Prevalence and predictors of myopic macular degeneration among Asian adults: pooled analysis from the Asian Eye Epidemiology Consortium

Lacquer cracks in pathological myopia: a clinical review

Lacquer cracks, described as breaks in the Bruch's membrane, are unique lesions in the spectrum of fundus changes associated with pathological myopia. Lacquer cracks are generally believed to be relatively innocuous lesions by themselves; however, progression to other features of myopic macular degeneration, such as patchy chorioretinal atrophy and choroidal neovascularization, may result in irreversible visual impairment. With the rising prevalence of pathological myopia to epidemic proportions, particularly in the Asian countries, ophthalmologists expect to encounter lacquer cracks more frequently in clinical practice. Therefore, it is crucial for the ophthalmic community to be aware of lacquer cracks and to actively look for these lesions in myopic patients so that early detection and close monitoring can help prevent blinding complications. This article provides a comprehensive review on lacquer cracks in eyes with pathological myopia from a clinical perspective.

Associations of Socioeconomic Status Inequity with Incident Age-related Macular Degeneration in Middle-Aged and Elderly Population

Background: The relationship between socioeconomic status (SES) inequity and incident age-related macular degeneration (AMD) remains unclear. We aim to investigate whether low SES increases the risk of AMD and to explore the effect of a healthy lifestyle on this association. Methods: This prospective cohort study included 316,663 UK Biobank individuals. SES inequity was identified via latent class analysis using education, household income, and occupational status. Healthy lifestyle score was calculated based on smoking, alcohol drinking, and physical activity (PA). Incident AMD was defined according to diagnosis records. Cox proportional hazards models were used to evaluate the relationship of low SES and AMD. Interrelationships of healthy lifestyle score on SES-AMD association were explored, including modification, mediation, and joint effects. Results: During the average 12.2 years of follow-up, 6,355 AMD cases were diagnosed. Participants with medium SES (hazard ratio: 1.10 [95% confidence interval (CI) 1.01 to 1.21]) and low SES (hazard ratio: 1.22 [95% CI 1.11 to 1.34]) had an increased risk of incident AMD compared to participants with high SES. PA significantly affected this association. Moreover, the association between low SES and AMD was significantly mediated (11.3%, 95% CI: 6.56 to 23.0) by smoking. Similarly, alcohol drinking suppressed (9.59%, 95% CI: 4.00 to 23.2) the association between high SES and AMD. Besides, a significant joint effect of SES and healthy lifestyle score was found. Conclusions: We provide further evidence for the relationship of socioeconomic inequity, healthy lifestyle, and incident AMD. Future public health strategies should aim to reduce socioeconomic inequity to prevent AMD.

Factors associated with pathologic myopia onset and progression: A systematic review and meta-analysis

PURPOSE

To synthesise evidence across studies on factors associated with pathologic myopia (PM) onset and progression based on the META-analysis for Pathologic Myopia (META-PM) classification framework.

METHODS

Findings from six longitudinal studies (5-18 years) were narratively synthesised and meta-analysed, using odds ratio (OR) as the common measure of association. All studies adjusted for baseline myopia, age and sex at a minimum. The quality of evidence was rated using the Grades of Recommendation, Assessment, Development and Evaluation framework.

RESULTS

Five out of six studies were conducted in Asia. There was inconclusive evidence of an independent effect (or lack thereof) of ethnicity and sex on PM onset/progression. The odds of PM onset increased with greater axial length (pooled OR: 2.03; 95% CI: 1.71-2.40; p < 0.001), older age (pooled OR: 1.07; 1.05-1.09; p < 0.001) and more negative spherical equivalent refraction, SER (OR: 0.77; 0.68-0.87; p < 0.001), all of which were supported by an acceptable level of evidence. Fundus tessellation was found to independently increase the odds of PM onset in a population-based study (OR: 3.02; 2.58-3.53; p < 0.001), although this was only supported by weak evidence. There was acceptable evidence that greater axial length (pooled OR: 1.23; 1.09-1.39; p < 0.001), more negative SER (pooled OR: 0.87; 0.83-0.92; p < 0.001) and higher education level (pooled OR: 3.17; 1.36-7.35; p < 0.01) increased the odds of PM progression. Other baseline factors found to be associated with PM progression but currently supported by weak evidence included age (pooled OR: 1.01), severity of myopic maculopathy (OR: 3.61), intraocular pressure (OR: 1.62) and hypertension (OR: 0.21).

