Association between Axial Length and Myopic Maculopathy

Novel loci for ocular axial length identified through extreme-phenotype genome-wide association study in Chinese populations

PURPOSE

To investigate genetic loci associated with ocular axial length (AL) in the Chinese population.

METHODS

A genome-wide association study meta-analysis was conducted in totalling 2644 Chinese individuals from 3 cohorts: the Guangzhou cohort (GZ, 537 high myopes and 151 hyperopes), Wenzhou cohort (334 high myopes and 6 hyperopes) and Guangzhou Twin Eye Study (1051 participants with normally distributed AL). Functional mapping was performed to annotate the significant signals, possible tissues and cell types by integrating available multiomics data. Logistic regression models using AL-associated SNPs were constructed to predict three AL status in GZ.

RESULTS

Two novel loci (1q25.2 FAM163A and 7p22.2 SDK1) showed genome-wide significant associations with AL, together explaining 29.63% of AL variance in GZ. The two lead SNPs improved the prediction accuracy for AL status, especially for hyperopes. The frequencies of AL decreasing (less myopic) alleles of the two SNPs were lowest in East Asians as compared with other populations (rs17370084: f EAS=0.03, f EUR=0.24, f AFR=0.05; rs73046501: f EAS=0.06, f EUR=0.07, f AFR=0.20), which was in line with the global distribution of myopia. The cerebral cortex and gamma-aminobutyric acidergic interneurons showed possible functional involvement in myopia development, and the galactose metabolic pathways were significantly enriched.

CONCLUSION

Our study identified two population-specific novel loci for AL, expanding our understanding of the genetic basis of AL and providing evidence for a role of the nervous system and glucose metabolism in myopia pathogenesis.

Development and validation of a deep learning model to predict axial length from ultra-wide field images

BACKGROUND

To validate the feasibility of building a deep learning model to predict axial length (AL) for moderate to high myopic patients from ultra-wide field (UWF) images.

METHODS

This study included 6174 UWF images from 3134 myopic patients during 2014 to 2020 in Eye and ENT Hospital of Fudan University. Of 6174 images, 4939 were used for training, 617 for validation, and 618 for testing. The coefficient of determination (R2), mean absolute error (MAE), and mean squared error (MSE) were used for model performance evaluation.

RESULTS

The model predicted AL with high accuracy. Evaluating performance of R2, MSE and MAE were 0.579, 1.419 and 0.9043, respectively. Prediction bias of 64.88% of the tests was under 1-mm error, 76.90% of tests was within the range of 5% error and 97.57% within 10% error. The prediction bias had a strong negative correlation with true AL values and showed significant difference between male and female (P < 0.001). Generated heatmaps demonstrated that the model focused on posterior atrophy changes in pathological fundus and peri-optic zone in normal fundus. In sex-specific models, R2, MSE, and MAE results of the female AL model were 0.411, 1.357, and 0.911 in female dataset and 0.343, 2.428, and 1.264 in male dataset. The corresponding metrics of male AL models were 0.216, 2.900, and 1.352 in male dataset and 0.083, 2.112, and 1.154 in female dataset.

CONCLUSIONS

It is feasible to utilize deep learning models to predict AL for moderate to high myopic patients with UWF images.

Global prevalence of myopic macular degeneration in general population and patients with high myopia: A systematic review and meta-analysis

The prevalence of myopic macular degeneration (MMD) in the general population and patients with high myopia worldwide has not been fully investigated. Therefore, we screened all population-based studies that reported the prevalence of MMD, and pooled prevalence of MMD using a random-effect model. Subgroup analyses were performed to explore the differences in MMD prevalence in the general population and patients with high myopia according to ethnicity, region of residence (urban/rural), and grading system. Finally, 16 studies were included in this meta-analysis. Results obtained from 2,963 patients from seven countries on four continents indicated that the pooled prevalence of MMD in patients with high myopia was 49.0% (95% CI: 31.5%-66.7%). Results obtained from 71,052 participants from 10 countries on four continents suggested that the pooled prevalence of MMD in the general population was 1.7% (95% CI: 1.1%-2.6%). In the general population, living in urban areas and East Asians were associated with a high prevalence of MMD. Among patients with high myopia, only East Asians were at a higher risk of developing MMD. In conclusion, MMD was particularly prevalent in patients with high myopia. Compared with Europeans, East Asians (Chinese and Japanese) have a higher propensity of developing MMD, both in the general population and in patients with high myopia. It remains unclear whether the higher prevalence of MMD in patients with high myopia in East Asia is caused by differences in given age or given degree of myopia.Systematic review registration number: 202270014 (INPLASY.COM).

Axial Elongation Trajectories in Chinese Children and Adults With High Myopia

Importance

Understanding the long-term axial elongation trajectory in high myopia is important to prevent blindness.

Objective

To evaluate axial elongation trajectories and related visual outcomes in children and adults with high myopia.

Design, Setting, and Participants

In this cohort study, participants in the Zhongshan Ophthalmic Centre-Brien Holden Vision Institute high myopia cohort were followed up every other year for 8 years. Participants with axial length measurements at baseline (2011 or 2012) and at least 1 follow-up visit were included. Participants were grouped according to baseline age as children and adolescents (7 to <18 years), young adults (18 to <40 years), and older adults (≥40 to 70 years). Data were analyzed from November 1, 2022, to June 1, 2023.

Exposure

High myopia (spherical power ≤-6.00 diopters).

Main Outcomes and Measures

Longitudinal axial elongation trajectories were identified by cluster analysis. Axial elongation rates were calculated by linear mixed-effects models. A 2-sided P < .05 was defined as statistically significant.

