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).

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.

Tear inflammatory cytokines as potential biomarkers for myopic macular degeneration

Previous studies have reported that inflammatory cytokine levels increase in the intraocular fluids (aqueous humor and vitreous) of highly myopic eyes, However, there has been currently no study revealing the levels of inflammatory cytokines in tear. Therefore, this study aimed to determine tear cytokine levels of highly myopic eyes, and their relationships with myopic macular degeneration (MMD). This case-control study screened inflammatory cytokines of tear samples from 132 highly myopic and 105 emmetropic eyes using a multiplex cytokine antibody array, and cytokines showing significant intergroup differences were further validated using ProQuantum immunoassays in tear samples from another 60 highly myopic and 60 emmetropic eyes. Ultra-widefield fundus photographs of eyes were classified according to the meta-analyses of the Pathologic Myopia Classification. Associations between tear cytokine levels and MMD category were investigated. As a result, tear levels of interleukin (IL)-6, IL-13 and monocyte chemoattractant protein (MCP)-1 were screened significantly higher in highly myopic eyes than in emmetropic controls (IL-6: 11.70 ± 16.81 versus 8.22 ± 10.76 pg/mL; MCP-1: 63.60 ± 54.40 versus 33.87 ± 43.82 pg/mL; both P < 0.05). Validation assays further demonstrated the elevated concentrations of IL-6 and MCP-1 (IL-6: 13.97 ± 8.41 versus 8.06 ± 7.94 pg/mL, P < 0.001; MCP-1: 32.69 ± 8.41 versus 18.07 ± 8.41 pg/mL, P = 0.003). Tear levels of IL-6 and MCP-1 differed significantly among MMD categories (both P < 0.05). The area under receiver operating characteristic curve were 0.783 and 0.682 respectively (both P < 0.05), when using tear IL-6 and MCP-1 levels to predict the presence of MMD (category ≥2). The ordered logistic regression model also indicated that longer axial length, and higher IL-6 and MCP-1 tear levels were independent predictors of higher MMD category. In our study, highly myopic eyes presented significantly higher levels of tear IL-6 and MCP-1, which may also serve as potential biomarkers for MMD.

Myopic macular Bruch's membrane defects

Purpose

To examine histologic characteristics of macular Bruchś membrane defects (BMD) in axially elongated eyes.

Design

Histomorphometric study.

Methods

Using light microscopy, we examined enucleated human globes for BMDs.

Results

In 247 eyes, BMDs were detected in 15 (6.1%) eyes (axial length:27.0-36.0 mm), in 10 of them in the macular region. Prevalence and size of BMDs (mean:1.93 ± 1.62 mm; range:0.22mm-6.24 mm) correlated with longer axial length (OR:1.52; 95%CI:1.19,1.94; P = 0.001) and higher prevalence of scleral staphylomas (OR:16.3; 95%CI:2.67,99.3; P < 0.001). The BMDs were smaller than corresponding gaps in the retinal pigment epithelium (RPE) (1.93 ± 1.62 mm versus 2.61 mm ± 1.73 mm; P = 0.003), and larger than corresponding gaps in the inner nuclear layer (0.43 ± 0.76 mm; P = 0.008) and inner limiting membrane bridges (0.13 ± 0.33 mm; P = 0.001). Choriocapillaris thickness, BM thickness and RPE cell density did not vary (all P > 0.05) between the BDM border and adjacent areas. In the BMD, choriocapillaris and RPE were absent. The sclera was thinner in the BDM area than in adjacent areas (0.28 ± 0.19 mm versus 0.36 ± 0.13 mm; P = 0.006).

Conclusions

BMDs as hallmarks of myopic macular degeneration are characterized by longer gaps in the RPE and smaller gaps in the outer nuclear layer and inner nuclear layer, by localized scleral thinning, and by a spatial association with scleral staphylomas. Thickness of the choriocapillaris and density of the RPE cell layer, both absent within the BDMs, do not vary between the BMD border and adjacent regions. The results suggest an association between BDMs and absolute scotomas, stretching of the adjacent retinal nerve fiver layer, and an axial elongation-associated stretching effect on BM as etiology of the BDMs.

Long-term Incidence and Risk Factors of Macular Fibrosis, Macular Atrophy, and Macular Hole in Eyes with Myopic Neovascularization

PURPOSE

To identify the risk factors associated with myopic macular neovascularization (mMNV)-related complications in patients treated with intravitreal anti-VEGF agents.

DESIGN

Longitudinal cohort study.

