REDUCED CHORIOCAPILLARIS FLOW IN EYES WITH TYPE 3 NEOVASCULARIZATION AND AGE-RELATED MACULAR DEGENERATION

Choroidal and Choriocapillaris OCT-A Analysis in Patients Affected by Active Central Serous Chorioretinopathy

Purpose

To analyze choroidal and choriocapillaris changes in eyes affected by active unilateral central serous chorioretinopathy (CSC).

Methods

A total of 17 eyes suffering from naïve CSC were enrolled. In addition, 17 healthy fellow eyes were analyzed, and 10 eyes were enrolled as controls. Main outcome measures were choroidal vascularity index (CVI), best-corrected visual acuity (BCVA), central macular thickness (CMT), subfoveal choroidal thickness (SFCT), and pigment epithelial detachment (PED) presence and maximum height (PED-MH). In addition, choriocapillaris and choroidal flow analysis in the two concentric areas surrounding the fovea were analyzed.

Results

CCT was higher in affected eyes than healthy ones (P = 0.007). CVI was significantly higher in affected eyes (P = 0.027) and in fellow eyes (P = 0.027) compared to healthy. The choriocapillaris analysis showed interesting results in the first ring, with statistically significant differences between diseased eyes and fellow eyes and in diseased eyes compared to healthy ones. Besides, in the second ring analysis a lower flow in choriocapillaris was found in diseased eyes compared with healthy (P = 0.019). The choroidal flow analysis showed lower flow in affected eyes in the first and second ring when comparing diseased eyes with healthy controls (P = 0.006).

Conclusions

Choroidal and choriocapillaris flow abnormalities occur in both eyes affected by CSC and fellow eyes with different trends depending on the area of study reinforcing the key role of choroid and choriocapillaris in the pathogenesis of disease.

Translational Relevance

Understanding choroidal and choriocapillaris flow abnormalities in CSC eyes could give us new biomarkers able to monitor disease.

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.

Structural OCT and OCT angiography biomarkers associated with the development and progression of geographic atrophy in AMD

BACKGROUND

Geographic atrophy (GA) is an advanced, irreversible, and progressive form of age-related macular degeneration (AMD). Structural optical coherence tomography (OCT) and OCT angiography (OCTA) have been largely used to characterize this stage of AMD and, more importantly, to define biomarkers associated with the development and progression of GA in AMD.

METHODS

Articles pertaining to OCT and OCTA biomarkers related to the development and progression of GA with relevant key words were used to search in PubMed, Researchgate, and Google Scholar. The articles were selected based on their relevance, reliability, publication year, published journal, and accessibility.

RESULTS

Previous reports have highlighted various OCT and OCTA biomarkers linked to the onset and advancement of GA. These biomarkers encompass characteristics such as the size, volume, and subtype of drusen, the presence of hyperreflective foci, basal laminar deposits, incomplete retinal pigment epithelium and outer retinal atrophy (iRORA), persistent choroidal hypertransmission defects, and the existence of subretinal drusenoid deposits (also referred to as reticular pseudodrusen). Moreover, biomarkers associated with the progression of GA include thinning of the outer retina, photoreceptor degradation, the distance between retinal pigment epithelium and Bruch's membrane, and choriocapillaris loss.

CONCLUSION

The advent of novel treatment strategies for GA underscores the heightened need for prompt diagnosis and precise monitoring of individuals with this condition. The utilization of structural OCT and OCTA becomes essential for identifying distinct biomarkers associated with the initiation and progression of GA.

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.

Acquired Vitelliform Lesions in Intermediate Age-Related Macular Degeneration: A Cross Sectional Study

PURPOSE

This study aims to define the characteristics of acquired vitelliform lesions (AVLs) in patients with intermediate age-related macular degeneration (iAMD).

DESIGN

Retrospective, observational, cross sectional study.

SUBJECTS

This study included 217 eyes with AVLs associated with iAMD, and an equivalent number of control patients.