Results

A total of 793 participants (median [range] age, 17.8 [6.8-69.7] years; 418 females [52.7%]) and 1586 eyes were included in the analyses. Mean axial elongation rates were 0.46 mm/y (95% CI, 0.44-0.48 mm/y) for children and adolescents, 0.07 mm/y (95% CI, 0.06-0.09 mm/y) for young adults, and 0.13 mm/y (95% CI, 0.07-0.19 mm/y) for older adults. Cluster analysis identified 3 axial elongation trajectories, with the stable, moderate, and rapid progression trajectories having mean axial elongation rates of 0.02 mm/y (95% CI, 0.01-0.02 mm/y), 0.12 mm/y (95% CI, 0.11-0.13 mm/y), and 0.38 mm/y (95% CI, 0.35-0.42 mm/y), respectively. At 8 years of follow-up, compared with the stable progression trajectory, the rapid progression trajectory was associated with a 6.92 times higher risk of developing pathological myopic macular degeneration (defined as diffuse or patchy chorioretinal atrophy or macular atrophy; odds ratio, 6.92 [95% CI, 1.07-44.60]; P = .04), and it was associated with a 0.032 logMAR decrease in best-corrected visual acuity (β = 0.032 [95% CI, 0.001-0.063]; P = .04).

Conclusions and Relevance

The findings of this 8-year follow-up study suggest that axial length in high myopia continues to increase from childhood to late adulthood following 3 distinct trajectories. At 8 years of follow-up, the rapid progression trajectory was associated with a higher risk of developing pathological myopic macular degeneration and poorer best-corrected visual acuity compared with the stable progression trajectory. These distinct axial elongation trajectories could prove valuable for early identification and intervention for high-risk individuals.

Prevalence and Cause of Loss of Visual Acuity and Visual Field in Highly Myopic Eyes: The Beijing Eye Study

PURPOSE

To explore the prevalence and causes of loss of visual acuity and visual field in highly myopic eyes.

DESIGN

Population-based study.

PARTICIPANTS

4439 subjects of the Beijing Eye Study underwent ophthalmological and systemic examinations including frequency doubling technology perimetry.

METHODS

High myopia was defined by a refractive error of ≤-6 diopters (D) or axial length >26.0 mm.

MAIN OUTCOME MEASURES

Prevalence of vision impairment causes.

RESULTS

212 highly myopic eyes from 154 participants were included with a mean age of 56.2 ± 9.6 years, a mean refractive error of -9.87 ± 3.70 D and a mean axial length of 27.2 ± 1.3 mm. We observed moderate/severe vision impairment (MSVI) in 40 eyes (18.9%; 95% confidence interval [CI], 13.6-24.2) and blindness in 10 eyes (4.7%; 95% CI, 1.8-7.6). Primary causes for MSVI and blindness were myopic macular degeneration (MMD) (29/50; 58%), age-related macular degeneration (1/50; 2%), and branch macular retinal vein occlusion (1/50; 2%). Secondary causes were MMD (4/50; 8%) and optic nerve atrophy (14/50, 28%), further differentiated into non-glaucomatous optic atrophy (NGOA) (9/50; 18%) and glaucomatous optic atrophy (GOA) (5/50; 10%). Prevalence of MMD as vision impairment cause increased significantly from 1/61 (1.6%) in the refractive error group of -6.00 to ≥-7.00 D, to 16/25 (64%) in the group of <-15.0 D. Higher MMD prevalence correlated with higher myopic refractive error (P < 0.001) and increased likelihood of concomitant optic neuropathy (P < 0.001). Similarly, prevalence of optic neuropathy as vision impairment cause increased from 0/61 (0%) in the refractive error group of -6.00 D to ≥-7.00 D, to 9/25 (36%) in the group of <-15.0 D. Higher optic neuropathy prevalence correlated with more myopic refraction (P < 0.001) and older age (P = 0.02).

CONCLUSIONS

In this population-based recruited cohort of highly myopic patients, optic neuropathy accounted for vision impairment in 9.0% eyes, which was lower than the prevalence of MMD as vision impairment cause (18.9%). Notably, optic neuropathy became a significant contributor to vision impairment in more advanced high myopia, reaching 36% in the group with refractive error of <-15.0 D.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Association Between Choroidal Thickness and Myopic Maculopathy in a Japanese Population: The Hisayama Study

Purpose

To examine the association between choroidal thickness and myopic maculopathy in a general Japanese population.

Design

Population-based cross-sectional study.

Participants

A total of 2841 residents of a Japanese community aged ≥ 40 years, who consented to participate and had available data of choroidal thickness and fundus photographs, were enrolled in this study.

Methods

The choroidal thickness was measured by swept-source OCT. Participants were divided into quartiles of choroidal thickness. Myopic maculopathy was defined according to the classification system of the Meta-analysis of Pathologic Myopia Study Group. Main outcome measures were odds ratios (ORs) of choroidal thickness for prevalent myopic maculopathy. The ORs and 95% confidence intervals (CIs) were estimated using a logistic regression model.

Main Outcome Measures

Prevalent myopic maculopathy.

Results

Eighty-one participants had myopic maculopathy (45 diffuse chorioretinal atrophy, 31 patchy chorioretinal atrophy, and 5 macular atrophy). Individuals in the lowest quartile of choroidal thickness had a significantly greater OR for the presence of myopic maculopathy than those in the highest quartile of choroidal thickness (OR: 4.78 [95% CI: 1.78-16.72]) after adjusting for confounders, including axial length. The sensitivity analysis among the 1176 myopic individuals with axial length of ≥ 24.0 mm also showed that thinner choroidal thickness was significantly associated with prevalent myopic maculopathy.

Conclusions

The present study demonstrated the significant inverse association between choroidal thickness and the likelihood of myopic maculopathy, suggesting that the measurement of choroidal thickness in addition to axial length would be useful for assessing the risk of myopic maculopathy and elucidating its pathogenesis.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

Deep learning-based estimation of axial length using macular optical coherence tomography images

Background

This study aimed to develop deep learning models using macular optical coherence tomography (OCT) images to estimate axial lengths (ALs) in eyes without maculopathy.