PARTICIPANTS

Myopic eyes (n = 313) with active mMNV and median (interquartile range) follow-up of 42 months (interquartile range, 18-68 months) after initiation of anti-VEGF treatment.

METHODS

Data regarding patients' clinical and mMNV-related characteristics were collected at baseline. Subsequent OCT scans were inspected for mMNV-related complications. Best-measured visual acuity (BMVA) values were retrieved from each visit.

MAIN OUTCOME MEASURES

Incidence rate and hazard ratio (HR, with 95% confidence interval [CI]) of risk factors for fibrosis and macular atrophy calculated with Kaplan-Meier curves and Cox regression models. Crude incidence of macular hole (MH). Longitudinal BMVA changes.

RESULTS

Five-year incidence of fibrosis, atrophy, and MH were 34%, 26%, and 8%, respectively. The rate of fibrosis was 10.3 (95% CI, 8.25-12.6) per 100 person-years. Risk factors were subfoveal mMNV location (HR [95% CI] = 12.7 [2.70-56.7] vs. extrafoveal, P = 0.001) and intraretinal fluid at baseline (HR [95% CI] = 1.75 [1.05-2.98], P = 0.03). The rate of macular atrophy was 6.5 (95% CI, 5-8.3) per 100 person-years. Risk factors were diffuse (HR, 2.20 vs. tessellated fundus; 95% CI, 1.13-5.45; P = 0.02) or patchy chorioretinal atrophy (HR, 3.17 vs. tessellated fundus; 95% CI, 1.32-7.64; P = 0.01) at baseline and more numerous anti-VEGF injections before baseline (HR, 1.21; 95% CI, 1.06-1.38 for each treatment; P = 0.005). Eyes with fibrosis and macular atrophy had faster BMVA decay over follow-up. Twenty eyes (6%) developed MH. Two subtypes of MH were identified: "atrophic" and "tractional."

CONCLUSIONS

Myopic MNV-related complications are common in the long term despite initially successful treatment and have detrimental effects on visual acuity. Insights into their incidence and risk factors may help for future treatments to mitigate sight-threatening outcomes.

Prevalence and related factors of myopic retinopathy - a hospital-based cross-section study in Vietnam

CLINICAL RELEVANCE

Myopia prevention and anti-myopia treatment is of great importance in South East Asia.

BACKGROUND

To evaluate the prevalence and related factors of myopic retinopathy in Vietnam.

METHODS

A cross-sectional study was conducted on 168 eyes of 88 patients with high myopia presenting to the Refraction Department of Vietnam National Eye Hospital. Inclusion criteria were high myopia (≤-6.00D with cycloplegic retinoscopy). Consecutive presenting patients recruited between January 2020 and August 2020 consented to participate.

RESULTS

Participant age range was 12-47 years. Peripapillary atrophy was present in 70.2% of participants, most commonly atrophy of one-quarter of the disc (38.7%). Central retinal changes were present in 66.1% of participants, subclassified as tessellated fundus in 60.7%, diffuse chorioretinal atrophy in 4.2% and patchy chorioretinal atrophy in 1.2%. Peripheral retinal lesions were present in 43.5% of participants, consisting of white-without-pressure in 32.1%, lattice degeneration in 16.1%, snail track degeneration in 4.2% and microcystoid degeneration in 1.2%. Myopia ≤-8.00D and axial length ≥26.5 mm were associated with additional risk of posterior ocular complications. Furthermore, age ≥19 years increased risk of central myopic retinopathy and ≥10 years since initial myopia diagnosis increased the risk of peripapillary atrophy and central retinal changes. Other factors such as the age of onset of myopia and family myopia history did not appear to alter the risk of peripheral retina damage.

CONCLUSIONS

Retinal disorders were common in Vietnamese people with high myopia. Within the current cohort with high myopia, myopia ≤-8.00D and axial length ≥26.5 mm were associated with a significant further elevation of risk.

Large choroidal excavation in myopic macular degeneration: A case report

PURPOSE

To report the morphological and clinical features of a case of myopic macular degeneration with large choroidal excavation.

METHODS

A myopic patient underwent multimodal imaging, including optical coherence tomography and fluorescein angiography, over a 8-year follow-up.

RESULTS

A choroidal excavation was found in left eye, superior to the fovea. The excavation started as a focal choroidal excavation (FCE) and got deeper and larger during the 8-years-long follow-up, thus resulting in a large choroidal excavation (LCE).

CONCLUSIONS

LCE may be the evolution of FCE in highly myopic eyes, further studies are needed to describe the natural history of choroidal excavations in degenerative myopia.