Intravitreal panitumumab and myopic macular degeneration

BACKGROUND

In experimental studies, intravitreally applied antibodies against epidermal growth factor (EGF), EGF family members (amphiregulin, neuregulin-1, betacellulin, epigen, epiregulin) and against the EGF receptor (EGFR) were associated with a reduction in lens-induced axial elongation and decrease in physiological eye elongation in guinea pigs and in non-human primates. Here, we investigated the intraocular tolerability and safety of a fully human monoclonal IgG2-antibody against EGFR, already in clinical use in oncology, as a potential future therapeutic approach for axial elongation in adult eyes with pathological myopia.

METHODS

The clinical, monocentre, open-label, multiple-dose, phase-1 study included patients with myopic macular degeneration of stage 4, who received intravitreal injections of panitumumab in various doses and in intervals ranging between 2.1 months and 6.3 months.

RESULTS

The study included 11 patients (age:66.8±6.3 years), receiving panitumumab injections in doses of 0.6 mg (4 eyes; 1×1 injection, 3×2 injections), 1.2 mg (4 eyes; 1×1 injection, 2×2 injections, 1×3 injections) and 1.8 mg (3 eyes; 1×1 injection, 2×2 injections), respectively. None of the participants showed treatment-emergent systemic adverse events or intraocular inflammatory reactions. Best-corrected visual acuity (1.62±0.47 logarithm of the minimal angle of resolution (logMAR) vs 1.28±0.59 logMAR; p=0.08) and intraocular pressure (13.8±2.4 mm Hg vs 14.3±2.6 mm Hg; p=0.20) remained unchanged. In nine patients with a follow-up of >3 months (mean:6.7±2.7 months), axial length did not change significantly (30.73±1.03 mm vs 30.77±1.19 mm; p=0.56).

CONCLUSIONS

In this open-labelled, phase-1 study with a mean follow-up of 6.7 months, panitumumab repeatedly administered intravitreally up to a dose of 1.8 mg was not associated with intraocular or systemic adverse effects. During the study period, axial length remained unchanged.

TRIAL REGISTRATION NUMBER

DRKS00027302.

Quality of refractive error care in Pakistan: an unannounced standardised patient study

OBJECTIVE

Undercorrected refractive errors are the primary cause of vision impairment worldwide, including in Pakistan. However, limited data exist on the quality of refractive error care. Our study assessed the quality of refractive error care in Punjab, Pakistan by estimating the proportion of spectacles that were optimally prescribed.

METHODS AND ANALYSIS

In this cross-sectional study, 12 unannounced standardised patients (USPs) from Jhang, Khanewal and Sahiwal districts were recruited. USPs underwent baseline subjective refraction and were trained to attend optical services, observe consultations, request spectacles and obtain prescriptions. The spectacles received were compared with baseline refraction to determine quality. We also examined the associations between spectacle quality, service and patient characteristics.

RESULTS

Out of 276 attempted visits to 69 optical services, 241 pairs of spectacles were dispensed. A population size-weighted percentage of 42.7% (95% CI 36.4% to 49.3%) of spectacles were optimal quality, with the range varying from 13.8% in Jhang to 67.0% in Khanewal. Half the suboptimal quality spectacles had horizontal prism deviations outside of tolerance limits. Optimal spectacles were associated with performing focimetry (unadjusted OR=7.15, 95% CI (3.02 to 16.94), p<0.001) and good communication (OR=2.23, 95% CI (1.06 to 4.67), p=0.03). Hyperopic USPs were less likely to receive optimal spectacles (OR=0.01 95% CI (0.00 to 0.11), p<0.001).

CONCLUSION

The quality of refractive error care in Pakistan requires improvement, particularly in the Jhang district. Key areas for enhancing refractive error care in Pakistan include refining dispensing and refraction skills for hyperopic prescriptions, providing training on the risks of using previous spectacles, and emphasising the importance of effective communication skills.

Prediction of refractive error and its progression: a machine learning-based algorithm

OBJECTIVE

Myopia is the refractive error that shows the highest prevalence for younger ages in Southeast Asia and its projection over the next decades indicates that this situation will worsen. Nowadays, several management solutions are being applied to help fight its onset and development, nonetheless, the applications of these techniques depend on a clear and reliable assessment of risk to develop myopia.

METHODS AND ANALYSIS

In this study, population-based data of Chinese children were used to develop a machine learning-based algorithm that enables the risk assessment of myopia's onset and development. Cross-sectional data of 12 780 kids together with longitudinal data of 226 kids containing age, gender, biometry and refractive parameters were used for the development of the models.

RESULTS

A combination of support vector regression and Gaussian process regression resulted in the best performing algorithm. The Pearson correlation coefficient between prediction and measured data was 0.77, whereas the bias was -0.05 D and the limits of agreement was 0.85 D (95% CI: -0.91 to 0.80D).

DISCUSSION

The developed algorithm uses accessible inputs to provide an estimate of refractive development and may serve as guide for the eye care professional to help determine the individual best strategy for management of myopia.

Multivariate analysis of refractive state in eyes with keratoconus

OBJECTIVE

To demonstrate a multivariate method of analysis of the short-term variation of refractive state in keratoconus (KC) patients.

METHODS AND ANALYSIS

In this observational study, 19 eyes with KC and 19 healthy control eyes were measured. The study included both male and female participants and the mean age was 23.6 years (range 18-34 years) and 23.2 years (range 22-26 years) for KC and control participants, respectively. Forty consecutive autorefractor measurements were taken for each participant and the short-term variation thereof was analysed using multivariate methods of analysis.

RESULTS AND CONCLUSION

Short-term variation of refractive state is greater in eyes with KC than in healthy control eyes and variation increases with severity of disease. A novel finding was that there was much more ortho-astigmatic and oblique-astigmatic variation seen in KC eyes than in control eyes which had predominately stigmatic variation. Refractive state is described by three components, namely, sphere, cylinder and axis. Although it is multivariate in nature, it is often analysed using univariate statistical methods. In diseases such as KC, where early diagnosis is crucial for a good prognosis, it is necessary that researchers endeavour to investigate the disease from different perspectives to fully understand the nature of the disease. This paper comprehensively demonstrates the multivariate statistical methods of analysis of refractive data. The implementation of this analysis provides insight into the short-term variation of refractive data in healthy and keratoconic eyes, and these findings have not been demonstrated before using univariate statistics.

Refractive error, eye care needs and attitude towards spectacle wearing among older Zanzibari craftswomen and implications for developing women-targeted services: a cross-sectional study

BACKGROUND

Aged Zanzibari women are in a disadvantaged position, having high demand for near-vision spectacles. Currently, there is no information on the eye health status of craftswomen, which makes planning a women-targeted project to deliver eye health services to older craftswomen in Zanzibar difficult. We assessed the prevalence of vision impairment, refractive error, presbyopia, effective spectacle coverage (distance and near) and attitude towards spectacle wearing among older Zanzibari craftswomen.

METHODS AND ANALYSIS

This was a cross-sectional study. Unaided and presenting distance and near vision of craftswomen 35 years and older were assessed at the women's co-operatives. We determined the number of those with distance vision poorer than 6/12 and their causes (distance-vision impairment), the number of those with near vision poorer than N8 at 40 cm (presbyopia) and the number of those whose distance and/or near-vision needs were met adequately with their habitual spectacles (effective distance and near spectacle coverages). A piloted and validated questionnaire (15 statements) was used to determine their attitude towards spectacle wearing.

RESULTS

In all, 263 craftswomen participated in the survey (mean age 52.1 years±9.4 years). The prevalence of distance vision impairment among the craftswomen was 29.7% (95% CI 24.2% to 35.6%), the primary cause being uncorrected refractive error (n=51, 65.4%), and none were corrected. The prevalence of presbyopia was 86.6% (95% CI 81.5% to 90.7%, n=231) and the effective near spectacle coverage was 0.99%. The craftswomen showed a positive attitude towards spectacle wearing (strongly agree or agree) based on 12 out of 15 statements.

CONCLUSION

The high burden of vision impairment, uncorrected distance refractive error and presbyopia, and a positive attitude towards spectacle wearing among older craftswomen in Zanzibar indicated the need for women-targeted eye health programmes in low-resource settings.

Surgeon effects on cataract refractive outcomes are minimal compared with patient comorbidity and gender: an analysis of 490 987 cases

AIM

To investigate effect of patient age, gender, comorbidities and surgeon on refractive outcomes following cataract surgery.

METHODS

Study population: patients on UK national ophthalmic cataract database on cataract operations undertaken between 1 April 2010 and 31 August 2018. Variables examined included gender, age, diabetic retinopathy, glaucoma, high myopia, inherited retinal disease, optic nerve disease, uveitis, pseudoexfoliation, vitreous opacities, retinal pathology, cataract type, previous surgery and posterior capsular rupture. A multivariate normal cross-classified model was fitted to the refractive outcome using Markov Chain Monte Carlo (MCMC) methods with diffuse priors to approximate maximum likelihood estimation. A MCMC chain was generated with a burn-in of 5000 iterations and a monitoring chain of 50 000 iterations.

RESULTS

490 987 cataract operations were performed on 351 864 patients by 2567 surgeons. Myopic and astigmatic errors were associated with posterior capsule rupture (-0.38/+0.04×72), glaucoma (-0.10/+0.05×95), previous vitrectomy (-0.049/+0.03×66) and high myopia (-0.07/+0.03×57). Hyperopic and astigmatic errors were associated with diabetic retinopathy (+0.08/+0.03×104), pseudoexfoliation (+0.07/+0.01×158), male gender (+0.12/+0.05×91) and age (-0.01/+0.06×97 per increasing decade). Inherited retinal disease, optic nerve disease, previous trabeculectomy, uveitis, brunescent/white cataract had no significant impact on the error of the refractive outcome. The effect of patient gender and comorbidity was additive. Surgeons only accounted for 4% of the unexplained variance in refractive outcome.

CONCLUSION

Patient comorbidities and gender account for small but statistically significant differences in refractive outcome, which are additive. Surgeon effects are very small.