Methods

A total of 2,664 macular OCT images from 444 patients' eyes without maculopathy, who visited Beijing Hospital between March 2019 and October 2021, were included. The dataset was divided into training, validation, and testing sets with a ratio of 6:2:2. Three pre-trained models (ResNet 18, ResNet 50, and ViT) were developed for binary classification (AL ≥ 26 mm) and regression task. Ten-fold cross-validation was performed, and Grad-CAM analysis was employed to visualize AL-related macular features. Additionally, retinal thickness measurements were used to predict AL by linear and logistic regression models.

Results

ResNet 50 achieved an accuracy of 0.872 (95% Confidence Interval [CI], 0.840-0.899), with high sensitivity of 0.804 (95% CI, 0.728-0.867) and specificity of 0.895 (95% CI, 0.861-0.923). The mean absolute error for AL prediction was 0.83 mm (95% CI, 0.72-0.95 mm). The best AUC, and accuracy of AL estimation using macular OCT images (0.929, 87.2%) was superior to using retinal thickness measurements alone (0.747, 77.8%). AL-related macular features were on the fovea and adjacent regions.

Conclusion

OCT images can be effectively utilized for estimating AL with good performance via deep learning. The AL-related macular features exhibit a localized pattern in the macula, rather than continuous alterations throughout the entire region. These findings can lay the foundation for future research in the pathogenesis of AL-related maculopathy.

Prevalence and Associations of Nonglaucomatous Optic Nerve Atrophy in High Myopia: The Ural Eye and Medical Study

PURPOSE

To assess the prevalence of nonglaucomatous optic nerve atrophy (NGOA) in highly myopic individuals.

DESIGN

Population-based study.

PARTICIPANTS

The Ural Eye and Medical Study included 5899 (80.5%) of 7328 eligible individuals (80.5%).

METHODS

Nonglaucomatous optic nerve atrophy, graded into 5 arbitrary stages, was characterized by decreased visibility of the retinal nerve fiber layer (RNFL) on photographs, neuroretinal rim pallor, abnormally thin retinal arteriole diameter, and abnormally thin peripapillary RNFL as measured by OCT.

MAIN OUTCOME MEASURES

Nonglaucomatous optic nerve atrophy prevalence and degree.

RESULTS

Of 5709 participants (96.9%) with axial length measurements, 130 individuals (2.3%) were highly myopic, of whom 116 individuals (89.2%; age, 57.8 ± 11.1 years; axial length, 27.0 ± 1.2 mm) had available fundus photographs and OCT images and were included into the study. Nonglaucomatous optic nerve atrophy prevalence was 34/116 individuals (29.3%; 95% confidence interval [CI], 21.0-38.0), and mean NGOA degree in eyes with NGOA was 1.7 ± 1.0 arbitrary units. Higher NGOA degree correlated (multivariable analysis; regression coefficient, r2 = 0.59) with longer axial length (β, 0.22; P = 0.007), wider temporal parapapillary γ zone width (β, 0.50; P < 0.001), higher prevalence of diabetes (β, 0.20; P = 0.005), and higher systolic blood pressure (β, 0.15; P = 0.03). Higher NGOA prevalence was associated with longer axial length (odds ratio [OR], 7.45; 95% CI, 2.15-25.7), wider temporal parapapillary γ zone (OR, 6.98; 95% CI, 2.61-18.7), and higher systolic blood pressure (OR, 1.05; 95% CI, 1.01-1.10).

CONCLUSIONS

In this ethnically mixed population from Russia with an age of 40 years or more, high axial myopia showed a relatively high prevalence of NGOA, increasing with longer axial length and wider temporal parapapillary γ zone. For each 1 mm of axial elongation and γ zone widening, the odds for NGOA increased 7.45-fold and 6.98-fold, respectively. The axial elongation-associated and γ zone-related increase in the distance between the retinal ganglion cells and the optic disc may lead to a lengthening and stretching of the retinal ganglion cell axons and may be of importance pathogenetically. In highly myopic eyes, NGOA may be a reason for visual field and central visual acuity loss, unexplainable by myopic macular pathologic features.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Effects of posterior staphyloma on choroidal structure in myopic adults: a retrospective study

BACKGROUND

Studies on the choroid of myopic eyes with posterior staphyloma have shown that choroidal thickness decreased. This retrospective study further analysed the effects of posterior scleral staphyloma on choroidal blood vessels and matrix components compared to non-pathological myopia.

METHODS

In this cross-sectional study, ninety-one eyes were divided into pathological (posterior staphyloma) and non-pathological myopia. The latter was further divided into three groups (Group 1: 26 mm ≤ axial length; Group 2: 24 mm ≤ axial length < 26 mm; Group 3: 22 mm ≤ axial length < 24 mm). Choroidal thickness, total choroidal area, luminal area, stromal area, and choroidal vascularity index were calculated.

RESULTS

The CVI in N1, N2, I1, S2 of the posterior staphyloma group were lower than those of group 1 (both P < 0.05). The mean height of posterior staphyloma was associated with mean CT (Pearson correlation: r = -0.578, P = 0.039) but not with the mean CVI in posterior staphyloma group. In all groups, the mean choroidal thickness, total choroidal area, luminal area, and stromal area were significantly associated with axial length (P < 0.001), and the mean choroidal vascularity index was significantly associated with the mean choroidal thickness (P < 0.001).

CONCLUSION

The choroidal structure of pathological myopia with posterior staphyloma and non-pathological myopia with longer axial length demonstrates alterations in which choroidal vessels are more impaired than the stroma. A lower choroidal vascularity index should be alert to pathological changes for myopia with axial length > 26 mm.

Predictors of myopic macular degeneration in a 12-year longitudinal study of Singapore adults with myopia

PURPOSE

To investigate the predictive factors for myopic macular degeneration (MMD) and progression in adults with myopia.

