dynamic visual acuity is used. In order to improve dynamic visual acuity, it is important to understand the aspects of the visual system that can cause compromise.

BACKGROUND

To investigate the parameters of the visual system that may influence dynamic visual acuity in professional soccer players.

METHODS

In 2022, 40 professional players were analysed. Screening consisted of a survey, the measurement refractive error, and static and dynamic visual acuity and the binocular vision parameters. All athletes were men with a mean age of 24.9 ± 4.8 years.

RESULTS

The mean refractive error was -0.29 ± 0.61D, and 22.5% of athletes are myopic only and 7.5% hyperopic. Static visual acuity was R: -0.037 ± 0.094 LogMAR , L: -0.036 ± 0.098 LogMAR. Dynamic visual acuity was 0.154 ± 0.118 LogMAR . There is a positive and moderate correlation between monocular static visual acuity and dynamic visual acuity, with r = 0.524 (r2 = 0.275 , p < 0.001) for the right eye and r = 0.553 (r2 = 0.306, p < 0.001) for the left eye. For the component of astigmatism (J = 0) and for stereopsis in distance vision, the correlation was, r = -0.472 (r2 = 0.223, p = 0.002) and r = -0.467 (r2 = 0.218, p = 0.002), respectively.

CONCLUSION

Athletes with lower static visual acuity in distance vision, or with worse stereopsis in distance vision or more myopic astigmatism, have lower dynamic visual acuity than other athletes.

Delayed melatonin circadian timing, lower melatonin output, and sleep disruptions in myopic, or short-sighted, children

STUDY OBJECTIVES

This study investigated the differences in melatonin circadian timing and output, sleep characteristics, and cognitive function in myopic and non-myopic (or emmetropic) children, aged 8-15 years.

METHODS

Twenty-six myopes (refractive error [mean ± standard error mean] -2.06 ± 0.23 diopters) and 19 emmetropes (-0.06 ± 0.04 diopters), aged 11.74 ± 2.31 years were recruited. Circadian timing was assessed using salivary dim-light melatonin onset (DLMO), collected half-hourly for 7 hours, beginning 5 hours before and finishing 2 hours after individual average sleep onset in a sleep laboratory. Nocturnal melatonin output was assessed via aMT6s levels from urine voids collected from 05:30 pm to 8:00 am the following morning. Actigraphy-derived objective sleep timing were acquired for a week prior to the sleep laboratory visit. Cognitive assessments of sustained attention (using psychomotor vigilance task [PVT]) and working memory (using digit spans) were performed on the night of sleep laboratory.

RESULTS

Myopic children (9:07 pm ± 14 minutes) exhibited a DLMO phase-delay of 1 hour 8 minutes compared to emmetropes (7:59 pm ± 13 minutes), p = 0.002. aMT6s melatonin levels were significantly lower among myopes (18.70 ± 2.38) than emmetropes (32.35 ± 6.93, p = 0.001). Myopes also exhibited significantly delayed sleep onset, delayed wake-up time, poor and reduced sleep, and more evening-type diurnal preference than emmetropes (all p < 0.05). Finally, myopes showed a slower reaction time in the PVT (p < 0.05), but not digit span tasks at night.

CONCLUSIONS

These findings suggest a potential association between circadian rhythm dysfunction and myopia in children.

The prevalence of functional amblyopia and its related risk factors in preschool children in North-Eastern Iran

BACKGROUND

Purpose was to determine the prevalence of amblyopia and its related risk factors in children aged 3-6 years in Bojnurd, north-eastern Iran.

MATERIALS AND METHODS

In this cross-sectional study, from 12,331 children aged 3-6 in Bojnurd, 6600 children participated in annual amblyopic screening program and among them, around 1100 suspected cases were referred for full ophthalmic examinations. Measurement of visual acuity, cycloplegic refraction, subjective refraction, and cover test were performed for all participants. Amblyopia was defined as CDVA of 0.2 LogMar or less in each eye or 2-line difference or more in best-corrected visual acuity between two eyes.

RESULTS

The prevalence of amblyopia was estimated 0.95% (95% confidence interval [CI]: 0.73%-1.2%). There was no relationship between amblyopia with age and genders. Most amblyopic children were hyperopic (61.9%; 95% CI: 48.7-73.8). Strabismus was found in 17.4% of amblyopic patients (95% CI: 9.05%-29.09%). Approximately half of the amblyopic children were anisometropic (55.5%; 95% CI: 42.40%-68.08%). The most common type of amblyopia was anisohyperopic (55.56%; 95% CI: 42.5%-67.5%). The prevalence of bilateral amblyopia was more than unilateral amblyopia. The assessment of data showed that hyperopia, astigmatism, and anisometropia were the most common causes of amblyopia in this study.

CONCLUSIONS

The prevalence of amblyopia was estimated about 1% in north-eastern Iran. Our study indicated a valuable information around the effect of refractive error and anisometropia on amblyopia which could be helpful in designing a comprehensive vision screening program for preschool children.

Refractive outcomes following silicone oil tamponade in vitreoretinal surgery

PURPOSE

To evaluate the factors influencing the refractive outcomes following silicone oil tamponade (SOT) and silicone oil removal (SOR) in different lens statuses post-vitreoretinal surgery.

DESIGN

Retrospective analysis of three different lens statuses.

MATERIALS AND METHODS

This was a descriptive study that included 150 eyes of 147 patients who had undergone pars plana vitrectomy with SOT and SOR between January 2017 and June 2021. Demographic profile, spherical equivalent refraction (SER), and its association with clinical features were evaluated with SOT and post-SOR.

RESULTS

The mean (±standard deviation [SD]) age was 47 ± 17.8 years, including all three groups. SER was represented in diopters (D). The mean ± SD refraction with SOT in phakic, pseudophakic, and aphakic was 4.28 ± 2.59 D, 2.94 ± 2.58 D, and 3.98 ± 4.82 D. The mean SER post-SOR in phakic, pseudophakic, and aphakic was -2.72 ± 2.03 D, -1.12 ± 1.41 D, and 8.22 ± 3.70 D. The diagnosis of rhegmatogenous retinal detachment (RRD) among 96 eyes (64%) is the common indicator to perform vitreoretinal (VR) surgery. A minority of subjects were managed with retinal lasers before VR surgery (14%). The macula was attached in 100 eyes (67.6%), the belt buckle was done in 37 eyes (24.7%), and the silicone oil viscosity with 1000 centistoke was chosen in 129 eyes (86%).