Ray tracing intraocular lens calculation performance improved by AI-powered postoperative lens position prediction

AIMS

To assess whether incorporating a machine learning (ML) method for accurate prediction of postoperative anterior chamber depth (ACD) improves cataract surgery refraction prediction performance of a commonly used ray tracing power calculation suite (OKULIX).

METHODS AND ANALYSIS

A dataset of 4357 eyes of 4357 patients with cataract was gathered at the Kellogg Eye Center, University of Michigan. A previously developed machine learning (ML)-based method was used to predict the postoperative ACD based on preoperative biometry measured with the Lenstar LS900 optical biometer. Refraction predictions were computed with standard OKULIX postoperative ACD predictions and ML-based predictions of postoperative ACD. The performance of the ray tracing approach with and without ML-based ACD prediction was evaluated using mean absolute error (MAE) and median absolute error (MedAE) in refraction prediction as metrics.

RESULTS

Replacing the standard OKULIX postoperative ACD with the ML-predicted ACD resulted in statistically significant reductions in both MAE (1.7% after zeroing mean error) and MedAE (2.1% after zeroing mean error). ML-predicted ACD substantially improved performance in eyes with short and long axial lengths (p<0.01).

CONCLUSIONS

Using an ML-powered postoperative ACD prediction method improves the prediction accuracy of the OKULIX ray tracing suite by a clinically small but statistically significant amount, with the greatest effect seen in long eyes.

Visual and ocular findings in children with fetal alcohol spectrum disorders (FASD): validating the FASD Eye Code in a clinical setting

Objective

Fetal alcohol spectrum disorders (FASD) is an umbrella term covering a spectrum of medical conditions caused by prenatal alcohol exposure. The FASD Eye Code is a new complementary ophthalmological diagnostic tool created to corroborate the complex FASD diagnosis. The aim of this work was to validate the FASD Eye Code by testing it on a second group of children diagnosed with FASD in a clinical setting.

Methods and analysis

A clinical study was carried out in a group of 21 children (13 males, 8 females, mean age 13.3 years) investigated for suspected FASD and a healthy sex-matched and age-matched control group (n=21). The participants underwent a detailed ophthalmological examination including visual perception problems (VPPs) assessment. Clinical examination results were compiled, and total scores were calculated according to the FASD Eye Code protocol (range 4–16).

Results

The median total score in the FASD group was 8. Eight individuals in the FASD group and none of the controls obtained a total score of ≥9 corresponding to 38% sensitivity and 100% specificity with an area under the curve of 0.90. A cut-off total score of ≥8 showed 52% sensitivity and 95% specificity. One individual in the FASD group versus 12 controls had a total score of 4, representing normal findings. No significant difference between the two groups regarding VPPs was seen.

Conclusion

The FASD Eye Code can be used as a complementary diagnostic tool for FASD to assist in diagnosis and to detect ophthalmological abnormalities in individuals with suspected FASD.

Normative data and percentile curves for axial length and axial length/corneal curvature in Chinese children and adolescents aged 4-18 years

PURPOSE

To develop age-specific and gender-specific reference percentile charts for axial length (AL) and AL/corneal radius of curvature (AL/CR) and, to use percentiles to determine probability of myopia and estimate refractive error (RE).

METHODS

Analysis of AL, cycloplegic RE and CR of 14 127 Chinese participants aged 4-18 years from 3 studies. AL and AL/CR percentiles estimated using Lambda-Mu-Sigma method and compared for agreement using intraclass correlation (ICC). Logistic regression was used to model risk of myopia based on age, gender, AL and AL/CR percentiles. Accuracy of AL progression and RE estimated using percentiles was validated using an independent sample of 5742 eyes of children aged 7-10 years.

RESULTS

Age-specific and gender-specific AL and AL/CR (3rd, 5th, 10th, 25th, 50th, 75th, 90th and 95th) percentiles are presented. Concordance between AL and AL/CR percentiles improved with age (0.13 at 4 years to >0.75 from 13 years) and a year-to-year change was observed for all except <10th percentile from 15 years. Increasing age, AL and AL/CR was associated with a more myopic RE (r²=0.45,0.70 and 0.83, respectively). The sensitivity and specificity of the model to estimate probability of myopia was 86.0% and 84.5%, respectively. Estimation of 1-year change in AL using percentiles correlated highly with actual AL (ICC=0.98). Concordance of estimated to actual RE was high (ICC=0.80) and within ±0.50D and ±1.0D of actual RE for 47.4% and 78.9% of eyes, respectively.

CONCLUSION

Age-specific and gender-specific AL and AL/CR percentiles provide reference data, aid in identifying and monitoring individuals at risk of myopia and have utility in screening for myopia. AL/CR percentiles were more accurate in estimating probability of myopia in younger children.

Wide-field swept-source optical coherence tomography angiography in the assessment of retinal microvasculature and choroidal thickness in patients with myopia

BACKGROUND/AIMS

Pathological myopia (PM) is a leading cause of blindness worldwide. We aimed to evaluate microvascular and chorioretinal changes in different stages of myopia with wide-field (WF) swept-source (SS) optical coherence tomography angiography (OCTA).

METHODS

This prospective cross-sectional observational study included 186 eyes of 122 patients who had undergone imaging between November 2018 and October 2020. Vessel density (VD) and vessel skeletonised density (VSD) of superficial capillary plexus, deep capillary plexus and whole retina, as well as foveal avascular zone parameters, retinal thickness (RT) and choroidal thickness (CT), were calculated.

RESULTS

This study evaluated 75 eyes of 48 patients with high myopia (HM), 43 eyes of 31 patients with mild to moderate myopia and 68 eyes of 53 age-matched controls. Controlling for age and the presence of systemic hypertension, we found that HM was associated with decrease in VD and VSD in all layers on 12×12 mm² scans. Furthermore, HM was associated with a VD and VSD decrease in every Early Treatment Diabetic Retinopathy Study grid, with a larger decrease temporally (β_VD=-0.39, β_VSD=-10.25, p<0.01). HM was associated with decreased RT and CT. Reduction in RT was outside the macular region, while reduction in CT was in the macular region.

CONCLUSION

Using WF SS-OCTA, we identified reduction in microvasculature and structural changes associated with myopia. Decrease in VD and VSD was greater in the temporal quadrant, and reductions in RT and CT were uneven across the retina. Further work may help identify risk factors for the progression of PM and associated vision-threatening complications.

Five-year change in refractive error and its risk factors: results from the Gutenberg Health Study

BACKGROUND/AIMS

To examine the 5-year change in refractive error in phakic eyes and its risk factors in the general population.

METHODS

The Gutenberg Health Study (GHS) is a population-based cohort study including 15 010 participants from Germany aged 35-74 years at baseline examination (2007-2012). After 5 years, a follow-up examination was carried out (83% participation). 5-year change of spherical equivalent (SE) was computed as difference between follow-up and baseline objective refraction. Linear and logistic regression analysis were conducted analysing potential risk factors. Only phakic eyes at follow-up examination were included.

RESULTS

Right eyes of 10 175 subjects were included. An age-related shift of refractive error was identified, namely -0.12 D for age 35-44 years, 0.25 D for age 45-54 years, 0.25 D for age 55-64 years and 0.12 D for age 65-74 years during the 5-year follow-up. Smokers had a hyperopic shift (OR=1.31; p<0.001), while baseline SE (OR=0.89 per dioptre; p<0.001) and female sex (OR=1.49; p<0.001) were linked with a myopic shift. Education, occupation and other cardiovascular parameters were not associated with change in refractive error.

CONCLUSIONS

The GHS demonstrates a parabolic shift in refractive error with a myopic shift at age 35-44 years, followed by a hyperopic shift at age 45-64 years which decreases at higher age. Smoking is associated with a hyperopic shift whereas female sex and myopic baseline SE is associated with a myopic shift. Educational level and occupation were not linked to a change in refractive error at age 35-74 years.

Development and validation of a questionnaire-based myopia proxy in adults: the LifeLines Cohort Study

AIMS

To build a questionnaire-based myopia proxy and to validate the proxy by confirming its association with educational attainment and a Polygenic Risk Score (PRS) for myopia.

METHODS

Data were collected between 2014 and 2017 from 88 646 Dutch adults from the LifeLines Cohort. First, we performed principal component analysis (PCA) to responses of five refraction-status questions. Second, we measured the refractive state in a subset of LifeLines participants (n=326) and performed logistic regression using myopia (mean spherical equivalent <-0.5 D) as a dependent variable and the principal components (PCs) as independent variables. We identified specificity, sensitivity and the classification threshold. Third, the classification equation was applied to the remaining LifeLines participants. The value of the proxy was then explored by calculating its association with educational attainment and a PRS of myopia.

RESULTS

A total of 77 096 participants (58.1% women) were eligible for the PCA. The first two PCs had a specificity of 91.9% (95% CI 87.8% to 95.4%) and a sensitivity of 90.4% (95% CI 84.3% to 96.4%) for myopia. The area under the receiver operating characteristic curve was 95.0% (95% CI 92.2% to 97.8%). The age-standardised prevalence of proxy-inferred myopia was 33.8% (95% CI 33.4% to 34.3%). Compared with low education level, the ORs of proxy-inferred myopia were 1.66 (95% CI 1.58 to 1.74, p=5.94×10^-90) and 2.54 (95% CI 2.41 to 2.68, p=4.04×10^-271) for medium and high education levels, respectively. Similarly, individuals at the top 10% of PRS (vs lower 90%) had an OR of 2.18 (95% CI 1.98 to 2.41, p=6.57×10^-56) for proxy-inferred myopia, whereas those at the highest decile had an OR of 4.51 (95% CI 3.9 to 5.21, p=1.74×10^-89) when compared with the lowest decile.

CONCLUSION

Self-administered refractive error-related questions could be used as an effective tool to capture proxy-inferred myopic cases in a population-based setting.

Longitudinal associations of ocular biometric parameters with onset and progression of diabetic retinopathy in Chinese adults with type 2 diabetes mellitus

AIMS

To investigate the associations of ocular biometric parameters with incident diabetic retinopathy (DR), incident vision-threatening DR (VTDR) and DR progression.