METHODS

We examined 828 Malay and Indian adults (1579 myopic eyes) with myopia (spherical equivalent (SE) ≤-0.5 dioptres) at baseline who participated in both baseline and 12-year follow-up visits of the Singapore Malay Eye Study and the Singapore Indian Eye Study. Eye examinations, including subjective refraction and axial length (AL) measurements, were performed. MMD was graded from fundus photographs following the Meta-Analysis for Pathologic Myopia classification. The predictive factors for MMD development and progression were assessed in adults without and with MMD at baseline, respectively as risk ratios (RR) using multivariable modified Poisson regression models. The receiver operating characteristic curve was used to visualise the performance of the predictive models for the development of MMD, with performance quantified by the area under the curve (AUC).

RESULTS

The 12-year cumulative MMD incidence was 10.3% (95% CI 8.9% to 12.0%) among 1504 myopic eyes without MMD at baseline. Tessellated fundus was a major predictor of MMD (RR=2.50, p<0.001), among other factors including age, worse SE and longer AL (all p<0.001). The AUC for prediction of MMD development was found to be 0.78 (95% CI 0.76 to 0.80) for tessellated fundus and increased significantly to an AUC of 0.86 (95% CI 0.84 to 0.88) with the combination of tessellated fundus with age, race, gender and SE (p<0.001). Older age (p=0.02), worse SE (p<0.001) and longer AL (p<0.001) were found to be predictors of MMD progression.

CONCLUSIONS

In adults with myopia without MMD, tessellated fundus, age, SE and AL had good predictive value for incident MMD. In adults with MMD, 1 in 10 eyes experienced progression over the same period. Older age, more severe myopia and longer AL were independent risk factors for progression.

Myopia: Histology, clinical features, and potential implications for the etiology of axial elongation

Myopic axial elongation is associated with various non-pathological changes. These include a decrease in photoreceptor cell and retinal pigment epithelium (RPE) cell density and retinal layer thickness, mainly in the retro-equatorial to equatorial regions; choroidal and scleral thinning pronounced at the posterior pole and least marked at the ora serrata; and a shift in Bruch's membrane opening (BMO) occurring in moderately myopic eyes and typically in the temporal/inferior direction. The BMO shift leads to an overhang of Bruch's membrane (BM) into the nasal intrapapillary compartment and BM absence in the temporal region (i.e., parapapillary gamma zone), optic disc ovalization due to shortening of the ophthalmoscopically visible horizontal disc diameter, fovea-optic disc distance elongation, reduction in angle kappa, and straightening/stretching of the papillomacular retinal blood vessels and retinal nerve fibers. Highly myopic eyes additionally show an enlargement of all layers of the optic nerve canal, elongation and thinning of the lamina cribrosa, peripapillary scleral flange (i.e., parapapillary delta zone) and peripapillary choroidal border tissue, and development of circular parapapillary beta, gamma, and delta zone. Pathological features of high myopia include development of macular linear RPE defects (lacquer cracks), which widen to round RPE defects (patchy atrophies) with central BM defects, macular neovascularization, myopic macular retinoschisis, and glaucomatous/glaucoma-like and non-glaucomatous optic neuropathy. BM thickness is unrelated to axial length. Including the change in eye shape from a sphere in emmetropia to a prolate (rotational) ellipsoid in myopia, the features may be explained by a primary BM enlargement in the retro-equatorial/equatorial region leading to axial elongation.

Visual and patient-reported outcomes of a diffractive trifocal intraocular lens in highly myopic eyes: a prospective multicenter study

BACKGROUND

To investigate the visual and patient-reported outcomes of a diffractive trifocal intraocular lens (IOL) in highly myopic eyes.

METHODS

Patients with planned cataract removal by phacoemulsification and implantation of a trifocal IOL (AT LISA tri 839MP) were enrolled in the prospective, multicenter cohort study. Patients were allocated into three groups according to their axial length (AL): control group, AL < 26 mm; high myopia group, AL 26-28 mm; extreme myopia group, AL ≥ 28 mm. At 3 months post-surgery, data for 456 eyes of 456 patients were collected, including visual acuity, defocus curve, contrast sensitivity (CS), visual quality, spectacle independence, and overall satisfaction.

RESULTS

After surgery, the uncorrected distance visual acuity improved from 0.59 ± 0.41 to 0.06 ± 0.12 logMAR (P < 0.001). In all three groups, about 60% of eyes achieved uncorrected near and intermediate visual acuity of 0.10 logMAR or better, but significantly fewer eyes in the extreme myopia group achieved uncorrected distance visual acuity of 0.10 logMAR or better (P < 0.05). Defocus curves revealed that the visual acuity was significantly worse in the extreme myopia group than others at 0.00, - 0.50, and - 2.00 diopters (P < 0.05). CS did not differ between the control and high myopia groups but was significantly lower in the extreme myopia group at 3 cycles per degree. The extreme myopia group also had greater higher-order aberrations and coma, lower modulation transfer functions and VF-14 scores, more glare and halos, worse spectacle independence at far distance, and consequently lower patient satisfaction than others (all P < 0.05).

CONCLUSIONS

In eyes with a high degree of myopia (AL < 28 mm), trifocal IOLs have been shown to provide similar visual outcomes to those in non-myopic eyes. However, in extremely myopic eyes, acceptable results may be obtained with trifocal IOLs, but a reduced level of uncorrected distance vision is expected.

Macular Vascularity and Ganglion Cell Complex Parameters in the Young Adults with Myopia and Progressive Myopia

Purpose

The purpose of this study is to determine the relationships between foveal avascular zone (FAZ), foveal vascular density (FD) and GCC (ganglion cell complex) parameters in a healthy myopic population using optical coherence tomography angiography (angio-OCT).