CONCLUSION

SOT was used as a tamponade in VR surgeries irrespective of lens status. The significant predictor for post-SOR refraction in phakic and aphakic is post-SOT refraction. In pseudophakic, gender and diagnosis of RRD are the predictors of SOR refraction.

Reasons for declining corneal refractive laser correction for refractive candidates in Southern India

PURPOSE

To analyze the reasons for declining corneal refractive laser correction procedures in patients presenting to tertiary eye care centers in Tamil Nadu, Southern India, and review the literature.

METHODS

Retrospective case records of subjects presenting from January 2019 to December 2021 for refractive surgery workup were analyzed. Demographic details and refractive parameters of patients rejected for corneal refractive laser corrections (CRLC) were documented and reviewed.

RESULTS

A total of 2358 patients presented for refractive surgery evaluation during the study period, and out of them, 395 patients (16.8%) were not considered ideal candidates for undergoing CRLC. The common reasons for rejecting the patients were unfit topography (n = 110, 27.8%), unstable refraction over a one-year duration (n = 9, 2.27%), low corneal thickness (n = 85, 21.5%), keratoconus (n = 5, 12.9%), and other ocular and systemic disorders (n = 48, 12.1%).

CONCLUSION

There was a marked change in magnitude and rationalization for not performing either laser-assisted in situ keratomileusis (LASIK) or photorefractive keratectomy in our study. The reasons are unfit topography, keratoconus, and systemic disorders, which were diagnosed during pre-LASIK screening workup, being the most common cause for rejecting patients for corneal refractive corrections.

Myopia progression in school children with prolonged screen time during the coronavirus disease confinement

Background

Myopia, the most common refractive error, is a global public health problem with substantial visual impairment if left untreated. Several studies have investigated the association between increased near-work and restricted outdoor activities in children with myopia; however, such studies in children without myopia are scarce. We aimed to monitor the effect of the coronavirus disease-2019 (COVID-19) home confinement and mandatory virtual learning on myopic progression among myopic and non-myopic school-aged children.

Methods

We conducted a retrospective chart review of children aged 6 - 12 years attending regular visits to the pediatric ophthalmology clinic in a tertiary eye hospital in Eastern Province, Saudi Arabia. Cycloplegic refraction was determined from three visits at least six months apart: two visits before the start of the COVID-19 pandemic and one during the COVID-19 home confinement. Parents were asked about the time spent in near-work and outdoor activities, the devices used during virtual learning, and the demographic characteristics of the children. Statistical analyses were conducted to compare myopia progression before and during the COVID-19 home confinement.

Results

A total of 160 eyes of 80 children were analyzed. The boy (n = 46) to girl (n = 34) ratio was 1.4:1. The hyperopia (n = 131 eyes) to myopia (n = 29 eyes) ratio was 4.5:1. Most eyes exhibited a hyperopic shift before the confinement; however, all eyes displayed a myopic shift during the confinement. When comparing both eyes of the same individual, the more myopic or less hyperopic eye in the same child had a significantly greater myopic shift than the fellow eye (both P < 0.05). Children who used tablets showed a significant myopic shift (P < 0.05). Likewise, children in both age categories ( ≤ 8 and > 8 years), boys, those living in an apartment, and those having parents with bachelor's degrees experienced a significant myopic shift during COVID-19 home confinement compared to before (all P < 0.05). The mean myopic shift was greater in children aged > 8 years than in those aged ≤ 8 years. Children with and without a family history of myopia had a myopic shift in the mean spherical equivalent during COVID-19 home confinement; however, that of children with no family history was statistically significant (P < 0.05).

Conclusions

Progression of myopia accelerated in children during the COVID-19 pandemic. Excessive time spent on digital screen devices at near distances is considered a substantial environmental contributor to myopic shift in children. Further multicenter studies with extended follow-up periods are needed to assess the factors contributing to myopic progression in our population.

Anterior Segment Changes and Refractive Outcomes after Cataract Surgery Combined with Gonioscopy-Assisted Transluminal Trabeculotomy in Open-Angle Glaucoma

Objectives

To compare the accuracy of intraocular lens (IOL) calculation formulas in patients undergoing phacoemulsification combined with gonioscopy-assisted transluminal trabeculotomy (phaco-GATT) and to determine the predictive factors for refractive errors.

Materials and Methods

Fifty-three eyes of 53 patients undergoing phaco-GATT were retrospectively reviewed. The preoperative and postoperative 3-month anterior segment (AS) parameters were measured by Scheimpflug camera. The mean prediction error (PE), mean absolute error (MAE) in the Sanders-Retzlaff-Kraft/theoretical (SRK/T), Barrett- Universal II, Hill-radial basis function (Hill-RBF) and Kane formulas were compared. The influence of biometric parameters on PE were analyzed by correlation analysis.

Results

Postoperatively, there was a statistically significant decrease in axial length (AL) and significant enlargement in anterior chamber depth (ACD), anterior chamber angle (ACA), and anterior chamber volume (p<0.001). The mean PE using SRK/T (-0.08 diopters [D]) was more myopic than in the Barret (0.01 D) and Hill-RBF (0.01 D). The PE closest to zero was in the Kane formula (0.001 D). The Kane formula provided a lower MAE (0.30±0.28 D) than the SRK/T (0.38±0.32 D) and Barrett (0.36±0.30 D) (p<0.001). The MAE in Hill-RBF (0.32±0.28) was comparable with that in Kane (p=0.02). Preoperative AL was significantly associated with PE in all formulas except Kane. Barrett was the only formula that did not have a significant correlation between PE and postoperative ACD and ACA.

Conclusion

The Kane formula may provide higher predictability of the IOL power calculation than the SRK/T and Barrett-Universal II formulas in phaco-GATT surgery, which can cause significant changes in the AS and AL.

Spectacles Under Utilization and Associated Factors Among Adults in Hawassa, South Ethiopia, June, 2022

Background

The commonest and cheapest treatment modality for correcting refractive error is spectacles or eyeglasses. In Ethiopia, the rate of spectacles under utilization and its impact on visual impairment was not known.

Objective

To assess spectacles under utilization and associated factors among adults in Hawassa, Ethiopia, 2022.

Methods and Materials

Community-based cross-sectional study design was conducted from Jan 2021 to May 2022 with a final sample size of 664. Multi-stage random sampling technique was used during the sampling process. Using an interviewer-based questionnaire, the selected individuals were asked about demographic characteristics, spectacles use, and satisfaction with spectacles, knowledge, and attitude about spectacles. An odds ratio with a 95% CI was used to display the results. A P-value less than 0.05 in multivariate logistic regressions is used to show statistical significance.