METHODS

This community-based prospective cohort study recruited participants with type 2 diabetes aged 35-80 years from 2017 to 2019 in Guangzhou, China. Refractive error and ocular biometric parameters were measured at baseline, including axial length (AL), axial length-to-corneal radius (AL/CR) ratio, corneal curvature (CC), lens thickness (LT), anterior chamber depth (ACD), lens power and corneal diameter (CD).

RESULTS

A total of 1370 participants with a mean age of 64.3±8.1 years were followed up for two consecutive years. During the follow-up period, 342 out of 1195 (28.6%) participants without DR at baseline had incident DR, 15 out of 175 (8.57%) participants with baseline DR had DR progression and 11 of them progressed to VTDR. After multiple adjustments, a longer AL (OR=0.76; 95% CI, 0.66 to 0.86; p<0.001) and a larger AL/CR ratio (OR=0.20; 95% CI, 0.07 to 0.55; p=0.002) were associated with significantly reduced risks of incident DR but were not associated with incident VTDR or DR progression. Refractive status and other ocular biometric parameters investigated, including ACD, CC, CD, lens power and LT were not associated with any of the DR outcomes (all p>0.05).

CONCLUSIONS

A longer AL and a larger AL/CR ratio are protective against incident DR. These parameters may be incorporated into future DR risk prediction models to individualise the frequency of DR screening and prevention measures.

Higher-order aberrations and their association with axial elongation in highly myopic children and adolescents

BACKGROUND

Vision-dependent mechanisms play a role in myopia progression in childhood. Thus, we investigated the distribution of ocular and corneal higher-order aberrations (HOAs) in highly myopic Chinese children and adolescents and the relationship between HOA components and 1-year axial eye growth.

METHODS

Baseline cycloplegic ocular and corneal HOAs, axial length (AL), spherical equivalent (SE), astigmatism and interpupillary distance (IPD) were determined for the right eyes of 458 highly myopic (SE ≤-5.0D) subjects. HOAs were compared among baseline age groups (≤12 years, 13-15 years and 16-18 years). Ninety-nine subjects completed the 1-year follow-up. Linear mixed model analyses were applied to determine the association between HOA components, other known confounding variables (age, gender, SE, astigmatism and IPD) and axial growth. A comparison with data from an early study of moderate myopia were conducted.

RESULTS

Almost all ocular HOAs and few corneal HOAs exhibited significant differences between different age groups (all p<0.05). After 1 year, only ocular HOA components was significantly negative associated with a longer AL, including secondary horizontal comatic aberration (p=0.019), primary spherical aberration (p<0.001) and spherical HOA (p=0.026). Comparing with the moderate myopia data, the association of comatic aberration with AL growth was only found in high myopia.

CONCLUSION

In highly myopic children and adolescents, lower levels of annual ocular secondary horizontal comatic aberration changes, besides spherical aberrations, were associated with axial elongation. This suggests that ocular HOA plays a potential role in refractive development in high myopia.

Progression of myopia in teenagers and adults: a nationwide longitudinal study of a prevalent cohort

BACKGROUND

The prevalence of myopia is increasing worldwide. The purpose of this study was to evaluate the progression of myopia in teenagers and adults in France.

METHODS

This nationwide prospective study followed 630 487 myopic adults and teenagers (mean age 43.4 years±18.2, 59.8% of women) between January 2013 and January 2019. Myopia and high myopia were defined as a spherical equivalent less than or equal to -0.50 and -6.00 diopters (D), respectively. Demographic data were collected at first visit and refractive characteristics were collected at each visit. Analysis of short-term progression (first 12 to 26 months postbaseline) was modelled using analysis of variance (ANOVA). Progression of myopia was stratified according to age, gender and spherical equivalent at first visit.

RESULTS

Higher proportions of progressors were observed in the youngest age groups: 14-15 (18.2 %) and 16-17 years old (13.9 %). In multivariate analysis, after adjustment for over age, spherical equivalent and gender, the mean short-term progression decreased from -0.36 D in the 14-15 years age group to -0.13 D in the 28-29 years age group. Young age and higher myopia at baseline together were strongly associated with the risk of developing high myopia, the 5-year cumulative risk being 76% for youngest teenager with higher myopia status at baseline.

CONCLUSION

In this large cohort of myopic teenagers and adults, myopia progression was reported in 18.2% and 13.9% of the 14-15 and 16-17 age groups, respectively. The risk to develop high myopia was higher for younger individuals with higher myopia at baseline examination.

Universal architecture of corneal segmental tomography biomarkers for artificial intelligence-driven diagnosis of early keratoconus

AIMS

To develop a comprehensive three-dimensional analyses of segmental tomography (placido and optical coherence tomography) using artificial intelligence (AI).

METHODS

Preoperative imaging data (MS-39, CSO, Italy) of refractive surgery patients with stable outcomes and diagnosed with asymmetric or bilateral keratoconus (KC) were used. The curvature, wavefront aberrations and thickness distributions were analysed with Zernike polynomials (ZP) and a random forest (RF) AI model. For training and cross-validation, there were groups of healthy (n=527), very asymmetric ectasia (VAE; n=144) and KC (n=454). The VAE eyes were the fellow eyes of KC patients but no further manual segregation of these eyes into subclinical or forme-fruste was performed.

RESULTS

The AI achieved an excellent area under the curve (0.994), accuracy (95.6%), recall (98.5%) and precision (92.7%) for the healthy eyes. For the KC eyes, the same were 0.997, 99.1%, 98.7% and 99.1%, respectively. For the VAE eyes, the same were 0.976, 95.5%, 71.5% and 91.2%, respectively. Interestingly, the AI reclassified 36 (subclinical) of the VAE eyes as healthy though these eyes were distinct from healthy eyes. Most of the remaining VAE (n=104; forme fruste) eyes retained their classification, and were distinct from both KC and healthy eyes. Further, the posterior surface features were not among the highest ranked variables by the AI model.

CONCLUSIONS

A universal architecture of combining segmental tomography with ZP and AI was developed. It achieved an excellent classification of healthy and KC eyes. The AI efficiently classified the VAE eyes as 'subclinical' and 'forme-fruste'.

Birth weight and refractive state measured by Spot Vision Screener in children aged 40 months

Objectives

Children with retinopathy of prematurity (ROP) often have myopia. Even without ROP, birth weight and refractive state are related immediately after birth, but this relationship is reduced with increasing age. Here, we examined whether refractive state and birth weight were associated in 40-month-old children.

Methods and analysis

Of 541 children aged 40 months in Tsubame City, Japan, who underwent a medical examination between April 2018 and March 2019, this cross-sectional study enrolled 411 whose birth weights were available (76% of all).We measured the non-cycloplegic refraction using a Spot Vision Screener and correlated this with birth weight. Children were divided into three groups according to normal (2500-3500 g), high (>3500 g) or low (<2500 g) birth weights, and mean differences in spherical equivalent (SE) between the groups were analysed.

Results

The average SE for the right eye was 0.34 D (95% CI 0.28 to 0.40). Average birth weight was 3032.1 g (95% CI 2990.2 to 3073.9). Birth weight did not correlate with SE for the right eye (Pearson's correlation, r=-0.015, p=0.765) or with the degree of anisometropia (Pearson's correlation, r=-0.05, p=0.355). Furthermore, the mean SE showed no significant difference across the three groups of children with different birth weights (one-way analysis of variance, p=0.939).

Conclusion

Data on refractive states and birth weight for 411 children of similar age in one Japanese city were analysed, showing that birth weight did not influence SE, J0, J45 and the absolute degree of anisometropia at about 40 months of age.

MRI-based 3D retinal shape determination

Objective

To establish a good method to determine the retinal shape from MRI using three-dimensional (3D) ellipsoids as well as evaluate its reproducibility.

Methods and analysis

The left eyes of 31 volunteers were imaged using high-resolution ocular MRI. The 3D MR-images were segmented and ellipsoids were fitted to the resulting contours. The dependency of the resulting ellipsoid parameters on the evaluated fraction of the retinal contour was assessed by fitting ellipsoids to 41 different fractions. Furthermore, the reproducibility of the complete procedure was evaluated in four subjects. Finally, a comparison with conventional two-dimensional (2D) methods was made.

Results

The mean distance between the fitted ellipsoids and the segmented retinal contour was 0.03±0.01 mm (mean±SD) for the central retina and 0.13±0.03 mm for the peripheral retina. For the central retina, the resulting ellipsoid radii were 12.9±0.9, 13.7±1.5 and 12.2±1.2 mm along the horizontal, vertical and central axes. For the peripheral retina, these radii decreased to 11.9±0.6, 11.6±0.4 and 10.4±0.7 mm, which was accompanied by a mean 1.8 mm posterior shift of the ellipsoid centre. The reproducibility of the ellipsoid fitting was 0.3±1.2 mm for the central retina and 0.0±0.1 mm for the peripheral retina. When 2D methods were used to fit the peripheral retina, the fitted radii differed a mean 0.1±0.1 mm from the 3D method.

Conclusion

An accurate and reproducible determination of the 3D retinal shape based on MRI is provided together with 2D alternatives, enabling wider use of this method in the field of ophthalmology.

The FASD Eye Code: a complementary diagnostic tool in fetal alcohol spectrum disorders

Objective

To create an easy-to-use complementary ophthalmological tool to support a fetal alcohol spectrum disorder (FASD) diagnosis.

Methods and Analysis

The FASD Eye Code was derived from 37 children with FASD evaluated along with 65 healthy age-matched and sex-matched controls. Four ophthalmological categories, which are abnormalities commonly found in children with FASD, were ranked independently on a 4-point scale, with 1 reflecting normal finding and 4 a strong presence of an abnormality: visual acuity, refraction, strabismus/binocular function and ocular structural abnormalities. The tool was validated on 33 children with attention deficit/hyperactivity disorder (ADHD), 57 children born moderate-to-late premature (MLP) and 16 children with Silver-Russell syndrome (SRS). Among children with ADHD none was born prematurely or small for gestational age (SGA) or diagnosed with FASD. Among children born MLP none was SGA, had a diagnosis of ADHD or FASD, or a history of retinopathy of prematurity. Children with SRS were all born SGA, half were born preterm and none had FASD. Children with FASD were re-examined as young adults.