Patients and Methods

Three hundred and eighty-one eyes of 381 healthy participants were included into this study and assigned to three groups according to their spherical equivalent (SE) values and an additional progressive myopia group. One randomly chosen eye from each patient was analyzed. GCC mean thickness, focal loss of volume (FLV), global loss of volume (GLV), FAZ area, FAZ perimeter, and FD parameters were obtained with the RTVue AngioOCT device.

Results

FAZ area and its perimeter were strongly correlated with the belonging spherical equivalent group (p = 0.0001, p = 0.0008 accordingly), being the largest in progressive myopia subgroup (mean size 0.42mm²). Other factors that were significantly higher in myopic eyes were FLV (p = 0.0023), GLV (p = 0.0020). There were no differences in FD between groups. In the myopic and progressive myopia groups, there was a significant relationship between FAZ area and FLV, GLV, and GCC thickness. We found that in myopic eyes with AXL exceeding 26.6 mm, FAZ becomes negatively correlated to mean GCC thickness.

Conclusion

In myopia, compared to non-myopic groups, there is a greater loss of neural tissue represented by a thinner GCC layer, greater FLV and GLV parameters, and worse blood supply represented by a larger FAZ area. Eye axial length of 26.6 mm is a breaking point, where the negative FAZ area to GCC thickness relationship curve is getting significantly steeper.

Peripheral Refraction and Visual Function of Novel Perifocal Ophthalmic Lens for the Control of Myopia Progression

This study aimed to evaluate the peripheral defocus induced with a novel perifocal ophthalmic lens for myopia progression control and the potential impact on visual function. This experimental, non-dispensing crossover study evaluated 17 myopic young adults. The peripheral refraction was measured using an open-field autorefractor, at 2.50 m from the target point, in two eccentric points, 25° temporal, 25° nasal, and central vision. Visual contrast sensitivity (VCS) was measured at 3.00 m with a Vistech system VCTS 6500 in low light conditions. Light disturbance (LD) was assessed with a light distortion analyzer 2.00 m away from the device. Peripheral refraction, VCS, and LD were assessed with a monofocal lens and perifocal lens (with an add power of +2.50 D on the temporal side of the lens, and +2.00 D on the nasal side). The results showed that the perifocal lenses induced an average myopic defocus of -0.42 ± 0.38 D (p-value < 0.001) in the nasal retina, at 25° The changes induced by the lower add power in the nasal part of the lens did not induce statistically significant changes in the refraction of the temporal retina. The VCS and LD showed no significant differences between the monofocal and perifocal lenses.

Artificial Intelligence for the Estimation of Visual Acuity Using Multi-Source Anterior Segment Optical Coherence Tomographic Images in Senile Cataract

Purpose

To investigate an artificial intelligence (AI) model performance using multi-source anterior segment optical coherence tomographic (OCT) images in estimating the preoperative best-corrected visual acuity (BCVA) in patients with senile cataract.

Design

Retrospective, cross-instrument validation study.

Subjects

A total of 2,332 anterior segment images obtained using swept-source OCT, optical biometry for intraocular lens calculation, and a femtosecond laser platform in patients with senile cataract and postoperative BCVA ≥ 0.0 logMAR were included in the training/validation dataset. A total of 1,002 images obtained using optical biometry and another femtosecond laser platform in patients who underwent cataract surgery in 2021 were used for the test dataset.

Methods

AI modeling was based on an ensemble model of Inception-v4 and ResNet. The BCVA training/validation dataset was used for model training. The model performance was evaluated using the test dataset. Analysis of absolute error (AE) was performed by comparing the difference between true preoperative BCVA and estimated preoperative BCVA, as ≥0.1 logMAR (AE_≥0.1) or <0.1 logMAR (AE _<0.1). AE_≥0.1 was classified into underestimation and overestimation groups based on the logMAR scale.

Outcome Measurements

Mean absolute error (MAE), root mean square error (RMSE), mean percentage error (MPE), and correlation coefficient between true preoperative BCVA and estimated preoperative BCVA.

Results

The test dataset MAE, RMSE, and MPE were 0.050 ± 0.130 logMAR, 0.140 ± 0.134 logMAR, and 1.3 ± 13.9%, respectively. The correlation coefficient was 0.969 (p < 0.001). The percentage of cases with AE_≥0.1 was 8.4%. The incidence of postoperative BCVA > 0.1 was 21.4% in the AE_≥0.1 group, of which 88.9% were in the underestimation group. The incidence of vision-impairing disease in the underestimation group was 95.7%. Preoperative corneal astigmatism and lens thickness were higher, and nucleus cataract was more severe (p < 0.001, 0.007, and 0.024, respectively) in AE_≥0.1 than that in AE _<0.1. The longer the axial length and the more severe the cortical/posterior subcapsular opacity, the better the estimated BCVA than the true BCVA.

Conclusions

The AI model achieved high-level visual acuity estimation in patients with senile cataract. This quantification method encompassed both visual acuity and cataract severity of OCT image, which are the main indications for cataract surgery, showing the potential to objectively evaluate cataract severity.

Relationship between axial length and spherical equivalent refraction in Chinese children

Purpose

To evaluate the relationship between axial length (AL) and spherical equivalent refraction (SER) in Chinese children.

Methods

This hospital-based cross-sectional study included 1208 eyes (from 617 Chinese boys and 591 Chinese girls), ranging between 2 and 12 years. All subjects were divided into subgroups according to the spherical equivalent refraction (SER) (hyperopia, emmetropia, and myopia) and age (2-6 years, 7-9 years, and 10-12 years). Comparisons were made between age, sex, and SER groups. Multiple linear regression analysis was used to evaluate the correlation of AL and SER for all groups.