CONCLUSIONS

Most PM risk/prognostic factors are not supported by an adequate evidence base at present (an indication that PM remains understudied). Current factors for which an acceptable level of evidence exists (limited in number) are unmodifiable in adults and lack personalised information. More longitudinal studies focusing on uncovering modifiable factors and imaging biomarkers are warranted.

Is Kidney Function Associated with Age-Related Macular Degeneration?: Findings from the Asian Eye Epidemiology Consortium

PURPOSE

Chronic kidney disease (CKD) may elevate susceptibility to age-related macular degeneration (AMD) because of shared risk factors, pathogenic mechanisms, and genetic polymorphisms. Given the inconclusive findings in prior studies, we investigated this association using extensive datasets in the Asian Eye Epidemiology Consortium.

DESIGN

Cross-sectional study.

PARTICIPANTS

Fifty-one thousand two hundred fifty-three participants from 10 distinct population-based Asian studies.

METHODS

Age-related macular degeneration was defined using the Wisconsin Age-Related Maculopathy Grading System, the International Age-Related Maculopathy Epidemiological Study Group Classification, or the Beckman Clinical Classification. Chronic kidney disease was defined as estimated glomerular filtration rate (eGFR) of less than 60 ml/min per 1.73 m2. A pooled analysis using individual-level participant data was performed to examine the associations between CKD and eGFR with AMD (early and late), adjusting for age, sex, hypertension, diabetes, body mass index, smoking status, total cholesterol, and study groups.

MAIN OUTCOME MEASURES

Odds ratio (OR) of early and late AMD.

RESULTS

Among 51 253 participants (mean age, 54.1 ± 14.5 years), 5079 had CKD (9.9%). The prevalence of early AMD was 9.0%, and that of late AMD was 0.71%. After adjusting for confounders, individuals with CKD were associated with higher odds of late AMD (OR, 1.46; 95% confidence interval [CI], 1.11-1.93; P = 0.008). Similarly, poorer kidney function (per 10-unit eGFR decrease) was associated with late AMD (OR, 1.12; 95% CI, 1.05-1.19; P = 0.001). Nevertheless, CKD and eGFR were not associated significantly with early AMD (all P ≥ 0.149).

CONCLUSIONS

Pooled analysis from 10 distinct Asian population-based studies revealed that CKD and compromised kidney function are associated significantly with late AMD. This finding further underscores the importance of ocular examinations in patients with CKD.

FINANCIAL DISCLOSURE(S)

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

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.

Establishing a method to estimate the effect of antimyopia management options on lifetime cost of myopia

BACKGROUND

Informed decisions on myopia management require an understanding of financial impact. We describe methodology for estimating lifetime myopia costs, with comparison across management options, using exemplars in Australia and China.

METHODS

We demonstrate a process for modelling lifetime costs of traditional myopia management (TMM=full, single-vision correction) and active myopia management (AMM) options with clinically meaningful treatment efficacy. Evidence-based, location-specific and ethnicity-specific progression data determined the likelihood of all possible refractive outcomes. Myopia care costs were collected from published sources and key informants. Refractive and ocular health decisions were based on standard clinical protocols that responded to the speed of progression, level of myopia, and associated risks of pathology and vision impairment. We used the progressions, costs, protocols and risks to estimate and compare lifetime cost of myopia under each scenario and tested the effect of 0%, 3% and 5% annual discounting, where discounting adjusts future costs to 2020 value.