Results

An FASD Eye Code cut-off total score of ≥10 showed an area under the curve (AUC) of 0.78 (95% CI 0.69 to 0.87), with 94% specificity and 43% sensitivity, in discriminating between FASD and controls, MLP and ADHD, corresponding to a positive likelihood ratio (LR+) of 7.5. Between FASD and controls, an AUC of 0.87 (CI 0.80 to 0.95), with 100% specificity and 43% sensitivity, was found; between FASD and SRS, an AUC of 0.60 (CI 0.45 to 0.75) was found, with 88% specificity and 43% sensitivity. A cut-off score of≥9 showed a specificity of 98% and a sensitivity of 57% for FASD versus controls, corresponding to an LR+ of 36.9. Scores in individuals with FASD were stable into young adulthood.

Conclusion

The FASD Eye Code has the potential to serve as a complementary tool and help to strengthen an FASD diagnosis.

Genotype-phenotype correlation and interaction of 4q25, 15q14 and MIPEP variants with myopia in southern Chinese population

BACKGROUND/AIMS

To determine the association and interaction of genome-wide association study-reported variants for Asian populations with myopia and ocular biometric parameters in southern Chinese population.

METHODS

Totally, 1462 unrelated Han Chinese subjects were recruited with complete ophthalmic examinations, including 1196 myopia and 266 control subjects. A total of nine variants were selected for TaqMan genotyping. The genetic association, joint additive effect and genotype-phenotype correlation were investigated.

RESULTS

The 4q25 variant rs10034228 (p=0.002, OR=0.56) and MIPEP variant rs9318086 (p=0.004, OR=1.62) were found to be significantly associated with myopia as well as different severity of myopia. Moreover, 15q14 variant rs524952 (p=0.015, OR=1.49) also showed mild association with myopia and high myopia. However, there was no significant association of CTNND2, vasoactive intestinal peptide receptor 2 and syntrophin beta 1 variants with myopia. Joint additive analysis revealed that the subjects carrying 6 risk alleles of the 3 associated variants were 10-fold higher risk predisposed to high myopia. Genotype-phenotype correlation analysis revealed that high myopia subjects carrying 4q25 rs10034228 T allele showed thicker central corneal thickness, whereas high myopia subjects carrying 15q14 rs524952 A allele were associated with longer axial length and larger curvature ratio.

CONCLUSION

This study revealed significant association of 4q25, 15q14 and MIPEP variants with myopia and different severity of myopia in southern Chinese population, joint additively enhancing 10-fold of risk predisposing to high myopia. The correlation of these associated variants with axial length and corneal parameters suggests their contribution to the refractive status in high myopia subjects.

Ophthalmological findings in children with non-syndromic craniosynostosis: preoperatively and postoperatively up to 12 months after surgery

Aims

Craniosynostosis is a congenital condition characterised by premature fusion of one or more cranial sutures. The aim of this study was to analyse ophthalmic function before and after cranial surgery, in children with various types of non-syndromic craniosynostosis.

Methods

Children referred to Uppsala University Hospital for surgery of non-syndromic craniosynostosis were examined preoperatively. Visual acuity was measured with Preferential Looking tests or observation of fixation and following. Strabismus and eye motility were noted. Refraction was measured in cycloplegia and funduscopy was performed. Follow-up examinations were performed 6–12 months postoperatively at the children’s local hospitals.

Results

One hundred twenty-two children with mean age 6.2 months were examined preoperatively. Refractive values were similar between the different subtypes of craniosynostosis, except for astigmatism anisometropia which was more common in unicoronal craniosynostosis. Strabismus was found in seven children, of which four had unicoronal craniosynostosis.

Postoperatively, 113 children were examined, at mean age 15.9 months. The refractive values decreased, except for astigmatism and anisometropia in unicoronal craniosynostosis. Strabismus remained in unicoronal craniosynostosis. Two new cases with strabismus developed in unicoronal craniosynostosis and one in metopic, all operated with fronto-orbital techniques. No child had disc oedema or pale discs preoperatively or postoperatively.

Conclusion

Ophthalmic dysfunctions were not frequent in children with sagittal craniosynostosis and preoperative ophthalmological evaluation may not be imperative. Children with unicoronal craniosynostosis had the highest prevalence of strabismus and anisometropia. Fronto-orbital techniques used to address skull deformity may be related to a higher prevalence of strabismus postoperatively.

Association of polymorphisms in ZFHX1B, KCNQ5 and GJD2 with myopia progression and polygenic risk prediction in children

AIMS

To assess the association of single-nucleotide polymorphisms (SNPs) with myopia progression for polygenic risk prediction in children.

METHODS

Six SNPs (ZC3H11B rs4373767, ZFHX1B rs13382811, KCNQ5 rs7744813, MET rs2073560, SNTB1 rs7839488 and GJD2 rs524952) were analysed in 1043 school children, who completed 3-year follow-up, using TaqMan genotyping assays. SNP associations with progression in spherical equivalent (SE) were analysed by logistic regression. Polygenic risk scores (PRS) were applied for computing the sum of the risk alleles of multiple SNPs corresponding to myopia progression, weighted by the effect sizes of corresponding SNPs.

RESULTS

GJD2 rs524952 showed significant association with fast progression (OR=1.32, 95% CI 1.10 to 1.59; p=0.003) and KCNQ5 rs7744813 had nominal association (OR=1.32, 95% CI 1.04 to 1.67; p=0.02). In quantitative traits locus analysis, GJD2 rs524952 and KCNQ5 rs7744813 were associated with progression in SE (β=-0.038 D/year, p=0.008 and β=-0.042 D/year, p=0.02) and axial elongation (β=0.016 mm/year, p=0.01 and β=0.017 mm/year, p=0.027). ZFHX1B rs13382811 also showed nominal association with faster progression in SE (β=-0.041 D/year, p=0.02). PRS analysis showed that children with the highest PRS defined by rs13382811, rs7744813 and rs524952 had a 2.26-fold of increased risk of fast myopia progression (p=4.61×10^-5). PRS was also significantly associated with SE progression (R²=1.6%, p=3.15×10^-5) and axial elongation (R²=1.2%, p=2.6×10^-4).

CONCLUSIONS

In this study, multi-tiered evidence suggested SNPs in ZFHX1B, KCNQ5 and GJD2 as risk factors for myopia progression in children. Additional attention and appropriate interventions should be given for myopic children with high-risk PRS as defined by GJD2 rs524952, KCNQ5 rs7744813 and ZFHX1B rs13382811.

One-year myopia control efficacy of spectacle lenses with aspherical lenslets

Aims

To evaluate the 1-year efficacy of two new myopia control spectacle lenses with lenslets of different asphericity.

Methods

One hundred seventy schoolchildren aged 8–13 years with myopia of −0.75 D to −4.75 D were randomised to receive spectacle lenses with highly aspherical lenslets (HAL), spectacle lenses with slightly aspherical lenslets (SAL), or single-vision spectacle lenses (SVL). Cycloplegic autorefraction (spherical equivalent refraction (SER)), axial length (AL) and best-corrected visual acuity (BCVA) were measured at baseline and 6-month intervals. Adaptation and compliance questionnaires were administered during all visits.

Results

After 1 year, the mean changes in the SER (±SE) and AL (±SE) in the SVL group were −0.81±0.06 D and 0.36±0.02 mm. Compared with SVL, the myopia control efficacy measured using SER was 67% (difference of 0.53 D) for HAL and 41% (difference of 0.33 D) for SAL, and the efficacy measured using AL was 64% (difference of 0.23 mm) for HAL and 31% (difference of 0.11 mm) for SAL (all p<0.01). HAL resulted in significantly greater myopia control than SAL for SER (difference of 0.21 D, p<0.001) and AL (difference of 0.12 mm, p<0.001). The mean BCVA (−0.01±0.1 logMAR, p=0.22) and mean daily wearing time (13.2±2.6 hours, p=0.26) were similar among the three groups. All groups adapted to their lenses with no reported adverse events, complaints or discomfort.

Conclusions

Spectacle lenses with aspherical lenslets effectively slow myopia progression and axial elongation compared with SVL. Myopia control efficacy increased with lenslet asphericity.

Trial registration number

ChiCTR1800017683.

Parents' willingness to pay for children's spectacles in Cambodia

Background/aim

To determine willingness to pay for children's spectacles, and barriers to purchasing children's spectacles in Cambodia.

Methods

We conducted vision screenings, and eye examinations as indicated, for all consenting children at 21 randomly selected secondary schools. We invited parents/guardians of children found to have refractive problems to complete a willingness to pay for spectacles survey, using a binary-with-follow-up technique.

Results

We conducted vision screenings on 12 128 secondary schoolchildren, and willingness to pay for spectacles surveys with 491 parents/guardians (n=491) from Kandal and Phnom Penh provinces in Cambodia. We found 519 children with refractive error, 7 who had pre-existing spectacles and 14 recommended spectacles for lower ametropias. About half (53.2%; 95% CI 44.0% to 62.1%) of parents/guardians were willing to pay KHR70 000 (US$17.5; average market price) or more for spectacles. Mean willingness-to-pay price was KHR74 595 (US$18.6; 95% CI KHR64 505 to 86 262; 95% CI US$16.1 to US$21.6) in Phnom Penh and KHR55 651 (US$13.9; 95% CI KHR48 021 to 64 494; 95% CI US$12.0 to US$16.1) in Kandal province. Logistic regression suggested parents/guardians with college education (OR 6.8; p<0.001), higher household incomes (OR 8.0; p=0.006) and those wearing spectacles (OR 2.2; p=0.01) were more likely to be willing to pay ≥US$17.5. The most common reasons for being unwilling to pay US$17.5 were related to cost (58.8%). The most common barrier to spectacle wear was fear that spectacles weaken children's eyes (36.0%).