Results

The prevalence of spectacles under utilization was 307 (48.7%). The spectacles under utilization was more prevalent in individuals with unaided visual acuity of 6/6 -6/12 (46.1%), no eye checkup (38.4%), no surgery on the eye (46.6%), willingness to accept spectacles (35.9%), good knowledge about spectacles (32.6%) and poor attitude about spectacles (35%). The most common reasons for not utilizing spectacles were believed not necessary (14.9%), expensive cost (13.1%), and discomfort (11.4%). Among the spectacles users (33.64%) who wore spectacles for 2 years, 31.17% procured the spectacles without physician orders and 46.6% purchased the spectacles in the optical workshop. The most common purpose to use spectacles was for protection (41.4%).

Conclusion and Recommendation

The spectacles under utilization in Hawassa town was high. Rural residency, occupation, eye check, eye surgery, no willingness to wear spectacles, and attitude towards spectacles were significantly associated with spectacles under utilization. It is necessary to provide health education to improve the poor attitude regarding spectacles and eye checks.

How long does the recovery of corneal sensitivity in different corneal regions take after LASEK?

AIM

To determine the corneal sensitivity recovery period after laser-assisted sub-epithelial keratectomy (LASEK) refractive surgery and investigate the effects of ablation depth on it.

METHODS

In this study examinations were performed on 90 right eyes of 90 people (34 males and 56 females) with an age range of 20-35 and an average of 22.26±3.8 years old. A sensation of 5 corneal regions, including the center and 4 mid-peripheral regions, i.e., nasal, inferior, temporal, and superior, each at a distance of 2 mm from the center of the cornea were measured with a Cochet-Bonnet esthesiometer device in 3-time points including before LASEK, 1 and 3mo after the surgery, respectively. LASEK was performed on individuals with stabilized myopia of -1.00 to -7.00 diopters and astigmatism of less than 2.00 diopters. Furthermore, the individuals were divided into three groups regarding ablation depth.

RESULTS

The highest level of corneal sensitivity before surgery was related to the center of the cornea (59.1±7.76), and the highest level of corneal sensitivity loss was also related to this region. The sensation of all measured corneal regions significantly reduced 1mo postoperatively and returned to their preoperative levels 3mo after surgery (mean of 5 corneal regions in levels of preoperation: 58.2±6.48, 1mo postoperation: 57.3±5.84, 3mo postoperation: 58.2±5.49; P<0.05). A significant relationship was found between ablation depth and corneal sensitivity changes in the center and temporal regions (P<0.05).

CONCLUSION

Corneal sensitivity in myopia and low astigmatism decreases after LASEK and reaches the preoperative level within 3mo. The depth of ablation during surgery affected the recovery of corneal sensitivity.

Epidemiology of eye diseases: outcomes from a free provincial eye clinic in Papua New Guinea

Aim

To ascertain the prevalence and pattern of eye problems in Madang Province, Papua New Guinea.

Materials and methods

A six-month retrospective study was performed at Madang Provincial Hospital Eye Clinic. Convenience sampling was used in this study and all patient records from January to June 2020 were included. Data was extracted using Microsoft Excel and the data included gender, age, occupation, district where the patient lived, presenting visual acuity, and diagnosis. It was then analyzed using International Business Machines Corporation's Statistical Package for the Social Sciences version 26. A p-value of ≤0.05 was considered statistically significant.

Results

A total of 1,715 patients received services at the eye clinic between January and June 2020, and 1,664 were included in this study. The mean age of the patients was 39.3 ± 20.3 years. There were slightly more males (50.4%) than females. The overall leading ocular morbidities were corneal ulcers and keratitis (20.7%), refractive errors (17.4%), and cataracts (16.8%). More than half of the patients (56.2%) were either visually impaired or blind. Nearly half of the patients (41.8%) traveled long distances to seek services at the eye clinic. There was a significant association between demographic characteristics, diagnosis, and level of visual impairment.

Conclusion

There is a high prevalence of potential causes of visual impairment and blindness in Madang Province and these conditions affect all age groups and genders. It is essential to increase accessibility to eye care services in the country.

Prevalence and Patterns of Refractive Error Among School-Age Children in Bisha, Saudi Arabia

BACKGROUND

A widespread and serious eye condition is a refractive error (RE). Globally, uncorrected refractive defects affect numerous individuals, with some who are blind. Numerous studies in Saudi Arabia have been conducted to assess reflective error. However, there is a lack of knowledge regarding RE among school-age children in Bisha province, southwest Saudi Arabia. This study aimed to determine the prevalence and types of RE among school-age children in Bisha, Saudi Arabia.

METHODS

A cross-sectional study involved 360 schoolchildren from primary schools was carried out between December 2022 and November 2023 in Bisha. A validated questionnaire form was used to collect sociodemographic information and clinical data (history of the ocular problem, visual acuity test findings, and the refractor machine's result).

RESULT

A total of 360 schoolchildren aged from seven to 14 years, with a mean of 10.1 years (standard deviation (SD)=2.05). The prevalence of hyperopia was 21% in the right eye and 23% in the left eye. In addition, the prevalence of myopia was 20% in the right eye and 22.5% in the left eye. A significant association between visual acuity and myopia (p=0.001). By contrast, there was no significant correlation between hyperopia and visual acuity (p=0.412).

CONCLUSION

The current study summarized the prevalence of REs among school-age children in Bisha, Saudi Arabia. The study population included nearly half of those with at least some degree of RE. These results highlight the need for prompt and careful screening programs to detect and treat refractive disorders across this age range.

Epidemiology and trends in the uptake of refractive error services in Harare, Zimbabwe: a hospital-based retrospective study

Aim

The study aimed to determine the epidemiology and evaluate the trends in the uptake of refractive error services in Harare.

Methods

A clinic-based retrospective study at the Greenwood Park Eye Centre and its three subsidiaries was conducted from January 1, 2015 to December 31, 2020.

Results

12,216 patients' records were retrieved, out of which 1074 (8.79%) had refractive error cases. The prevalence of visual impairment at presentation was 5.80% [95% CI: 5.39 - 6.23]. Among those with refractive error, the sample prevalence of visual impairment before correction was 41.30% [CI: 38.3 - 44.3, 95%], and 2.20% [95% CI: 1.4 - 3.3] after correction. There was inconsistency in the percentage utilization of refractive error services, with the highest being 42.60% in 2015. Refractive error types were related to age, employment position, and type of visual impairment prior to refractive error treatment.