Results

The mean AL and SER were significantly different among the three age groups: 2-6 years group (AL: 22.24 ​± ​1.59 ​mm; SER: 0.73 ​± ​2.67 D); 7-9 years group (AL: 23.49 ​± ​1.10 ​mm; SE: -0.68 ​± ​1.97 D) and 10-12 years group (AL: 24.33 ​± ​1.02 ​mm; SER: -1.72 ​± ​1.86 D). Boys showed longer AL compared with the girls (23.66 ​± ​1.51 ​mm vs 23.05 ​± ​1.32 ​mm). However, as for SER, the girls (-0.70 ​± ​2.17 D) showed smaller SER (more myopia) compared with the boys (-0.4 ​± ​2.48 D). After adjusting for age and sex, the SER tended to decrease (became more myopic) 1.23 D (95% CI: 1.15-1.30D) with a 1 ​mm increase of AL. Among the different SER groups, the SER tended to become more myopic per mm of AL by 1.09 D (95% CI: 0.97-1.21D) for the myopia group, 1.38 D (95% CI: 1.23-1.54 D) for the hyperopia group, and 0.05 D (95% CI: 0.02-0.08 D) for the emmetropic group. In addition, an increase of 1 ​mm elongation of AL showed a decrease of SER by 1.05 D (95% CI: 0.90-1.20 D) among 2 - 6-year-olds, by 1.40 D (95% CI: 1.30-1.51 D) among 7 - 9-year-olds, and by 1.37 D (95% CI: 1.21-1.52 D) among 10-12-year-olds. As for sexual differences, the girls 1.68 D, (95% CI: 1.57-1.79 D) showed a more significant myopic shift of SER with a 1 ​mm increase of AL compared with the boys (0.94 D, 95% CI: 0.84-1.04 D).

Conclusions

Our results indicated a strong linear relationship between SER and AL and an early-rising trend of myopia in Chinese children.

Racial and ethnic differences in foveal avascular zone in diabetic and nondiabetic eyes revealed by optical coherence tomography angiography

Purpose

The purpose of this study was to examine whether racial and ethnic differences in retinal microvasculature are detectable with quantitative measures derived from optical coherence tomography angiography (OCTA).

Methods

OCTA scans and fundus photography were obtained in 447 eyes from 271 patients with and without diabetes between April and October 2018. Fundus photos were graded by the hospital reading center for diabetic retinopathy (DR) severity. Eight OCTA parameters relating to the foveal avascular zone (FAZ), superficial vascular perfusion, and deep vascular perfusion were analyzed for significant differences between race and ethnicity groups, self-reported by patients and organized according to National Center for Health Statistics groupings. Multiple regression was then used to adjust estimates for possible confounding by age, gender, hypertension, and last hemoglobin A1c level.

Results

Significant differences in FAZ area were found between white and non-white patients. After adjustment, the differences between white and all non-white groups were statistically significant (p<0.05) among patients with mild to moderate DR. In those without diabetes, the Hispanic and Asian groups had significantly larger FAZ areas (p<0.005) than NH white patients. In those with mild to moderate non-proliferative diabetic retinopathy (NPDR), NH Black, Hispanic, and Asian patients also had significantly larger FAZ areas than NH white patients (p<0.005).

Conclusion

Significant differences in FAZ area exist among different racial and ethnic groups. These results highlight the importance of considering and further studying race and ethnicity in OCTA analyses of the retinal microvasculature.

Dome-Shaped Macula versus Ridge-Shaped Macula Eyes in High Myopia Based on the 12-line Radial Optical Coherence Tomography Scan Pattern. Differences in Clinical Features

PURPOSE

To study clinical features in patients with ridge-shaped macula (RSM) compared with those with dome-shaped macula (DSM) having been previously classified by the number of swept-source optical coherence tomography (SS-OCT) radial scans affected.

METHODS

Retrospective observational study including 49 highly myopic eyes from 31 patients who underwent SS-OCT. DSM eyes were defined as those that showed a complete round inward convexity in all their axes, presenting an inward convexity ≥50 µm in the 12-line radial OCT scans. Eyes that did not meet this criterion and had at least one flat radial scan were grouped into the RSM group, defined as a macular inward convexity in some meridians across the fovea, whereas the opposite perpendicularly oriented meridians were flat. Age, spherical equivalent, axial length (AL), and best-corrected visual acuity (BCVA) were collected. Height of the bulge, scleral and choroidal thicknesses, Bruch´s membrane defects, and presence of perforating scleral vessels were recorded.

RESULTS

Thirty-seven (75.5%) eyes were classified into the RSM group and 12 (24.5%) into the DSM group. Twenty-six (53.0%) eyes showed macular elevation only in the horizontal direction. Mean AL showed statistically significant differences (28.8 ± 2.7 vs. 30.5 ± 1.5 mm in the RMS vs. DSM group, respectively) and the presence of Bruch´s membrane defects was more frequently seen in DSM (p < 0.001). Mean age, spherical equivalent, BCVA, height of the inward convexity, retinal foveal thickness, foveal scleral thickness, subfoveal choroidal thickness, and the presence of perforating scleral vessels did not show significant differences between groups.

CONCLUSION

This study shows the reliability of using the 12 equal radial OCT scans as an objective method to define and differentiate DSM versus RSM. Patients with RSM showed differences in AL compared with those with DSM, being longer in DSM, and regarding the presence of Bruch´s membrane defects, being more common in DSM. This may contribute to identifying those patients that, in daily clinical practice, have a higher risk of developing complications due to their myopia.

Pathologic myopia and severe pathologic myopia: correlation with axial length

Purpose

This study had three aims: (1) correlate axial length (AL), age and best-corrected visual acuity in high myopic patients scored on the ATN grading system; (2) determine AL cut-off values to distinguish between pathologic myopia (PM) and severe PM; and (3) identify clinical differences between PM and severe PM.