Conclusions

With almost half of parents/guardians unwilling to pay for spectacles at the current average market price, financial support through a subsidised spectacle scheme might be required for children to access spectacles in Cambodia.

Analysis of opacification patterns in intraocular lenses (IOL)

Objective

Intraocular lens (IOL) opacification may cause severe visual impairment. The pathogenesis remains unclear. The aim of this study was to analyse opacification patterns in different IOLs. Therefore, this multicentre, retrospective, observational study was conducted at Ludwig-Maximilians-University, Munich, Germany and University-Hospital Basel, Switzerland.

Methods and analysis

In this study, 75 opacified IOLs were identified and classified after extraction. Macroscopical photo documentation, light and electron microscopic analysis were done.

Results

68 acrylic-hydrophilic single-piece-IOLs, 1 acrylic-hydrophilic 3-piece-IOL, 6 acrylic-hydrophobic 3-piece-IOLs were extracted. The dataset comprised IOLs known for opacification and IOLs not having been reported yet. 67 IOLs showed a fine-granular and 8 IOLs a crust-like opacification pattern. According to literature, 62 of the fine-granular opacified IOLs were graded into type 1 (processing/packaging-induced primary opacification) and 13 into type 2 (secondary opacification of unknown aetiology). The anterior surface of the IOLs was affected in all 75 IOLs, the posterior surface only in 23 cases. Of all 67 fine-granular IOLs, 43 had a central defect and 21 had a zone without opacification (clear islet).

Conclusion

In our series, the morphology of IOL opacification did not follow the existing pathogenetic classification that strictly discriminates between primary and secondary causes. Fine-granular IOL opacification occurs with similar patterns in both type 1 and type 2 IOL opacification, while a crust-like pattern was only detected in type 2 IOL opacifications. Consequently, susceptibility of an IOL to opacification is caused by a multifactorial combination of material and processing properties as well as individual (pathological) conditions of the patient.

Development of the retina and its relation with myopic shift varies from childhood to adolescence

Aims

To elucidate the influence of age and myopic shift on retinal development.

Methods

This 1-year longitudinal study included 769 participants aged 6–17 years. Cycloplegic refraction, axial length and swept-source optical coherence tomography were examined at baseline and follow-up. The thickness changes in the retina, ganglion cell complex (GCC) and outer retinal layers (ORL) in the macular region were calculated, and their relation with age and myopic shift was analysed with multiple linear regression analysis.

Results

The thickness of the central foveal retinal layers was increased in children (<10 years) but unchanged or decreased in adolescents (>13 years). The thickness changes in the retina, GCC and ORL decreased with age (r=−0.24,–0.23, −0.15, respectively, all p<0.01). Multiple regression analysis showed that the changes in central foveal retinal thickness (RT) and GCC thickness were independently associated with age and baseline spherical equivalent (SE), while the changes in ORL thickness were associated with age and SE changes. In children 8–9 years, a greater increase was observed in central foveal ORL thickness in those with no myopic shift (p<0.01). The thickness of the most parafoveal and perifoveal retinal layers was less increased or more decreased in children <9 years with myopic shift (p<0.05).

Conclusions

Retinal development and its relation with myopic shift varies from childhood to adolescence. Myopia-related retinal thinning may result from less increase in the RT in childhood rather than a decrease in RT in adolescents. Children under 9 years old could be at a critical age for future myopia-related retinal thinning.

Project hyperopic power prediction: accuracy of 13 different concepts for intraocular lens calculation in short eyes

PURPOSE

To evaluate the accuracy of intraocular lens (IOL) power calculation in a patient cohort with short axial eye length to assess the performance of IOL power calculation schemes in strong hyperopes.

METHODOLOGY

The study was a single centre, single surgeon retrospective consecutive case series at the Augen- und Laserklinik, Castrop-Rauxel, Germany. Inclusion of patients after uneventful cataract surgery implanting either spherical (SA60AT) or aspheric (ZCB00) IOLs. Inclusion criteria were axial eye length <21.5 mm and/or emmetropising IOL power >28.5 D. Lens constants were optimised on a separate patient cohort considering the full bandwidth of axial eye length. Data of one single eye per patient were randomly included. The outcome measures were: mean absolute prediction error (MAE), median absolute prediction error, mean prediction error with SD and median prediction error and the percentage of eyes with an MAE within 0.25 D, 0.5 D, 0.75 D and 1.0 D.

RESULTS

A total of 150 eyes from 150 patients were assessed. Okulix, PEARL-DGS, Kane and Castrop provided a statistically significantly smaller MAE compared with the Hoffer Q and SRK/T formulae.

CONCLUSION

In our patient cohort with short axial eye length, the use of PEARL-DGS, Okulix, Kane or Castrop formulae showed the lowest MAE. The Castrop formula has not been published before, but will be disclosed with a ready-to-use Excel sheet as an addendum to this paper.

Refractive change and incidence of myopia among rural Chinese children: the Handan Offspring Myopia Study

PURPOSE

To assess the refractive change and incidence of myopia, as well as their risk factors, among Chinese rural children aged 6-17 years.

METHODS

Children who completed the baseline vision examination of the Handan Offspring Myopia Study were re-examined, including both cycloplegic and non-cyloplegic autorefraction, with a mean follow-up time of 42.4±1.47 months.

RESULTS

A total of 601 children (68.5%) who completed both baseline and the follow-up examinations were enrolled. The cumulative refractive change and axial length change were -0.53±1.03 diopter and 0.39±0.46 mm (-0.15 diopter/year and 0.11 mm/year), respectively. A hundred and five out of the 469 non-myopic children at baseline become myopic at the follow-up, yielding a cumulative myopia incidence of 22.4% (95% CI: 18.6% to 26.2%), or annual myopia incidence of 6.3%. After adjustment, younger age (β=0.08, p<0.001), more myopic baseline refraction (β=0.31, p<0.001), larger difference between cycloplegic and non-cycloplegic refraction (β=-0.20, p=0.007) and more myopic paternal refraction (β=0.09, p=0.007) were found to be associated with more rapid myopic refractive change. More myopic baseline refraction (relative risk (RR), 95% CI: 0.19, 0.13-0.28, p<0.001) and more myopic paternal refraction (RR, 95% CI: 0.92, 0.84-1.00, p=0.039) were also associated with myopia incidence.

CONCLUSION

Relatively low myopic refractive change and myopia incidence were found in this study cohort. Children's refraction and paternal refraction were associated with both myopic refractive change and myopia incidence. Such information will be helpful for further comparisons in other rural versus urban areas of China, and other countries.

Refractive accuracy in eyes undergoing combined cataract extraction and Descemet membrane endothelial keratoplasty

PURPOSE

To evaluate the refractive accuracy of current intraocular lens (IOL) formulas and propose a modification in calculation of corneal power in eyes undergoing combined cataract extraction and Descemet membrane endothelial keratoplasty (DMEK).

DESIGN

Retrospective cohort study.

METHODS

Patients with Fuchs endothelial corneal dystrophy undergoing uncomplicated combined cataract surgery and DMEK at a single institution were included. The Hoffer Q, SRK/T, Holladay I, Barrett Universal II and Haigis formulas were compared. A modified corneal power was calculated using a thick lens equation based on anterior and posterior corneal radii and corneal thickness from Pentacam imaging. Error calculations were adjusted based on the difference in optical biometry and the modified corneal power. Mean absolute error (MAE) for each formula was compared between the corneal power modification and optical biometry corneal power.

RESULTS

In 86 eyes, the mean error ranged from 0.90 D for the Barrett Universal II formula to -0.10 D for the Haigis formula, with 4 of 5 formulas resulting in a mean hyperopic error. The corneal power modification resulted in a significantly lower MAE for the Hoffer Q (0.82 D), Holladay I (0.85 D), SRK/T (0.85 D) and Barrett Universal II (0.90 D) formulas compared with optical biometry corneal power for the Hoffer Q (1.02 D; p<0.005), Holladay I (0.97 D; p<0.005), SRK/T (0.93 D; p<0.01) and Barrett Universal II (1.16 D; p<0.005) formulas.

CONCLUSIONS

All formulas except the Haigis formula resulted in a hyperopic error. The corneal power modification significantly reduced error in four out of five IOL formulas.

Influence of age on small incision lenticule extraction outcomes

PURPOSE

To evaluate the influence of patient's age at the time of surgery on small incision lenticule extraction (SMILE) refractive outcomes.

METHODS

This is a retrospective, consecutive, comparative study. We compared the refractive outcomes after myopic SMILE from two groups of patients divided by age (patients ≤35 and ≥40 years old). All eyes were evaluated preoperatively and at 1 and 6 months postoperatively. Main outcome measures were differences on efficacy, safety, predictability and astigmatic changes by vector analysis with ASSORT software between both study groups.

RESULTS

102 matched eyes of 53 patients were included. Preoperatively, we evidenced no differences in the mean SE or astigmatism between groups. However, 6 months postoperatively we observed a significantly worse mean astigmatism (p=0.019), while not regarding SE, in the older population, with a trend towards undercorrection of the refractive cylinder in the ≥40 group. We also observed a statistically significant difference in the efficacy (0.86-1 month and 0.97-6 months in ≥40group vs 0.97-1 month and 1.07-6 months in the ≤35 group; p=0.003) and safety indexes (0.93-1 month and 1.04-6 months in ≥40 group vs 1.0-1 month and 1.11-6 months in the ≤35 group; p=0.008) at 6 months among groups.

CONCLUSIONS

Post-SMILE refractive outcomes in those patients over 40 years of age, although acceptable, are not as good as those obtained in younger patients, showing a significantly lower efficacy and safety indexes, and poorer astigmatic outcomes, with a tendency towards undercorrection. We hypothetise that the increased corneal stroma stiffness in the aged group modifies the post-SMILE corneal stroma remodelling capacity, thus affecting the SMILE refractive and visual response.