Conclusion

There was a low percentage of refractive error services uptake in urban Zimbabwe.

Prevalence and pattern of refractive errors among school-going children in district Baramulla, Kashmir: A cross sectional study

PURPOSE

Uncorrected refractive error is one of the most important causes of visual impairment worldwide. Addressing childhood vision impairment (VI) is one of the main goals of the World Health Organization (WHO) to combat blindness strategies.

OBJECTIVE

To ascertain the prevalence and pattern of refractive errors among children aged 10 to 16 years in Baramulla district, Kashmir.

METHODS

A cross-sectional study was carried out among 680 school children during an eye camp under the school health program of the national program for control of blindness. The screening was conducted in four schools in Baramulla district, Kashmir. The schools were selected using the non-probability convenient sampling technique.

RESULTS

A total of 680 school children from classes sixth to tenth aged 10-16 years participated in the study. Out of 680 students, 545 (80%) had normal vision, 97 (14%) had impaired visual acuity ranging between 6/9 and 6/24, and 38 (6%) had severe VI ranging from 6/36 to 6/60. Among the various types of refractive errors, myopia was the most prevalent affecting 54 children. Age distribution of refractive errors showed myopia to be more prevalent in the age group 13-14 years (16, 14 cases), hypermetropia was more prevalent in the age group 14-15 years (10, 8 cases), and astigmatism 5 cases in the age group 14-15 years.

CONCLUSION

The study provides useful and baseline data about the refractive error amongst the school children of the Baramulla district. A larger study needs to be conducted in all schools of the state to get a clear picture of RE and other eye-related problems to detect vision problems earlier.

Measurement Accuracy When Using Spot Vision Screener With or Without Cycloplegia in Young Adults

Purpose

There are many unclear points about the accuracy of measurement of cycloplegic refraction using the Spot Vision Screener (SVS). This study aimed to investigate the accuracy of SVS measurements with cycloplegia for myopia.

Materials and Methods

Forty-nine healthy subjects were included, and refraction was measured. Objective refractions were measured by SVS, table-mounted autorefractometer (RT7000), and handheld autorefractometer (Retinomax Screeen) at noncycloplegic and cycloplegic conditions by 1% cyclopentolate. Subjective noncycloplegic refraction was obtained by a visual acuity and refraction test performed by certified orthoptists using a cross-cylinder. One-way repeated-measures analysis of variance was used to examine whether the measured refractions fluctuate due to different reflection tests.

Results

In the noncycloplegic condition, the mean (±standard deviation) spherical equivalent (SE) measured by subjective method, SVS, RT7000, and Retinomax Screeen were -2.56 ± 3.00, -2.62 ± 2.38, -3.05 ± 2.84, and -3.26 ± 2.97, respectively. The subjective SE and objective SE measured by SVS had significantly less myopic value than the objective SE measured by two autorefractometers (p < 0.001). In the cycloplegic condition, the mean (± standard deviation) SE measured by SVS, RT7000, and Retinomax Screeen were -2.07 ± 2.66, -2.62 ± 2.98, and -2.66 ± 3.02, respectively. The objective SE measured by SVS had significantly less myopic value than SEs measured using other methods (p < 0.001). In the cycloplegic condition, SVS showed a fixed error wherein the SE was more hyperopic than that with the subjective method and SVS had a proportional error.

Conclusion

In the measurement under cycloplegic conditions, use of an autorefractometer rather than a photorefractometer such as SVS was preferable.

Kaleidos-based binocular vision analyzer for the estimation of refractive errors and horizontal ocular deviation in children

CLINICAL RELEVANCE

Knowing the agreement and interobserver variability of the 2WIN-S photorefractometer with cycloplegic retinoscopy and prism cover test is important for judging the clinical usefulness of the device.

BACKGROUND

This study aims to determine an agreement and interobserver reliability between 2WIN-S photorefractometer and cycloplegic retinoscopy for estimating refractive errors and between 2WIN-S and prism cover test for measuring horizontal ocular deviation in children.

METHODS

Two groups of 129 and 64 participants (range, 5 to 16 years) were recruited for the agreement and interobserver reliability studies, respectively. Non-cycloplegic 2WIN-S refraction was compared with cycloplegic retinoscopy for low and moderate myopia and hyperopia. Similarly, corneal reflex-function (CR-function) of 2WIN-S was compared with prism cover test for horizontal ocular deviation. Bland-Altman plots were used to depict agreement, and the intraclass correlation coefficient (ICC) was used for determining interobserver reliability of repeated measures.

RESULTS

The mean differences in spherical equivalent, J0 (Cartesian astigmatism) and J45 (oblique Jackson cross-cylinder) between cycloplegic retinoscopy and 2WIN-S were 1.10 (95% CI = 0.97 to 1.21, p < 0.001), -0.06 (95% CI = -0.09 to -0.03, p < 0.001) and 0.009 (95% CI = -0.01 to 0.03, p = 0.35), respectively. The overall median difference in the horizontal ocular deviation between prism cover test and 2WIN-S was -4.5 (Interquartile range = -12.0 to 4.0). For constant strabismus, this difference was insignificant (median= -2.0, interquartile range = -11.0 to 6.7, p = 0.19) between prism cover test and 2WIN-S. The ICC was high for the spherical equivalent (0.997; p < 0.001), J0 (0.932; p < 0.001) and J45 (0.901; p < 0.001), whereas it was low-to-moderate for horizontal ocular deviation (0.50; p < 0.001).

CONCLUSION

2WIN-S refraction was in agreement with cycloplegic retinoscopy for low and moderate myopia and hyperopia, and requires an adjustment for the consistent differences between cycloplegic retinoscopy and 2WIN-S refraction. The measurement of constant strabismus with 2WIN-S is comparable to that of prism cover test.

Design and delivery of the Refractive Errors Among Children (REACH) school-based eye health programme in India

CLINICAL RELEVANCE

Optimisation of vision screening programmes can result the detection of refractive anomalies in a high proportion of school children.

BACKGROUND

The Refractive Errors Among Children (REACH) programme aims to optimise outcomes of school-based vision screening in India by collaborating with hospitals and monitoring eye care throughout school attendance.

METHODS

REACH delivers school vision screening using pocket vision screeners (cards presenting rows of seven 0.2 logMAR Sloan letters at a 3 m viewing distance) in five states across India. Children who fail screening are referred for detailed evaluation including refraction, those requiring cycloplegic refraction are referred to partner hospitals. Spectacles are dispensed as needed and compliance is assessed. All data are recorded electronically.