RESULTS

Low-dose atropine, antimyopia spectacles, antimyopia multifocal soft contact lenses and orthokeratology met our AMM inclusion criteria. Lifetime cost for TMM with 3% discounting was US$7437 (CI US$4953 to US$10 740) in Australia and US$8006 (CI US$3026 to US$13 707) in China. The lowest lifetime cost options with 3% discounting were antimyopia spectacles (US$7280, CI US$5246 to US$9888) in Australia and low-dose atropine (US$4453, CI US$2136 to US$9115) in China.

CONCLUSIONS

Financial investment in AMM during childhood may be balanced or exceeded across a lifetime by reduced refractive progression, simpler lenses, and reduced risk of pathology and vision loss. Our methodology can be applied to estimate cost in comparable scenarios.

IMI 2023 Digest

Myopia is a dynamic and rapidly moving field, with ongoing research providing a better understanding of the etiology leading to novel myopia control strategies. In 2019, the International Myopia Institute (IMI) assembled and published a series of white papers across relevant topics and updated the evidence with a digest in 2021. Here, we summarize findings across key topics from the previous 2 years. Studies in animal models have continued to explore how wavelength and intensity of light influence eye growth and have examined new pharmacologic agents and scleral cross-linking as potential strategies for slowing myopia. In children, the term premyopia is gaining interest with increased attention to early implementation of myopia control. Most studies use the IMI definitions of ≤-0.5 diopters (D) for myopia and ≤-6.0 D for high myopia, although categorization and definitions for structural consequences of high myopia remain an issue. Clinical trials have demonstrated that newer spectacle lens designs incorporating multiple segments, lenslets, or diffusion optics exhibit good efficacy. Clinical considerations and factors influencing efficacy for soft multifocal contact lenses and orthokeratology are discussed. Topical atropine remains the only widely accessible pharmacologic treatment. Rebound observed with higher concentration of atropine is not evident with lower concentrations or optical interventions. Overall, myopia control treatments show little adverse effect on visual function and appear generally safe, with longer wear times and combination therapies maximizing outcomes. An emerging category of light-based therapies for children requires comprehensive safety data to enable risk versus benefit analysis. Given the success of myopia control strategies, the ethics of including a control arm in clinical trials is heavily debated. IMI recommendations for clinical trial protocols are discussed.

SS-OCT-based ocular biometry in an adult Korean population with cataract

PURPOSE

To evaluate the characteristics of ocular biometric parameters in adult Korean patients with cataract.

SETTING

Department of Ophthalmology, Seoul National University Hospital, Seoul, South Korea.

DESIGN

Retrospective case series.

METHODS

Ocular biometric values of 5273 eyes of 5273 Korean patients undergoing cataract surgery measured with the IOLMaster 700 at the Seoul National University Hospital between November 2019 and December 2021 were reviewed.

RESULTS

A total of 5273 eyes of 5273 Korean patients were analyzed. The mean ± SD age was 66.1 ± 12.8 years, and 62% were female. Overall, age and ocular biometric parameters were correlated with each other. Particularly, age showed a negative correlation with anterior chamber depth (ACD; r = -0.357), axial length (AL; r = -0.344), and posterior keratometry (PK; r = -0.054) and a positive correlation with lens thickness (LT; r = 0.484), angle α ( r = 0.194), total keratometry (TK; r = 0.137), anterior keratometry (AK; r = 0.129), and angle κ ( r = 0.071). AL showed a positive correlation with ACD ( r = 0.503) and PK ( r = 0.339) and a negative correlation with AK ( r = -0.342), TK ( r = -0.334), LT ( r = -0.288), angle α ( r = -0.220), and angle κ ( r = -0.040). With age, anterior and total corneal astigmatism changed from with-the-rule (WTR) to against-the-rule (ATR) astigmatism. Posterior corneal astigmatism was ATR regardless of age; however, the magnitude decreased with age.

