Nascent Type 3 Neovascularization in Age-Related Macular Degeneration

Non-exudative OCT findings in neovascular AMD

In this narrative review we describe the main optical coherence tomography biomarkers appearing in eyes with neovascular age-related macular degeneration (AMD) that do not directly correspond to exudation. We highlight those signs that may mimic exudation and therefore do not require active treatment, such as outer retinal tubulations, pseudocysts, lipid globules, or hyporeflective wedges. Other signs may indicate impending exudation such as hyperreflective foci or shallow irregular retinal pigment epithelium elevation, and therefore should be carefully monitored. We also review and summarize the different origins of subretinal hyperreflective material and describe the main signs of degeneration seen in eyes with AMD, such as outer retinal tubulation, thinning of the retinal layers, outer retinal atrophy, and choroidal changes.

Type 3 Macular Neovascularization in Age-related Macular Degeneration: Baseline Predictors of 3-Year Macular Atrophy Development

PURPOSE

To identify baseline OCT predictors of the 3-year macular atrophy (MA) development for type 3 (T3) macular neovascularization (MNV) secondary to neovascular age-related macular degeneration (nAMD) treated by anti-VEGF therapy.

DESIGN

Multicenter, retrospective, longitudinal study.

PARTICIPANTS

We included patients with treatment-naive T3 MNV secondary to nAMD at baseline, treated with anti-VEGF during a 3-year follow-up.

METHODS

Patients were identified from 6 retinal referral institutions: (1) San Raffaele University, Milan, Italy; (2) University of Genova, Genova, Italy; (3) Doheny Eye Institute, Los Angeles; (4) Stein Eye Institute, Los Angeles; (5) University of Paris Est, Creteil, France; and (6) Istituto di Ricovero e Cura a Carattere Scientifico Bietti Foundation, Rome, Italy. Several baseline predictors of 3-year MA area were analyzed based on structural OCT and demographics.

MAIN OUTCOME MEASURES

Multivariate analysis to identify baseline independent predictors of the 3-year MA development for T3 MNV secondary to nAMD treated by anti-VEGF therapy.

RESULTS

We included 131 eyes of 131 patients (mean age, 80 ± 6 years; 81% females). Best-corrected visual acuity was 0.49 ± 0.40 logarithm of the minimum angle of resolution (logMAR) at the baseline and significantly decreased to 0.59 ± 0.43 logMAR at the end of 3-year follow-up (P < 0.001). Patients were treated with 11 ± 6 anti-VEGF injections and developed atrophy in 75% of cases (from 18% at the baseline). Eyes that developed 3-year MA were treated with a significantly lower number of injections compared with eyes without MA (9.9 ± 5.5 vs. 14.7 ± 7.2 injections, P < 0.001). The most relevant independent predictors at baseline of MA area at 3-year follow-up were: area of MA at baseline (P < 0.001), age-related macular degeneration phenotype (presence of reticular pseudodrusen) (P = 0.017), baseline presence of nascent geographic atrophy (P = 0.008), and the baseline presence of subretinal hyperreflective material (P = 0.002).

CONCLUSIONS

Macular atrophy development is a frequent complication of T3 MNV treated with anti-VEGF injections. Several factors could be considered baseline predictors of atrophy development during the anti-VEGF treatment.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Small Hyperreflective Retinal Foci as in vivo imaging feature of resident microglia activation in geographic atrophy

Geographic atrophy (GA), the atrophic late stage of age-related macular degeneration (AMD), is one of the leading causes of vision loss in developed countries. Based on genetic, histological and preclinical studies, the role of the innate immune system in the development and progression of GA is well established. Microglia, the principal resident immune cells, are recognized as key players in innate immunity and contributors to AMD development. Optical coherence tomography (OCT) allows to identify small hyperreflective retinal foci (HRF) with specific features known as aggregates of activated microglial cells as possible in vivo imaging feature of local neuroretinal inflammation. The purpose of this study was to evaluate the presence and amount of small HRF in the eyes of patients with different macular atrophic phenotypes. Patients with GA in both eyes (bilateral GA: B-GA group), patients with GA in one eye and macular new vessels (MNV) in the fellow-eye (unilateral GA: U-GA group) and patients with extensive macular atrophy with pseudodrusen (EMAP), a rare and aggressive variant of atrophic AMD, were retrospectively analyzed. HRF, defined as isolated punctiform elements of small dimensions (≤30 μm) with intermediate reflectivity (similar to that of the nerve fiber layer) and without a shadow cone, were manually identified and quantified. The amount of HRF was correlated to best corrected visual acuity (BCVA), GA lesion size, measured both at near infrared reflectance (NIR), and blue wavelength fundus autofluorescence (FAF) images, to some GA features (multifocal versus unifocal GA; presence versus absence of foveal sparing) and to central retinal thickness (CRT). Forty-six patients (26 in the B-GA group, 16 in the U-GA group and 4 in the EMAP group) were studied. Patients with EMAP were younger compared to patients with B-GA and to patients with U-GA (63.5 ± 6.8 years vs 80.4 ± 8.4 years B-GA, and vs 83.3 ± 6.1 years U-GA; p = 0.0004 and p= <0.0001, respectively). Mean BCVA, mean GA area at NIR and at FAF images, foveal sparing and multifocal versus unifocal GA distribution and mean CRT were not significantly different among groups. GA area was wider on NIR versus FAF in all groups, significantly in B-GA and U-GA groups (11.7 ± 7.6 mm2 vs 10.6 ± 7.1 mm2, p = 0.0087 in B-GA; 7.8 ± 9.2 mm2 vs 7.7 ± 9.4 mm2, p = 0.004 in U-GA). The number of HRF was significantly higher in U-GA compared to B-GA and to EMAP (47.4 ± 7.1 vs 31.6 ± 7.3 B-GA and 28.0 ± 4.9 EMAP, p < 0.0001 for both), while mean HRF number did not significantly differ between B-GA and EMAP (p = 0.1960). HRF count correlated only to CRT, positively in B-GA and negatively in U-GA group. The increase of small HRF, which mirrors retinal microglial activation, characterizes eyes with unilateral GA (and MNV in the fellow eye) but not eyes with bilateral GA or EMAP. The role of activated microglia in the retina of GA eyes needs to be better investigated, mainly considering the actual and new therapeutic strategies with which to reduce either the development or progression of the atrophic macular changes.

