AN UPDATED STAGING SYSTEM OF TYPE 3 NEOVASCULARIZATION USING SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY

Rediscovering Age-Related Macular Degeneration with Swept-Source OCT Imaging: The 2022 Charles L. Schepens, MD, Lecture

PURPOSE

Swept-source OCT angiography (SS-OCTA) scans of eyes with age-related macular degeneration (AMD) were used to replace color, autofluorescence, infrared reflectance, and dye-based fundus angiographic imaging for the diagnosis and staging of AMD. Through the use of different algorithms with the SS-OCTA scans, both structural and angiographic information can be viewed and assessed using both cross sectional and en face imaging strategies.

DESIGN

Presented at the 2022 Charles L. Schepens, MD, Lecture at the American Academy of Ophthalmology Retina Subspecialty Day, Chicago, Illinois, on September 30, 2022.

PARTICIPANTS

Patients with AMD.

METHODS

Review of published literature and ongoing clinical research using SS-OCTA imaging in AMD.

MAIN OUTCOME MEASURES

Swept-source OCT angiography imaging of AMD at different stages of disease progression.

RESULTS

Volumetric SS-OCTA dense raster scans were used to diagnose and stage both exudative and nonexudative AMD. In eyes with nonexudative AMD, a single SS-OCTA scan was used to detect and measure structural features in the macula such as the area and volume of both typical soft drusen and calcified drusen, the presence and location of hyperreflective foci, the presence of reticular pseudodrusen, also known as subretinal drusenoid deposits, the thickness of the outer retinal layer, the presence and thickness of basal laminar deposits, the presence and area of persistent choroidal hypertransmission defects, and the presence of treatment-naïve nonexudative macular neovascularization. In eyes with exudative AMD, the same SS-OCTA scan pattern was used to detect and measure the presence of macular fluid, the presence and type of macular neovascularization, and the response of exudation to treatment with vascular endothelial growth factor inhibitors. In addition, the same scan pattern was used to quantitate choriocapillaris (CC) perfusion, CC thickness, choroidal thickness, and the vascularity of the choroid.

CONCLUSIONS

Compared with using several different instruments to perform multimodal imaging, a single SS-OCTA scan provides a convenient, comfortable, and comprehensive approach for obtaining qualitative and quantitative anatomic and angiographic information to monitor the onset, progression, and response to therapies in both nonexudative and exudative AMD.

FINANCIAL DISCLOSURE(S)

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

Topographical Quantification of Retinal Fluid in Type 3 MNV and Associations with Short-Term Visual Outcomes

PURPOSE

This study aims to quantify the volume of intraretinal fluid (IRF), subretinal fluid (SRF), and sub-retinal pigment epithelium (sub-RPE) fluid in treatment-naïve Type 3 macular neovascularization (MNV) eyes with age-related macular degeneration (AMD) and to investigate the correlation of these fluid volumes with visual acuity (VA) outcomes at baseline and following anti-vascular endothelial growth factor (VEGF) treatment.

DESIGN

Retrospective, clinical cohort study.

METHODS

In this study, we analyzed patients diagnosed with exudative AMD and treatment-naïve Type 3 MNV undergoing a loading dose of anti-VEGF therapy. Using a validated deep-learning segmentation strategy, we processed optical coherence tomography (OCT) B-scans to segment and quantify IRF (i.e., both in the inner and outer retina), SRF, and sub-RPE fluid volumes at baseline. The study correlated baseline fluid volumes with baseline and short-term VA outcomes post-loading dose of anti-VEGF injections.

RESULTS

Forty-six eyes from 46 patients were included in this study. Visual acuity was 0.51±0.30 LogMAR at baseline and 0.33±0.20 LogMAR after the loading dose of anti-VEGF (p=0.001). Visual acuity at the follow-up visit was 0.40±0.17 LogMAR in patients with no complete resolution of retinal fluid and 0.31±0.20 LogMAR in eyes without retinal fluid after treatment (P=0.225). In the multivariable analysis, the IRF volume in the inner retina (P=0.032) and the distance of the MNV from the fovea (P=0.037) were predictors of visual acuity at baseline. The baseline IRF volume in the inner retina also predicted the visual acuity at follow-up (p=0.023).

CONCLUSION

The present study highlights the fluid volume in the inner retina as a crucial predictor of short-term visual outcomes in Type 3 MNV, underscoring the detrimental effect of IRF on neuroretinal structures.

Predictors of 24-month onset of macular fibrosis in type 3 macular neovascularisation

AIMS

To explore prognostic multimarker models for progression to macular fibrosis (MF) over 24 months specific to type 3 macular neovascularisation (T3 MNV).

METHODS

This retrospective, exploratory, single-centre, cohort study comprised 65 eyes of 43 Caucasian patients with treatment naive T3 MNV, all with a 24-month follow-up post anti-VEGF therapy using a strict pro-re-nata (PRN) regimen. Data on demographic features, clinical findings, frequency of intravitreal treatments and optical coherence tomography biomarkers were collected at baseline and after 12 and 24 months of follow-up. Logistic regression models (LRM) and receiver-operating curve (C-index) analyses were performed to evaluate the prognostic ability of the studied biomarkers in discriminating between MF affected and unaffected patients.

RESULTS

At final follow-up, MF was present in 46.2% of eyes. Subretinal hyper-reflective material (SHRM) and subretinal pigment epithelium multilaminar hyper-reflectivity (multilaminae) emerged as significant predictors for MF, with adjusted odds ratios (OR) of 18.0 (95% CL 13.4 to 24.1) and 11.8 (95% CL 8.66 to 16.0), respectively. Additionally, the presence of multifocal lesions (OR 0.04, 95% CL 0.01 to 0.30) appeared to decrease the likelihood of MF. C-indexes for the selected LRMs ranged between 0.92 and 0.88, indicating a comparably high discriminant ability. Despite consistent treatment schedules between the two groups (MF: median intravitreal treatment (IVT) number=10.5, IQR=7; non-MF: median IVT=10, IQR=6), a decline in best-corrected visual acuity was noted in the group with MF onset over the 24-month follow-up (-13.0 ETDRS letters; 95% CL -22.1 to -3.9; p=0.006).

CONCLUSION

Our study identifies SHRM and multilaminae as relevant predictors of 24-month onset of MF in patients with T3 MNV. These findings enrich our understanding of the development of MF in T3 MNV and can guide improved risk prognostication. Future research should consider larger samples and prospective designs to validate these predictors.

An Automated Comparative Analysis of the Exudative Biomarkers in Neovascular Age-Related Macular Degeneration, The RAP Study: Report 6

PURPOSE

To investigate differences in volume and distribution of the main exudative biomarkers across all types and subtypes of macular neovascularization (MNV) using artificial intelligence (AI).

DESIGN

Cross-sectional study.

METHODS

An AI-based analysis was conducted on 34,528 OCT B-scans consisting of 281 (250 unifocal, 31 multifocal) MNV3, 55 MNV2, and 121 (30 polypoidal, 91 non-polypoidal) MNV1 treatment-naive eyes. Means (SDs), medians and heat maps of cystic intraretinal fluid (IRF), subretinal fluid (SRF), pigment epithelial detachments (PED), and hyperreflective foci (HRF) volumes, as well as retinal thickness (RT) were compared among MNV types and subtypes.

RESULTS

MNV3 had the highest mean IRF with 291 (290) nL, RT with 357 (49) µm, and HRF with 80 (70) nL, P ≤ .05. MNV1 showed the greatest mean SRF with 492 (586) nL, whereas MNV3 exhibited the lowest with 218 (382) nL, P ≤ .05. Heat maps showed IRF confined to the center, whereas SRF was scattered in all types. SRF, HRF, and PED were more distributed in the temporal macular half in MNV3. Means of IRF, HRF, and PED were higher in the multifocal than in the unifocal MNV3 with 416 (309) nL,114 (95) nL, and 810 (850) nL, P ≤ .05. Compared to the non-polypoidal subtype, the polypoidal subtype had greater means of SRF with 695 (718) nL, HRF 69 (63) nL, RT 357 (45) µm, and PED 1115 (1170) nL, P ≤ .05.

CONCLUSIONS

This novel quantitative AI analysis shows that SRF is a biomarker of choroidal origin in MNV1, whereas IRF, HRF, and RT are retinal biomarkers in MNV3. Polypoidal MNV1 and multifocal MNV3 present with higher exudation compared to other subtypes.

Effect of baseline fluid localization on visual acuity and prognosis in type 1 macular neovascularization treated with anti-VEGF

PURPOSE

To assess the prognostic value of subretinal (SRF) and intraretinal fluid (IRF) localizations in type 1 macular neovascularization (MNV) due to age-related macular degeneration (AMD).

SUBJECTS

Eyes were prospectively treated with anti-vascular epithelial growth factor (anti-VEGF) intravitreal injections (IVT) according to a Pro-Re-Nata (PRN) or Treat and Extend (TAE) regimen during 24 months. A total of 211 eyes with treatment-naïve type 1 MNV secondary to AMD were consecutively included. Eyes were divided between 2 groups according to the fluid localization: presence of SRF alone (SRF group), or presence of IRF associated or not with SRF (IRF ± SRF group).