CONCLUSIONS

Age showed a significant correlation in the order of LT, ACD, and AL. With age, angle α and κ increased, and total corneal astigmatism changes from WTR to ATR, which is mainly affected by changes in anterior corneal astigmatism. AL showed a significant correlation in the order of ACD, AK, PK, and TK. These data are pertinent for improving the result after cataract surgery, especially when using premium intraocular lenses.

Prevalence and associated health and lifestyle factors of myopic maculopathy in northern China: the Kailuan eye study

BACKGROUND

To evaluate the prevalence and associated health and lifestyle factors of myopic maculopathy (MM) in a northern Chinese industrial city.

METHODS

The cross-sectional Kailuan Eye Study included subjects who participated in the longitudinal Kailuan Study in 2016. Ophthalmologic and general examinations were performed on all the participants. MM was graded based on fundus photographs using the International Photographic Classification and Grading System. The prevalence of MM was evaluated. Univariate and multiple logistic regression were adopted to evaluated risk factors of MM.

RESULTS

The study included 8330 participants with gradable fundus photographs for MM and ocular biometry data. The prevalence of MM was 1.11% (93/8330; 95% confidence interval [CI] 0.89-1.33%). Diffuse chorioretinal atrophy, patchy chorioretinal atrophy, macular atrophy, and plus lesions were observed in 72 (0.9%), 15 (0.2%), 6 (0.007%), and 32 eyes (0.4%), respectively. MM was more common in eyes with longer axial length (OR 4.517; 95%CI 3.273 to 6.235) and in participants with hypertension (OR 3.460; 95%CI 1.152 to 10.391), and older age (OR 1.084; 95%CI 1.036 to 1.134).

CONCLUSIONS

The MM was present in 1.11% of the northern Chinese individuals 21 years or older and the associate factors include longer axial length, older age, and hypertension.

Clinical Feasibility and Safety of Scleral Collagen Cross-Linking by Riboflavin and Ultraviolet A in Pathological Myopia Blindness: A Pilot Study

INTRODUCTION

To investigate the feasibility and safety of scleral ultraviolet A (UVA) cross-linking (scleral CXL) on pathologically blindness.

METHODS

This was a prospective, observational clinical study. Five patients with monocular blindness due to pathological myopic maculopathy were enrolled. Eyes with best corrected visual acuity (BCVA) under 0.05 were defined as experimental eyes. The fellow eyes were defined as control eyes. Patients first underwent posterior scleral reinforcement (PSR) surgery in the control eye. Thereafter, scleral CXL surgery was performed in the experimental eye on the same day. Visual acuity, BCVA, slit lamp biomicroscopic examination, intraocular pressure measurement, corneal specula microscopies, axis length measurement, funduscopy with pupil dilation, color fundus photography, full-field flash electroretinography, optical coherence tomography, and color Doppler flow imaging were performed at baseline, 1 week, 1 month, 3 months, 6 months, and 12 months after surgery.

RESULTS

No signs of inflammation were observed after operation and throughout the follow-up period. Retinoschisis was improved, while choroidal neovascularization fibrosis and retinal and choroidal atrophy were unchanged after scleral CXL. There were no statistically significant differences in the ophthalmic artery, central retinal artery, and posterior ciliary artery parameters of color Doppler flow imaging or in retinal thickness, within experimental and control eyes, at baseline, 1 week, 1 month, 3 months, or 12 months (P > 0.05).

CONCLUSIONS

This pilot study verified the feasibility and safety of scleral CXL on human blindness. The UVA-CXL on the sclera of human eyes seems to have the same effect as PSR in preventing progressive pathological myopia in the future.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2100042422).

