Treatment-naïve quiescent macular neovascularization secondary to AMD: The 2019 Young Investigator Lecture of Macula Society

MORPHOLOGICAL BIOMARKERS PREDICTING EXUDATIVE CONVERSION IN TYPE 1 NONEXUDATIVE MACULAR NEOVASCULARIZATION USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY

PURPOSE

To investigate the incidence and morphological biomarkers to predict the exudative conversion in eyes with type 1 nonexudative macular neovascularization using swept-source optical coherence tomography angiography.

METHODS

Macular neovascularizations were detected using the retinal pigment epithelium-to-retinal pigment epithelium-fit slab of swept-source optical coherence tomography angiography scan. Depending on whether exudation developed within a year, the eyes were divided into two groups: active and silent. Qualitative and quantitative optical coherence tomography angiography parameters of the two groups were evaluated to discriminate the biomarkers associated with exudative conversion.

RESULTS

Of the 40 eyes, nine developed exudation within 1 year (incidence rate 22.5%). The active group exhibited a significantly higher "anastomosis and loops" pattern, greater "vessel density," increased "junction density," fewer "number of end points," and lower "lacunarity" compared with the silent group. "Anastomosis and loops" and higher "vessel density" were correlated with the active group in multivariate analyses. A predictive model combining these biomarkers achieved 95% accuracy in predicting exudative conversion.

CONCLUSION

At 12 months, the risk of exudation was 22.5%, and "anastomosis and loops" and "vessel density" were useful optical coherence tomography angiography biomarkers for predicting exudative conversion in eyes with type 1 nonexudative macular neovascularization. For eyes with a high risk of exudative conversion, more frequent follow-up is recommended.

Optical coherence tomography biomarkers in early and intermediate age-related macular degeneration: A clinical guide

Advanced forms of age-related macular degeneration (AMD), characterised by atrophic and neovascular changes, are a leading cause of vision loss in the elderly population worldwide. Prior to the development of advanced AMD, a myriad of risk factors from the early and intermediate stages of AMD have been published in the scientific literature over the last years. The ability to precisely recognise structural and anatomical changes in the ageing macula, altogether with the understanding of the individual risk implications of each one of them is key for an accurate and personalised diagnostic assessment. The present review aims to summarise updated evidence of the relative risk conferred by diverse macular signs, commonly seen on optical coherence tomography, in terms of progression to geographic atrophy or macular neovascularization. This information may also serve as a basis for tailored follow-up monitoring visits.

Optical Coherence Tomography Angiography: A 2023 Focused Update on Age-Related Macular Degeneration

Optical coherence tomography angiography (OCTA) has extensively enhanced our comprehension of eye microcirculation and of its associated diseases. In this narrative review, we explored the key concepts behind OCTA, as well as the most recent evidence in the pathophysiology of age-related macular degeneration (AMD) made possible by OCTA. These recommendations were updated since the publication in 2020, and are targeted for 2023. Importantly, as a future perspective in OCTA technology, we will discuss how artificial intelligence has been applied to OCTA, with a particular emphasis on its application to AMD study.

Reduction of retinal vessel density in non-exudative macular neovascularization: a retrospective study

Purpose

The purpose of this study is to identify predictive activation biomarkers in retinal microvascular characteristics of non-exudative macular neovascularization (MNV) and avoid delayed treatment or overtreatment of subclinical MNV. The main objective is to contribute to the international debate on a new understanding of the role of retinal vessel features in the pathogenesis and progression of non-exudative MNV and age-related macular degeneration (AMD). A discussion on revising-related clinical protocols is presented.

Methods

In this retrospective study, the authors included eyes with non-exudative MNV, eyes with exudative AMD, and normal eyes of age-matched healthy subjects. The parameters were obtained by optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA).

Results

In total, 21 eyes with exudative AMD, 21 eyes with non-exudative MNV, and 20 eyes of 20 age-matched healthy subjects without retinal pathology were included. Vessel density (VD) of the deep vascular complex (DVC) in eyes with non-exudative MNV was significantly greater than that in eyes with exudative AMD (p = 0.002), while for superficial vascular plexus (SVP) metrics, no VD differences among sectors were observed between eyes with non-exudative MNV and eyes with exudative AMD.

Conclusion

The reduction in retinal vessel density, especially in the DVC, seems to be involved in or be accompanied by non-exudative MNV activation and should be closely monitored during follow-up visits in order to ensure prompt anti-angiogenic therapy. A discussion on applicable clinical protocols is presented aiming to contribute to new insights into ophthalmology service development which is directed to this specific type of patient and diagnosis.