RESULTS

At baseline the mean BCVA was 66.2 letters. SRF was present in 94.8% of eyes, IRF in 30.8%, and both in 25.6%. Data were available for 201 eyes at 12 months, and 157 eyes at 24 months. The presence of IRF at baseline was associated with lower baseline BCVA and significantly lower BCVA at 12 months (p < 0.001) and 24 months (p < 0.001). Eyes with SRF alone displayed better visual outcomes (BCVA at month 12, SRF = 74.3 letters, IRF ± SRF = 56.9 letters). In the presence of baseline IRF, fibrosis (p = 0.03) and atrophy (p < 0.001) were more frequently found at 24 months. In a multivariate model, the presence of baseline IRF was significantly associated with lower BCVA at month 12 but not at month 24.

CONCLUSION

In type 1 MNV, the presence of baseline IRF was associated with worse visual outcomes compared to SRF alone, and more frequent atrophy and fibrosis.

The potential key role of choroidal non-perfusion and rod degeneration in the pathogenesis of macular neovascularization type 3

Macular neovascularization type 3 (MNV3) is a multifactorial disease with distinct epidemiological, clinical, pathomorphological and topographical characteristics. This review of the literature discusses the latest experimental and clinical outcomes that could explain the pathogenesis of retinal neovascularization. Although patients with MNV3 are usually older than those with MNV1 or 2, their lesions do not coexist with, precede, or follow other types in the same eye. The regional distribution of MNV3 lesions is characterized as confined to the parafoveal macula without any involvement of the rod-free foveal area. Focal outer retinal atrophy and choroidal non-perfusion are the main structural features that occur prior to the development of retinal neovascularization. Also, histological and experimental studies of MNV3 and other non-neovascular age-related macular degeneration diseases complicated with MNV3-like lesions strongly suggest rod degeneration contributes to the pathogenesis. Therefore, the retinal neovascularization in MNV3 has a different pathogenesis from the choroidal neovascularization in MNV1 and 2 and emerging evidence indicates that choroidal non-prefusion and rod degeneration play a key role in the pathogenesis of MNV3. Accordingly, we suggest a sequence of pathological events that start with choroidal non-perfusion due to advanced age followed by hypoxia of the outer retina at the parafoveal area. This induces a remarkable degeneration of rods that triggers the growth of retinal neovascularization due to the imbalance of the angiogenic factors in the outer retina.

Effect of Pro Re Nata Regimen with Anti-VEGF on Type 3 Macular Neovascularization: Long-Term Outcomes

INTRODUCTION

The purpose of this study was to investigate long-term outcomes of intravitreal injections (IVI) of antivascular endothelial growth factor (VEGF) in neovascular age-related macular degeneration (nAMD) with type 3 macular neovascularization (MNV).

METHODS

This retrospective study included 19 eyes of 17 patients with nAMD and type 3 MNV treated with anti-VEGF IVI with a loading dose and a PRN regimen. Best corrected visual acuity (BCVA), central macular thickness (CMT), presence of macular intraretinal fluid (IRF) and subretinal fluid (SRF), flow area (FA), subfoveal choroidal thickness (CT), and macular atrophy (MA) were assessed at baseline (T0) and during follow-up (T1, post-loading phase; T2, 1 year; T3, 2 years; T4 >2 years). The correlations between MA at the last follow-up and standard deviation (SD) values of CMT and CT during follow-up were assessed. The influence of the number of injections on the change in MA over time was also analyzed. MA differences at T4 were assessed for pseudodrusen presence.

RESULTS

BCVA improved significantly during follow-up (p = 0.013) particularly increasing from baseline to post-loading phase and then did not modify significantly thereafter. CMT significantly reduced from T0 to T1 and remained stable during follow-up (p = <0.001). MNV flow area showed a trend toward an increase in the post-loading phase that was not statistically significant (p = 0.082) and CT decreased significantly during follow-up (p < 0.001). MA changed significantly during follow-up (p < 0.001) with a significant increase from T0 to T3 and from T0 to T4 (p < 0.010). A Cochran-Armitage test for trend showed a significant reduction (p = 0.001) of macular IRF and SRF during follow-up. MA at T4 showed a significant positive correlation with SD (standard deviation) values of CMT (p = 0.040) and CT (p = 0.020). Indeed, the number of injections did not influence the change over time of MA (p = 0.709). MA at T4 was not statistically significantly different between patients with pseudodrusen at baseline (p = 0.497).

CONCLUSIONS

Intravitreal anti-VEGF injections with PRN regimen in MNV type 3 showed functional and anatomical benefits. Variations of retinal thickness and choroidal thickness during treatment were related to MA modification over time.

Distinct Pathways of Macular Atrophy in Type 3 Macular Neovascularization Associated With AMD

Purpose

To explore the occurrence of macular atrophy (MA) in eyes with age-related macular degeneration (AMD)-associated Type 3 macular neovascularization (MNV) treated with anti-vascular endothelial growth factor (anti-VEGF) therapy. Importantly, we aimed at describing the existence of separate pathways leading to MA.

Methods

We analyzed 41 participants (41 eyes) with treatment-naïve Type 3 MNV who were followed up for a duration of 12 months after beginning the anti-VEGF therapy. At the one-year follow-up visit, optical coherence tomography (OCT) scans were reviewed for the presence of MA. MA regions of interest (ROIs) were selected and traced back to their original dominant baseline lesion (i.e., precursor) through previous serially captured OCT scans. Baseline lesions included precursors associated with the development and exudation of MNV and causes external to the neovascularization itself.

Results

At the one-year follow-up visit, MA was graded to be present in 38 (92.7%) out of 41 eyes. These 78 MA ROIs were divided into two subgroups according to the precursor lesion, yielding a group of 53 MA lesions with precursors associated with the development and exudation of MNV (i.e., MA caused by physical harm from Type 3 neovessels, collapse of a serous pigment epithelium detachment, and fibrosis) and 25 MA regions with precursors external to the neovascularization itself (i.e., MA caused by drusen or subretinal drusenoid deposits).

Conclusions

Eyes with Type 3 MNV are commonly complicated by MA and precursors of MA include causes associated with the development and exudation of MNV, as well as lesions unrelated to the neovascularization process itself.

Incidence and multimodal imaging characteristics of macular neovascularisation subtypes in Chinese neovascular age-related macular degeneration patients

AIMS

To investigate the incidence of macular neovascularisation (MNV) subtypes of neovascular age-related macular degeneration (nAMD) and summarise these subtypes' clinical features in the Chinese population using multimodal imaging.

METHODS

We retrospectively analysed 506 consecutive treatment-naïve nAMD patients (582 eyes). Incidence of MNV subtypes and clinical features were recorded based on their multimodal images. The classification of MNV subtypes in nAMD patients were referred to Consensus on Neovascular Age-related Macular Degeneration Nonmenclature (CONAN) study group classifications.

RESULTS

460 eyes of 389 nAMD patients were included in our study. 68.5% (315/460) of nAMD eyes were from male. According to CONAN, we identified type 1 macular neovascularisation (MNV) in 61.1% of eyes (281/460), type 2 MNV in 16.3% of eyes (75/460), type 3 MNV in 2.0% of eyes (9/460), mixed type 1 and type 2 MNV in 20.6% of eyes (95/460). 58% of eyes (267/460) were diagnosed as polypoidal choroidal vasculopathy lesions (PCV). 45.2% of eyes (208/460) with PCV lesions were type 1 MNV and 12.8% of eyes (59/460) with PCV lesions were co-occurred with type 2 MNV.

CONCLUSION

Based on the consensus anatomical classification system developed by the CONAN Study Group, we updated the incidence of MNV subtypes and found that PCV was the most common subtype and type 3 MNV was the least common subtype among Chinese nAMD patients. In addition, the co-occurrence of PCV and type 2 MNV was typically observed, and its frequency was reported in our study.

FROM DRUSEN TO TYPE 3 MACULAR NEOVASCULARIZATION

PURPOSE

To investigate the imaging features preceding the occurrence of type 3 (T3) macular neovascularization (MNV) using tracked spectral-domain optical coherence tomography.

METHOD

From a cohort of eyes with T3 MNV and ≥ 12 months of previously tracked spectral-domain optical coherence tomography, T3 lesions that developed above soft drusen were selected for optical coherence tomography analysis. Retinal imaging findings at the location where type T3 MNV occurred were analyzed at each follow-up until the onset of T3 MNV. The following optical coherence tomography parameters were assessed: drusen size (height and width), outer nuclear layer/Henle fiber layer thickness at the drusen apex, and the presence of intraretinal hyperreflective foci, retinal pigment epithelium disruption, incomplete retinal pigment epithelium and outer retina atrophy, and complete retinal pigment epithelium and outer retina atrophy.

RESULTS

From a cohort of 31 eyes with T3 MNV, T3 lesions developed above soft drusen in 20 eyes (64.5%). Drusen showed progressive growth ( P < 0.001) associated with outer nuclear layer/Henle fiber ( P < 0.001) thinning before T3 MNV. The following optical coherence tomography features were identified preceding the occurrence of T3 MNV, typically at the apex of the drusenoid lesion: disruption of the external limiting membrane/ellipsoid zone and/or the retinal pigment epithelium, hyperreflective foci, and incomplete retinal pigment epithelium and outer retina atrophy/complete retinal pigment epithelium and outer retina atrophy.

CONCLUSION

The results demonstrate specific anatomic alterations preceding the occurrence of T3 MNV that most commonly originates above soft drusen. Drusen growth, reduced outer nuclear layer/Henle fiber thickness, and retinal pigment epithelium atrophy at the drusen apex precede the development of T3 MNV. Identifying these optical coherence tomography features should warrant close monitoring for identification of T3 MNV, which can benefit from prompt intravitreal anti-vascular endothelial growth factor therapy.