RESULTS

Out of 2,240,805 children aged 5 to 18 (mean 11.5; SD ±3.3) years, 2,024,053 have undergone REACH screening in 10,309 schools predominantly in rural locations (78.7%) and government-funded (76%). Of those screened, 174,706 (8.6%) underwent detailed evaluation. A higher proportion of children in private or urban schools (11.8% and 10.4% respectively) were referred for detailed evaluation than those in government-funded or rural schools (5.9% and 7.2%, respectively; p < 0.001). The proportion referred for detailed evaluation differed by state (p < 0.001), from 4.0% in West Bengal to 14.4% in Kerala.

CONCLUSION

The REACH programme screened a high proportion of school children, providing further care and follow-up to optimise visual outcomes.

Levodopa/Carbidopa to Augment the Treatment of Amblyopia: A Report by the American Academy of Ophthalmology

PURPOSE

To review the published literature on the use of levodopa/carbidopa to augment the treatment of amblyopia.

METHODS

Literature searches for English language studies were last conducted in October 2022 in the PubMed database with no date restrictions. The combined searches yielded 55 articles, of which 23 were reviewed in full text. Twelve of these were considered appropriate for inclusion in this assessment and were assigned a level of evidence rating by the panel methodologist. Nine studies were rated level I, and 3 studies were rated level II; there were no level III studies.

RESULTS

The duration of treatment was limited to 3 to 16 weeks because of concern about long-term adverse effects such as tardive dyskinesia. This complication was not reported in any of the study participants. The dose of levodopa ranged from 1.5 to 8.3 mg/kg/day, generally divided into 3 daily doses. The carbidopa dose was approximately 25% of the levodopa dose in all treatments. Evidence from these studies indicates that augmenting traditional patch occlusion therapy with the oral administration of levodopa/carbidopa can improve the vision of amblyopic children, but the effect was small (0.17-0.3 logarithm of the minimum angle of resolution [logMAR] units) and only statistically significant when compared with patching alone in 2 of the 12 studies cited. Regression of vision was reported in the majority of studies (9 of 12 reported; range, 0-0.17 logMAR unit regression) after discontinuation of therapy. Short-term side effects of the medications were not consistently reported but were most frequently mild and included headache and nausea.

CONCLUSIONS

The best available evidence is currently insufficient to show that augmenting amblyopia therapy using up to 16 weeks of levodopa/carbidopa will result in meaningful improvement in visual acuity. Given the potential for significant side effects such as tardive dyskinesia with long-term therapy, levodopa/carbidopa does not appear to be a viable option for amblyopia therapy FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Associations between systemic melatonin and human myopia: A systematic review

PURPOSE

Experimental models have implicated the role of melatonin circadian rhythm disruption in refractive error development. Recent studies have examined melatonin concentration and its diurnal patterns on refractive error with equivocal results. This systematic review aimed to summarise the literature on melatonin circadian rhythms in myopia.

RECENT FINDINGS

PubMed, EMBASE, Web of Science, Scopus, ProQuest Central, LILACS, Cochrane and Medline databases were searched for papers between January 2010 and December 2022 using defined search terms. Seven studies measured melatonin and circadian rhythms in three biological fluids (blood serum, saliva and urine) in both myopes and non-myopes. Morning melatonin concentrations derived from blood serum varied significantly between studies in individuals aged 10-30 years, with a maximum of 89.45 pg/mL and a minimum of 5.43 pg/mL using liquid chromatography and mass spectrometry. The diurnal variation of salivary melatonin was not significantly different between myopes and emmetropes when measured every 4 h for 24 h and quantified with enzyme-linked immunosorbent assay. Significantly elevated salivary melatonin concentrations were reported in myopes compared with emmetropes, aged 18-30 years when measured hourly from evening until their habitual bedtime using liquid chromatography. However, the relationship between dim light melatonin onset and refractive group was inconsistent between studies. The 6-sulphatoxymelatonin concentration derived from overnight urine volume, measured using a double antibody radioimmunoassay, was found to be significantly lower in myopes (29.17 pg/mL) than emmetropes (42.51 pg/mL).

SUMMARY

The role of melatonin concentration and rhythm in myopia has not been studied extensively. This systematic review confirms conflicting findings across studies, with potential relationships existing. Future studies with uniform methodological approaches are required to ascertain the causal relationship between melatonin dysregulation and myopia in humans.

A Comparison of Optical Biometers Used in Children for Myopia Control

PURPOSE

To assess the reproducibility (i.e., inter-device reliability) of the biometers Topcon MYAH, Oculus Myopia Master, and Haag-Streit Lenstar LS900 with the Carl Zeiss IOLMaster 700 and the intra-subject repeatability in myopic children in order to reliably detect axial growth for myopia management.

METHODS

Twenty-two myopic children (11.1 ± 2.4 yr) with a spherical equivalent of - 3.53 ± 2.35 D were examined with each of the biometers to assess axial length (AL) and corneal parameters (steepK, flatK, meanK, vectors J0, J45), and16 of these children agreed to a second round of measurements. Reproducibility of the first measurements between the IOLMaster and every other biometer was assessed employing a Bland-Altman approach and paired Student's t-test. Repeatability was assessed as intra-subject standard deviation and was used to estimate the minimum time interval required between two AL measurements to reliably detect axial growth of an eye of at least 0.1 mm/year.

RESULTS

Repeatability for AL measurements was as follows: IOLMaster: 0.05 mm, Myopia Master: 0.06 mm, Myah: 0.06 mm, Lenstar: 0.04 mm; the respective minimal time interval for axial growth assessment in myopia management was estimated as 5.6, 6.6, 6.7, and 5.0 months, respectively. Best reproducibility of the AL measurement was found between IOLMaster and Lenstar [95% Limits of Agreement (LoA) for reproducibility - 0.06 to 0.02]. As regards to the measured means, Lenstar gave measures of AL that were longer than with the IOLMaster by 0.02 mm (p < 0.001). Myopia Master measures of meanK were significantly lower (by 0.21 D with p < 0.001) than the values from the IOLMaster. As for J0, all biometers deviated significantly from IOLMaster measurements (p < 0.05).

CONCLUSION

Generally good agreement was observed between all the biometers. When assessing myopia progression in children, a time frame of at least 6 months between the AL measurements is advisable in order to reliably determine any deviation from a normal growth pattern.

Prevalence of Myopia and Its Related Factors Among University Students in Madinah, Saudi Arabia

BACKGROUND

Myopia, a common refractive error, is a growing global health burden influenced by both genetic and environmental factors. Despite its high prevalence, studies on its prevalence and risk factors among university students are lacking.

