FIVE-YEAR INCIDENCE OF FELLOW EYE NEOVASCULAR INVOLVEMENT IN AGE-RELATED MACULAR DEGENERATION AND POLYPOIDAL CHOROIDAL VASCULOPATHY IN AN ASIAN POPULATION

Bilateral Involvement of Age-Related Macular Degeneration in South Korea: Findings from the Korea National Health and Nutrition Examination Survey 2017-2020

PURPOSE

To evaluate the bilateral involvement of age-related macular degeneration (AMD) in South Koreans.

METHODS

This was a cross-sectional study of the Korean National Health and Nutrition Examination Survey (2017-2020). This study included 13,737 participants aged 40 years or older. Participants were evaluated to determine the prevalence of bilateral early and late AMD. In cases in which exudative AMD or geographic atrophy (GA) was diagnosed in a single eye, the fellow eye was evaluated to determine the presence and type of late AMD.

RESULTS

The overall prevalence of bilateral AMD was 6.12% (95% confidence interval [CI], 5.63-6.61). The prevalence of bilateral early AMD was 5.71% (95% CI, 5.24-6.18), while that of late AMD was 0.14% (95% CI, 0.08-0.20). The prevalence of the bilateral involvement of late AMD increased with age. A 0.02% prevalence (95% CI, 0.00-0.06) of late AMD was observed in participants aged 50-59. The prevalence increased to 0.08% (95% CI, 0.00-0.18) in participants aged 60-69, while the prevalence in participants aged 70-79 and over 80 was 0.45% (95% CI, 0.12-0.78) and 1.97% (95% CI, 0.75-3.19), respectively. The prevalence of early AMD in one eye and late AMD in the fellow eye was 0.26% (95% CI, 0.16-0.36).

CONCLUSIONS

An assessment of the incidence of AMD revealed that a significant number of persons had bilateral involvement. The treatment burden may significantly increase for participants with bilateral late AMD compared to those with unilateral involvement. Therefore, the study may be helpful with the establishment of private and national insurance policies.

Predict and Protect: Evaluating the Double-Layer Sign in Age-Related Macular Degeneration

INTRODUCTION

Advanced age-related macular degeneration (AMD) is a major cause of vision loss. Therefore, there is interest in precursor lesions that may predict or prevent the onset of advanced AMD. One such lesion is a shallow separation of the retinal pigment epithelium (RPE) and Bruch's membrane (BM), which is described by various terms, including double-layer sign (DLS).

METHODS

In this article, we aim to examine and clarify the different terms referring to shallow separation of the RPE and BM. We also review current evidence on the outcomes associated with DLS: firstly, whether DLS is predictive of exudative neovascular AMD; and secondly, whether DLS has potential protective properties against geographic atrophy.

RESULTS

The range of terms used to describe a shallow separation of the RPE and BM reflects that DLS can present with different characteristics. While vascularised DLS appears to protect against atrophy but can progress to exudation, non-vascularised DLS is associated with an increased risk of atrophy. Optical coherence tomography (OCT) angiography (OCTA) is the principal method for identifying and differentiating various forms of DLS. If OCTA is unavailable or not practically possible, simplified classification of DLS as thick or thin, using OCT, enables the likelihood of vascularisation to be approximated. Research is ongoing to automate DLS detection by applying deep-learning algorithms to OCT scans.

CONCLUSIONS

The term DLS remains applicable for describing shallow separation of the RPE and BM. Detection and classification of this feature provides valuable information regarding the risk of progression to advanced AMD. However, the appearance of DLS and its value in predicting AMD progression can vary between patients. With further research, individualised risks can be confirmed to inform appropriate treatment.

Development and validation of optical coherence tomography (OCT) and OCT angiography prediction model for short-term vitreous haemorrhage secondary to polypoidal choroidal vasculopathy

AIMS

To construct and validate an optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) image model for predicting the occurrence of short-term vitreous haemorrhage (VH) in polypoidal choroidal vasculopathy (PCV) patients.