Current Perspectives on Type 3 Macular Neovascularization due to Age-Related Macular Degeneration

BACKGROUND

The aim of this review was to systematically summarize the current knowledge on type 3 macular neovascularization (MNV3) in age-related macular degeneration (AMD).

SUMMARY

Recent histopathologic and multimodal imaging findings led to the consensus definition of the new term "type 3 macular neovascularization" in AMD. MNV3 originates in the deep vascular plexus as a neovascular process without connection with the retinal pigment epithelium in the initial stages. This type has numerous clinical and pathomorphologic features that separate it from the other two types of MNV in AMD. Besides, its frequency appears to be higher than previously thought. In optical coherence tomography (OCT), MNV3 can be classified into stages 1-3. Hyperreflective foci in the outer retina possibly represent a precursor lesion. In addition, MNV3 is characterized by a strong association with reticular pseudodrusen, a high rate of bilaterality, close associations with advanced age and arterial hypertension, decreased choroidal thickness, and decreased choriocapillaris flow signals. Data from latest anti-vascular endothelial growth factor studies in MNV3 suggest that the OCT biomarkers in intraretinal and subretinal fluids should be interpreted differently than in the other types. Additionally, data from MNV3 eyes should be analyzed separately, allowing optimal type-specific treatment strategies in the future.

KEY MESSAGES

This review highlights the need for accurate characterization of neovascular AMD lesions and an MNV type-specific approach, particularly for MNV3.

Choroidal Changes After Anti-VEGF Therapy in AMD Eyes With Different Types of Macular Neovascularization Using Swept-Source OCT Angiography

Purpose

Choroidal changes before and after anti-VEGF therapy were investigated in eyes with exudative AMD to determine if there was a difference between eyes with macular neovascularization (MNV) that arises from the choroid (type 1 or 2) versus the retinal circulation (type 3).

Methods

Patients with treatment-naïve AMD were imaged with swept-source optical coherence tomography angiography using a 12 × 12-mm scan pattern. The mean choroidal thickness and choroidal vascularity index (CVI) were measured within 5-mm and 11-mm fovea-centered circles before, at the onset of, and after anti-VEGF therapy.

Results

Forty-one eyes of 37 patients were included; 24 eyes with type 1 MNV, 4 eyes with type 2 MNV, and 13 eyes with type 3 MNV. Within the 5-mm and 11-mm circles, the mean choroidal thickness and CVI measurements increased from pretreatment to the onset of exudation (P ≤ 0.03). The mean choroidal thickness and CVI measurements decreased from the onset of exudation to after treatment (P < 0.001). No significant changes in mean choroidal thickness or CVI were observed when comparing measurements before or after treatment (P ≥ 0.38). No significant differences in mean choroidal thickness or CVI measurements were observed between eyes with type 1 or 2 MNV and type 3 MNV.

Conclusions

In treatment-naïve AMD eyes with MNV, the choroidal thickness and vascularity increased at the onset of exudation and then decreased after anti-VEGF therapy. This finding suggests that these choroidal changes develop in response to the proangiogenic milieu before treatment and in response to treatment, regardless of the site of origin for the MNV.

Pushing Retinal Imaging Forward: Innovations and Their Clinical Meaning - The 2022 Ophthalmologica Lecture

Retinal imaging has greatly expanded our understanding of various pathological conditions. This article presents a summary of the key points covered during the 2022 Ophthalmologica Lecture held at the Euretina Congress in Hamburg. The first part of the article focuses on the use of optical coherence tomography angiography to examine and comprehend the choroid in age-related macular degeneration (AMD). Subsequently, we delve into the discussion of the "postreceptor neuronal loss" theory in AMD, which was studied using en face structural optical coherence tomography (OCT). Following that, we explore pertinent findings obtained through cross-sectional OCT in retinal and optic nerve diseases, such as AMD, diabetic macular edema, pathologic myopia, central serous chorioretinopathy, and Leber's hereditary optic neuropathy.

INCIDENCE AND TIMING OF PIGMENT EPITHELIAL DETACHMENT AND SUBRETINAL FLUID DEVELOPMENT IN TYPE 3 MACULAR NEOVASCULARIZATION ASSOCIATED WITH AGE-RELATED MACULAR DEGENERATION

PURPOSE

To evaluate the incidence and timing of pigment epithelial detachment (PED) and subretinal fluid (SRF) development in type 3 macular neovascularization.

METHODS

This retrospective study included 84 patients who were diagnosed with treatment-naïve type 3 macular neovascularization who did not show SRF at diagnosis. All patients were initially treated with three loading injections of ranibizumab or aflibercept. After the initial loading injections, as-needed regimen was performed for retreatment. The development of either PED or SRF was identified. The incidence and timing of PED development in patients without PED at diagnosis and that of SRF development in patients with PED at diagnosis were evaluated.

RESULTS

The mean follow-up period was 41.3 ± 20.7 months after diagnosis. Among the 32 patients without serous PED at diagnosis, PED developed in 20 (62.5%) at a mean of 10.9 ± 5.1 months after diagnosis. PED development was noted within 12 months in 15 patients (46.8%; 75.0% among the PED development cases). In 52 patients with serous PED and without SRF at diagnosis, 15 developed SRF (28.8%) at a mean of 11.2 ± 6.4 months after diagnosis. SRF development was noted within 12 months in nine patients (17.3%; 66.6% among the SRF development cases).

CONCLUSION

PED and SRF developed in a substantial proportion of patients with type 3 macular neovascularization. The average period of development of these pathologic findings was within 12 months of diagnosis, suggesting the need for active treatment during the early treatment period to improve treatment outcomes.

Biologically Guided Optimization of Test Target Location for Rod-mediated Dark Adaptation in Age-related Macular Degeneration: Alabama Study on Early Age-related Macular Degeneration 2 Baseline

Purpose

We evaluate the impact of test target location in assessing rod-mediated dark adaptation (RMDA) along the transition from normal aging to intermediate age-related macular degeneration (AMD). We consider whether RMDA slows because the test locations are near mechanisms leading to or resulting from high-risk extracellular deposits. Soft drusen cluster under the fovea and extend to the inner ring of the ETDRS grid where rods are sparse. Subretinal drusenoid deposits (SDDs) appear first in the outer superior subfield of the ETDRS grid where rod photoreceptors are maximal and spread toward the fovea without covering it.

Design

Cross-sectional.

Participants

Adults ≥ 60 years with normal older maculas, early AMD, or intermediate AMD as defined by the Age-Related Eye Disease Study (AREDS) 9-step and Beckman grading systems.

Methods

In 1 eye per participant, RMDA was assessed at 5° and at 12° in the superior retina. Subretinal drusenoid deposit presence was identified with multi-modal imaging.

Main Outcome Measures

Rod intercept time (RIT) as a measure of RMDA rate at 5° and 12°.

Results

In 438 eyes of 438 persons, RIT was significantly longer (i.e., RMDA is slower) at 5° than at 12° for each AMD severity group. Differences among groups were bigger at 5° than at 12°. At 5°, SDD presence was associated with longer RIT as compared to SDD absence at early and intermediate AMD but not in normal eyes. At 12°, SDD presence was associated with longer RIT in intermediate AMD only, and not in normal or early AMD eyes. Findings were similar in eyes stratified by AREDS 9-step and Beckman systems.

Conclusions

We probed RMDA in relation to current models of deposit-driven AMD progression organized around photoreceptor topography. In eyes with SDD, slowed RMDA occurs at 5° where these deposits typically do not appear until later in AMD. Even in eyes lacking detectable SDD, RMDA at 5° is slower than at 12°. The effect at 5° may be attributed to mechanisms associated with the accumulation of soft drusen and precursors under the macula lutea throughout adulthood. These data will facilitate the design of efficient clinical trials for interventions that aim to delay AMD progression.

Nascent Geographic Atrophy as a Predictor of Type 3 Macular Neovascularization Development

PURPOSE

To investigate the association of nascent geographic atrophy (GA) preceding the development of exudative type 3 macular neovascularization (MNV) in patients with age-related macular degeneration (AMD).

DESIGN

Retrospective longitudinal study.

PARTICIPANTS

Patients with AMD diagnosed with treatment-naive exudative type 3 MNV in 1 or both eyes were evaluated. Inclusion criteria included serial tracked structural OCT examinations for ≥ 2 years before the detection of exudative type 3 MNV.

METHODS

Clinical characteristics and retinal imaging, including structural OCT at baseline and at each follow-up examination, were analyzed. Eyes showing the presence of nascent GA during the follow-up were selected for analysis of prevalence, and clinical characteristics at the site of subsequent type 3 MNV development.

MAIN OUTCOME MEASURES

Description of the prevalence and clinical characteristics of nascent GA at the site of subsequent type 3 MNV development.

RESULTS

Overall, 97 eyes affected by type 3 MNV meeting inclusion criteria were analyzed. Of 97 eyes (71 patients), 22 eyes of 21 patients (mean age 82 ± 9 years) showed nascent GA preceding exudative type 3 MNV. The observed prevalence of nascent GA preceding exudative type 3 MNV was 22.7% (95% confidence interval, 14.4%-31.0%). Exudative type 3 MNV developed a mean of 9 ± 6 months after detection of nascent GA. The presence of reticular pseudodrusen in the study eye did not significantly influence the timing of exudative type 3 MNV development after the observation of nascent GA (P > 0.1 in all analyses). Reduced best-corrected visual acuity was recorded at the exudative type 3 stage in comparison with the nascent GA stage (P = 0.003).