Comparative analysis of objective and subjective outcomes of two different intraocular lenses: trifocal and extended range of vision

Objective

To evaluate objective and subjective outcomes after bilateral implantation of two different multifocal intraocular lenses, which correct pseudophakic presbyopia in an adequate and homogeneous population court.

Methods and analysis

Fifty patients were evaluated at 3 months after bilateral implantation, at the Eye Clinic of University of Verona and at the Carones Ophthalmology Center Milano, as follows: Tecnis Symfony (25 patients), Alcon PanOptix (25 patients). Main outcomes were uncorrected and best-corrected distance visual acuity (UDVA and BCVA) at 4 m, 60 cm (best distance corrected intermediate visual acuity (BDCIVA) and uncorrected intermediate visual acuity), 40 cm (best distance corrected near visual acuity (BDCNVA) and uncorrected near visual acuity (UNVA)), objective refractive outcome, defocus curve, contrast sensitivity (Modulation Transfer Function (MTF) cut-off), optical quality (Strehl ratio), aberrometry (root mean square RMS 4 mm), subjective quality of life (National Eye Institute Refractive Error Quality of Life score (NEI-RQL-42 score) test).

Results

Symfony and PanOptix showed BCVA and UDVA comparable results. Symfony presented significant better outcomes at BDCIVA (p=0.001), while PanOptix showed better performances at BDCNVA and UNVA (p=0.01). Symfony achieved better results in RMS 4 mm (p=0.024) and in MTF cut-off (p=0.041). In the questionnaire NEI-RQL-42, PanOptix presented better scores in 'near vision' and 'spectacles independence', whereas Symfony in 'symptoms' and 'clarity of vision'.

Conclusion

Both intraocular lenses are valid options to avoid pseudophakic presbyopia, even though they present different features which make them unique. Symfony allows patients to achieve a better objective and subjective quality of vision and contrast sensitivity; PanOptix provides better outcomes in near vision and spectacles independence requirements.

Myopia in school-aged children with preterm birth: the roles of time spent outdoors and serum vitamin D

AIMS

To analyse the factors associated with myopia in school-aged children with preterm birth and with or without retinopathy of prematurity (ROP).

METHODS

Children born prematurely between January 2010 and December 2011 were enrolled in this cross-sectional study when they reached school age between April 2017 and June 2018 in a referral centre. The main parameters were cycloplegic refraction, time spent outdoors and serum 25-hydroxyvitamin D (25(OH)D) concentration.

RESULTS

A total of 99 eyes from 99 children with a mean age of 6.8 years underwent analysis. The average time spent outdoors was significantly higher in the non-myopic group (0.9 ± 0.5 hours/day) than in the myopic group (0.7 ± 0.3 hours/day) (p = 0.032). After adjustment for age, sex, number of myopic parents, ROP severity, near-work time and serum 25(OH)D concentration, more time spent outdoors was correlated with a lower odds of myopia (OR, 0.13 per additional hour per day; 95% CI, 0.02-0.98; p = 0.048). Mean serum 25(OH)D concentrations were similar between the myopic and non-myopic groups (49.7 ± 13.6 and 48.8 ± 14.0 nmol/mL; p = 0.806) and were not correlated with spherical equivalence power (r = -0.09; p = 0.418). Vitamin D insufficiency was present in 57% of the participants.

CONCLUSIONS

Among preterm children with or without ROP, more time spent outdoors was associated with lower odds of myopia. The serum 25(OH)D concentration was not associated with myopia, but a high proportion of the participants had insufficient levels.

Four-year observation of the changes in corneal endothelium cell density and correlated factors after Implantable Collamer Lens V4c implantation

Background

To evaluate the changes in corneal endothelium cell density (ECD) and the correlated factors after Implantable Collamer Lens (ICL) V4c implantation.

Methods

In this retrospective, consecutive study, 48 eyes of 25 patients with myopia who underwent ICL V4c implantation were enrolled. Patients were followed up for at least 4 years, during which manifest refraction, uncorrected distance visual acuity, corrected distance visual acuity (CDVA), intraocular pressure, ECD, anterior chamber depth, anterior chamber volume (ACV), anterior chamber angle (ACA), vault and distance from the corneal endothelium to the central ICL (C-ICL) were measured. Spearman’s correlation analysis was used to identify variables correlated with changes in ECD, and generalised estimating equation model adjusting within-patient intereye correlations was used to predict changes in ECD.

Results

All surgeries were performed safely with no complications during follow-up (average 52±2.9 months). Safety and efficacy indices were 1.23±0.22 and 1.04±0.16, respectively. No eyes had decreased CDVA, and 67% gained one or more lines. Further, 79% were within ±0.50 D, and 100% were within ±1.0 D of the attempted refraction. Additionally, a 4.03%±2.2% reduction in ECD compared with the preoperative value was observed at the last follow-up visit. Changes in ECD were significantly correlated with vault, C-ICL, change in ACA and change in ACV. Vault was the most significant factor for changes in ECD.

Conclusions

ICL V4c implantation is safe and effective for myopia correction. Anterior segment biometric parameters including the vault, ACA and C-ICL may influence changes in ECD; specifically, the vault plays a major role.

Orthokeratology with increased compression factor (OKIC): study design and preliminary results

OBJECTIVE

To present the study design and the baseline data of a prospective cohort study investigating the safety, refractive correction and effectiveness of myopia control in subjects fitted with orthokeratology (ortho-k) lenses of different compression factors.

METHODS AND ANALYSIS

This study is a 2-year longitudinal, double-masked, partially randomised study. Myopic children aged between 6 and 10 years are recruited and they may choose to participate in either the ortho-k or spectacle-wearing group. Subjects in the ortho-k group are randomly assigned to wear ortho-k lenses of either conventional compression factor (CCF, 0.75 D) or increased compression factor (ICF, 1.75 D). For the ortho-k subjects, the time and between-group effects within the first month of lens wear were analysed.

RESULTS

Sixty-nine ortho-k subjects (CCF: 34; ICF: 35) and 30 control subjects were recruited. There were no significant differences in baseline demographic data among the three groups of subjects (p>0.19). At the 1-month visit, the first fit success rates were 97% and 100% in the CCF and ICF ortho-k group, respectively. A higher percentage of ICF subjects could achieve full correction (CCF: 88.2%; ICF: 94.3%). The change in axial length was significantly higher in the ICF group (CCF, 0.003 mm; ICF, -0.031 mm) (p<0.05). No significant between-group differences in daytime vision or in the coverage and depth of corneal staining between the two ortho-k groups (p>0.05) were observed at any visit.

CONCLUSION

ICF did not compromise the corneal integrity and the lens centration within the first month of lens wear. The preliminary performance of ortho-k lenses with ICF of 1.00D shows that it was safe to be used in the longer term for the investigation of myopia control.

TRIAL REGISTRATION NUMBER

NCT02643342.

Puberty could regulate the effects of outdoor time on refractive development in Chinese children and adolescents

Aim

To explore the impact of puberty on refractive development and its interaction with outdoor time in children and adolescents.

Methods

In this 2-year observational study, students aged 7–13 years were selected with cluster sampling. All participants underwent cycloplegic refraction and axial length measurements once every year. Information of related factors was acquired through proper questionnaire or inquiry. The level of testosterone/estradiol was detected from the saliva of the subjects using the ELISA kit. Multiple linear regression and generalised estimating equation (GEE) were used to analyse the relationship among puberty, outdoor activities and refractive indicators.

Results

A total of 776 children and adolescents were included, with an average baseline age of 9.64±1.54 years and 53.6% boys. There were 350 myopes (55.2% of the 634 cyclopleged subjects) at baseline. There was a significant difference in the mean axial length changes and outdoor time among different puberty groups (for axial length: p=0.017, for outdoor time: p=0.015). Myopic parents, less outdoor time and more changes in estradiol were associated with greater changes in axial length and spherical equivalent (SE) (axial length changes: parental myopia β=0.230, outdoor time β=−0.250, changes in estradiol β=0.261; SE changes: parental myopia β=−0.267, outdoor time β=0.256, changes in estradiol β=−0.297). In the GEE model, the interaction between outdoor time and puberty was significantly associated with axial length (p=0.024, β=1.199).

Conclusions

This study implies puberty may play a regulating role on the relationship between outdoor time and refractive development among Chinese children and adolescents, which provides clues for in-depth mechanism interpretation and efficient intervention strategies.

Four-year outcomes of small incision lenticule extraction (SMILE) to correct high myopic astigmatism

AIMS

To evaluate the long-term outcomes of small incision lenticule extraction (SMILE) in subjects with myopic astigmatism of ≥2.00 dioptres (D).

METHODS

Patients who underwent SMILE 4 years prior with astigmatism ≥2.00 D and ≤1.00 D were assigned to the high astigmatic group (HA group) or the low astigmatic group (LA group), respectively. The visual and refractive results as well as corneal wavefront aberrations were measured.

RESULTS

The preoperative cylinder was -2.47±0.54 D in 43 eyes in the HA group and -0.55±0.28 D in 31 eyes in the LA group. At 4 years, the residual cylinder was -0.31±0.29 D in the HA group and -0.20±0.28 D in the LA group (p=0.088). An uncorrected distance visual acuity of 20/20 was achieved in 88.4% of eyes in the HA group and 93.5% of eyes in the LA group. The efficacy index was 0.99±0.14 and 1.10±0.21 (p=0.025), and the safety index was 1.11±0.20 and 1.22±0.21 in the HA and LA groups, respectively (p=0.012). Eighty-six per cent and 90.3% of eyes were within ±0.50 D of the attempted cylindrical correction in the HA and LA groups, respectively. Vector analysis showed that the magnitude of error was -0.14±0.28 D and -0.05±0.16 D (p=0.085), the angle of error was -0.13±4.48 degrees and -2.57±29.42 degrees (p=0.592), the correction index was 0.94±0.13 and 0.94±0.35 (p=0.959), the index of success was 0.15±0.14 and 0.46±0.62 (p=0.517), and the flattening index was 0.93±0.13 and 0.71±0.59 (p=0.450) in the HA and LA groups, respectively.