A deep network using coarse clinical prior for myopic maculopathy grading

Pathological Myopia (PM) is a globally prevalent eye disease which is one of the main causes of blindness. In the long-term clinical observation, myopic maculopathy is a main criterion to diagnose PM severity. The grading of myopic maculopathy can provide a severity and progression prediction of PM to perform treatment and prevent myopia blindness in time. In this paper, we propose a feature fusion framework to utilize tessellated fundus and the brightest region in fundus images as prior knowledge. The proposed framework consists of prior knowledge extraction module and feature fusion module. Prior knowledge extraction module uses traditional image processing methods to extract the prior knowledge to indicate coarse lesion positions in fundus images. Furthermore, the prior, tessellated fundus and the brightest region in fundus images, are integrated into deep learning network as global and local constrains respectively by feature fusion module. In addition, rank loss is designed to increase the continuity of classification score. We collect a private color fundus dataset from Beijing TongRen Hospital containing 714 clinical images. The dataset contains all 5 grades of myopic maculopathy which are labeled by experienced ophthalmologists. Our framework achieves 0.8921 five-grade accuracy on our private dataset. Pathological Myopia (PALM) dataset is used for comparison with other related algorithms. Our framework is trained with 400 images and achieves an AUC of 0.9981 for two-class grading. The results show that our framework can achieve a good performance for myopic maculopathy grading.

Prevalence of Myopic Macular Features in Dutch Individuals of European Ancestry With High Myopia

Question

What is the prevalence of myopic macular degeneration in Dutch individuals of European ancestry with high myopia?

Findings

In this cross-sectional study of 626 individuals with European ancestry with high myopia, the prevalence of myopic macular degeneration was 25.9% and increased with older age, lower spherical equivalent of refractive error, and higher axial length.

Meaning

Myopic retinal features were frequent in this highly myopic study population, but not different than patients of Asian ancestry with similar risk profiles.

Importance

High myopia incidence and prevalence is increasing worldwide, and the visual burden caused by myopia is expected to rise accordingly. Studies investigating the occurrence of myopic complications in individuals of European ancestry with high myopia are scarce, hampering insights into the frequency of myopic retinal complications in European individuals and their visual burden.

Objective

To assess the frequency of myopic macular features in individuals of European ancestry with high myopia.

Design, Setting, and Participants

This cross-sectional analysis of the Dutch Myopia Study (MYST) and individuals with high myopia from the Rotterdam Study (RS) included 626 patients with high myopia (spherical equivalent of refractive error [SER] ≤−6 diopters [D] or axial length [AL] ≥26 mm) who underwent an extensive ophthalmic examination including multimodal retinal imaging. In addition to this combination of a population-based cohort study and mix-based high myopia study, a systematic literature review was also performed to compare findings with studies of individuals of Asian ancestry.

Exposures

High myopia, age, and AL.

Main Outcomes and Measures

Frequency of myopic macular and optic disc features: tessellated fundus, myopic macular degeneration (MMD), staphyloma, peripapillary intrachoroidal cavitation, peripapillary atrophy (PPA), and “plus” lesions (choroidal neovascularization, Fuchs spot, and lacquer cracks).

Results

The mean (SD) SER of the combined study population (MYST and RS) was −9.9 (3.2) D; the mean (SD) age was 51.4 (15.1) years, and 387 (61.8%) were women. The prevalence of MMD was 25.9% and increased with older age (P for trend <.001), lower SER (odds ratio [OR], 0.70; 95% CI, 0.65-0.76; P < .001), and higher AL (OR, 2.53; 95% CI, 2.13-3.06; P < .001). Choroidal neovascularization or Fuchs spot was present in 2.7% (n = 17), both lesions in 0.3% (n = 2), and lacquer cracks in 1.4% (n = 9). Staphyloma, PPA, and MMD were highly prevalent in visual impaired and blind eyes (frequency was 73.9% [20 of 27], 90.5% [19 of 21], and 63.0% [17 of 27] of unilateral blind eyes for MMD, staphyloma, and PPA, respectively). Seven previous studies in Asian populations reported a variable MMD frequency ranging from 8.3% to 64%, but frequencies were similar for comparable risk profiles based on age and SER.