CONCLUSIONS

As nascent GA may precede the development of exudative type 3 MNV, the detection of nascent GA in eyes with AMD may warrant closer surveillance to identify early exudative type 3 MNV warranting treatment.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Difference in characteristics and lesion reactivation between type 3 macular neovascularization with and without subretinal fluid at baseline

PURPOSE

To compare the characteristics and incidence rates of lesion reactivation after anti-vascular endothelial growth factor (VEGF) treatment in type 3 macular neovascularization (MNV) with and without subretinal fluid (SRF) at baseline.

METHODS

This retrospective study included 95 patients diagnosed with type 3 MNV. After the initial loading injections, re-treatment was performed when lesion reactivation occurred defined as the re-accumulation of subretinal or intraretinal fluid or the new development of a retinal/subretinal hemorrhage. The differences in the baseline characteristics and the incidence rates of lesion reactivation were compared between patients with SRF (SRF group, n = 42) and those without SRF (non-SRF group, n = 53).

RESULTS

At diagnosis, the mean visual acuity was worse (0.68 ± 0.41 vs 0.50 ± 0.36; P = 0.032), mean central retinal thickness was greater (515.4 ± 145.9 μm vs 383.8 ± 105.5 μm; P < 0.001), and the incidence of focal retinal hemorrhages was higher (90.5% vs 66.0%; P = 0.005) in the SRF group than in the non-SRF group. In the SRF group, the first lesion reactivation was noted in 89.7% at a mean of 5.8 ± 4.4 months after the third injection. In the non-SRF group, the first lesion reactivation was noted in 70.6% at a mean of 6.1 ± 3.8 months. There was a significant difference in lesion reactivation between the two groups (P = 0.019).

CONCLUSIONS

The difference in the baseline characteristics and incidence of lesion reactivation between type 3 MNV with and without SRF suggests that the presence of SRF may be indicative of more advanced disease with a high risk of visual deterioration. This result also suggests the need for more active treatment to preserve vision in patients with SRF.

Histology of type 3 macular neovascularization and microvascular anomalies in treated age-related macular degeneration: a case study

Purpose

To investigate intraretinal neovascularization and microvascular anomalies by correlating in vivo multimodal imaging with corresponding ex vivo histology in a single patient.

Design

A case study comprising clinical imaging from a community-based practice, and histologic analysis at a university-based research laboratory (clinicopathologic correlation).

Participants

A White woman in her 90s treated with numerous intravitreal anti-VEGF injections for bilateral type 3 macular neovascularization (MNV) secondary to age-related macular degeneration (AMD).

Methods

Clinical imaging comprised serial infrared reflectance, eye-tracked spectral-domain OCT, OCT angiography, and fluorescein angiography. Eye tracking, applied to the 2 preserved donor eyes, enabled the correlation of clinical imaging signatures with high-resolution histology and transmission electron microscopy.

Main Outcome Measures

Histologic/ultrastructural descriptions and diameters of vessels seen in clinical imaging.

Results

Six vascular lesions were histologically confirmed (type 3 MNV, n = 3; deep retinal age-related microvascular anomalies [DRAMAs], n = 3). Pyramidal (n = 2) or tangled (n = 1) morphologies of type 3 MNV originated at the deep capillary plexus (DCP) and extended posteriorly to approach without penetrating persistent basal laminar deposit. They did not enter the subretinal pigment epithelium (RPE)-basal laminar space or cross the Bruch membrane. Choroidal contributions were not found. The neovascular complexes included pericytes and nonfenestrated endothelial cells, within a collagenous sheath covered by dysmorphic RPE cells. Deep retinal age-related microvascular anomaly lesions extended posteriorly from the DCP into the Henle fiber and the outer nuclear layers without evidence of atrophy, exudation, or anti-VEGF responsiveness. Two DRAMAs lacked collagenous sheaths. External and internal diameters of type 3 MNV and DRAMA vessels were larger than comparison vessels in the index eyes and in aged normal and intermediate AMD eyes.

Conclusions

Type 3 MNV vessels reflect specializations of source capillaries and persist during anti-VEGF therapy. The collagenous sheath of type 3 MNV lesions may provide structural stabilization. If so, vascular characteristics may be useful in disease monitoring in addition to fluid and flow signal detection. Further investigation with longitudinal imaging before exudation onset will help determine if DRAMAs are part of the type 3 MNV progression sequence.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

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.

Comparison of 24-month treatment outcomes between as-needed treatment and switching to treat-and-extend in type 3 macular neovascularization

This study aimed to compare 24-month treatment outcomes between patients with type 3 macular neovascularization (MNV) treated using an as-needed regimen and those who switched to treat-and-extend (TAE). This retrospective study included 32 patients who were initially treated with an as-needed regimen but switched to TAE (TAE group) and 74 patients who were treated with an as-needed regimen throughout the follow-up period (as-needed group). The number of anti-vascular endothelial growth factor (VEGF) injections and degree of change in best-corrected visual acuity (BCVA) over 24 months were compared between the two groups. The incidence of fibrotic scarring, tears of the retinal pigment epithelium (RPE), and subretinal hemorrhage was also evaluated. The number of anti-VEGF injections was higher in the TAE group (mean: 11.7) than in the as-needed group (mean: 6.9; P < 0.001). The BCVA outcome (measured using the mean logarithm of the minimal angle of resolution [logMAR]) was significantly better in the TAE group (mean improvement of logMAR 0.15) than in the as-needed group (mean deterioration of logMAR 0.15). The incidence of fibrotic scarring (6.3% vs. 18.9%), RPE tears (3.1% vs. 6.8%), and subretinal hemorrhage (0% vs. 9.5%) was relatively lower in the TAE group. Treatment outcomes of the TAE group were better than those of the as-needed group, suggesting that switching to the TAE regimen would be a useful approach for patients with type 3 MNV requiring efficient treatment.

Type 3 macular neovascularization in a patient with pentosan polysulfate maculopathy

Purpose

To report the development of type 3 macular neovascularization (MNV) in a patient with pentosan polysulfate sodium (PPS) maculopathy one year after PPS cessation.

Observation

A 72-year-old woman presented for decreased visual acuity in the left eye. Medical history was significant for interstitial cystitis treated with PPS for 11 years (cumulative dose of 1205 g) and PPS maculopathy. PPS was discontinued 1 year prior to presentation. Blue-light fundus autofluorescence and spectral domain optical coherence tomography confirmed the diagnosis of bilateral PPS maculopathy. OCT-angiography illustrated the development of type 3 MNV with intraretinal fluid in the left eye. Intravitreal injections of aflibercept were initiated with a good visual and anatomical response.

Conclusion and importance

This report describes the development of type 3 MNV in a patient with PPS macular toxicity one year after PPS cessation. This complication emphasizes the need for regular retinal surveillance even after discontinuation of the inciting drug.

Atypical case of perifoveal exudative vascular anomalous complex associated with pachychoroid pigment epitheliopathy

Purpose

Observations

Conclusion and importance

Characterisation of macular neovascularisation subtypes in age-related macular degeneration to optimise treatment outcomes

The aim of this review is to identify the common characteristics and prognoses of different subtypes of neovascular age-related macular degeneration (nAMD). We also propose recommendations on how to tailor treatments to the subtype of neovessels to optimise patient outcomes. The authors, selected members of the Vision Academy, met to discuss treatment outcomes in nAMD according to macular neovascularisation (MNV) subtypes, using evidence from a literature search conducted on the PubMed database (cut-off date: March 2019). This review article summarises the recommendations of the Vision Academy on how the characterisation of MNV subtypes can optimise treatment outcomes in nAMD. The identification of MNV subtypes has been facilitated by the advent of multimodal imaging. Findings from fluorescein angiography, indocyanine green angiography and spectral-domain optical coherence tomography collectively help refine and standardise the determination of the MNV subtype. To date, three subtypes have been described in the literature and have specific characteristics, as identified by imaging. Type 1 MNV is associated with better long-term outcomes but usually requires more intense anti-vascular endothelial growth factor dosing. Type 2 MNV typically responds quickly to treatment but is more prone to the development of fibrotic scars, which may be associated with poorer outcomes. Type 3 MNV tends to be highly sensitive to anti-vascular endothelial growth factor treatment but may be associated with a higher incidence of outer retinal atrophy, compared with other subtypes. Accurately assessing the MNV subtype provides information on prognosis and helps to optimise the management of patients with nAMD.

Clinical features associated with the atrophy of fellow eyes in patients with unilateral type 3 macular neovascularization

PURPOSE

We sought to investigate the clinical features of eyes with unilateral type 3 macular neovascularization (MNV) according to the degenerative features of fellow eyes.

METHODS

We retrospectively reviewed 55 patients with unilateral type 3 MNV and identified degenerative features including geographic atrophy (GA) in fellow eyes using multimodal imaging. Then, the clinical features of eyes with type 3 MNV at baseline and during follow-up with anti-vascular endothelial growth factor treatment and an as-needed regimen were compared according to the degenerative features of fellow eyes.