OBJECTIVES

The objective of this study is to investigate the prevalence of myopia and its associated factors among college students in Saudi Arabia's Madinah region.

METHODS

A cross-sectional study was conducted in Al-Madinah, Saudi Arabia, from February to June 2023, utilizing a survey that was distributed to college students through a social media application.

RESULTS

A total of 433 university students from Al-Madinah province were enrolled in this study; 66.3% were females and 33.7% were males. Participants' ages ranged from 18 to 33 years with a mean of 21.3 ± 2.0 years. The prevalence of myopia among college students in Al-Madinah and its provinces was 57.3%, and 87.9% of them had myopia in both eyes. Respondents with an electronic screen time of more than three hours and a reading distance of less than 15cm were at significant risk of myopia with p-values of 0.037 and 0.019, respectively.

CONCLUSIONS

A significant prevalence of myopia has been observed among university students in Madinah. Studying in scientific and medical fields, having eye diseases, prolonged use of digital devices, limiting daily outdoor activities to one hour, and having a reading distance of less than 15 cm significantly increased the risk of myopia. Encouraging education and screening programs for myopia prevention and control is crucial.

Time Spent Outdoors Partly Accounts for the Effect of Education on Myopia

Purpose

The purpose of this study was to investigate if education contributes to the risk of myopia because educational activities typically occur indoors or because of other factors, such as prolonged near viewing.

Methods

This was a two-sample Mendelian randomization study. Participants were from the UK Biobank, Avon Longitudinal Study of Parents and Children, and Generation R. Genetic variants associated with years spent in education or time spent outdoors were used as instrumental variables. The main outcome measures were: (1) spherical equivalent refractive error attained by adulthood, and (2) risk of an early age-of-onset of spectacle wear (EAOSW), defined as an age-of-onset of 15 years or below.

Results

Time spent outdoors was found to have a small genetic component (heritability 9.8%) that tracked from childhood to adulthood. A polygenic score for time outdoors was associated with children's time outdoors; a polygenic score for years spent in education was inversely associated with children's time outdoors. Accounting for the relationship between time spent outdoors and myopia in a multivariable Mendelian randomization analysis reduced the size of the causal effect of more years in education on myopia to -0.17 diopters (D) per additional year of formal education (95% confidence interval [CI] = -0.32 to -0.01) compared with the estimate from a univariable Mendelian randomization analysis of -0.27 D per year (95% CI = -0.41 to -0.13). Comparable results were obtained for the outcome EAOSW.

Conclusions

Accounting for the effects of time outdoors reduced the estimated causal effect of education on myopia by 40%. These results suggest about half of the relationship between education and myopia may be mediated by children not being outdoors during schooling.

Addressing Health Disparities in Pediatric Eye Care for School-Age Children: A Call to Action

Disparities in access to pediatric eye care among school-age children pose significant challenges to their health and well-being; addressing these disparities will necessitate coordination across multiple systems. Although vision screenings are mandated in most US states, differences persist in terms of who receives screenings and subsequent follow-up care. Racial, ethnic, and socioeconomic factors exacerbate the issue, with potential ramifications of unaddressed eye problems on learning performance and the risk of widening preexisting educational disparities. To address these challenges, various initiatives and strategic plans have emphasized the need to improve access, enhance diversity in the workforce, and promote health literacy. School-based vision programs (SBVPs) have shown promise in improving access to care and academic outcomes, but issues with integration into the health care system exist. This article explores opportunities to address structural barriers, establish resilient and equitable systems for delivering pediatric eye care to school-age children, and leverage the success of SBVPs to build stronger connections with community providers. Proposed strategies include developing standardized guidelines; establishing referral mechanisms; fostering communication with parents, teachers, and community providers; and promoting eye health literacy across the school community. Collectively, these measures aim to improve health outcomes, address social determinants of health, and reduce disparities in access to care.

Accuracy of new intraocular lens calculation formulas in Chinese eyes with short axial lengths

Purpose

To compare the measurement accuracy of new/updated intraocular lens (IOL) power calculation methods, namely, Kane, Emmetropia Verifying Optical (EVO), with existing methods (Barrett Universal II, Olsen, Haigis, Hoffer Q, Holladay 1, SRK/T) in Chinese eyes with axial lengths ≤ 22.5 mm.

Methods

The study included data from patients who underwent uneventful cataract surgery with the insertion of ZCB00 IOL. Refractive prediction errors were determined by calculating the difference between postoperative refraction and the predicted refraction using each formula. Various parameters were evaluated, including mean prediction error (ME), mean absolute error (MAE), median absolute error (MedAE), and the percentage of eyes with prediction errors (PE) within different ranges.

Results

The study enrolled 38 eyes of 38 patients, and the Barrett Universal II formula demonstrated the lowest MAE and MedAE among the tested formulas. Post hoc analysis using Wilcoxon signed-rank pairwise comparisons for non-parametric samples with Bonferroni correction revealed no significant difference in postoperative refractive prediction among all the formulas (P > 0.05). The percentage of eyes with PE within ± 0.5 D was as follows: Barrett Universal II, 81.58%; Haigis, 78.95%; EVO, 76.32%; Olsen, 76.32%; Holladay I, 73.68%; SRK/T, 71.05%; Kane, 68.42%; and Hoffer Q, 65.79%.

Conclusion

The Barrett Universal II formula was more accurate than the other formulas for Chinese eyes with AL ≤ 22.5 mm.

Refractive Status and Biometric Characteristics of Children With Familial Exudative Vitreoretinopathy

Purpose

To compare biometric characteristics between patients with early-stage familial exudative vitreoretinopathy (FEVR) and healthy controls.

Methods

This case-control study included 50 FEVR eyes in stage 1-2 and 50 control eyes matched by age, gender and spherical equivalent (SE). Biometric parameters including axial length (AL), white-to-white diameter (WTW), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), pupil diameter, vitreous chamber depth, anterior and posterior corneal surface curvature radius (ACR and PCR), anterior lens surface curvature radius (ALR) and posterior lens surface curvature radius were measured using IOLMaster 700 and compared between cases and controls using paired t-test. Correlations between SE and biometric measures were assessed using Pearson correlation coefficient (r) in cases and controls.