Choroidal biomarkers in age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of central visual impairment in the elderly. The exact pathophysiological mechanisms for AMD remain uncertain. Several studies suggest that choroidal abnormalities and alterations are critical in AMD progression. The transition from manual to automated segmentation and binarization techniques has resulted in accurate and precise measurements of different choroidal parameters. These qualitative and quantitative parameters, known as choroidal imaging biomarkers, have advanced from basic vertical subfoveal choroidal thickness to more intricate 3-dimensional choroidal reconstruction methods in the last decade. Therefore, a comprehensive evaluation of choroidal metrics may investigate valuable insights into AMD, potentially guiding the future development of customized therapeutic strategies and personalized patient care in AMD management. We describe the role of different choroidal biomarkers in evaluating patients with AMD and their contribution to management.

Review of type 3 macular neovascularization in age-related macular degeneration: no DRAMA (Deep Retinal Age-related Microvascular Anomalies)

Type 3 macular neovascularization (MNV) is a unique form of neovascular age-related macular degeneration (AMD) that presents distinct pathogenetic features, clinical manifestations, and prognostic considerations when compared to types 1 and 2 MNV. Insights gained from clinicopathological correlations, bridging in vivo examination techniques with ex vivo histological analysis, have significantly enhanced our comprehension of this MNV phenotype, shaped current management strategies and influenced future directions for therapeutics. The particularities of type 3 MNV, which may largely stem from its origin from the retinal vasculature, are critically important for predicting the disease course. Our current understanding suggests that type 3 MNV occurs in response to retinal pigment epithelium (RPE) disruption and photoreceptor loss when neovessels originating from the deep capillary plexus are accompanied by activated Müller glia as they infiltrate sub-retinal pigment epithelium basal laminar deposits. Dysregulation of angiogenic and angiostatic factors are thought to play a key role in its pathogenesis. The prognosis for type 3 MNV is likely bilateral involvement and progression towards macular atrophy. It may be imperative for practitioners to distinguish type 3 MNV from other mimicking pathologies such as intraretinal microvascular anomalies, which are also part of the type 3 disease spectrum. For instance, deep retinal age-related microvascular anomalies (DRAMA) may present with similar features on multimodal imaging yet may necessitate distinct management protocols. Distinguishing between these conditions may be vital for implementing tailored treatment regimens and improving patient outcomes in the diverse landscape of AMD phenotypes in the future.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Non-exudative choroidal and macular neovascularizations: An overview

Non-exudative choroidal and/or macular neovascularizations (NV) represent nowadays a common finding in different retinal disorders. The introduction of non-invasive techniques such as structural optical coherence tomography (OCT) and OCT angiography (OCTA) allowed for easy detection and follow-up of non-exudative NVs. Recognized as a distinct entity, these lesions demonstrate a high variability in terms of pathophysiology, morphology, and prognostic implications. In the absence of a consensus regarding correct classification of subtypes of non-exudative NVs, accurate management through strict follow-up strategies and prompt treatment is required. In this review we offer a comprehensive overview of the non-exudative NV spectrum in various retinal diseases aiming to provide a deeper insight into this clinical entity.

Spectral-domain OCT characteristics of intraretinal hyper-reflective foci associated with age-related macular degeneration and diabetic retinopathy

OBJECTIVE

The purpose of this study was to quantitatively analyze and compare OCT characteristics of intraretinal hyper-reflective foci (IHRF) in eyes with diabetic retinopathy (DR) versus age-related macular degeneration (AMD).

DESIGN

a retrospective observational study.

PARTICIPANTS

54 treatment-naïve eyes (27 DR and 27 AMD).

METHODS

The IHRF lesions in OCT B-scan were semi-automatically segmented. Mean reflectivity (MR), maximum diameter, circularity index (Cir), area, and the angle between the greatest linear dimension (GLD) and the horizontal were computed for each IHRF lesion. The presence and absence of a posterior shadow and the axial location were assessed. The MR was normalized using the vitreous and nerve fiber layer reflectance as dark and bright reference standards, respectively.

RESULTS

A total of 1149 IHRF (1051 in DR and 98 in the AMD group) were identified, with a mean of 39 ± 36 lesions in DR eyes compared to only 4 ± 4 in AMD eyes (p < 0.001). The mean area of individual IHRF lesions was greater in DR eyes (1305 ± 1647 μm² vs 1031 ± 750 μm²; p = 0.016), but IHRF in AMD eyes had higher reflectivity (1.17 ± 0.14 vs 1.03 ± 0.17; p < 0.001). The angle of the GLD relative to the horizontal was greater in AMD eyes, indicating that IHRF in AMD eyes were more horizontally oriented. In AMD eyes, 88.8% of IHRF were located beneath the inner border of the outer nuclear layer (ONL), while in DR eyes, 56.9% were located there (p < 0.001).

CONCLUSIONS

IHRF lesions in eyes with DR and AMD demonstrate significant differences, with IHRF in DR eyes tending to be larger and less hyper-reflective compared to AMD eyes.

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.

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.

A pilot optical coherence tomography angiography classification of retinal neovascularization in retinopathy of prematurity

Extraretinal neovascularization is a hallmark of treatment-requiring retinopathy of prematurity (ROP). Optical coherence tomography angiography (OCTA) offers vascular flow and depth information not available from indirect ophthalmoscopy and structural OCT, but OCTA is only commercially available as a tabletop device. In this study, we used an investigational handheld OCTA device to study the vascular flow in and around retinal neovascularization in seven preterm infants with treatment-requiring ROP and contrasted them to images of vascular flow in six infants of similar age without neovascular ROP. We showed stages of retinal neovascularization visible in preterm infants from 32 to 47 weeks postmenstrual age: Intraretinal neovascularization did not break through the internal limiting membrane; Subclinical neovascular buds arose from retinal vasculature with active flow through the internal limiting membrane; Flat neovascularization in aggressive ROP assumed a low-lying configuration compared to elevated extraretinal neovascular plaques; Regressed neovascularization following treatment exhibited decreased vascular flow within the preretinal tissue, but flow persisted in segments of retinal vessels elevated from their original intraretinal location. These findings enable a pilot classification of retinal neovascularization in eyes with ROP using OCTA, and may be helpful in detailed monitoring of disease progression, treatment response and predicting reactivation.