RESULTS

Eighteen patients (32.7%) had GA in fellow eyes; initial disease manifestations of type 3 MNV eyes including stage, best-corrected visual acuity, and choroidal thickness (CT) did not vary between groups (all P > 0.05). During follow-up, a rate of complete fluid resolution after three monthly loading injections was not associated with GA in fellow eyes (P = 0.703), while a lower rate of early recurrence within 3 months after loading treatment was associated with thinner CT in type 3 MNV eyes and GA over one disc area in fellow eyes (P = 0.025 and P = 0.021).

CONCLUSION

Degenerative features of fellow eyes in patients with unilateral type 3 MNV may be associated with the clinical characteristics of affected eyes.

Chorioretinal thickness and retinal pigment epithelial degeneration of fellow eyes in patients with unilateral neovascular age-related macular degeneration with subretinal drusenoid deposits

Background

We sought to investigate the chorioretinal thickness and retinal pigment epithelial (RPE) degenerative features of eyes with early age-related macular degeneration (AMD) and subretinal drusenoid deposits (SDDs) according to the presence of macular neovascularization (MNV) in the fellow eyes.

Methods

We classified 70 eyes into two groups of 47 eyes with non-neovascular AMD and 23 eyes with neovascular AMD, respectively, according to the presence of MNV in the fellow eyes. The mean macular retinal, ganglion cell–inner plexiform layer (GCIPL), and choroidal thickness values and RPE features of the 6-mm-diameter zone were compared. RPE degeneration was defined as a lesion with an incomplete RPE and outer retinal atrophy (iRORA) or attenuated RPE reflectivity with diffuse basal laminar deposits, which was defined as when the eye showed an attenuated RPE line with granular features and mixed reflectivity in combination with sub-RPE deposits with a lesion ≥ 1,000 µm in length.

Results

Mean retinal, GCIPL, and choroidal thickness values (286.69 ± 15.02 µm, 64.36 ± 4.21 µm, and 156.11 ± 33.10 µm) of the neovascular AMD group were greater than those (278.61 ± 13.96 µm, 61.44 ± 4.63 µm, and 133.59 ± 34.33 µm) of the non-neovascular AMD group (all P < 0.05). RPE degeneration was more prevalent in the neovascular AMD group (65.2%) than the non-neovascular AMD group (38.3%; P = 0.034). Greater mean GCIPL and choroidal thickness values and the presence of RPE degeneration were associated with type 3 MNV in fellow eyes (all P < 0.05).

Conclusions

Different degenerative features according to MNV in fellow eyes of patients with AMD and SDDs suggest that variable degenerative features might be present during disease progression and have an association with the phenotype.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02518-4.

OCT Predictors of 3-Year Visual Outcome for Type 3 Macular Neovascularization

PURPOSE

To identify baseline OCT predictors of the 3-year visual outcome for type 3 (T3) macular neovascularization (MNV) secondary to age-related macular degeneration (AMD) treated by anti-vascular endothelial growth factor (VEGF) therapy.

DESIGN

Retrospective longitudinal study.

PARTICIPANTS

Forty eyes of 30 patients affected by exudative treatment-naive T3 MNV were enrolled.

METHODS

Baseline best-corrected visual acuity (BCVA) and several baseline OCT features were assessed and included in the analysis. Univariate and multivariate analyses served to identify risk factors associated with the 3-year BCVA.

MAIN OUTCOME MEASURES

Baseline OCT features that are associated with bad or good visual outcomes of T3 MNV treated by anti-VEGF injections.

RESULTS

Mean baseline BCVA was 0.34 ± 0.28 logarithm of the minimum angle of resolution (LogMAR), which significantly decreased to 0.52 ± 0.37 LogMAR at the end of the 3-year follow-up (P = 0.002). In the univariate analysis, the following baseline features were associated with the 3-year BCVA outcome: baseline BCVA (P = 0.004), foveal involvement of exudation (P = 0.004), and presence of subretinal fluid (SRF; P = 0.004). In the multivariate model, baseline BCVA (P = 0.032), central macular thickness (P = 0.036), number of active T3 lesions (P = 0.034), and presence of SRF (P = 0.008) were associated with the 3-year BCVA outcome. Interestingly, 3-year BCVA was significantly lower in 19 eyes with SRF at the baseline (0.69 ± 0.42 LogMAR) than 21 eyes without SRF (0.37 ± 0.24 LogMAR; P = 0.004).

CONCLUSION

We identified structural OCT features associated with BCVA outcome after 3-year treatment with anti-VEGF injections. In contrast to previous studies on neovascular AMD, in our series, the presence of SRF at baseline was the most significant independent negative predictor of functional outcomes. Current findings may be employed to identify less favorable T3 patterns potentially deserving a more intensive treatment.

Development of subretinal hemorrhage after treatment discontinuation for neovascular age-related macular degeneration and polypoidal choroidal vasculopathy

PURPOSE

To investigate the incidence, risk factors, and their influence on visual outcomes of subretinal hemorrhage (SRH) in patients with neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy(PCV) who discontinue treatment.

METHODS

This retrospective study included 148 patients with nAMD and PCV who discontinued treatment. The development of a 3-disc area or greater extent of SRH after treatment discontinuation was identified. Visual acuity at the final visit was compared between patients with and those without SRH. Factors associated with SRH were then analyzed.

RESULTS

During the mean 56.8 ± 18.2 months of follow-up, treatment was discontinued at a mean 24.1 ± 16.3 months after diagnosis. SRH developed in 24 (16.2%) patients at a mean 21.5 ± 17.6 months after treatment discontinuation. The visual acuity at the final follow-up was significantly worse in patients with SRH than in those without SRH (P < 0.001). There was a significant difference in the incidence of SRH among the different types of macular neovascularization (MNV) (P = 0.024). In particular, the incidence of type 3 MNV was relatively high (36.0%).

CONCLUSIONS

The development of SRH may lead to very poor visual prognosis in patients who discontinue treatment. The high risk of SRH in type 3 MNV suggests the need for caution when choosing treatment discontinuation in cases of type 3 MNV.

Tissue engineering in age-related macular degeneration: a mini-review

Age-related macular degeneration (AMD) is a progressive, degenerative disease of the macula, leading to severe visual loss in the elderly population. There are two types of AMD: non-exudative ('dry') AMD and exudative ('wet') AMD. Non-exudative AMD is characterized by drusen formation and macular atrophy, while the blood vessels are not leaky. Exudative AMD is a more advanced form of the disease, featured with abnormal blood vessel growth and vascular leakage. Even though anti-angiogenic therapies have been effective in treating wet AMD by normalizing blood vessels, there is no treatment available to prevent or treat dry AMD. Currently, the mechanisms of drusen formation and macular atrophy in the dry AMD are poorly understood, in part because the currently available in vivo models of AMD could not decouple and isolate the complex biological and biophysical factors in the macular region for a detailed mechanism study, including the complement system, angiogenesis factors, extracellular matrix, etc. In the present review article, we describe the biological background of AMD and the key cells and structures in AMD, including retinal epithelium, photoreceptor, Bruch's membrane, and choriocapillaris. We also discuss pre-clinical animal models of AMD and in vivo tissue-engineered approaches, including cell suspension injection and organoid-derived cell sheet transplantation. We also discuss in vitro tissue-engineered models for AMD research. Specifically, we evaluate and compare currently available two- and three-dimensional AMD tissue-engineered models that mimic key anatomical players in AMD progression, including pathophysiological characteristics in Bruch's membrane, photoreceptor, and choriocapillaris. Finally, we discuss the limitation of current AMD models and future directions.

THE RAP STUDY, REPORT 5: REDISCOVERING MACULAR NEOVASCULARIZATION TYPE 3: Multimodal Imaging of Fellow Eyes over 24 months

PURPOSE

To explore the condition of fellow eyes of patients with macular neovascularization Type 3 (MNV3) and to verify whether the retinal-choroidal anastomosis (RCA) develops equally in all MNV types.

METHODS

The contralateral eyes of 94 patients with MNV3, 96 patients with MNV1, and 96 patients with MNV2 were included. Multimodal imaging was performed. The MNV3 stage including the development of fibrosis and RCA over 24 months was determined.

RESULTS

In the contralateral eyes of patients of the solitary (one lesion) MNV3 group, 32 eyes (42.1%) showed early/intermediate age-related macular degeneration, 25 eyes (33%) showed MNV3, and 11 eyes (14.5%) experienced fibrosis, of which 4 eyes (5.2%) had a RCA, 7 eyes (9.2%) had atrophy after resolved MNV3, and 1 eye (1.3%) developed MNV1. In the multifocal (more than one lesion) MNV3 group, 2 eyes (11.1%) showed early/intermediate age-related macular degeneration, 9 eyes (50%) showed 15 MNV3 lesions, and 4 eyes (22.2%) showed fibrosis, of which 2 eyes (11.1%) manifested with a RCA and 3 eyes (16.7%) showed atrophy after resolved MNV3. The number of eyes with a RCA accounted for 40% of all eyes with fibrosis. The count of simultaneous bilateral multifocal MNV3 was 5 (55.6%). In the MNV1 and MNV2 groups, no eye developed a RCA. The incidence of RCAs in the scarred eyes in MNV3 was significantly higher (P < 0.0001).

CONCLUSION

Retinal-choroidal anastomosis is an exclusive clinical feature of MNV3. The development of the multifocal MNV3 is usually bilateral and simultaneous. The occurrence of fibrosis in MNV3 has decreased dramatically after the introduction of the antiangiogenic therapy.