Conclusions and Relevance

In this cross-sectional study of a highly myopic Dutch population of European ancestry, myopic retinal features were frequent; were associated with age, SER, and AL; and occurred in all visually severely impaired eyes. The absence of treatment options for most of these retinal complications emphasizes the need for effective strategies to prevent high myopia.

Progression Patterns of Myopic Traction Maculopathy in the Fellow Eye After Pars Plana Vitrectomy of the Primary Eye

Purpose

This retrospective study investigated the patterns and risk factors of progression of myopic traction maculopathy (MTM) of fellow eyes after pars plana vitrectomy (PPV) of primary eyes.

Methods

The study population comprised 153 patients with MTM in both myopic eyes who sequentially underwent PPV (2006–2021). Observation periods were from PPV of the primary eye (baseline) to PPV of the fellow (end). MTM was graded based on optical coherence tomography (OCT) images and the ATN (atrophy [A], traction [T], and neovascularization [N]) system. An increase in T grade was considered MTM progression.

Results

MTM progressed in 43.8% of fellow eyes during 34.57 ± 34.08 months. The progression of fellow eyes correlated with T grade of primary eyes (P < 0.001). Risk factors for the progression of MTM in fellow eyes were primary eyes in T4–T5, age at baseline <60 years, and fellow eyes with partial posterior vitreous detachment (PVD; P < 0.001, P = 0.042, and P = 0.002, respectively). Fellow eyes in T1/T2 at baseline progressed faster compared with those in T0 (P < 0.001); the annual rate of progression to T3–T5 of the T0 (T1–T2) groups was 9.98% (24.59%).

Conclusions

Risk factors for the progression of MTM in fellow eyes included PPV when relatively young, primary eye at high T grade, and partial PVD of the fellow eye. Personalized follow-up for fellow eyes should be based on the severity of MTM of both eyes.

Retinal Nerve Fiber Layer Thickness and Rim Area Profiles in Asians: Pooled Analysis from the Asian Eye Epidemiology Consortium

PURPOSE

To evaluate ethnic variations, ocular and systemic determinants of retinal nerve fibre layer (RNFL) thickness and neuroretinal rim area among Asians, using a large consortium of population-based eye studies.

DESIGN

Cross-sectional pooled-analysis.

PARTICIPANTS

22436 participants (22436 eyes) from 10 population-based studies (China, Hong Kong, India, Japan, Russia and Singapore) of the Asian Eye Epidemiology Consortium.

METHODS

Participants aged ≥40 years without glaucoma were included. All participants underwent spectral domain optical coherence tomography (OCT) imaging, systemic and ocular examinations. Data were pooled from each study. Multivariable regression analysis was performed to evaluate inter-ethnic, inter-machine variations, ocular and systemic factors associated with RNFL thickness and rim area, adjusting for age, gender, diabetes, intraocular pressure (IOP), spherical equivalent (SE), ethnicity, OCT model, and study group. When evaluating body mass index, smoking, and hypertension as exposures, these factors were additionally adjusted in the model.