Biomarkers for the Progression of Intermediate Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a leading cause of severe vision loss worldwide, with a global prevalence that is predicted to substantially increase. Identifying early biomarkers indicative of progression risk will improve our ability to assess which patients are at greatest risk of progressing from intermediate AMD (iAMD) to vision-threatening late-stage AMD. This is key to ensuring individualized management and timely intervention before substantial structural damage. Some structural biomarkers suggestive of AMD progression risk are well established, such as changes seen on color fundus photography and more recently optical coherence tomography (drusen volume, pigmentary abnormalities). Emerging biomarkers identified through multimodal imaging, including reticular pseudodrusen, hyperreflective foci, and drusen sub-phenotypes, are being intensively explored as risk factors for progression towards late-stage disease. Other structural biomarkers merit further research, such as ellipsoid zone reflectivity and choriocapillaris flow features. The measures of visual function that best detect change in iAMD and correlate with risk of progression remain under intense investigation, with tests such as dark adaptometry and cone-specific contrast tests being explored. Evidence on blood and plasma markers is preliminary, but there are indications that changes in levels of C-reactive protein and high-density lipoprotein cholesterol may be used to stratify patients and predict risk. With further research, some of these biomarkers may be used to monitor progression. Emerging artificial intelligence methods may help evaluate and validate these biomarkers; however, until we have large and well-curated longitudinal data sets, using artificial intelligence effectively to inform clinical trial design and detect outcomes will remain challenging. This is an exciting area of intense research, and further work is needed to establish the most promising biomarkers for disease progression and their use in clinical care and future trials. Ultimately, a multimodal approach may yield the most accurate means of monitoring and predicting future progression towards vision-threatening, late-stage AMD.

Choroidal Hyper-Reflective Foci in Geographic Atrophy

Purpose

The purpose of this study was to describe the presence of choroidal hyper-reflective foci (HRF) on optical coherence tomography (OCT) in patients with geographic atrophy (GA). The relationship between the presence and quantity of choroidal HRF and other clinical and imaging factors was also investigated.

Methods

A total of 40 participants (40 eyes) with GA and age-related macular degeneration (AMD) were retrospectively analyzed. OCT images were reviewed for the presence, characteristics, and localization of choroidal HRF. The amount of choroidal HRF was quantified in different choroidal layers by two different (i.e. threshold reflectivity and manual counting) methodologies. The primary outcome was to describe and quantify choroidal HRF and correlate them with GA lesion size.

Results

Structural OCT images showed that all patients had multiple hyper-reflective deposits in different layers of the choroid. These hyper-reflective deposits in the choroid were located near Bruch's membrane or the edges of the blood vessels, particularly in the Sattler's layer, and none were observed inside the vessels. Choroidal HRF exhibited variable size and shape and varying effects on the posterior signal, including shadowing or hypertransmission. Mean ± SD number of choroidal HRF per B-scan was 21.5 ± 15.4 using the threshold reflectivity methodology and 25.1 ± 16.0 using the manual counting methodology. A significant correlation between the untransformed GA size and number of HRF was found, considering both quantitative strategies.

Conclusions

Hyper-reflective dots in the choroid of subjects with GA may be readily identified with structural OCT. These HRF might represent a natural component of the choroid that becomes more visible due to the absence of the retinal pigment epithelium.

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.

Blood flow pattern in eye before development of type 3 macular neovascularization

PURPOSE

To determine the blood flow pattern of eyes before the development of type 3 macular neovascularization (MNV) by optical coherence tomography angiography (OCTA).

STUDY DESIGN

Retrospective study.

SUBJECTS

Ten eyes of 10 patients (4 men and 6 women, mean age 80.4 years) diagnosed with unilateral Type 3 MNV who developed type 3 MNV in the fellow normal eye during the follow-up period were studied.

METHODS

The time of onset of type 3 MNV was defined as the time when retinal exudation was detected by OCT. The blood flow of a 3 x 3 mm or 6 x 6 mm area in the deep capillary plexus (DCP) and the outer retina (OR) including the central fovea were assessed at the onset and at 6 months prior to the onset of the type 3 MNV.

RESULTS

All MNVs that developed in the fellow eye were type 3 MNVs. Abnormal blood flow signals in the MNVs were detected in the DCP and/or the OR by OCTA at the onset in all cases. Eight of the 10 eyes had OCTA recordings prior to the development of the MNV: 3 eyes had non-exudative MNVs only in the DCP and 5 eyes had non-exudative MNVs in the DCP and OR. The exudation appeared on the average 3.5 months after the non-exudative MNV was observed in the fellow eyes.

CONCLUSIONS

A non-exudative MNV in the fellow eyes can already be observed by OCTA in eyes before the onset of the exudation. Knowing this will help clinicians not only how to treat these eyes appropriately but will also help in determining the origin of the MNV.

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.

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.

Volume Rendering of Deep Retinal Age-Related Microvascular Anomalies

PURPOSE

To characterize and distinguish non-neovascular deep retinal age-related microvascular anomalies (DRAMA) from type 3 macular neovascularization (MNV) using volume rendering of OCT and OCT angiography (OCTA).

DESIGN

Retrospective, consecutive case series.

SUBJECTS

Consecutive patients with age-related macular degeneration (AMD) exhibiting de novo non-neovascular abnormalities within the deep vascular plexus (DCP), as detected using high-resolution (High-Res) spectral-domain (SD) and swept-source (SS) OCT or OCTA. Patients with retinal vascular alterations attributable to other disease entities were excluded.

METHODS

Complete ophthalmic examination and multimodal imaging, including confocal fundus photography (CFP), SD-OCT, High-Res SD-OCT and OCTA, and volume-averaged SS-OCTA. The volume renderings of High-Res OCTA and averaged SS-OCTA were used to analyze capillary abnormalities and inflow or outflow connectivity pathways.

MAIN OUTCOME MEASURES

The primary outcomes were the characteristics of capillary abnormalities (number, size, shape, reflectivity, and location) and inflow or outflow connectivity pathways. The secondary outcomes were nearby changes in CFP and structural OCT (hyperreflective foci [HRF], outer retinal atrophy, and retinal pigment epithelium [RPE] atrophy).

RESULTS

From 8 eyes of 8 patients, 2 subtypes of DRAMA were identified: small-diameter perifoveal capillary dilations with hyperreflective walls within the inner nuclear layer (type 1, n = 4) and vascular outpouchings, typically multiple, extending posteriorly into the Henle fiber layer, with reflectivity similar to adjacent normal retinal capillaries (type 2, n = 10). Four eyes had both subtypes of DRAMA. The 3-dimensional visualization of OCTA data demonstrated DRAMA corresponding to the dilations of DCP capillaries without direct inflow or outflow connections to the superficial plexus. Fundus photographs showed circular red dots in 3 eyes, all corresponding to type 1 DRAMA. In all the cases, DRAMA colocalized with HRF. No lesions were found anterior to the areas of the RPE or outer retina atrophy. Asymptomatic intraretinal exudation varied through a follow-up duration of up to 6 years, with no lesions progressing to type 3 MNV.