METHODS

We retrospectively collected clinical and imaging information from patients diagnosed with PCV at Peking Union Medical College Hospital, Beijing, China, between January 2015 and October 2022. Six different screening strategies, including univariate analysis, multivariate analysis, least absolute shrinkage and selection operator, stepwise logistic regression, random forest and clinical-data-only approach, were used to select variables and build models. The nomogram was constructed based on the model with the best area under the curve (AUC) and was evaluated using receiver operating characteristic curves, calibration curves, decision curve analysis and clinical impact curves.

RESULTS

A total of 147 PCV patients were included and randomly divided into a training set (103 patients) and a validation set (44 patients), with an average follow-up time of 17.56±14.99 months. The optimal model that achieved higher AUC in both training and validation sets incorporated seven significant variables identified through univariate analysis: male [OR=2.76, p=0.022], central macular thickness [OR=1.003, p=0.002], the presence of haemorrhagic pigment epithelial detachment (HPED) [OR=6.99, p<0.001], the height of HPED [OR=1.002, p<0.001], the area of HPED [OR=1.16, p<0.001], the presence of multiple PEDs [OR=2.94, p=0.016] and the presence of subretinal haemorrhage [OR=3.11, p=0.011]. A predictive nomogram based on these variables yielded an AUC of 0.896 (95% CI 0.827 to 0.965) in the training set and 0.861 (95% CI 0.749 to 0.973) in the validation set, demonstrating good calibration and clinical usefulness.

CONCLUSION

The proposed OCT/OCTA-based image nomogram, as a novel and non-invasive tool, achieved satisfactory prediction of VH secondary to PCV.

Importance of optical coherence tomography raster scans in early detection of active fellow-eye neovascularization in unilateral neovascular age-related macular degeneration

PURPOSE

To investigate the incidence of and risk factors for failure of detection of active fellow-eye neovascularization on optical coherence tomography(OCT) crosshair scans in patients with unilateral neovascular age-related macular degeneration(AMD).

METHODS

In this retrospective study, patients who experienced the development of active neovascularization in the fellow eye during the follow-up period were included(n = 75). Cases in which the neovascularization in the fellow eye could be identified solely through crosshair scans were defined as the crosshair scan detection group(n = 63). Cases in which the aforementioned findings could not be identified through crosshair scans but could be identified through raster scans were defined as the raster scan detection group(n = 12). The factors were compared between the two groups. Risk factors related to undetected neovascularization on crosshair scans were additionally identified.

RESULTS

Active fellow-eye neovascularization, was not detected on OCT crosshair scans in 12 cases(16.0%) but was identified on raster scans in all cases. There was a significant difference in the proportion of neovascularization types between the crosshair scan detection group and the raster scan detection group(P = 0.023). Among the 35 fellow-eye neovascularization cases in patients with type 3 macular neovascularization(MNV), 10(28.6%) were not detected on crosshair scans. Multivariate analysis revealed a significantly higher risk for undetectable fellow-eye neovascularization on crosshair scans in patients with type 3 MNV than in those with typical neovascular AMD(P = 0.037,β = 9.600).

CONCLUSIONS

Our findings suggest the need for routine OCT raster scans during fellow-eye examinations in patients with unilateral neovascular AMD, particularly when the first-affected eye is diagnosed with type 3 MNV.

Pachychoroid disease: review and update

The pachychoroid disease spectrum is a phenotype characterized by alterations in choroidal vasculature which result in outer retinal and choriocapillaris damage and visual loss. The presence of pachyvessels is one of the key features of the pachychoroid phenotype. Recent imaging studies suggest that pachyvessels may form because of choroidal venous congestion in one or more quadrants. The formation of intervortex anastomosis may function as a compensatory mechanism to dissipate the increased venous pressure, while outflow obstruction has been hypothesized to occur at the site of the vortex vein exiting the sclera. This review aims to summarize recent imaging findings and discuss evolution in the understanding of pathogenesis of the pachychoroid disease spectrum. We have summarized notable treatment trials in central serous chorioretinopathy and polypoidal choroidal vasculopathy and included an update of the current diagnostic and management strategies of the entities that are part of the pachychoroid disease spectrum.