MAIN OUTCOME MEASURE

Average RNFL thickness (μm) and rim area (mm²) RESULTS: Indian and Japanese eyes showed thinner RNFL, compared to other Asian ethnicities (β values ranging 7.31-12.76μm, P<0.001 for all pair-wise comparisons). Compared to measurements by Cirrus HD-OCT, RNFL was on average 7.29μm thicker when measured by Spectralis, 12.85μm thicker by Nidek, and 17.48μm thicker by Optovue (all P<0.001). Additionally, older age (per decade, β=-2.70; 95% confidence interval [CI], -2.85 to -2.55), diabetes (β=-0.72; 95%CI, -1.20 to -0.24), ), higher IOP (per mmHg, β=-0.07; 95% CI, -0.10 to -0.04), more myopic SE (per dioptre, β=-1.13; 95% CI, -1.19 to -1.07), cardiovascular disease (CVD, β=-0.94; 95% CI, -1.49 to -0.40), and hypertension (β=-0.68; 95% CI, -1.04 to -0.32), were associated with thinner RNFL (all P≤0.003). Similarly, older age (β=-0.019; 95% CI, -0.028 to -0.009), higher IOP (β=-0.010; 95% CI, -0.013 to -0.008) and more myopic SE (β=-0.025; 95% CI, -0.029 to -0.021) were associated with smaller rim area (all P<0.001).

CONCLUSIONS

In this large pooled-analysis of multiple Asian population studies, Indian and Japanese eyes were observed to have thinner RNFL profiles. In addition to previously known determinants, hypertension and CVD were associated with thinner RNFL. These findings further suggest the need of ethnic-specific normative database to improve glaucoma detection.

Choroidal remodeling distribution pattern in the macular region in Chinese young patients with myopia

Background

The pathogenesis of myopia has been found to be associated with the blood supply of the choroid. This study aimed to determine the relationship between the distribution pattern of choroidal remodeling and the degree of myopia in young patients.

Methods

Young patients (age < 18 years) with the spherical equivalent of less than − 12 diopters (D) were included. Spectral-domain optical coherence tomography (SD-OCT) with enhanced depth imaging (EDI) modality was used to measure the choroidal thickness (CT) and choroidal vascularity index (CVI) in the macular regions. CVI was calculated as the proportion of luminal area to choroidal area and was measured within 1 mm and 3 mm nasal (N1 and N3), temporal (T1 and T3), superior (S1 and S3), and inferior (I1 and I3) to the foveal center. CVI was compared across different ages (i.e., 5 ~ 9 years, 10 ~ 13 years, and 14 ~ 18 years), axial lengths (ALs) (i.e., 21.00 ~ 25.00 mm and 25.01 ~ 29.00 mm), and spherical equivalents (SEs) (i.e., SE > -0.5D, − 0.5 ~ − 3.0D, − 3.01 ~ − 6.0D, and < − 6.0D). Linear regression analysis was applied to assess the association between independent (i.e., age, AL, SE, and intraocular pressure) and dependent variables (i.e., CVI of different regions).

Results

One hundred sixty-four eyes from 85 volunteers were included. The mean CT in the central foveal was 269.87 ± 63.32 μm (93.00 μm to 443.00 μm). The mean subfoveal-CVI was 67.66 ± 2.40% (57.84 to 79.60%). Multiple linear regression results revealed significant correlations between SE and T1-CVI (p < 0.05, r² = 0.082, β = 0.194), N1-CVI (p < 0.05, r² = 0.039, β = 0.212). Simple linear regression results revealed that T1-CVI (p < 0.05, r² = 0.09) and T3-CVI (p < 0.05, r² = 0.05) were negatively correlated with SE; N1-CVI (p < 0.05, r² = 0.05) and N3-CVI (p < 0.05, r² = 0.04) were negatively correlated with SE.

Conclusions

CVI in the horizontal meridian underwent the largest change as myopia worsened. Temporal and nasal CVIs within the r = 1 mm, and r = 3 mm subfoveal range were positively associated with the degree of myopia in young patients. The CVI value may be used to assess the vascular status of the choroid and be a potential marker of myopic progression.

Health insurance enrollment and vision health in rural China: an epidemiological survey

Background

Vision health is an important aspect of health worldwide. Visual impairment (VI) is associated with poor quality of life and is usually more prevalent in rural areas. To help rural populations obtain vision care, health insurance policies have emerged throughout the world. However, some existing literatures show that health insurance enrollment’s impact on the overall physical health of rural population has been minimal. Focusing on vision health among adults in rural China, our study aims to investigates the impact of health insurance on vision health, heterogeneity of the effect, and the moderating effect of health insurance enrollment on the impact of chronic physical diseases and basic eye diseases on vision health.