METHODS

OCT scans were evaluated for qualitative and quantitative parameters at both the eye and lesion level. Eye-level parameters included the presence of: hyporeflective core drusen, intraretinal hyperreflective foci (IHRF), subretinal drusenoid deposits, macular pachyvessels, central retinal thickness, and central choroidal thickness. Lesion-level qualitative parameters included the presence of ellipsoid zone (EZ) and external limiting membrane disruption overlying the AVL, IHRF overlying the AVL, AVL overlying drusen, pachyvessels under the AVL, a solid core within AVL, and AVL location. Lesion-level quantitative characteristics included AVL height and width, AVL distance from the fovea, and sub-AVL choroidal thickness.

MAIN OUTCOME MEASURES

The primary outcomes assessed included the frequency of IHRF, the presence of macular pachyvessels, central choroidal thickness, and the dimensions (both height and width) of AVLs.

RESULTS

Comparing the AVL and control groups, the frequency of IHRF (AVL: 49.3% vs. control: 26.3%) and macular pachyvessels (37.3% vs. 6.9%) was significantly higher in the AVL case group, and the central choroidal thickness (256.8 ± 88 μm vs. 207.1± 45 μm) was thicker in the AVL group. Acquired vitelliform lesions located over drusen, with overlying IHRF, or situated subfoveally, and AVL lesions with EZ disruption were found to have a greater lesion height and width compared with AVL lesions lacking these characteristics (P value < 0.001 for all). Additionally, a significant negative correlation was observed between the distance from the fovea and AVL height (Spearman rho: -0.19, P = 0.002) and width (Spearman rho: -0.30, P = 0.001).

CONCLUSIONS

This study represents the largest reported cohort of AVL lesions associated with iAMD. Novel findings include the higher frequency of pachyvessels in addition to the presence of a thicker choroid in these eyes, as well as the greater height and width of AVL closer to the foveal center. These findings may offer insights into pathophysiologic mechanisms underlying the development of AVL.

FINANCIAL DISCLOSURE(S)

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

Relationship between visual acuity and OCT angiography parameters in diabetic retinopathy eyes after treatment

PURPOSE

To assess the relationship between visual acuity and OCT angiography parameters in diabetic retinopathy eyes after treatment, and to analyze the relative factors in PDR eyes.

METHODS

A total of 89 eyes, including 42 eyes with non-PDR (NPDR), and 47 eyes after vitrectomy with PDR were included and underwent OCTA. All images were processed by Python or FIJI. Multivariable linear regression models were used to analyze the associations between postoperative BCVA and OCTA parameters in PDR patients.

RESULTS

Postoperative OCTA parameters including deep capillary plexus (DCP) parafoveal and perifoveal vessel density (VD), DCP parafoveal and perifoveal vessel length density (VLD), DCP fractal dimension (FD), choriocapillaris plexus (CCP) VD, CCP VLD, were significantly lower in the PDR group than in the NPDR group. In the superficial capillary plexus (SCP), we found a negative correlation between the postoperative BCVA and VD (parafovea: β coefficient = -0.351, p = 0.023; perifovea: β coefficient = -0.338, p = 0.036). Perifoveal VLD (β coefficient = -0.343, p = 0.031) and FD (β coefficient = -0.375, p = 0.016) of the SCP were also negatively correlated with postoperative BCVA. Regarding the DCP, perifoveal VD (β coefficient = -0.396, p = 0.008), perifoveal VLD (β coefficient = -0.334, p = 0.025), vessel tortuosity (VT) (β coefficient = -0.369, p = 0.015) were negatively correlated with postoperative BCVA. In CCP, VLD (β coefficient = -0.373, p = 0.023) and number of flow voids (β coefficient = -0.334, p = 0.036) exhibited a negative association with postoperative BCVA.

CONCLUSIONS

Postoperative BCVA of PDR patients was related to OCTA parameters of the SCP (parafoveal and perifoveal VD, perifoveal VLD and FD), DCP (perifoveal VD, VLD, and VT) and CCP (VLD and number of flow voids).

Choriocapillaris in Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a multifactorial disease characterized by progressive alterations of different retinal structures ultimately leading to vision loss. Among these, the choriocapillaris (CC) has been found to be affected in different stages of AMD. In this review we provide a discussion on the different stages of AMD, focusing particularly on the alterations involving the CC. This has been possible thanks to the introduction of optical coherence tomography-angiography, a recently developed imaging technique which allows the detection of blood flow in choroidal vessels. Therefore, the aim of this review is to provide a description of the various alterations involving the CC in the different stages of AMD.