CONCLUSIONS

In eyes with non-neovascular AMD, DRAMA include 2 types of capillary dilations occurring without the remodeling of the surrounding vascular network. Deep retinal age-related microvascular anomalies can resemble microvascular changes due to other causes and can masquerade as type 3 MNV. Mild intraretinal exudation can vary during follow-up, without progression to type 3 MNV.

Early OCTA Changes of Type 3 Macular Neovascularization Following Brolucizumab Intravitreal Injections

Background and Objectives: Brolucizumab is a novel anti-vascular endothelial growth factor (VEGF), whose efficacy has been shown in the Hawk and Harrier phase 3 clinical studies. The goal of the present case series is to report initial results of brolucizumab intravitreal injections (IVI) on type 3 neovascularization in neovascular age-related macular degeneration (nAMD), evaluated by optical coherence tomography angiography (OCTA). Materials and Methods: This is a bicentric retrospective case series. Patients with newly diagnosed type 3 MNV treated with brolucizumab IVI and at least 6 months follow-up were enrolled. OCTA en face images and B-scans were analyzed for lesions at baseline, 1 month, 3 months, and 6 months. Whenever detectable, lesion area on outer retina and choriocapillaris layers was measured. Results: Twelve eyes of 12 patients were included into the study. The most consistent OCTA sign at baseline was the presence of a vascular tuft in the outer retina (100%). The highest response was achieved at 3 months, with statistically significant decrease in lesion detection in the outer retina, in the choriocapillaris, and outer retinal lesion size. At 6 months, 58% of outer retinal lesions had disappeared. Conclusions: Brolucizumab IVI shows a good short-term efficacy for the treatment of type 3 neovascularizations. Further studies with greater number of patients and longer follow-up are warranted to confirm these findings.

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.

Intraretinal Cysts as a Manifestation of Retinal Angiomatous Proliferation in Optical Coherence Tomography Angiography

Background and Objectives: Intraretinal cysts are common pathology observed inspectral domain optical coherence tomography (SDOCT) in patients with neovascular form of age-related macular degeneration (AMD). The aim of the study was to determine if the presence of intraretinal cysts is positively correlated with diagnosis of retinal angiomatous proliferation (RAP) in optical coherence tomography angiography (OCTA). Material and Methods: A total of 21 eyes with intraretinal cysts in SDOCT exam (Group1) and 21 eyes with subretinal fluid(Group 2) were enrolled into the study. In each eye, the presence of intraretinal neovascularization (IRN) and chorioretinal anastomosis (CRA) was evaluated in OCTA by two experienced graders. Results: IRN was observed in 20 eyes (95.2%) from Group 1 and 5 eyes (23.8%) from Group 2. Features of CRA were found in 18 eyes (80.95%) and 16 eyes (76.2%) respectively for Group 1 and 2. Patients with cysts are 50 (95% CI: 5.43−460.52) times more likely to have IRN (p < 0.001). Conclusions: The presence of intraretinal cysts on SDOCT retinal sections in eyes with neovascular AMD corresponds to the presence of IRN on OCTA examination. The results indicate that the absence of a cyst does not exclude the presence of IRN and CRA which can be identified on OCTA.

MULTIMODAL ASSESSMENTS OF DRUSENOID PIGMENT EPITHELIAL DETACHMENTS IN THE AGE-RELATED EYE DISEASE STUDY 2 ANCILLARY SPECTRAL-DOMAIN OPTICAL COHERENCE TOMOGRAPHY STUDY COHORT

PURPOSE

To identify features correlating with drusenoid pigment epithelial detachment (DPED) progression in the Age-Related Eye Disease Study 2 Ancillary spectral-domain optical coherence tomography study cohort.

METHODS

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

RESULTS

Thirty-one eyes of 25 participants (mean age 72.6 years) in the Age-Related Eye Disease Study 2 Ancillary spectral-domain OCT substudy (A2A study) had DPED identified in color fundus images. Spectral-domain optical coherence tomography inspection confirmed a subretinal pigment epithelium drusenoid elevation of ≥433 µm diameter in 25 eyes (80.6%). 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 age-related macular degeneration, and 11 (45.8%) maintaining DPED persistence without late age-related macular degeneration. On Kaplan-Meier analysis, mean time to DPED collapse was 3.9 years. Both DPED collapse and progression to neovascular age-related macular degeneration 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. Spectral-domain optical coherence tomography can confirm retinal pigment epithelial elevation caused by drusenoid accumulation and facilitate the identification of high-risk features that correlate with progression.

Discerning Between Macular Hemorrhages Due to Macular Neovascularization or Due to Spontaneous Bruch’s Membrane Rupture in High Myopia: A Comparative Analysis Between OCTA and Fluorescein Angiography

Introduction

To evaluate the sensitivity and specificity of optical coherence tomography angiography (OCTA) in comparison to fluorescein angiography (FA) in discerning between macular hemorrhages due to myopic macular neovascularization (m-MNV) and idiopathic macular hemorrhage (IMH) in patients with high myopia (HM).

Methods

In this retrospective study, 14 eyes of 14 patients (mean age 60 ± 16 years) affected by macular hemorrhage due to HM were included. All patients underwent OCTA and FA at the time of macular hemorrhage (i.e., baseline) and were followed for a 3-month follow-up.

Results

By means of FA, 8 out of 14 eyes with macular hemorrhage (57%) were diagnosed as type 2 m-MNV, whereas 6 eyes (43%) were diagnosed as IMH. Interestingly, OCTA displayed the presence of a neovascular network in all cases previously diagnosed as m-MNV using FA, and also excluded the presence of anomalous flow in all IMH eyes. This accounted for the high sensitivity and specificity of OCTA for m-MNV detection in HM cases with macular hemorrhage. After 3-month follow-up, BCVA improved from 0.39 ± 0.15 to 0.21 ± 0.14 logMAR (p = 0.006) in patients with m-MNV treated by a mean of 2.3 ± 0.9 intravitreal anti-VEGF injections. Conversely, BCVA improved without treatment (from 0.55 ± 0.48 to 0.17 ± 0.08 logMAR, p = 0.112) in patients with IMH.

Conclusions

OCTA is able to differentiate with excellent reliability between the presence of m-MNV in patients with HM presenting with a new macular hemorrhage and an IMH. This could be of paramount relevance in the clinical setting for the diagnosis and treatment of patients with HM.

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.

Choroidal Vascularity Index in Different Cohorts of Dry Age-Related Macular Degeneration

Purpose

The purpose of this study was to investigate the choroidal luminal and interstitial stromal alterations using choroidal vascularity index (CVI) among different cohorts of dry age-related macular degeneration (dAMD) compared to healthy subjects.