Results

Both FEVR cases and matched controls had a mean age of 7.6 years, 48% female and mean SE of -5.3 D (80% myopia). Compared to controls, FEVR eyes had smaller AL (P = 0.009), WTW (P = 0.001), ACD (P < 0.001), and ALR (P = 0.03), but larger CCT (P = 0.02) and LT (P = 0.01). In FEVR eyes, SE was negatively correlated with AL (r = -0.79, P < 0.001), positively correlated with ACR (r = 0.29, P = 0.04) and PCR (r = 0.33, P = 0.02), whereas in controls, SE was negatively correlated with AL (r = -0.82, P < 0.001) and LT (r = -0.34, P = 0.02), positively correlated with ALR (r = 0.29, P = 0.04).

Conclusions

Patients at early stage of FEVR exhibited a unique eye morphology resembling ocular development arrest, which may help to develop screening and early detection tools for FEVR. In FEVR patients, myopia is very prevalent and significantly associated with corneal curvature increase.

Ocular abnormalities in children with developmental delay

Purpose

To describe the presence of ocular abnormalities in children with developmental delay (DD) and compare with normal children; to analyze associated risk factors, systemic problems, and the possible treatment that can be delivered.

Methods

This was a cross sectional, observational study. We included children between one and 18 years, diagnosed as developmental delay in DD group, and next immediate age- and sex-matched children without developmental delay on the same day or during the same period in the control group. Detailed history and neuroimaging findings were noted. Uncorrected visual acuity, best-corrected visual acuity for distance and near, cycloplegic refraction, anterior, and posterior segment examination was carried out. Various ocular problems, delayed visual maturation (DVM), and cortical visual impairment (CVI) were diagnosed based on examination. Data were analyzed statistically, and P value <0.05 was considered as statistically significant.

Results

Ninety-four children were included in each group. Mean age was 4.97 ± 3.84 years, and 64.89% were males. In DD group: Most common abnormal neuroimaging finding was gliotic changes; systemic associations: 39 children; 83 children had ocular problems: refractive error-70, strabismus-39, cataract-five, amblyopia-16; DVM-13; CVI-13 children; glasses and vision stimulation were advised in 39 and 65 children, respectively; whereas, in control group: refractive error-36, strabismus-15, cataract-two; amblyopia-20 children.

Conclusion

88.29% of developmental delay children had ocular abnormalities, commonest was refractive error (74.47%); these values were higher than in control group; common risk factors were low birthweight and consanguineous marriage; epilepsy was the most common systemic association.

Clinical features and refractive profile of Brown syndrome

CLINICAL SIGNIFICANCE

Understanding the refractive profile, amblyopia prevalence, binocular status, and head position in patients with Brown syndrome help clinicians become more familiar with this syndrome.

BACKGROUND

Brown syndrome is identified as an active and passive restricted elevation of the eye in adduction. There is little information on clinical features, including refractive status, amblyopia, abnormal head posture (AHP), and types of deviation in these patients.

METHODS

This study retrospectively evaluated records of 100 Brown syndrome patients from 2015 to 2022 at Farabi Eye Hospital, Iran.

RESULTS

The mean age was 6.99 ± 6.33 years, including 48 (48%) males. A congenital source was found in 74 (74%) and 96 (96%) patients had unilateral involvement. The mean CDVA for the affected and non-affected eyes were 0.05 ± 0.11 and 0.03 ± 0.06 logMAR, respectively (P = 0.31). In unilateral cases, hyperopia, myopia, and emmetropia were observed in 55 (57.29%), 2 (2.08%), and 39 (40.63%) affected eyes, respectively. The most common type of deviation was pure hypotropia, which was found in 53 (53%) cases, followed by 'combined exotropia and hypotropia' observed in 26 (26%) patients. The mean angle of hypotropia and horizontal deviation in the primary position at distance was 12.10 ± 8.50 and 8 ± 13.20 prism dioptre, respectively. A V-pattern was found in 76 (76%) patients. Amblyopia was observed in 13 (21.67%) of 60 cooperative patients, and AHP was noticed in 66 (66%) patients, in which "combined chin up and contralateral face turn" was the most common type.

CONCLUSION

About 75% of cases were congenital, 50% had pure hypotropia, 75% showed V-pattern, 20% had amblyopia, and AHP was observed in 67% of patients. The remarkable prevalence of amblyopia alongside the high occurrence of AHP should alert clinicians to carefully assess patients with Brown syndrome for sensory fusion and amblyopia.

Development of the University of Houston near work, environment, activity, and refraction (UH NEAR) survey for myopia

CLINICAL RELEVANCE

There is a need to better elucidate demographic and behavioural factors that are contributing to the rising prevalence of myopia. Doing so will aid in developing evidence-based recommendations for behavioural modifications to prevent onset and slow progression of myopia in children.

BACKGROUND

The contributions of environmental and behavioural factors in myopia remain unclear. The goal of this work was to provide a standardised survey to better understand risk factors for myopia.

METHODS

Development of the survey was carried out in 4 phases. In phase 1, three methods (direct, lay terms, and indirect) of parental reporting for the presence of myopia in their child were investigated through a questionnaire (N = 109) to determine sensitivity and specificity. The best method determined from phase 1 was used in phase 2, where questions regarding demographics, ocular history, and visual behaviour were compiled and refined. In phase 3, the survey was administered to focus groups of parents (N = 9). In phase 4, a scoring system was developed.

RESULTS

The highest sensitivity for parental reporting for myopia of their child was the indirect method (0.84), and the lowest sensitivity was the direct method (0.41). The highest specificity was the direct method (0.86), once excluding the 'do not know' responses, and the lowest specificity was the indirect method (0.53). The direct method yielded a 53.2% 'do not know' response rate, 50.5% for the lay method, and 1.8% for the indirect method. Time to complete the survey was 10:09 ± 2:45 minutes.

CONCLUSION

This study provides a comprehensive and up-to-date myopia risk factor survey that can be utilised by researchers and clinicians. Parents found the survey to be easy to understand and relatively quick to answer, and the scoring system allows quantification of behaviours across different categories using provided equations.

Refractive Error and Axial Length and Their Related Factors in 8-Year-Old Japanese Children: The Yamanashi Adjunct Study of the Japan Environment and Children's Study (JECS)

PURPOSE

To investigate the distribution of visual acuity, refractive error, and axial length in 8-year-old children who participated in an additional survey in Yamanashi Prefecture of the Japan Environmental Children's Study (hereafter referred to as JECS-Y) conducted from 2019 to 2021.

PARTICIPANTS AND METHODS

Eight-year-old children who participated in the JECS-Y study were subjected to noncycloplegic measurements of refractive error and axial length. If the uncorrected visual acuity was less than 20/20, the best corrected visual acuity was evaluated in accordance with the autorefraction data. A questionnaire was administered regarding the parent's history of eyeglass wear or contact lens use.