Multimodal assessments of drusenoid pigment epithelial detachments in the Age-Related Eye Disease Study 2 Ancillary (A2A) spectral-domain optical coherence tomography (SD-OCT) study cohort

PURPOSE

To identify features correlating with drusenoid pigment epithelial detachment (DPED) progression in the AREDS2 Ancillary (A2A) spectral-domain optical coherence tomography (SD-OCT) study cohort.

METHODS

In this retrospective analysis of a prospective longitudinal study, eyes with intermediate age-related macular degeneration (AMD) and DPEDs were followed longitudinally with annual multimodal imaging.

RESULTS

Thirty-one eyes of 25 participants (mean age 72.6 years) in the A2A AREDS2 substudy had DPED identified in color fundus images. SD-OCT inspection confirmed a sub-retinal pigment epithelium drusenoid elevation of ≥433 µm diameter in 25 (80.6%) eyes. Twenty-four of these eyes were followed longitudinally (median 4.0 years) during which 7 eyes (29.2%) underwent DPED collapse (with 3/7 further progressing to geographic atrophy), 6 (25.0%) developing neovascular AMD, and 11 (45.8%) maintaining DPED persistence without late AMD. On Kaplan-Meier analysis, mean time to DPED collapse was 3.9 years. Both DPED collapse and progression to neovascular AMD were preceded by the presence of hyperreflective foci over the DPED.

CONCLUSION

The natural history of DPED comprises: collapse - sometimes followed by the development of atrophy, vascularization followed by exudation, or DPED persistence. SD-OCT can confirm RPE elevation caused by drusenoid accumulation and facilitate the identification of high-risk features that correlate with progression.

Difference Between the Incidence of Retinal Fluid Subtypes and Their Association with Visual Outcomes According to the Types of Macular Neovascularization in a Korean Population

Purpose: To investigate differences in the incidence of retinal fluid subtypes among different subtypes of macular neovascularization (MNV) and evaluate the influence of the presence of retinal fluid subtypes on visual outcome in each subtype of MNV. Methods: This retrospective study included 248 patients (248 eyes) diagnosed with treatment-naive neovascular age-related macular degeneration and polypoidal choroidal vasculopathy (PCV). The incidence of retinal fluid subtypes at diagnosis and during the 24-month follow-up was compared among the different subtypes of MNV. In addition, visual acuity was compared between patients with and without the retinal fluid subtypes. Results: At diagnosis, there was a significant difference in the incidence of subretinal fluid (SRF), intraretinal fluid (IRF), and subretinal pigment epithelial fluid among type 1 MNV, type 2 MNV, type 3 MNV, and PCV (P < 0.001). The incidence of SRF (P < 0.001) during follow-up also differed among the 4 groups. In patients with type 1 MNV and IRF, the visual acuity at diagnosis (P = 0.004) and at 24 months (P < 0.001) were significantly worse. However, the presence of SRF was not associated with poor visual acuity. In type 3 MNV, there was no significant difference in visual acuity between patients with and without SRF/IRF. Conclusion: The results of this study indicate that the clinical significance of retinal fluid subtypes may differ in different subtypes of MNV, suggesting the need for analysis in isolation of each MNV subtype in fluid-based prognostication.

The RAP study, report 3: Discoloration of the macular region in patients with macular neovascularization type 3

BACKGROUND/AIMS

To explore whether the existence and pattern of distribution of macular haemorrhage or exudate can be valuable diagnostic markers for macular neovascularization type 3 (MNV3) in patients with neovascular age-related macular degeneration.

METHODS

Eighty-three eyes of 83 consecutive treatment naïve patients with stage 3 MNV3 were enrolled. The diagnosis was based on fluorescein angiography (FA) and optical coherence tomography (OCT). Subretinal and intraretinal haemorrhage and dense exudates were evaluated on colour fundus photography. Fluorescein angiography (FA) images and OCT scans were used to identify the axial location of the haemorrhage. 83 patients with MNV1 and 83 with MNV2 were included as two control groups.

RESULTS

In the MNV3 group, 62 (75%) eyes had intraretinal haemorrhage and 52 (63%) had dense exudates. 73 (88%) eyes had intraretinal haemorrhage and/or dense exudates. 41 (49%) had both pathologies. The intraretinal haemorrhage was flame shaped over the lesion and punctate or semi-punctate further away from it and directed to the fovea. No subretinal haemorrhage was noticed. In the MNV1 and MNV2 groups, 11 (13%) and 24 (29%) eyes had subretinal haemorrhage or dense exudates, respectively. No intraretinal haemorrhage was seen in the two control groups. The prevalence of exudates and haemorrhage (irrespective of its location) was greater in MNV3 than in MNV1 or 2 (p < 0.0001).

CONCLUSION

The existence and pattern of distribution of intraretinal haemorrhage is pathognomonic of MNV3. It makes (alone or with dense exudates) the diagnose MNV3 possible using fundoscopy or colour fundus photo and without further diagnostic expenditure.

Bacillary Layer Detachment in a Korean Cohort with Neovascular Age-Related Macular Degeneration

PURPOSE

To evaluate the incidence and characteristics of bacillary layer detachment (BALAD) in neovascular age-related macular degeneration (AMD).

METHODS

This retrospective study was performed at Kim's Eye Hospital in South Korea. Patients who were diagnosed with neovascular AMD between January 2017 and December 2017 were included. The incidence of BALAD was compared among different types of macular neovascularization. The best-corrected visual acuity (BCVA) and central retinal thickness (CRT) at diagnosis were compared between patients showing BALAD at diagnosis and those who did not.

RESULTS

Among the 442 patients included, BALAD was observed in 20 patients(4.5%). There was a significant difference in the incidence of BALAD between type 1 MNV(2.7%), type 2 MNV(12.5%), and type 3 MNV (0%)(P<0.001). The BCVA was significantly worse (mean 1.26±0.79 vs 0.62±0.50, P=0.001), and the CRT was significantly greater (mean 648.2±211.1 µm vs 464.0±175.5 µm, P<0.001) in patients with BALAD than in those without it. After anti-vascular endothelial growth factor therapy, all BALADs resolved.

CONCLUSIONS

This study first reported the incidence of the BALAD in neovascular AMD in Korean population. The incidence of BALAD was the highest in type 2 MNVs. BALAD generally develops in eyes with great macular thickness and poor visual acuity.

The RAP study, report 4: morphological and topographical characteristics of multifocal macular neovascularization type 3

PURPOSE

To report on the morphological characteristics and regional distribution of multifocal macular neovascularization type 3 (mMNV3).

METHODS

Twenty-two consecutive eyes of 21 patients with mMNV3 were included using multimodal imaging. The count and stage of lesions of all MNV types and the existence of exudate and hemorrhage were determined. Also, we addressed the regional distribution of MNV3 lesions between the superior-inferior and the nasal-temporal halves of the macula, and the range of the distance of the lesions from the central fovea. Furthermore, we explored the number of feeding vessels including the cilioretinal artery.

RESULTS

We found 51 lesions in 22 eyes of 21 patients. They were bifocal in 16 (73%) eyes, trifocal in 5 (23%), and quadrifocal in one (4%). No lesion of MNV1 or 2 was found. Fifteen (68%), 2 (9%), and 16 (73%) eyes were associated with retinal hard exudate, subretinal pigment epithelium exudate, and intraretinal hemorrhage, respectively. Thirty (59%) lesions were located in the temporal half of the macula, whereas 21 (41%) were located nasally (p = 0.07). One (2%) lesion was closer than 500 µm, 49 (96%) between 500 and 1500 µm, and one (2%) between 1500 and 3000 µm. The lesions were supplied by one arteriole in one (4%) eye, two arterioles in 16 (73%) eyes, and 3 arterioles in 5 (23%) eyes. The CRA contributed as a feeding vessel in 5 (23%) eyes.

CONCLUSION

The multifocal variant of MNV3 has specific morphological and topographical characteristics. Multimodal imaging allows the understanding of the pathomorphological condition in more detail.

Significance of Hyperreflective Foci as an Optical Coherence Tomography Biomarker in Retinal Diseases: Characterization and Clinical Implications

Hyperreflective foci (HRF) is a term coined to depict hyperreflective dots or roundish lesions within retinal layers visualized through optical coherence tomography (OCT). Histopathological correlates of HRF are not univocal, spacing from migrating retinal pigment epithelium cells, lipid-laden macrophages, microglial cells, and extravasated proteinaceous or lipid material. Despite this, HRF can be considered OCT biomarkers for disease progression, treatment response, and prognosis in several retinal diseases, including diabetic macular edema, age-related macular degeneration (AMD), retinal vascular occlusions, and inherited retinal dystrophies. The structural features and topographic location of HRF guide the interpretation of their significance in different pathological conditions. The presence of HRF less than 30 μm with reflectivity comparable to the retinal nerve fiber layer in the absence of posterior shadowing in diabetic macular edema indicates an inflammatory phenotype with a better response to steroidal treatment. In AMD, HRF overlying drusen are associated with the development of macular neovascularization, while parafoveal drusen and HRF predispose to macular atrophy. Thus, HRF can be considered a key biomarker in several common retinal diseases. Their recognition and critical interpretation via multimodal imaging are vital to support clinical strategies and management.