Methods

Primary data were collected through a nation-wide epidemiological survey of vision health conducted in rural China in 2018, with a sample size of 28,787 used in our statistical analysis. Instrumental variables regression and Heckman selection models were conducted to examine the impact of health insurance enrollment and reimbursement ratio adults’ vision health outcomes. Subsample regressions by sex, age, education level, and whether with eye diseases were further conducted to explore the heterogeneity in our results. We then examined whether health insurance enrollment moderates the impact of chronic physical diseases and basic eye diseases on vision health through the method of introducing interaction terms.

Results

Participating in health insurance reduced the probability of VI by 2.15 %. The reimbursement rate increasing by 1 % point may reduce the probability of worsening VI by 6.12 %. Men (-0.0235, P = 0.0002) benefit more from insurance enrollment than women (-0.0201, P = 0.0082) with respect to vision health. From the young adult group to the oldest group, the marginal effect of health insurance increased from − 0.0068 (P = 0.0394) to -0.0753 (P < 0.0001). The marginal effect on VI was most significant in people with lower education levels and weakened with increased education levels. People with basic eye diseases (-0.0496, P = 0.0033) benefit more from participating insurance than the people without basic eye diseases (-0.0196, P = 0.0001) with respect to vision health. The moderating effects of health insurance enrollment on the impacts of cerebral infarction (-0.1225, P < 0.0001), diabetes (-0.0398, P = 0.0245), hyperlipidemia (-0.1364, P = 0.0271), mental illness (-0.1873, P = 0.0010), glaucoma (-0.1369, P = 0.0073), diabetic retinopathy (-0.1560, P = 0.0043), and retinal vein obstruction (-0.2018, P = 0.0155) on vision health were significantly negative.

Conclusions

The results suggest that participation in health insurance and higher health insurance reimbursement ratios reduced the risk of VI in the sampled adults. Health insurance has the most significant effect in in vulnerable groups. Heath insurance enrollment moderates the impacts of several chronic physical and basic eye conditions on vision health. Our findings have potential implications for reforming health insurance policies to improve vision health conditions in rural areas of developing countries.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-06754-0.

Optic nerve head anatomy in myopia and glaucoma, including parapapillary zones alpha, beta, gamma and delta: Histology and clinical features

The optic nerve head can morphologically be differentiated into the optic disc with the lamina cribrosa as its basis, and the parapapillary region with zones alpha (irregular pigmentation due to irregularities of the retinal pigment epithelium (RPE) and peripheral location), beta zone (complete RPE loss while Bruch's membrane (BM) is present), gamma zone (absence of BM), and delta zone (elongated and thinned peripapillary scleral flange) within gamma zone and located at the peripapillary ring. Alpha zone is present in almost all eyes. Beta zone is associated with glaucoma and may develop due to a IOP rise-dependent parapapillary up-piling of RPE. Gamma zone may develop due to a shift of the non-enlarged BM opening (BMO) in moderate myopia, while in highly myopic eyes, the BMO enlarges and a circular gamma zone and delta zone develop. The ophthalmoscopic shape and size of the optic disc is markedly influenced by a myopic shift of BMO, usually into the temporal direction, leading to a BM overhanging into the intrapapillary compartment at the nasal disc border, a secondary lack of BM in the temporal parapapillary region (leading to gamma zone in non-highly myopic eyes), and an ocular optic nerve canal running obliquely from centrally posteriorly to nasally anteriorly. In highly myopic eyes (cut-off for high myopia at approximately -8 diopters or an axial length of 26.5 mm), the optic disc area enlarges, the lamina cribrosa thus enlarges in area and decreases in thickness, and the BMO increases, leading to a circular gamma zone and delta zone in highly myopic eyes.