Exudative Progression of Treatment-Naïve Nonexudative Macular Neovascularization in Age-Related Macular Degeneration: A Systematic Review With Meta-Analyses

PURPOSE

To systematically review and report the rate of exudative progression over time in patients with nonexudative macular neovascularization (MNV) in age-related macular degeneration (AMD).

DESIGN

Systematic review with prevalence meta-analyses and individual participant meta-analysis.

METHODS

We searched 10 literature databases on March 26, 2023, for studies of consecutive patients with treatment-naïve nonexudative MNV in AMD. The primary outcome of interest was time from diagnosis to exudative progression. We conducted meta-analyses on the prevalence of exudative progression at 1 and 2 years. Where possible, we extracted individual participant data from studies and conducted an individual participant meta-analysis and explored the exudative progression using a time-to-event curve.

RESULTS

We identified 16 eligible studies with a total of 384 eyes with nonexudative MNV. Exudative progression had occurred in 20.9% (95% CI 13.1%-29.8%) of eyes at 1 year and in 30.7% (95% CI 21.8%-40.4%) at 2 years. Similar results were observed in the individual participant meta-analysis, showing exudative progression in 18.9% (95% CI 13.5%-26.3%) of eyes at 1 year and 31.3% (95% CI 24.2%-40.0%) at 2 years. Risk factors for a fast exudative progression were the presence of subretinal lipid globules, large MNV areas, rapid MNV growth, growth in pigment epithelium detachment height and width, appearance of a branching pattern, and development of a hyporeflective halo around the MNV.

CONCLUSIONS

Nonexudative MNVs in AMD are at high risk of exudative progression. Recognition of these lesions may allow for better individualized follow-up regimens in which closer monitoring may facilitate earlier diagnosis of exudative progression.

Morphological changes of macular neovascularization during long-term anti-VEGF-therapy in neovascular age-related macular degeneration

PURPOSE

To analyze the morphological changes of macular neovascularization (MNV) in exudative neovascular age-related macular degeneration under long-term intravitreal anti-vascular endothelial growth factor (VEGF) therapy in a retrospective cohort study.

METHODS AND PATIENTS

We evaluated 143 nAMD eyes of 94 patients (31 male, 63 female; initial age 55-97 y, mean age 75.9 ± 7.5 y), who started anti-VEGF therapy (IVAN pro re nata (PRN) protocol) between 2009-2018 and received ongoing therapy until the last recorded visit (mean follow-up 5.3 ± 2.9 y, range 1-14 y). The mean total number of injections was 33.3 ± 19.8 with 7.0 ± 2.3 injections/year. MNV size and, if present, associated complete retinal pigment epithelium (RPE) and outer retina atrophy (cRORA) size were measured on optical coherence tomography (OCT) volume scans at the initial visit and for each year of follow-up. MNV and cRORA were identified on B-scans and their respective borders were manually transposed onto the en-face near infrared image and measured in mm2.

RESULTS

MNV enlarged through follow-up, with a mean growth rate of 1.24 mm2 / year. The mean growth in MNV size was independent of initial MNV size, age, gender, MNV subtypes or number of injections per year. Nevertheless, a great interindividual variation in size and growth was observed. cRORA developed in association with increasing MNV size and its incidence increased linearly over follow-up. cRORA lesions also showed continuous growth by a rate of 1.22 mm2 / year.

CONCLUSIONS

Despite frequent long-term anti-VEGF therapy, we observed ongoing MNV growth. This is consistent with the concept that the development of MNV may be a physiological biological repair mechanism to preserve RPE and photoreceptor function, provided hyperpermeability and fluid exudation are controlled. Whether recurring low VEGF levels or other factors are responsible for MNV growth remains controversial.

Towards a better understanding of non-exudative choroidal and macular neovascularization

Non-exudative macular and choroidal neovascularization (MNV and CNV) usually refers to the entity of treatment-naïve type 1 neovascularization in the absence of associated signs of exudation. Histopathological studies, dating back in the early 70s, identified the presence of non-exudative MNV, but the first clinical report of this finding was in the late 90s using indocyanine green angiography in eyes with age-related macular degeneration (AMD). With more advanced retinal imaging, there has been an ever increasing appreciation of non-exudative MNV associated with AMD and CNV with other macular disorders. However, consensus regarding the exact definition and the clinical management of this entity is lacking. Furthermore, there may be variation in the imaging features and clinical course suggesting that a spectrum of disease may exist. Herein, we review the large body of published work that has provided a better understanding of non-exudative MNV and CNV in the last decade. The prevalence, multimodal imaging features, clinical course, and response to treatment are discussed to elucidate further key insights about this entity. Based on these observations, this review also proposes a new theory about the origin and course of different sub-types of non-exudative MNV/CNV which can have different etiologies and pathways according to the clinical context of disease.