Methods

Four distinct cohorts were collected: three different cohorts of patients with dAMD (i.e. drusen, reticular pseudodrusen [RPD], and geographic atrophy [GA]) and an age-matched cohort of healthy subjects (controls). CVI (the ratio between the luminal choroidal area [LCA] and the total choroidal area [TCA]) was calculated in the subfoveal 1000 µm area.

Results

One hundred twenty eyes (from 120 patients) were included (30 eyes in each cohort). The mean age was 76.6 ± 7.1 years. No statistical differences were disclosed in terms of age, axial length, and central macular thickness among study groups. TCA showed a different distribution among the four cohorts (P = 0.003), mainly due to the LCA changes (P = 0.001). Interestingly, CVI showed a different distribution among the four cohorts (P < 0.001). RPD showed a lower CVI in comparison to controls (P = 0.040), whereas GA showed a lower CVI in comparison to drusen, RPD, and controls (P = 0.001, P = 0.046, and P < 0.001, respectively).

Conclusions

Different cohorts of dAMD are characterized by different impairments of the choroidal vascular and stromal components, reflecting different degrees of AMD severity.

Translational Relevance

CVI provides insights for better understanding the pathogenesis of AMD.

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.

Quantitative Optical Coherence Tomography Angiography Biomarkers for Alport Syndrome

PURPOSE

The aim of this study was to evaluate microvascular abnormalities of patients with Alport syndrome (AS) using optical coherence tomography angiography (OCT-A) quantitative biomarkers.

METHODS

This was cross sectional, prospective evaluation of consecutive patients with AS and healthy subjects. AS diagnosis was performed by the genetic test. All participants underwent a retinal vasculature evaluation by spectral-domain optical coherence tomography (SD-OCT) and OCT-A of the macula. Quantitative analysis included whole vascular density, foveal avascular zone area, fractal dimension (FD), and lacunarity (LAC).

RESULTS

Ninety-four eyes were included in this study, 45 eyes from patients with AS and 49 eyes from healthy subjects. The pathogenic mutation in the COL4A5 gene on the chromosome X was found in 14 patients; the pathogenic autosomal recessive mutations in the COL4A3 gene were found in 9 patients. Quantitative evaluation demonstrated a significant difference between AS and healthy subjects on LAC of the superficial capillary plexus and deep capillary plexus (DCP) (p < 0.001 and p < 0.001, respectively) and on FD in the DCP (p < 0.001).

CONCLUSION

The DCP Alport patients have a higher vessel nonuniformity than DCP of healthy subjects. We hypothesize that endothelial cell lesion in the setting of low resistance at the DCP circuit could lead to long-term structural disorganization.

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.

Unaffected fellow eye neovascularization in patients with type 3 neovascularization: Incidence and risk factors

Purpose

To evaluate the incidence and risk factors of neovascularization in unaffected fellow eyes of patients diagnosed with type 3 neovascularization in Korea.

Methods

This retrospective study included 93 unaffected fellow eyes of 93 patients diagnosed with type 3 neovascularization. For initial type 3 neovascularization diagnosis, optical coherence tomography and angiography were conducted. These baseline data were compared between patients with and without neovascularization in their fellow eyes during the follow-up period.

Results

The mean follow-up period was 66.1±31.1 months. Neovascularization developed in 49 (52.8%) fellow eyes after a mean period of 29.5±19.6 months. In the fellow eye neovascularization group, the incidence of soft drusen and reticular pseudodrusen was significantly higher than that in the non-neovascularization group (83.7% vs. 36.5%, p<0.001; 67.3% vs. 40.9%, p = 0.017, respectively), but the choroidal vascularity index (CVI) showed a significantly lower value (60.7±2.0% vs. 61.7±2.5%; p = 0.047). The presence of reticular pseudodrusen was related with the duration from baseline to development of fellow eye neovascularization (p = 0.038).

Conclusion

Neovascularization developed in 52.8% of unaffected fellow eyes. The presence of soft drusen, reticular pseudodrusen, and lower CVI values can be considered risk factors of neovascularization in unaffected fellow eyes of patients with type 3 neovascularization. The lower CVI values suggest that choroidal ischemic change may affect the development of choroidal neovascularization in these patients.

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.

Characterisation of macular neovascularisation in geographic atrophy

AIM

To characterise macular neovascularisation (MNV) developing in eyes affected by geographic atrophy (GA).

METHODS

In this multicentric longitudinal study involving three retina referral centres, patients previously affected by GA who developed an active MNV were included. Patients were investigated using structural optical coherence tomography (OCT), fundus autofluorescence, OCT-angiography and dye angiographies. Patients were treated with ProReNata antivascular endothelial growth factor (VEGF) injections and were revaluated after treatment.

RESULTS

Among 512 patients previously diagnosed with GA, 40 eyes of 40 patients (mean age 80.8±7.9 years, mean GA area 8.73±7.39 mm²) presented with treatment-naïve exudative MNV (accounting for an estimated prevalence of 7.81%; 5.49 to 10.13, 95% CIs) and thus were included in the analysis. 67.5% of MNVs were classified as type 2 MNV, 25% as type 1, 2.5% as type 3 and 5% as mixed phenotype. In 92.5% of cases, active MNV in GA showed subretinal hyperreflective material with or without evidence of subretinal/intraretinal hyporeflective exudation. During a mean follow-up of 28±25 months, patients were treated with 6.6±6.3 anti-VEGF injections, with 2.9±1.4 injections in the first year of treatment. No patient developed GA enlargement in the area of MNV.

CONCLUSIONS

MNVs in GA showed different features and therapeutic response in comparison to previously reported features of MNV in age-related macular degeneration (AMD) without GA. For these reasons, the combined phenotype (ie, GA with neovascular AMD) should be considered as a distinct entity in the research and clinical setting.

Optical Coherence Tomography Angiography of the Choriocapillaris in Age-Related Macular Degeneration

The advent of optical coherence tomography angiography (OCTA) has allowed for remarkable advancements in our understanding of the role of the choriocapillaris in age-related macular degeneration (AMD). As a relatively new imaging modality, techniques to analyze and quantify choriocapillaris images are still evolving. Quantification of the choriocapillaris requires careful consideration of many factors, including the type of OCTA device, segmentation of the choriocapillaris slab, image processing techniques, and thresholding method. OCTA imaging shows that the choriocapillaris is impaired in intermediate non-neovascular AMD, and the severity of impairment may predict the advancement of disease. In advanced atrophic AMD, the choriocapillaris is severely impaired underneath the area of geographic atrophy, and the level of impairment surrounding the lesion predicts the rate of atrophy enlargement. Macular neovascularization can be readily identified and classified using OCTA, but it is still unclear if neovascularization features with OCTA can predict the lesion’s level of activity. The choriocapillaris surrounding macular neovascularization is impaired while the more peripheral choriocapillaris is spared, implying that choriocapillaris disruption may drive neovascularization growth. With continued innovation in OCTA image acquisition and analysis methods, advancement in clinical applications and pathophysiologic discoveries in AMD are set to follow.