CONCLUSIONS

This study demonstrates that SMILE is effective and safe for correcting high astigmatism. Vector analysis shows a tendency for the undercorrection of astigmatism in subjects with high astigmatism.

Review: Myopia control strategies recommendations from the 2018 WHO/IAPB/BHVI Meeting on Myopia

Myopia is a major public health problem, particularly in East Asia. In this summary report, we present key findings and recommendations on strategies for myopia control discussed during the meeting jointly organised by the WHO Regional Office for the Western Pacific, the International Agency for the Prevention of Blindness and the Brien Holden Vision Institute. First, myopia prevalence was reported to be increasing, with up to 80% of junior school students with myopia in East Asia. However, common challenges in implementing myopia control strategies on a national level included lack of school screening programme, and paucity of accurate prevalence data. Second, there continues to be broad public misconception about myopia and myopia control, including lack of parental awareness and resistance to wearing spectacles. Third, best practices for myopia management were shared, and recommendations for policy implementation are presented in this review. Key recommendations from this meeting include increased public education to raise parent and teacher awareness; encouragement of increased outdoor time of 2-3 hours per day for schoolchildren-as a practical public health intervention that has been shown to potentially reduce onset and progression of myopia. Governments and non-governmental organisations are encouraged to collaborate, especially education and health ministries to develop national myopia prevention programme. Lastly, it is important to emphasise that the key recommendations, such as increasing outdoor time for schoolchildren, are specific for East Asian nations in the Western Pacific region and may not be entirely applicable for Western nations.

Effect of low-dose atropine on myopia progression, pupil diameter and accommodative amplitude: low-dose atropine and myopia progression

PURPOSE

To evaluate the effects of 0.01% and 0.02% atropine eye drops on myopia progression, pupil diameter and accommodative amplitude in myopic children.

METHODS

A cohort study assessed 400 myopic children divided into three groups: 138 and 142 children were randomised to use either 0.02% or 0.01% atropine eye drops, respectively. They wore single-vision (SV) spectacles, with one drop of atropine eye drop applied to both eyes once nightly. Control children (n=120) only wore SV spectacles. Repeated measurements of spherical equivalent refractive errors (SERs), axial length (AL), pupil diameter and accommodative amplitude were performed at baseline, and 4, 8 and 12 months after treatment.

RESULTS

After 12 months, the SER change was -0.38±0.35D, -0.47±0.45D, -0.70±0.60D and AL change was 0.30±0.21 mm, 0.37±0.22 mm, 0.46±0.35 mm in the 0.02%, 0.01% atropine and control groups, respectively. There were significant differences in the change in AL and SER between three groups (all p<0.001). Between baseline and the 12-month visit, the overall change in accommodative amplitude was 1.50±0.25D, 1.61±0.31D and change in pupil diameter was 0.78±0.42 mm, 0.69±0.39 mm, with 0.02% and 0.01% atropine, respectively. Accommodative amplitude significantly decreased and pupil diameter significantly increased in two atropine groups (all p<0.001). Moreover, there was no statistical difference in the change difference in accommodative amplitude and pupil diameter between two atropine groups (p=0.24, p=0.38), whereas the accommodative amplitude (p=0.45) and pupil diameter (p=0.39) in the control group remained stable.

CONCLUSIONS

0.02% atropine eye drops had a better effect on myopia progression than 0.01% atropine, but 0.02% and 0.01% atropine showed similar effects on pupil diameter and accommodative amplitude after 12 months of treatment.

TRIAL REGISTRATION NUMBER

ChiCTR-IPD-16008844.

Objectively measured near work, outdoor exposure and myopia in children

Aim

To reassess the association between near work, outdoor exposure and myopia in children through an objective approach.

Methods

Eighty-six children (10.13±0.48 years) were asked to wear Clouclip, a newly developed wearable device that is able to measure working distance and eye-level illuminance, for a complete week to obtain information on near work and outdoor exposure. The mean daily Clouclip wearing time was 11.72±1.14 hour. The spherical equivalent refraction was determined by cycloplegic autorefraction.

Results

The myopic children were found to be exposed to light intensities >3000 lux (0.68±0.50 hour vs 1.02±0.53 hour, p=0.012) and >5000 lux (0.42±0.35 hour vs 0.63±0.31 hour, p=0.004) for shorter durations on average each day than the non-myopic children. Additionally, the myopic children spent more time on average each day on activities at a distance of <20 cm than non-myopic children (1.89±0.61 hour vs 1.52±0.77 hour, p=0.019). In the multivariate logistic analysis, the time spent with a higher light intensity (>3000 lux (OR=0.27, 95% CI: 0.10 to 0.72, p=0.009); >5000 lux (OR=0.11, 95% CI: 0.02 to 0.56, p=0.008)) and a working distance of <20 cm (in a circumstance of >3000 lux (OR=1.17, 95% CI: 1.09 to 1.86, p=0.038) or in that of >5000 lux (OR=1.12, 95% CI: 1.03 to 1.77, p=0.046)) were the independent protective factors and risk factors, respectively.

Conclusion

The current study provides novel evidence, based on objective data, to support the association between the intensity of near work, light intensity and myopia. However, the causality and the dose-effect relationship need to be investigated further.

Normative patterns and factors associated with presbyopia progression in a multiethnic Asian population: the Singapore Epidemiology of Eye Diseases Study

BACKGROUND/AIM

To investigate normative patterns and factors associated with presbyopia progression in a multiethnic Asian population.

METHODS

Malay, Indian and Chinese participants aged 40-80 years who had baseline and 6-year follow-up examinations with subjective refraction data were recruited from the Singapore Epidemiology of Eye Diseases Study. Presbyopia progression was defined as an increase in near addition power of ≥+0.50 dioptre (D) from baseline to follow-up visit. Modified Poisson regression analyses were used to determine baseline factors associated with presbyopia progression.

RESULTS

From the eligible 3974 eyes, 2608 eyes were included for final analysis after excluding eyes with a history of cataract surgery (929 eyes) and best-corrected distance visual acuity worse than 20/40 (342 eyes). Overall the mean near addition power change over 6 years was +0.25 D; Malays showed greater change (+0.37 D) compared with Indians (+0.23 D) and Chinese (+0.16 D). After adjusting for baseline age, gender, body mass index, hypertension, cataract, refractive error and daily hours of reading and writing, Malays were more likely to have presbyopia progression compared with Chinese (RR (relative risk)=1.67; 95% CI 1.43 to 1.95; p<0.001) and Indians (RR=1.45; 95% CI 1.25 to 1.68; p<0.001). Individuals aged 60-69 years (RR=0.77; p=0.006) and ≥70 years (RR=0.51; p<0.001) were less likely to progress in presbyopia compared with those aged 40-49.

CONCLUSION

In this Asian population, the near addition power change over 6 years was lower than the current near addition prescription guidelines (+0.25 D vs +0.60 D). Our findings may help update near addition prescription guidelines that can be more tailored to Asians.

Comparison of glistenings formation and their effect on forward light scatter between the Acrysof SN60WF and Eternity Natural Uni NW-60 intraocular lenses

Aims

To compare the characteristics of glistenings and forward light scatter between the Alcon Acrysof SN60WF and Santen Eternity Natural Uni NW-60 intraocular lenses (IOLs).

Methods

Five Acrysof SN60WF and five Eternity Natural Uni NW-60 IOLs were studied. All IOLs were single piece blue blockers with the same dioptric power (20D) and optic diameter (6.0 mm). Glistenings were induced by a thermal accelerated ageing process. Glistenings were objectively quantified using bespoke image processing software. The angular distribution of forward light scatter was measured using an optical bench system and the straylight parameter calculated from the light scatter function.

Results

The median increase in the number of glistenings was 15 and 525 for the Eternity and Acrysof IOLs, respectively, which was statistically significantly different (p=0.012). Median glistenings diameter was 23.8 μm (Acrysof) and 32.8 μm (Eternity). Four (80%) of the Acrysof lenses had straylight values higher than a 20-year-old CIE standard glare observer and in two cases the straylight exceeded that of the 70-year-old CIE standard glare observer. None of the Eternity lenses had straylight values that exceeded the value for the 20-year-old CIE standard glare observer.

Conclusions

The Eternity Natural Uni NW-60 IOLs resisted the induction of glistenings more than the Acrysof SN60WF IOLs. Although the Acrysof IOLs developed smaller glistenings than the Eternity IOLs, there were sufficient numbers to produce a higher straylight parameter.

How does spending time outdoors protect against myopia? A review

Myopia is an increasingly common condition that is associated with significant costs to individuals and society. Moreover, myopia is associated with increased risk of glaucoma, retinal detachment and myopic maculopathy, which in turn can lead to blindness. It is now well established that spending more time outdoors during childhood lowers the risk of developing myopia and may delay progression of myopia. There has been great interest in further exploring this relationship and exploiting it as a public health intervention aimed at preventing myopia in children. However, spending more time outdoors can have detrimental effects, such as increased risk of melanoma, cataract and pterygium. Understanding how spending more time outdoors prevents myopia could advance development of more targeted interventions for myopia. We reviewed the evidence for and against eight facets of spending time outdoors that may protect against myopia: brighter light, reduced peripheral defocus, higher vitamin D levels, differing chromatic spectrum of light, higher physical activity, entrained circadian rhythms, less near work and greater high spatial frequency (SF) energies. There is solid evidence that exposure to brighter light can reduce risk of myopia. Peripheral defocus is able to regulate eye growth but whether spending time outdoors substantially changes peripheral defocus patterns and how this could affect myopia risk is unclear. Spectrum of light, circadian rhythms and SF characteristics are plausible factors, but there is a lack of solid evidence from human studies. Vitamin D, physical activity and near work appear unlikely to mediate the relationship between time spent outdoors and myopia.

Low-dose (0.01%) atropine eye-drops to reduce progression of myopia in children: a multicentre placebo-controlled randomised trial in the UK (CHAMP-UK)-study protocol

BACKGROUND/AIMS

To report the protocol of a trial designed to evaluate the efficacy, safety and mechanism of action of low-dose atropine (0.01%) eye-drops for reducing progression of myopia in UK children.