Case Report: A Case of Perifoveal Exudative Vascular Anomalous Complex With a Good Prognosis

Significance: Perifoveal exudative vascular anomalous complex (PEVAC) is a unique clinical lesion. It manifests as isolated lesions and is easily misdiagnosed. Thus far, few PEVAC case reports have been published. PEVAC is typically inconsistent with other reported macular lesions. Purpose: To report our 24-month follow-up experience on the treatment of PEVAC with a micropulse laser (MPL). Case Report: A 56-year-old Chinese woman with no history of other diseases complained of decreased vision in her left eye that had persisted for more than 1 year. Comprehensive ophthalmic examinations were performed, including a vision test, slit lamp fundus exam, optical coherence tomography (OCT), optical coherence tomography angiography (OCT-A), fluorescein fundus angiography (FFA) and indocyanine green angiography (ICGA). Intravitreal injection of ranibizumab was ineffective, and bleeding, exudation and visual acuity were not improved. After two rounds of micropulse laser (MPL) treatment, the patient was followed up, and the prognosis was good. Conclusion: PEVAC is very rare, and early diagnosis is important, as the lesions readily cause irreversible damage. Our results indicate that an MPL can be used as an alternative treatment for PEVAC patients.

Impact of macular fluid features on outcomes of anti-vascular endothelial growth factor treatment for type 3 macular neovascularization

We evaluated the impact of macular fluid features on visual and anatomical outcomes in type 3 macular neovascularization (MNV) patients treated with anti-vascular endothelial growth factor (VEGF). We retrospectively enrolled 89 eyes with type 3 MNV with at least 12 months of follow-up. All patients were treatment-naïve and received a monthly loading injection of anti-VEGF for three months, followed by further injections as required. The association of baseline macular morphology, including intraretinal fluid (IRF) and subretinal fluid (SRF), with visual and anatomical outcomes was analyzed. At baseline, IRF was present in all enrolled patients (100%), and SRF was present in 43.8% (39/89) of them. After 12 months of treatment, no significant difference was found in terms of best-corrected visual acuity (BCVA) and changes in central foveal thickness between the eyes with (39) and without (50) SRF at baseline. In addition, the proportion of improved or worsened (gain or loss of more than three lines in the BCVA) visual acuity at 12 months was not significantly different among the groups. Incidence of macular atrophy during the treatment showed no difference between the groups, regardless of the presence of SRF. In conclusion, the macular fluid morphology, specifically SRF, in type 3 MNV showed no significant correlation with visual and anatomical outcomes during anti-VEGF treatment.

MULTIMODAL EVIDENCE OF TYPE 3 NEOVASCULARIZATION IN ENHANCED S-CONE SYNDROME

PURPOSE

To investigate, using multimodal imaging, the anatomy of neovascularization in eyes with enhanced S-cone syndrome.

METHODS

Three eyes with neovascularization, from two patients with enhanced S-cone syndrome, were analyzed using fluorescein angiography, indocyanine-green and optical coherence tomography angiography imaging.

RESULTS

The eyes reported had a demonstrable Type 3 neovascularization with evidence of retinal-retinal anastomoses on fluorescein angiography, indocyanine-green and optical coherence tomography angiography imaging. One eye that was initially without neovascularization, but with chronic macular edema developed a macular hemorrhage. This eye was treated with 8 injections of intravitreal bevacizumab over 29-months resulting in a final fibrovascular lesion. The characteristics of this final lesion share similarities to the two other eyes described. In all eyes and all exams, retinal vessels are observed to communicate with the subretinal fibrovascular lesion.

CONCLUSION

We provide evidence of retinal arteriovenous anastomosis of the superficial retinal plexus to a subretinal neovascular complex in patients with enhanced S-cone syndrome and point to similarities with Type 3 neovascularization in macular telengiectasia Type 2 (MacTel2) and age-related macular degeneration. These findings provide insights into the anatomy of neovascularization in these pathologies and may lead to hypotheses of their etiologies.

Characteristics and Associated Factors of Flat Irregular Pigment Epithelial Detachment With Choroidal Neovascularization in Chronic Central Serous Chorioretinopathy

Purpose: Flat irregular pigment epithelial detachment (FIPED) in chronic central serous chorioretinopathy (CSC) is strongly associated with type 1 choroidal neovascularization (CNV). The present study aimed to describe the multimodal imaging characteristics of FIPED in patients with chronic CSC and investigate the factors associated with vascularized FIPED.

Methods: We included 55 chronic CSC eyes with vascularized FIPED (47 patients) and 55 chronic CSC eyes with avascular FIPED from age-matched patients (47 patients). None of the included eyes had a history of previous treatment with anti-vascular endothelial growth factor, photodynamic therapy, focal laser, or vitrectomy. The demographic and multimodal imaging data were reviewed. The location, angiography features, height and width, presence of retinal pigment epithelium (RPE) aggregations, RPE thickness, and choroid status of the FIPED area were compared between the groups.

Results: The mean age of the included chronic CSC patients was 54.3 ± 7.8 years (range: 33–72 years), and 85.1% were male. Vascularized FIPED eyes had a larger width (1,556.4 ± 731.6 vs. 931.1 ± 486.2 μm, p < 0.001), larger subfoveal RPE thickness (33.4 ± 15.3 vs. 26.3 ± 6.6 μm, p = 0.004), larger maximum RPE thickness of the FIPED area (46.3 ± 20.5 vs. 31.5 ± 8.3 μm, p < 0.001), and more RPE aggregations in the FIPED area (94.5 vs. 54.5%, p < 0.001) than avascular FIPED eyes. RPE aggregations in the FIPED area were an independent factor strongly associated with vascularized FIPED (OR = 7.922, 95% CI = 1.346–46.623, p = 0.022).

Conclusion: FIPED with a larger width and RPE thickening may suggest the presence of an underlying type 1 CNV. FIPED with RPE aggregations had an increased occurrence of neovascularization in chronic CSC.

Clinical Pathological Features and Current Animal Models of Type 3 Macular Neovascularization

Type 3 macular neovascularization (MNV3), or retinal angiomatous proliferation (RAP), is a distinct type of neovascular age-related macular degeneration (AMD), which is a leading cause of vision loss in older persons. During the past decade, systematic investigation into the clinical, multimodal imaging, and histopathological features and therapeutic outcomes has provided important new insight into this disease. These studies favor the retinal origin of MNV3 and suggest the involvement of retinal hypoxia, inflammation, von Hippel–Lindau (VHL)–hypoxia-inducible factor (HIF)–vascular endothelial growth factor (VEGF) pathway, and multiple cell types in the development and progression of MNV3. Several mouse models, including the recently built Rb/p107/Vhl triple knockout mouse model by our group, have induced many of the histological features of MNV3 and provided much insight into the underlying pathological mechanisms. These models have revealed the roles of retinal hypoxia, inflammation, lipid metabolism, VHL/HIF pathway, and retinoblastoma tumor suppressor (Rb)–E2F cell cycle pathway in the development of MNV3. This article will summarize the clinical, multimodal imaging, and pathological features of MNV3 and the diversity of animal models that exist for MNV3, as well as their strengths and limitations.

CHORIOCAPILLARIS FLOW IMPAIRMENT IN TYPE 3 MACULAR NEOVASCULARIZATION: A Quantitative Analysis Using Swept-Source Optical Coherence Tomography Angiography

PURPOSE

To quantitatively analyze choriocapillaris alterations using swept-source optical coherence tomography angiography in eyes presenting with Type 3 macular neovascularization (MNV) and to compare these alterations with eyes presenting with intermediate AMD (iAMD).

METHODS

Macular 3 × 3-mm swept-source optical coherence tomography angiography scans were retrospectively analyzed in eyes with Type 3 MNV and in eyes with iAMD. The choriocapillaris en face slabs were extracted from the swept-source optical coherence tomography angiography device after manual segmentation. En face choriocapillaris flow images were compensated with en face choriocapillaris structure images, followed by the Phansalkar local thresholding method using a window radius of 4 and 8 pixels. The percentage of flow deficits (FD%), the number, size, and total area of FDs were computed for comparison. A secondary analysis was performed in the four corners of the image to include equidistant regions in all eyes.

RESULTS

Twenty-six Type 3 MNV eyes of 21 patients and 26 iAMD eyes of 17 patients were included. Compared with iAMD eyes, eyes with Type 3 MNV displayed a higher FD% (41.37% ± 14.74 vs. 19.80% ± 9.63 using radius 4 pixels [P < 0.001]; 45.24% ± 11.9 vs. 26.63% ± 8.96 using radius 8 pixels [P < 0.001]). The average size of FDs was significantly larger in Type 3 MNV eyes compared with iAMD eyes (P < 0.001), whereas the number of FDs was significantly lower in Type 3 MNV compared with iAMD eyes (P < 0.001).

CONCLUSION

Type 3 MNV eyes present with increased choriocapillaris flow impairment compared with iAMD eyes. Reduced choriocapillaris perfusion may contribute to Type 3 MNV development and pathogenesis.

The role of quantitative deep capillary plexus in the pathogenesis of type 3 macular neovascularization: an optical coherence tomography angiography study

Purpose

To quantitatively investigate the role of deep capillary plexus (DCP) in patients affected by type 3 macular neovascularization (MNV), compared to patients with reticular pseudodrusen (RPD) eyes and healthy controls, using optical coherence tomography angiography (OCTA).