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

PURPOSE

To analyze different clinical and anatomical features in treatment-naïve non-exudative macular neovascularizations (MNVs) secondary to age-related macular disease (AMD).

METHODS

In this retrospective longitudinal study with a minimum follow-up of 1 year, 31 eyes of 28 consecutive AMD patients (mean age 75 ± 9 years) with treatment-naïve non-exudative MNV were enrolled. Patients were divided in: short-term activated MNV group (exudation before 6-month) and quiescent MNV group (per definition no exudation during a minimum 6-month follow-up) showing no or late activation during follow-up (persistently quiescent and long-term activated MNV group, respectively).

RESULTS

During the follow-up (mean duration: 22 ± 9 months) four eyes (13%) showed exudation before 6-month follow-up (short-term activated MNV group), whereas 21 eyes (68%) did not develop signs of exudation (persistently quiescent group), and six eyes (19%) developed exudation after the minimum 6-month follow-up (long-term activated MNV group). Monthly MNV growth rate was significantly higher in the short-term activated MNV group (growth rate of 13.30%/month), vs persistently quiescent MNV group (0.64%/month, p < 0.001) and long-term activated quiescent MNV group (1.07%/month, p < 0.001). Furthermore, at the baseline, perfusion density of short-term activated MNV group was significantly greater in comparison to persistently quiescent MNV group (p = 0.001) and long-term activated MNV group (p = 0.106).

CONCLUSION

We reported two different patterns for subclinical MNVs: subclinical MNVs characterized by short-term activation which could represent simply a pre-exudative stage in the development of an ordinary type 1 MNV, and quiescent MNVs characterized by low rate of growth and possible long-term activation. Analysis of OCT-A features may predict short-term activation for subclinical MNV but no features could predict the long-term activation.

ANATOMICAL CHANGES ON SEQUENTIAL MULTIMODAL IMAGING IN PERIFOVEAL EXUDATIVE VASCULAR ANOMALOUS COMPLEX

PURPOSE

To report a series of 21 patients with perifoveal exudative vascular anomalous complex (PEVAC) and to investigate the anatomical changes over time.

METHODS

We conducted a retrospective study. Clinical data of consecutive patients, presenting at the Rotterdam Eye Hospital between 2014 and 2019, were analyzed. The data collected included best-corrected visual acuity, fundus photography, optical coherence tomography (OCT), OCT-angiography, fluorescence angiography, and indocyanine green angiography.

RESULTS

We included 21 patients with a PEVAC lesion with a mean follow-up of 24.3 ± 13.8 months (range, 9-46 months). Patients with PEVAC were on average 75.3 ± 11.1 years (range, 53-90 years). The large perifoveal vascular aneurysmal abnormality was associated with small retinal hemorrhages in six patients and hard exudates in three patients. The PEVAC lesion was associated with intraretinal cystic spaces on OCT in 15 patients. Twelve of 21 patients showed no changes in cystic spaces on OCT during follow-up: 9 patients had stable cystic spaces and 3 patients had no cystic spaces. In contrast, in 9 of 21 patients, we observed changes in cystic spaces on OCT during follow-up. In two patients, cystic spaces appeared during follow-up, and in seven patients, there was a spontaneous resolution of cystic spaces. In three of these seven patients, the PEVAC lesion completely disappeared. Two patients, with stable intraretinal cystic spaces on OCT, were treated with intravitreal injections of anti-vascular endothelial growth factor without improvement.

CONCLUSION

Perifoveal exudative vascular anomalous complex is an idiopathic perifoveal retinal vascular abnormality that is associated with intraretinal cystic spaces. These intraretinal cystic spaces associated with a PEVAC lesion, and even the PEVAC lesion itself, can have a spontaneous resolution over time.

SUB-RETINAL PIGMENT EPITHELIUM MULTILAMINAR HYPERREFLECTIVITY AT THE ONSET OF TYPE 3 MACULAR NEOVASCULARIZATION

PURPOSE

To report the prevalence and treatment outcomes of eyes with sub-retinal pigment epithelium (sub-RPE) multilaminar hyperreflectivity at the onset/clinical detection of Type 3 macular neovascularization (MNV) secondary to exudative age-related macular degeneration.

METHODS

Retrospective analysis of consecutive patients diagnosed with Type 3 MNV secondary to age-related macular degeneration was performed. Eyes presenting with sub-RPE multilaminar hyperreflectivity on structural optical coherence tomography at the onset of Type 3 MNV were included in this study. An age-, sex-, and stage-matched control group was composed of eyes affected by Type 3 MNV without sub-RPE multilaminar hyperreflectivity. Prevalence and treatment outcomes after anti-vascular endothelial growth factor injections at 1-year follow-up were analyzed in both groups.

RESULTS

Nineteen treatment-naïve eyes of 19 patients (8 men/11 women, mean age 83 ± 8 years old) presenting with sub-RPE multilaminar hyperreflectivity before or at the onset/clinical detection of Type 3 MNV were included from a cohort of 162 eyes with treatment-naïve Type 3 MNV. This accounts for an estimated prevalence of 11.7% (5.8-15.2, 95% confidence intervals). No significant differences were disclosed between cases studied and the control group (143 eyes of 143 patients) in age, sex, best-corrected visual acuity at baseline, and number of injections. Best-corrected visual acuity did not improve during the 1-year follow-up in patients showing sub-RPE multilaminar hyperreflectivity (P = 0.45), whereas best-corrected visual acuity significantly increased in the control group (P < 0.001). The presence of sub-RPE multilaminar hyperreflectivity in the context of Type 3 MNV was significantly associated with regressive calcific drusen (P < 0.001) and multiple Type 3 lesions/eye (P < 0.001).

CONCLUSION

The detection of multilaminar hyperreflectivity at the onset/clinical detection of Type 3 MNV suggests that chronic exudation (i.e., the "onion-sign") in the sub-RPE space (i.e., focal sub-RPE neovascularization) may precede the onset/clinical detection of Type 3 MNV. Sub-retinal pigment epithelium multilaminar hyperreflectivity at the onset of Type 3 MNV may be an important predictor of poor visual outcome in these eyes.