Methods

This is a cross-sectional, non-interventional study. All patients underwent complete ophthalmologic examination, ATN grading and multimodal imaging (colour fundus photography, swept-source OCT, fundus autofluorescence, OCT angiography and fluorescein angiography).

Results

Six hundred forty-four eyes from 345 high myopic patients were included. The eyes were graded on the ATN system and classified as PM (≥ A2) or severe PM (≥ A3, ≥ T3 and/or N2). Significant between-group (PM vs. severe PM) differences (p < 0.05) were observed on the individual ATN components (atrophic [A], tractional [T] and neovascular [N]), age, BCVA and AL. AL was also linearly correlated with the A, T and N components (r = 0.53, p < 0.01; r = 0.24, p < 0.01; r = 0.20, p < 0.01; respectively). ROC curve analysis showed the optimal AL cut-off value to distinguish between PM at 28 mm (AUC ROC curve: 0.813, specificity: 75%, sensitivity: 75%) and severe PM at 29.50 mm (AUC ROC curve: 0.760, specificity: 75%, sensitivity: 70%).

Conclusion

AL is the main variable associated with myopic maculopathy. Due to the clinical differences found between PM and severe PM, there is need to create an objective cut-off point to distinguish these two different entities being the optimal cut-off points for AL 28 mm and 29.5 mm, respectively. These objective AL cut-off values should be taken into account for determining a correct follow-up, ophthalmic management and treatment.

Association of Aberrant Posterior Vitreous Detachment and Pathologic Tractional Forces With Myopic Macular Degeneration

Purpose

The purpose of this study was to assess whether the tractional elements of pathologic myopia (PM; e.g. myopic traction maculopathy [MTM], posterior staphyloma [PS], and aberrant posterior vitreous detachment [PVD]) are associated with myopic macular degeneration (MMD) independent of age and axial length, among highly myopic (HM) eyes.

Methods

One hundred twenty-nine individuals with 239 HM eyes from the Myopic and Pathologic Eyes in Singapore (MyoPES) cohort underwent ocular biometry, fundus photography, swept-source optical coherence tomography, and ocular B-scan ultrasound. Images were analyzed for PVD grade, and presence of MTM, PS, and MMD. The χ² test was done to determine the difference in prevalence of MMD between eyes with and without PVD, PS, and MTM. Multivariate probit regression analyses were performed to ascertain the relationship between the potential predictors (PVD, PS, and MTM) and outcome variable (MMD), after accounting for possible confounders (e.g. age and axial length). Marginal effects were reported.

Results

Controlling for potential confounders, eyes with MTM have a 29.92 percentage point higher likelihood of having MMD (P = 0.003), and eyes with PS have a 25.72 percentage point higher likelihood of having MMD (P = 0.002). The likelihood of MMD increases by 10.61 percentage points per 1 mm increase in axial length (P < 0.001). Subanalysis revealed that eyes with incomplete PVD have a 22.54 percentage point higher likelihood of having MMD than eyes with early PVD (P = 0.04).

Conclusions

Our study demonstrated an association between tractional (MTM, PS, and persistently incomplete PVD) and degenerative elements of PM independent of age and axial length. These data provide further insights into the pathogenesis of MMD.

Longitudinal analysis of axial length growth in a German cohort of healthy children and adolescents

PURPOSE

To generate continuous growth curves for axial length (AL) in German children. We hypothesise that percentile curves of AL can be used as a predictive measure of myopia.

METHODS

In this longitudinal and cross-sectional LIFE Child Study, children's non-cycloplegic refraction data was collected using the Zeiss i.Profiler plus while AL was measured using the Haag-Streit Lenstar. Reference growth curves were estimated as a continuous non-parametric function of age.

RESULTS

Data from 4511 visits of 1965 participants (1021 boys and 944 girls) between 3 and 18 years of age were analysed. For all ages and percentiles, the estimated AL was higher in boys than girls. AL differences between boys and girls were most pronounced in the 98^th percentile at 3 years of age, being 0.93 mm longer eyes in boys. This difference decreased to 0.21 mm at 18 years of age. While the lower percentiles of AL reach their final value around age 13, the 50^th percentile was still increasing by 0.05 mm per year until the end of the observation period. While, in general, children with longer eyes are more likely to develop myopia, this relationship is weaker between the ages of 5 and 8.

CONCLUSION

The LIFE Child Study data provides European AL data. In both Germany and China, AL has comparable growth rates when the baseline ALs are compared as percentiles. Thus, percentile curves of AL can be used as a predictive measure for the likelihood of developing as well as the progression of myopia.

Clinical Characteristics of Highly Myopic Patients With Asymmetric Myopic Atrophic Maculopathy-Analysis Using Multimodal Imaging

Purpose

To evaluate the factors associated with asymmetric myopic atrophic maculopathy (MAM) in highly myopic patients.

Methods

We enrolled highly myopic patients with asymmetric MAM according to the atrophy, traction, and neovascularization (ATN) classification. The results of color fundus photography, optical coherence tomography (OCT), OCT angiography, and corneal visualization Scheimpflug technology (Corvis ST tonometry) were reviewed. The association between inter-eye differences in clinical features and MAM grading was analyzed using logistic regression analysis.

Results

Among the 72 eyes of 36 patients 61.0 ± 9.3 years of age, 9, 33, 17, and 13 eyes had A1, A2, A3, and A4, respectively. The mean axial length was 30.44 ± 1.92 mm, and there was no significant difference between eyes with less severe and more severe MAM. The inter-eye differences in MAM grading were associated with the inter-eye differences in the presence of Bruch's membrane defects (P = 0.014), ellipsoid zone disruption (P = 0.013), vessel density of the deep retinal layer (P = 0.022), foveal avascular zone circularity (P = 0.012), foveal avascular zone area (P = 0.049), flow area of the choriocapillaris (P = 0.013), vessel diameter (P = 0.045), and fractal dimension (P = 0.015). No Corvis ST parameter was statistically significant. A higher difference in the choriocapillaris flow area (P = 0.013; adjusted odds ratio = 1.10 [1.02–1.18]) remained associated with higher inter-eye differences in MAM grading in the multivariable regression.