Methods

In this prospective observational study, a total of seventy-eight eyes of 78 patients were included. Group 1 consisted of 40 eyes of 40 patients with stage 1 of type 3 MNV (22 males, 18 females, mean age 73.7, SD ± 6.60) and group 2 included 38 eyes of 38 patients with RPD (17 males, 21 females, mean age 73.2, SD ± 4.55). The control group included 40 eyes of 40 healthy subjects (20 males, 20 females, mean age 71.4, SD ± 6.36 years). We evaluated the retinal vessel density (VD) of superficial capillary plexus (SCP) and deep capillary plexus (DCP) using OCTA.

Results

Patients with diagnosis of type 3 MNV showed statistically lower values of VD in DCP with respect to controls and to RPD group (p < 0.001), while there were no statistical differences between RPD and control group in macular region. No significant differences in VD of SCP were detected among the three study groups.

Conclusion

OCTA provides a reproducible, non-invasive detailed quantitative analysis of retinal vascular features and changing in early-stage type 3 MNV patients, which allowed to shed the light on the main role of DCP ischemia in the development of type 3 MNV.

LONG-TERM CHANGES IN CHOROIDAL THICKNESS IN EYES WITH TYPE 3 MACULAR NEOVASCULARIZATION

PURPOSE

To evaluate the long-term changes in subfoveal choroidal thickness (SCT) in eyes with Type 3 macular neovascularization that underwent anti-vascular endothelial growth factor therapy.

METHODS

This retrospective study was performed with 47 patients diagnosed with Type 3 macular neovascularization and treated with anti-vascular endothelial growth factor therapy. All the patients initially received three loading injections. The SCT was compared at diagnosis, 3 months, 12 months, and at the final follow-up visit. The velocity of changes in SCT was also compared between each period.

RESULTS

The mean follow-up period was 52.1 ± 11.0 months. The mean SCT was 143.3 ± 51.2 µm at diagnosis, and it had significantly decreased to 128.6 ± 47.4 µm at 3 months (P < 0.001), 123.2 ± 45.7 µm at 12 months (P < 0.001), and 110.0 ± 43.0 µm at the final follow-up (P < 0.001). The mean velocity of the decrease in SCT was 4.9 ± 3.9 µm per month during the first 3 months, 0.6 ± 1.2 µm per month between the 3rd and the 12th months, and 0.3 ± 0.3 µm per month between the 12th month and the final follow-up. The velocity of the decrease was significantly greater during the first 3 months than during the 3rd to 12th month (P < 0.001) and 12th month to final follow-up (P < 0.001) periods. The difference was not significant between the 3rd to 12th month and 12th months to final follow-up (P = 0.836) periods.

CONCLUSION

Subfoveal choroidal thickness continuously decreased over time, with a significant decrease of 23% noted in eyes with Type 3 macular neovascularization. The thickness rapidly decreased during the initial loading phase. Subsequently, a continuous but gradual decrease in the thickness was noted.

Longitudinal assessment of type 3 macular neovascularization using three-dimensional volume-rendering OCTA

OBJECTIVE

To investigate the evolution of treatment-naive type 3 macular neovascularization (MNV) undergoing anti-vascular endothelial growth factor (VEGF) treatment through volume rendered three-dimensional (3D) optical coherence tomography angiography (OCTA).

DESIGN

Retrospective observational study.

PARTICIPANTS

Patients with type 3 MNV and age-related macular degeneration (AMD).

METHODS

Included subjects had three loading injections of an anti-VEGF agent. The OCTA volume data at baseline and follow-up were processed with a previously published algorithm in order to obtain a volume-rendered representation of type 3 MNV. Progressive changes in type 3 lesions were analyzed via 3D OCTA volume rendering.

RESULTS

A total of 14 treatment-naive eyes with type 3 MNV from 11 AMD patients (7 females) were included. At both baseline and follow-up visits, a type 3 MNV complex was identifiable. Each complex was composed of a mean number of 2.5 ± 0.7 vascular branches at baseline and 1.4 ± 0.6 at the follow-up visit (p < 0.0001). The mean changes in central macular thickness and visual acuity were significantly correlated with modifications in the number of type 3 MNV branches (ρ = -0.533, p = 0.049, and ρ = -0.581, and p = 0.040, respectively).

CONCLUSIONS

This study demonstrated that type 3 lesions do not disappear completely after loading treatment, as indicated previously by histopathologic studies. Importantly, quantitative volume changes in type 3 lesions are directly associated with treatment response.

Different Outcomes of Anti-VEGF Treatment for Neovascular AMD according to Neovascular Sutypes and Baseline Features: 2-Year Real-Life Clinical Outcomes

Purpose

To evaluate the effects of anti-VEGF treatment of neovascular age-related macular degeneration (nAMD) in a real-life clinical setting.

Methods

Study design is a retrospective case series. Naïve nAMD patients treated with intravitreal injection of aflibercept or ranibizumab were analyzed over a 24-month follow-up. Each patient received the loading dose, followed by a PRN regimen. Patients were further subdivided into subgroups according to macular neovascularization type, best corrected visual acuity (BCVA) at baseline (BCVA > 0.3 LogMAR and BCVA ≤ 0.3 LogMAR), and different anti-VEGF drugs. Primary outcome was the changes in BCVA and central macular thickness (CMT) over 24 months. Secondary outcomes included the influence of the selected drug and of the baseline BCVA on the final outcomes.

Results

439 patients (224 males; 51%) with naïve AMD-related macular neovascularization were included in the analyses. Mean age was 78 ± 8 years old. Compared to baseline evaluations, not significant BCVA changes were found at 1-year and 2-year examinations. CMT was significantly reduced at both 1-year and 2-year follow-ups (p < 0.01). Classic, polypoidal choroidal vasculopathy and mixed subtypes significantly correlated with worse visual outcome (p < 0.01). Overall, baseline BCVA significantly correlated with both 1-year and 2-year follow-up changes (p < 0.01). Moreover, BCVA at 1-year significantly correlated with BCVA changes at 2-year follow-up (p < 0.01). Furthermore, CMT changes from baseline significantly correlated with both 1-year and 2-year follow-up measurements (p < 0.01).

Conclusion

Anti-VEGF approach is generally effective in stopping nAMD progression in our real-life analysis. No difference was found comparing patients treated with ranibizumab and aflibercept, nor in patients with drug switching.

SUBRETINAL DRUSENOID DEPOSIT IN AGE-RELATED MACULAR DEGENERATION: Histologic Insights Into Initiation, Progression to Atrophy, and Imaging

PURPOSE

To clarify the role of subretinal drusenoid deposits (SDD; pseudodrusen) in the progression of age-related macular degeneration through high-resolution histology.

METHODS

In 33 eyes of 32 donors (early age-related macular degeneration, n = 15; geographic atrophy, n = 9; neovascular age-related macular degeneration, n = 7; unremarkable, n = 2), and 2 eyes of 2 donors with in vivo multimodal imaging including optical coherence tomography, examples of SDD contacting photoreceptors were assessed.

RESULTS

Subretinal drusenoid deposits were granular extracellular deposits at the apical retinal pigment epithelium (RPE); the smallest were 4-µm wide. Outer segment (OS) fragments and RPE organelles appeared in some larger deposits. A continuum of photoreceptor degeneration included OS disruption, intrusion into inner segments, and disturbance of neurosensory retina. In a transition to outer retinal atrophy, SDD appeared to shrink, OS disappeared, inner segment shortened, and the outer nuclear layer thinned and became gliotic. Stage 1 SDD on optical coherence tomography correlated with displaced OS. Confluent and disintegrating Stage 2 to 3 SDD on optical coherence tomography and dot pseudodrusen by color fundus photography correlated with confluent deposits and ectopic RPE.

CONCLUSION

Subretinal drusenoid deposits may start at the RPE as granular, extracellular deposits. Photoreceptor OS, RPE organelles, and cell bodies may appear in some advanced deposits. A progression to atrophy associated with deposit diminution was confirmed. Findings support a biogenesis hypothesis of outer retinal lipid cycling.

Assessing the long-term evolution of type 3 neovascularization in age-related macular degeneration using optical coherence tomography angiography

PURPOSE

To analyze the evolution of type 3 neovascularization in eyes with age-related macular degeneration during anti-vascular endothelial growth factor (VEGF) treatment using optical coherence tomography angiography (OCTA) analysis.

METHODS

Forty-one treatment-naïve eyes (37 patients) with type 3 neovascularization were retrospectively included in the study. The growth and morphological changes in the type 3 lesions, which were recorded using OCTA, were compared across time.

RESULTS

The high-flow signal of the lesion on OCTA was significantly increased at the sub-retinal pigment epithelium (RPE) and the choriocapillaris during anti-VEGF treatment. The detection rate of the flow signal in the sub-RPE increased from 50.0% at baseline and 51.2% at 12 months to 65.9% at 24 months (P = 0.013). The flow signal extending into the choriocapillaris was detected in 0% of the eyes at baseline, 9.8% of the eyes at 12 months, and 17.1% of the eyes at 24 months (P = 0.018). The presence of subretinal drusenoid deposits (SDD) was significantly more frequent in the group with extension into the choriocapillaris (100%) than in the group without (61.8%, P = 0.036). For the four eyes with extension into the choroid, the morphological feature of the lesion on en face OCTA evolved into a tangled vascular network, similar to type 1 neovascularization.

CONCLUSION

OCTA analysis revealed that type 3 neovascularization gradually extended downward toward the sub-RPE and choroid during anti-VEGF treatment. The extension of the lesion into the choriocapillaris, suggesting retinal-choroidal anastomosis, was significantly more frequent in eyes with SDD.