Optical Coherence Tomography Angiography in Intermediate and Late Age-Related Macular Degeneration: Review of Current Technical Aspects and Applications

Optical coherence tomography angiography (OCTA) is a non-invasive diagnostic instrument that has become indispensable for the management of age-related macular degeneration (AMD). OCTA allows quickly visualizing retinal and choroidal microvasculature, and in the last years, its use has increased in clinical practice as well as for research into the pathophysiology of AMD. This review provides a discussion of new technology and application of OCTA in intermediate and late AMD.

Long-term follow-up of perifoveal exudative vascular anomalous complex treated with intravitreal injections of anti-vascular endothelial growth factor and thermal laser photocoagulation

PURPOSE

To describe the long-term follow-up of a patient with perifoveal exudative vascular anomalous complex (PEVAC) treated initially with intravitreal injections of anti-vascular endothelial growth factor (VEGF) followed by focal thermal laser photocoagulation.

OBSERVATIONS

A 78 years-old man presented with large, soft drusen in both eyes. Optical coherence tomography and fluorescein angiography revealed the presence of PEVAC in the left eye. The patient was in good general health with no history of diabetes and had no signs of other retinal vascular disease. During the follow-up, the intraretinal fluid accumulation progressively increased and the best-corrected visual acuity (BCVA) dropped from 20/20 to 20/30 over a period of 33 months. As the intraretinal fluid continued to increase and BCVA further decreased to 20/50 despite two intravitreal injections of anti-VEGF, the patient underwent focal thermal laser photocoagulation with a reduction in intraretinal fluid observed 1 month later. Two months after laser, the BCVA increased to 20/25 with complete reabsorption of the intraretinal fluid. Ten months after laser, the BCVA remained stable at 20/25 with no recurrence of intraretinal fluid.

CONCLUSIONS AND IMPORTANCE

This case illustrates that a PEVAC lesion may remain non-exudative for an extended period of time, but when exudation develops, anti-VEGF therapy may be ineffective requiring the use of thermal laser photocoagulation.

Exudative non-neovascular age-related macular degeneration

PURPOSE

To describe the clinical and multimodal imaging (MMI) features of age-related macular degeneration (AMD) eyes presenting with intraretinal exudation and no evidence of neovascularization or structural alterations of native retinal vessels.

METHODS

This was a retrospective review of the MMI and electronic health records for 3 consecutive patients presenting with unilateral exudative non-neovascular age-related macular degeneration. MMI included confocal color fundus photography (CFP), fundus autofluorescence (FAF), fluorescein angiography (FA), spectral domain optical coherence tomography (SD-OCT), swept-source optical coherence tomography angiography (SS-OCTA), and spectral domain optical coherence tomography angiography (SD-OCTA). Dense B-scan OCTA (DB-OCTA) patterns and implemented image post-processing were used to improve spatial resolution in the OCTA analysis and remove projection artifacts.

RESULTS

Three eyes of 3 patients (1 male and 2 females, ages 72-87) developed intraretinal fluid (IRF) producing retinal edema during regular follow-up for non-neovascular AMD. FA, SS-OCTA, and DB-OCTA demonstrated no evidence of macular neovascularization or discrete retinal vascular abnormalities that could explain the IRF accumulation. Two eyes received intravitreal anti-VEGF therapy and demonstrated prompt resolution of IRF with periodic recurrences over time.

CONCLUSION

Exudative non-neovascular AMD is a novel clinical phenotype characterized by the presence of non-neovascular intraretinal exudation producing macular edema. Differentiating this condition from other manifestations of AMD requires appropriate use of MMI. Further study is needed to assess the clinical impact and optimal management of exudative non-neovascular AMD.

Nonexudative Perifoveal Vascular Anomalous Complex: The Subclinical Stage of Perifoveal Exudative Vascular Anomalous Complex?

PURPOSE

To describe the pre-exudative stage of exudative perifoveal vascular anomalous complex (ePVAC), referred to as nonexudative PVAC (nePVAC).

DESIGN

Retrospective noncomparative case series.

METHODS

Patients diagnosed with nePVAC were identified at 4 retina referral centers worldwide. Multimodal retinal imaging, including structural optical coherence tomography (OCT) and OCT-angiography (OCT-A), were performed at baseline and follow-up visits.

RESULTS

Six eyes (6 patients, mean 75 ± 10 years of age) were included. Unrelated chorioretinal diseases were diagnosed in the affected eyes in 5 of 6 cases. At baseline, nePVAC is characterized by microvascular abnormalities featuring an isolated, perifoveal, large intraretinal aneurysm surrounded by capillary rarefaction at OCT-A examination, without any sign of exudation with structural OCT, and without visual impairment. Four patients were followed for a mean of 21 ± 14 months. During the follow-up, 3 of 4 eyes (75%) developed signs of exudation after a mean of 15 ± 9 months, associated with metamorphopsia and visual decline at the time of exudation. Best-corrected visual acuity decreased from 20/25 to 20/40 Snellen equivalent (P = .035) and central macular thickness increased from 268 ± 27 μm to 339 ± 65 μm (P = .145). Three patients were treated with 2.3 ± 0.6 intravitreal injections of anti-vascular endothelial growth factor without significant improvement of best-corrected visual acuity or macular edema.

CONCLUSIONS

nePVAC may represent the subclinical pre-exudative stage of ePVAC, notable for an absence of exudation or visual impairment. nePVAC and ePVAC should be considered as part of the same spectrum, namely PVAC. Typically, nePVAC develops signs of exudation over time, causing metamorphopsia and visual decline and therefore these lesions warrant continued close monitoring with multimodal retinal imaging.

Perifoveal exudative vascular anomalous complex in a highly myopic eye

‘Perifoveal Exudative Vascular Anomalous Complex’ (PEVAC) is a perifoveal, unilateral, isolated, perifoveal aneurysm, in otherwise healthy patients. Here, we report a case of PEVAC in a highly myopic eye of a 86-year-old woman affected by a visual decline in the right eye (best-corrected visual acuity of 20/100). She had no other relevant past conditions and/or ocular impairment. Fundus examination in the right eye showed myopic chorioretinal degeneration with a concomitant PEVAC. Structural optical coherence tomography (OCT) showed a round lesion with a hyperreflective wall associated with intraretinal cystic spaces. OCT-angiography nicely disclosed an isolated large aneurysmal retinal dilation featuring the PEVAC with detectable flow in superficial capillary plexus, deep capillary plexus, and avascular slab. This case highlights the importance of discerning between different vascular disorders of the macula, in order to be able to offer the right treatment and/or follow-up to the patient.