Conclusions

A smaller choriocapillaris flow area was associated with more severe MAM, suggesting that vascular factors play pivotal roles in MAM.

Five-Year Incidence of Myopic Maculopathy in a General Japanese Population: The Hisayama Study

Importance

Myopic maculopathy is a leading cause of irreversible visual impairment worldwide. Moreover, the burden of myopic maculopathy has been expected to increase owing to the rising prevalence of myopia globally. However, there is limited epidemiologic evidence regarding the incidence of and risk factors for myopic maculopathy. This study from Japan, with a relatively high prevalence of myopia, could provide valuable information related to these issues.

Objective

To estimate the incidence of myopic maculopathy and its risk factors in Hisayama in southwestern Japan.

Design, Setting, and Participants

A population-based prospective cohort study in a Japanese community in Hisayama, Japan. The study included a total of 2164 residents 40 years or older who had no myopic maculopathy at the baseline eye examination in 2012 and underwent follow-up eye examinations in 2017.

Main Outcomes and Measures

Incidence of myopic maculopathy. The grades of myopic maculopathy were categorized based on the criteria of the Meta-analysis of Pathologic Myopia Study Group classification system.

Results

The mean (SD) age of the study participants was 62.4 (10.9) years, and the proportion of men was 42.5% (920 participants). In the follow-up examination in 2017, 24 patients developed myopic maculopathy. The 5-year cumulative incidence of myopic maculopathy was 1.1% (95% CI, 0.6-1.5) overall, 1.4% (95% CI, 0.6-2.2) for men, and 0.9% (95% CI, 0.4-1.4) for women. Multiple logistic regression analysis showed that older age (per 1 year; odds ratio [OR], 1.06; 95% CI, 1.01-1.11) and longer axial length (per 1 mm; OR, 2.94; 95% CI, 2.19-3.95) were associated with incident myopic maculopathy.

Conclusions and Relevance

Twenty-four study participants (1%) developed myopic maculopathy during the 5-year study period, which is much higher than the rate in a previous study on a Chinese population. We also confirmed that aging and longer axial length were independent and significant risk factors for myopic maculopathy. These findings should be reviewed among various populations in other parts of the world.

The Complications of Myopia: A Review and Meta-Analysis

Purpose

To determine the risk between degree of myopia and myopic macular degeneration (MMD), retinal detachment (RD), cataract, open angle glaucoma (OAG), and blindness.

Methods

A systematic review and meta-analyses of studies published before June 2019 on myopia complications. Odds ratios (OR) per complication and spherical equivalent (SER) degree (low myopia SER < -0.5 to > -3.00 diopter [D]; moderate myopia SER ≤ -3.00 to > -6.00 D; high myopia SER ≤ -6.00 D) were calculated using fixed and random effects models.

Results

Low, moderate, and high myopia were all associated with increased risks of MMD (OR, 13.57, 95% confidence interval [CI], 6.18-29.79; OR, 72.74, 95% CI, 33.18-159.48; OR, 845.08, 95% CI, 230.05-3104.34, respectively); RD (OR, 3.15, 95% CI, 1.92-5.17; OR, 8.74, 95% CI, 7.28-10.50; OR, 12.62, 95% CI, 6.65-23.94, respectively); posterior subcapsular cataract (OR, 1.56, 95% CI, 1.32-1.84; OR, 2.55, 95% CI, 1.98-3.28; OR, 4.55, 95% CI, 2.66-7.75, respectively); nuclear cataract (OR, 1.79, 95% CI, 1.08-2.97; OR, 2.39, 95% CI, 1.03-5.55; OR, 2.87, 95% CI, 1.43-5.73, respectively); and OAG (OR, 1.59, 95% CI, 1.33-1.91; OR, 2.92, 95% CI, 1.89-4.52 for low and moderate/high myopia, respectively). The risk of visual impairment was strongly related to longer axial length, higher myopia degree, and age older than 60 years (OR, 1.71, 95% CI, 1.07-2.74; OR, 5.54, 95% CI, 3.12-9.85; and OR, 87.63, 95% CI, 34.50-222.58 for low, moderate, and high myopia in participants aged >60 years, respectively).

Conclusions

Although high myopia carries the highest risk of complications and visual impairment, low and moderate myopia also have considerable risks. These estimates should alert policy makers and health care professionals to make myopia a priority for prevention and treatment.

Highlights from the 2019 International Myopia Summit on 'controversies in myopia'

Myopia is an emerging public health issue with potentially significant economic and social impact, especially in East Asia. However, many uncertainties about myopia and its clinical management remain. The International Myopia Summit workgroup was convened by the Singapore Eye Research Institute, the WHO Regional Office for the Western Pacific and the International Agency for the Prevention of Blindness in 2019. The aim of this workgroup was to summarise available evidence, identify gaps or unmet needs and provide consensus on future directions for clinical research in myopia. In this review, among the many 'controversies in myopia' discussed, we highlight three main areas of consensus. First, development of interventions for the prevention of axial elongation and pathologic myopia is needed, which may require a multifaceted approach targeting the Bruch's membrane, choroid and/or sclera. Second, clinical myopia management requires co-operation between optometrists and ophthalmologists to provide patients with holistic care and a tailored approach that balances risks and benefits of treatment by using optical and pharmacological interventions. Third, current diagnostic technologies to detect myopic complications may be improved through collaboration between clinicians, researchers and industry. There is an unmet need to develop new imaging modalities for both structural and functional analyses and to establish normative databases for myopic eyes. In conclusion, the workgroup's call to action advocated for a paradigm shift towards a collaborative approach in the holistic clinical management of myopia.