Optical Coherence Tomography Angiography for Detecting Nonexudative Macular Neovascularization in Age-Related Macular Degeneration

Purpose:

To compare the efficacy of optical coherence tomography angiography (OCTA) and indocyanine green angiography (ICGA) for detecting nonexudative macular neovascularization (MNV) in age-related macular degeneration (AMD).

Methods:

In this prospective study, patients with a new diagnosis of exudative AMD in 1 eye were imaged using OCTA, fluorescein angiography (FA), and ICGA in both eyes. The rates at which these imaging modalities detected nonexudative MNV in the nonexudative fellow eye were then compared.

Results:

This study comprised 41 eyes with a mean follow-up was 14 months. Nonexudative MNV was found in 3 eyes using OCTA and ICGA. No MNV exudation was detected on FA or structural OCT. One of 3 eyes with MNV progressed to exudative disease 6 months after the initial visit. During the follow-up, 5 of the 38 eyes without MNV developed exudation at 4 to 18 months.

Conclusions:

OCTA is similarly effective as ICGA at detecting nonexudative MNV patterns.

Neovascular age-related macular degeneration: advancement in retinal imaging builds a bridge between histopathology and clinical findings

PURPOSE

To provide a review of the salient histological and imaging features in neovascular age-related macular degeneration (AMD) that will be integrated in order to have a better comprehension of the pathogenesis and clinical aspects of this disease.

METHODS

A literature review of histology and imaging features in neovascular AMD was conducted.

RESULTS

Histology has granted a detailed characterization of neovascular AMD ex vivo. In details, histological features in these eyes have offered important insights into the pathogenesis of neovascular AMD. In addition, histology donated a detailed characterization of the different types of macular neovascularization (MNV) that may complicate AMD. The introduction of optical coherence tomography angiography (OCTA) has enormously amplified our knowledge of neovascular AMD through in vivo assessment of the anatomical and pathological characteristics of this disease. New insights elucidating the morphological features of the choriocapillaris confirmed that this vascular structure plays a crucial role in the pathogenesis of neovascular AMD. OCTA also offered a detailed visualization of MNV complicating neovascular AMD.

CONCLUSIONS

New imaging technologies offer a remarkable chance to build a bridge between histology and clinical findings in neovascular AMD.

Outer Retinal Layer Thickening Predicts the Onset of Exudative Neovascular Age-Related Macular Degeneration

PURPOSE

To assess changes in outer retinal layer (ORL) thickness before the development of exudative macular neovascularization (MNV) in eyes with age-related macular degeneration.

DESIGN

Retrospective observational case series.

METHODS

Eyes with age-related macular degeneration that eventually developed exudative MNV followed with sequential optical coherence tomography for ≥2 years before the exudation occurred were enrolled. The ORL thickness was automatically calculated by the optical coherence tomography software for each sector of the early treatment diabetic retinopathy study map at each follow-up visit. The ORL thickness change from baseline to the day when the exudative MNV developed was compared between sectors that eventually developed exudative MNV and those that did not.

RESULTS

Forty-seven eyes (47 patients) were included. At baseline (24 ± 3 months before exudative MNV), mean (standard deviation) ORL thickness of sectors that eventually developed exudative MNV was similar to that of sectors that did not (85.2 [8.2] µm vs 86.8 [5.7] µm, P = .08). ORL thickness significantly increased in sectors that developed exudative MNV compared with those that did not (+5.8 [10.4] µm vs -2.8 [3.6] µm, P < .01). The regression model based on these data predicted an increase in ORL thickness from baseline of +4.2% 55 days and +11.1% 30 days before exudative MNV was detected. The ORL thickness of areas that did not develop exudative MNV did not change.

CONCLUSION

Thickening of the ORL begins in the area where exudative MNV will develop long before the exudation, accelerating significantly in the last 2 months. The occurrence of exudative MNV could be predicted by 2 months using this simple analysis.