METHODS

Multicentre, double-masked, superiority, placebo-controlled, randomised trial. We will enrol children aged 6-12 years with myopia of -0.50 dioptres or worse in both eyes.We will recruit 289 participants with an allocation ratio of 2:1 (193 atropine; 96 placebo) from five centres. Participants will instil one drop in each eye every day for 2 years and attend a research centre every 6 months. The vehicle and preservative will be the same in both study arms.The primary outcome is SER of both eyes measured by autorefractor under cycloplegia at 2 years (adjusted for baseline). Secondary outcomes include axial length, best corrected distance visual acuity, near visual acuity, reading speed, pupil diameter, accommodation, adverse event rates and allergic reactions, quality of life (EQ-5D-Y) and tolerability at 2 years. Mechanistic evaluations will include: peripheral axial length, peripheral retinal defocus, anterior chamber depth, iris colour, height and weight, activities questionnaire, ciliary body biometry and chorioretinal thickness. Endpoints from both eyes will be pooled in combined analysis using generalised estimating equations to allow for the correlation between eyes within participant. Three years after cessation of treatment, we will also evaluate refractive error and adverse events.

CONCLUSIONS

The Childhood Atropine for Myopia Progression in the UK study will be the first randomised trial reporting outcomes of low-dose atropine eye-drops for children with myopia in a UK population.

TRIAL REGISTRATION NUMBER

ISRCTN99883695, NCT03690089.

Protective behaviours of near work and time outdoors in myopia prevalence and progression in myopic children: a 2-year prospective population study

AIM

To investigate the protective behaviours of longer near work distance, discontinuing near work and more time outdoors in recess from parent self-report in the myopia prevalence and progression among myopic children aged 9-11 years.

METHODS

Myopia Investigation study in Taipei is a longitudinal population-based study that enrolled elementary school students in Taipei. We provided vision and refraction examination every 6 months. Spherical equivalent (SE) of cycloplegic refraction ≤-0.50 Diopter (D) is defined as myopia. Total 10 743 (70.4%) students completed 2-year refraction data and questionnaire. The myopia prevalence and progression (difference of SE) in baseline, 6, 12, 18 and 24 months were compared by generalised estimating equations.

RESULTS

Children with persistent protective behaviour had significant lower prevalence of myopia. The protective impact was statistically significant from 6 to 24 months. In 2 years follow-up, risk ratio after adjusting the background variables and the other two behaviours in near work distance, near work time and outdoor time were 0.71, 0.89 and 0.77. In SE analysis, after adjusting the other two behaviours, near work distance >30 cm (-0.7 vs -1.04 D; p<0.001), discontinuing near work every 30 min (-0.77 vs -0.96 D, p=0.005) and more time outdoors in recess from parent self-report (-0.75 vs -0.98 D; p=0.012) revealed protective impacts on diminishing myopia progression from 6 to 24 months.

CONCLUSION

In myopic children aged around 10 years in Taipei, longer distance in near work, discontinuing near work every 30 min and more outdoor time from parent self-report are protective behaviours in myopia prevalence and progression in 6-24 months.

Association of the ZC3H11B, ZFHX1B and SNTB1 genes with myopia of different severities

OBJECTIVE

To investigate the associations of single-nucleotide polymorphisms (SNPs) in the ZC3H11B, ZFHX1B, VIPR2, SNTB1 and MIPEP genes with severities of myopia in Chinese populations.

METHODS

Based on previous myopia genome-wide association studies, five SNPs (ZC3H11B rs4373767, ZFHX1B rs13382811, VIPR2 rs2730260, SNTB1 rs7839488 and MIPEP rs9318086) were selected for genotyping in a Chinese cohort of 2079 subjects: 252 extreme myopia, 277 high myopia, 393 moderate myopia, 366 mild myopia and 791 non-myopic controls. Genotyping was performed by TaqMan assays. Allelic frequencies of the SNPs were compared with myopia severities and ophthalmic biometric measurements.

RESULTS

The risk allele T of ZC3H11B SNP rs4373767 was significantly associated with high myopia (OR=1.39, p=0.007) and extreme myopia (OR=1.34, p=0.013) when compared with controls, whereas ZFHX1B rs13382811 (allele T, OR=1.33, p=0.018) and SNTB1 rs7839488 (allele G, OR=1.71, p=8.44E-05) were significantly associated with extreme myopia only. In contrast, there was no significant association of these SNPs with moderate or mild myopia. When compared with mild myopia, subjects carrying T allele of rs4373767 had a risk of progressing to high myopia (spherical equivalent ≤-6 dioptres) (OR=1.29, p=0.017). Similarly, the T allele of rs13382811 also imposed a significant risk to high myopia (OR=1.36, p=0.007). In quantitative traits analysis, SNPs rs4373767, rs13382811 and rs7839488 were correlated with axial length and refractive errors.

CONCLUSIONS

We confirmed ZC3H11B as a susceptibility gene for high and extreme myopia, and ZFHX1B and SNTB for extreme myopia in Chinese populations. Instead of myopia onset, these three genes were more likely to impose risks of progressing to high and extreme myopia.

Binocular game versus part-time patching for treatment of anisometropic amblyopia in Chinese children: a randomised clinical trial

AIMS

To compare amblyopic-eye visual acuity (VA) and binocularity improvement of a binocular game with part-time patching in the treatment of Chinese children with anisometropic amblyopia.

METHODS

103 Chinese children aged 3-13 years with anisometropic amblyopia were recruited in a randomised clinical trial. Eligible participants were randomly assigned to the binocular, patching and combined groups. Primary outcome was amblyopic-eye VA improvement at 3 months. Secondary outcomes included reduction of suppression and change of stereoacuity.

RESULTS

Of 85 completed participants, 44 (52%) were women and mean (SD) age was 5.99 (2.33) years. At 3 months, mean (95% CI) amblyopic-eye VA improved 0.18 (0.10-0.26), 0.28 (0.19-0.36) and 0.30 (0.21-0.39) logarithm of the minimum angle of resolution in the binocular, patching and combined groups, respectively. After adjusting for baseline VA, the difference was statistically significant (F=6.29, p=0.003), favouring as follows: the combined group, the patching group and the binocular group. After treatment, Titmus (x² _binocular=9.75, p=0.007; x² _combined=9.35, p=0.009) and dynamic stereoacuity (x² _binocular=12.56, p=0.01; x² _combined=12.66, p=0.01) improved only in the binocular and combined groups. Among groups, only Titmus improvement differed significantly (F=49.55, p<0.001). Changes of other types of stereoacuity and interocular suppression were similar.

CONCLUSIONS

The binocular game used in this study could improve amblyopic-eye VA and binocularity in Chinese children with anisometropic amblyopia, but it was less effective than patching in amblyopic-eye VA improvement and showed no superiority in binocularity over patching. It remains unclear whether the low treatment response of this binocular game was due to limitations of the study or its low treatment effect.

Quality of eyeglass prescriptions from a low-cost wavefront autorefractor evaluated in rural India: results of a 708-participant field study

Objective

To assess the quality of eyeglass prescriptions provided by an affordable wavefront autorefractor operated by a minimally trained technician in a low-resource setting.

Methods and Analysis

708 participants were recruited from consecutive patients registered for routine eye examinations at Aravind Eye Hospital in Madurai, India, or an affiliated rural satellite vision centre. Visual acuity (VA) and patient preference were compared between trial lenses set to two eyeglass prescriptions from (1) a novel wavefront autorefractor and (2) subjective refraction by an experienced refractionist.

Results

The mean±SD VA was 0.30±0.37, –0.02±0.14 and −0.04±0.11 logarithm of the minimum angle of resolution units before correction, with autorefractor correction and with subjective refraction correction, respectively (all differences p<0.01). Overall, 25% of participants had no preference, 33% preferred eyeglass prescriptions from autorefraction, and 42% preferred eyeglass prescriptions from subjective refraction (p<0.01). Of the 438 patients 40 years old and younger, 96 had no preference and the remainder had no statistically significant difference in preference for subjective refraction prescriptions (51%) versus autorefractor prescriptions (49%) (p=0.52).

Conclusion

Average VAs from autorefractor-prescribed eyeglasses were one letter worse than those from subjective refraction. More than half of all participants either had no preference or preferred eyeglasses prescribed by the autorefractor. This marginal difference in quality may warrant autorefractor-based prescriptions, given the portable form factor, short measurement time, low cost and minimal training required to use the autorefractor evaluated here.

Two-year observation of posterior corneal elevations after small incision lenticule extraction (SMILE) for myopia higher than -10 dioptres

Aim

To investigate the change in posterior corneal elevations (PCEs) of eyes with extremely high myopia 2 years after small incision lenticule extraction (SMILE).

Methods

We evaluated 39 eyes of 39 patients with spherical equivalent higher than −10.00 dioptres (D). Using a Scheimpflug camera (Pentacam), we measured change in PCEs at 1 day, 3 months, 6 months and 2 years after SMILE. Another 34 eyes of 34 patients who underwent femtosecond laser-assisted in situ keratomileusis (FS-LASIK) were examined before, at 1 day and long-term after surgery as the control group. For each eye, elevations at central, thinnest, maximal points and 24 other predetermined points were measured.

Results

No significant forward displacements of PCEs were observed in both surgeries. The maximal but not significant forward displacement occurred around 3–6 months following SMILE, and all returned to original levels 6 months postoperatively except superior area. The peripheral area tended to displace backward, while the central area tended forwardly. In both procedures, elevations along horizontal meridians, inferior and temporal hemispheres were significantly higher than those along vertical meridians, superior and nasal hemispheres, respectively (p<0.05). Elevation on the 4 mm, 6 mm diameters at 1 day and on the 6 mm diameter and temporal hemisphere at long-term follow-up postoperatively were significantly higher in FS-LASIK than SMILE (p<0.05). Change in elevations on the 6 mm diameter circle correlated with residual bed thickness (p=0.047).

Conclusions

SMILE is a safe way to correct for myopia higher than −10 D, with PCEs remaining stable 2 years after surgery.