Optical Coherence Tomography Findings (SD-OCT and OCTA) in Early-Stage Type 3 Neovascularization

A 76-year-old male presented with a small hyperreflective density in the outer nuclear layer with subtle retinal pigment epithelium (RPE) elevation and few intraretinal cysts on spectral-domain optical coherence tomography (SD-OCT). Optical coherence tomography angiography (OCTA) confirmed the presence of a tuft-shaped intraretinal neovascular lesion. SD-OCT performed 2 months before showed a smaller RPE elevation at the same location without intraretinal fluid. A 79-year-old male presented with a small hyperreflective density in the outer retina surrounded by scant intraretinal fluid on SD-OCT and a bright vessel on OCTA, suggesting early-stage type 3 neovascularization. SD-OCT performed 2 months before showed a smaller hyperreflectivity at the same location, without intraretinal fluid. An 84-year-old female presented with hyperreflective foci in the outer retina overlying a serous pigment epithelium detachment (PED) with focal RPE disruption on SD-OCT. SD-OCT performed 2 months before showed the same hyperreflective lesion associated with a shallower PED. No neovascular lesions were found on OCTA after six injections of bevacizumab. To conclude, careful evaluation of SD-OCT allows for early detection of type 3 neovascularization at a pre-exudative stage. OCTA may be useful in confirming the presence of intraretinal neovascular lesion and monitoring response to anti-vascular endothelial growth factor agents.

OCT-A characterisation of recurrent type 3 macular neovascularisation

Purpose

To investigate optical coherence tomography angiography (OCT-A) findings in recurrent type 3 macular neovascularisation (MNV).

Methods

In this retrospective cohort study, consecutive patients with type 3 MNV secondary to age-related macular degeneration underwent OCT-A at three different time points: baseline, after anti-vascular endothelial growth factor treatment with complete resolution of the exudative signs (ie, non-exudative stage) and at the recurrence of exudation (ie, recurrence stage). Demographics and clinical findings were analysed, including OCT-A features of type 3 MNV recurrence.

Results

Twelve eyes (12 patients, mean age 78±7 years) were included. Using OCT-A, at baseline all type 3 MNVs showed the presence of detectable flow downgrowing from the deep vascular complex (DVC) to the retinal pigment epithelium (RPE)/sub-RPE space. 6/12 eyes (50%) showed anomalous flow under the RPE, while the other 6 eyes showed flow reaching the RPE without anomalous flow in the sub-RPE space. At the non-exudative stage (after treatment), BCVA and CMT significantly improved (p=0.004 and p=0.036), and flow inside the retinal lesions reduced; interestingly the connection to the RPE/sub-RPE space regressed. At the time of recurrence, all type 3 MNVs showed the presence of intra/sub-retinal exudation with restoration of the flow deepening from the DVC to the RPE/sub-RPE space.

Conclusions

Detectable flow deepening from the DVC to the RPE/sub-RPE space using OCT-A is mandatory to have a new exudation secondary to recurrent type 3 MNV. Early detection of type 3 MNV recurrence by OCT-A characterisation may prompt retreatment and potentially prevent progression to late stages of the disease.

Choriocapillaris flow impairment could predict the enlargement of geographic atrophy lesion

AIM

To analyse the choriocapillaris (CC) flow status in the area that subsequently showed geographic atrophy (GA) expansion secondary to age-related macular degeneration (AMD) during 1-year follow-up, matching optical coherence tomography angiography (OCT-A) and fundus autofluorescence (FAF).

METHODS

In this prospective longitudinal observational study, 30 eyes of 20 consecutive patients with GA secondary to AMD (mean age 75.5±7.4 years) were included. All patients underwent OCT-A and FAF at baseline and 1-year follow-up. Main outcome measures included analysis of perfusion density (PD) in the 'area surrounding GA margin' (between the GA border and 500 µm distance) in comparison with the 'control area' (area outside the 500 µm line), and of the 'expansion area' (area that subsequently developed GA expansion during 1-year follow-up).

RESULTS

During the 1-year follow-up, visual acuity significantly decreased from 0.34±0.38 Logarithm of the Minimum Angle of Resolution (LogMAR) to 0.39±0.40 LogMAR (p<0.001), and mean GA area increased from 6.82±5.47 mm² to 8.76±6.28 mm² (p<0.001). CC PD of the area surrounding the GA margin revealed a significant flow impairment compared with control area (PD 0.679±0.076 and 0.734±0.057, respectively (p<0.001)). Furthermore, the PD of the expansion area showed a greater CC flow impairment in comparison to the remaining area surrounding GA margin (p<0.001).

CONCLUSIONS

We reported a greater CC impairment in the area that subsequently developed GA expansion, suggesting that the CC flow impairment could predict the enlargement of GA lesion. The CC impairment could be considered as a new a risk factor for GA progression and a biomarker to be measured to determine efficacy of new interventions aiming to slow progression of GA.

Rotational Three-dimensional OCTA: a Notable New Imaging Tool to Characterize Type 3 Macular Neovascularization

This study explored whether rotational three-dimensional (3D) visualization of optical coherence tomography angiography (OCTA) volume data may yield valuable information regarding type 3 macular neovascularization (MNV). In this retrospective, cross-sectional study, we collected data from 15 eyes (13 patients) with treatment-naïve type 3 MNV in their post-nascent stage and age-related macular degeneration (AMD). Subjects were imaged with the SS-OCT system (PLEX Elite 9000, Carl Zeiss Meditec Inc., Dublin, CA, USA). The OCTA volume data were processed with a prototype volume projection removal algorithm and then analyzed using volumetric visualization techniques in order to obtain a 3D visualization of the region occupied by type 3 MNV. The two-dimensional and three-dimensional OCTA images were investigated. Mean ± SD age was 75.1 ± 7.4 years. BCVA was 0.42 ± 0.21 LogMAR in the study eyes. Considering the cohort of analyzed eyes, on rotational 3D OCTA images, a total of 35 neovascular lesions (vs 22 lesions detected on 2D OCTA images) rising from the deep vascular complex and variably spanning the outer retinal layers and eventually reaching the RPE/sub-RPE space were detected. Nine of 35 lesions had a saccular shape, while the remaining cases had a filiform shape. On rotational 3D OCTA images, these lesions were inclined on the three planes, instead of perpendicular to the RPE/Bruch’s membrane. In conclusion, this study used an algorithm to obtain rotational three-dimensional visualization of type 3 MNV. This approach seems to increase the detection rate for these lesions and to be useful to offer new insight into type 3 MNV.