RESULTS

Among the 400 participating children, the rate of uncorrected visual acuity of 20/20 or better in both eyes was 70.4%. The mean equivalent spherical equivalent error for both eyes was -0.366 ± 1.016 D. The mean axial length was 23.08 ± 0.225 mm in all patients. The males showed significantly longer axial length than the females despite no differences in body height. There was a significant correlation between axial length, spherical refractive, and uncorrected visual acuity. The children of parents with a history of wearing eyeglasses or contact lenses showed a significantly more myopic equivalent refractive error than those without a history.

CONCLUSIONS

This study clarified the current state of refractive error in 8-year-old children and the association of inheritance with refractive error. In addition, the axials were significantly longer in male patients.

Vision Impairments in Young Adults with Down Syndrome

People with Down syndrome have more visual problems than the general population. They experience premature ageing, and they are expected to also have an acceleration in worsening visual function. A prospective observational study which includes visual acuity, refractive error, accommodation, binocular and colour vision was performed on young adults with (n = 69) and without (n = 65) Down syndrome and on a senior group (n = 55) without Down syndrome. Results showed significant differences in visual acuity between groups (p < 0.001), and it can be improved with a new prescription in 40% of the participants with Down syndrome. Regarding the accommodative state, no significant differences were found between groups of young people. Concerning binocular vision, 64.7% of strabismus was observed in the group with Down syndrome (p < 0.001). Visual abnormalities are significant in young adults with Down syndrome and are different from those of older people without Down syndrome, some of which can be improved by providing the optimal prescription as well as regular eye examinations.

Sector-Based Regression Strategies to Reduce Refractive Error-Associated Glaucoma Diagnostic Bias When Using OCT and OCT Angiography

Purpose

This cross-sectional study aimed to investigate the sectoral variance of optical coherence tomography (OCT) and OCT angiography (OCTA) glaucoma diagnostic parameters across eyes with varying degrees of refractive error.

Methods

Healthy participants, including individuals with axial ametropia, enrolled in the Hong Kong FAMILY cohort were imaged using the Avanti/AngioVue OCT/OCTA system. The OCT and OCTA parameters obtained include peripapillary nerve fiber layer thickness (NFLT), peripapillary nerve fiber layer plexus capillary density (NFLP-CD), and macular ganglion cell complex thickness (GCCT). Sectoral measurements of NFLT, NFLP-CD, and GCCT were based on sectors and hemispheres.

Results

A total of 1339 eyes from 791 participants were stratified based on spherical equivalent refraction: high myopia (<-6 D), low myopia (-6 D to -1 D), emmetropia (-1 D to 1 D), and hyperopia (>1 D). Multivariable broken stick regression models, accounting for age, sex, and signal strength, showed that all NFLT sectors except temporally, the inferior GCCT hemisphere, and half of the NFLP-CD sectors were more affected by ametropia-related covariates than the corresponding global parameters. As expected, the false-positive rates in those sectors were elevated. Finally, sector-specific axial length (AL) and spherical equivalent (SE) adjustments helped reduce the elevated false-positive rates.

Conclusions

The effect of optical magnification is even more prominent among sectors than the global parameters. AL- and SE-based adjustments should be individualized to each sector to mitigate this magnification bias effectively.

Translational Relevance

Identifying sectoral differences among diagnostic parameters and adopting these sector-based adjustments into commercial OCT systems will hopefully reduce false-positive rates related to refractive error.

Relative peripheral hyperopia leads to greater short-term axial length growth in White children with myopia

PURPOSE

Controversy exists regarding the influence of peripheral visual experience on the onset and progression of childhood myopia. This longitudinal, observational study evaluated the relationship between relative peripheral refraction (RPR) and changes in refractive error and axial length (AL) over 12 months in White children aged 6-7 and 12-13 years with a range of baseline refractive errors.

METHODS

Cycloplegic baseline autorefraction at horizontal retinal eccentricities of 0° and ±30° were recorded with the Shin-Nippon NVision-K 5001 while AL was measured using the Zeiss IOLMaster 700. Measurements were repeated after 12 months on a subgroup. Refractive data were transposed into power vectors as mean spherical equivalent (M), J0 and J45 . RPR was calculated by subtracting central from peripheral measurements. Participants were defined as myopic (M ≤ -0.50 D), premyopic (-0.50 D < M ≤ +0.75 D), emmetropic (+0.75 D < M < +2.00 D) or hyperopic (M ≥ +2.00 D).

RESULTS

Data were collected from 222 and 245 participants aged 6-7 and 12-13 years, respectively. Myopic eyes demonstrated, on average, more hyperopic RPR. Emmetropes and premyopes displayed emmetropic RPR, and hyperopes showed a myopic RPR. Fifty-six 6- to 7-year-olds and seventy 12- to 13-year-olds contributed 12-month repeated measures. Longitudinal data demonstrated a significant relationship between a more hyperopic RPR in the nasal retina and greater short-term axial elongation in teens with myopia at baseline (β = 0.69; p = 0.04). Each dioptre of relative peripheral hyperopia in the nasal retina was associated with an additional 0.10 mm (95% CI: 0.02-0.18 mm) annual increase in AL.

CONCLUSIONS

Hyperopic RPR in the nasal retina of myopic children is indicative of increased risk for rapid axial elongation and may be a useful metric to support decision-making in myopia management.

Automatic Refractive Error Estimation Using Deep Learning-Based Analysis of Red Reflex Images

Purpose/Background: We evaluate how a deep learning model can be applied to extract refractive error metrics from pupillary red reflex images taken by a low-cost handheld fundus camera. This could potentially provide a rapid and economical vision-screening method, allowing for early intervention to prevent myopic progression and reduce the socioeconomic burden associated with vision impairment in the later stages of life. Methods: Infrared and color images of pupillary crescents were extracted from eccentric photorefraction images of participants from Choithram Hospital in India and Dargaville Medical Center in New Zealand. The pre-processed images were then used to train different convolutional neural networks to predict refractive error in terms of spherical power and cylindrical power metrics. Results: The best-performing trained model achieved an overall accuracy of 75% for predicting spherical power using infrared images and a multiclass classifier. Conclusions: Even though the model's performance is not superior, the proposed method showed good usability of using red reflex images in estimating refractive error. Such an approach has never been experimented with before and can help guide researchers, especially when the future of eye care is moving towards highly portable and smartphone-based devices.