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.

Deep Learning in Neovascular Age-Related Macular Degeneration

Background and objectives: Age-related macular degeneration (AMD) is a complex and multifactorial condition that can lead to permanent vision loss once it progresses to the neovascular exudative stage. This review aims to summarize the use of deep learning in neovascular AMD. Materials and Methods: Pubmed search. Results: Deep learning has demonstrated effectiveness in analyzing structural OCT images in patients with neovascular AMD. This review outlines the role of deep learning in identifying and measuring biomarkers linked to an elevated risk of transitioning to the neovascular form of AMD. Additionally, deep learning techniques can quantify critical OCT features associated with neovascular AMD, which have prognostic implications for these patients. Incorporating deep learning into the assessment of neovascular AMD eyes holds promise for enhancing clinical management strategies for affected individuals. Conclusion: Several studies have demonstrated effectiveness of deep learning in assessing neovascular AMD patients and this has a promising role in the assessment of these patients.

Functional and structural characteristics in patients with type 3 macular neovascularisation treated with anti-VEGF. Three-year results in real world settings

BACKGROUND

To evaluate the long-term anatomical and functional outcomes of anti-Vascular Endothelial Growth Factor intravitreal injections (anti-VEGF IVI) in patients with type 3 macular neovascularisation (MNV) in real-world settings.

METHODS

Retrospective review of patients with type 3 MNV who received anti-VEGF IVI between 2013 and 2020. Primary outcomes were best corrected visual acuity (BCVA) and central macular thickness (CMT). Secondary outcome was the development of new-onset of foveal-involving geographic atrophy (GA) and disciform scars.

RESULTS

We identified 59 eyes from 48 British patients that met the inclusion criteria. Treatment with anti- VEGF IVI resulted in a statistically significant reduction in median CMT, which was maintained throughout the study period. At 36 months, 24 eyes showed more than 50 μm reduction in CMT, 7 eyes remained stable and only 2 eyes showed an increase in CMT by more than 50μm compared to the baseline. At year three, deterioration was noticed in most eyes (52.78%) and vision remained stable or improved in 47.22% of the eyes. However, the median BCVA was not statistically significant different compared to baseline. During the study period new onset of macula-involving atrophy or scar was noted in 10.2% and 4.3% of the eyes, respectively.

CONCLUSION

In this real-world study, anatomic and functional improvement were recorded 12-months post anti-VEGF IVI in type 3 MNV. Despite sustained anatomical improvement, vision returned back to baseline levels at 36-months. The development of GA and macular scar was only partially responsible for this outcome suggesting a more severe nature of this form of nAMD.

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.

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.

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.

Recent Advances in Imaging Macular Atrophy for Late-Stage Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a leading cause of blindness worldwide. In late-stage AMD, geographic atrophy (GA) of dry AMD or choroidal neovascularization (CNV) of neovascular AMD eventually results in macular atrophy (MA), leading to significant visual loss. Despite the development of innovative therapies, there are currently no established effective treatments for MA. As a result, early detection of MA is critical in identifying later central macular involvement throughout time. Accurate and early diagnosis is achieved through a combination of clinical examination and imaging techniques. Our review of the literature depicts advances in retinal imaging to identify biomarkers of progression and risk factors for late AMD. Imaging methods like fundus photography; dye-based angiography; fundus autofluorescence (FAF); near-infrared reflectance (NIR); optical coherence tomography (OCT); and optical coherence tomography angiography (OCTA) can be used to detect and monitor the progression of retinal atrophy. These evolving diverse imaging modalities optimize detection of pathologic anatomy and measurement of visual function; they may also contribute to the understanding of underlying mechanistic pathways, particularly the underlying MA changes in late AMD.

Relationship between the distribution of intra-retinal hyper-reflective foci and the progression of intermediate age-related macular degeneration

PURPOSE

To assess the relationship between the distribution of intra-retinal hyper-reflective foci (IHRF) on optical coherence tomography (OCT) and progression of intermediate age-related macular degeneration (iAMD) over 2 years.

METHODS

Cirrus OCT volumes of the macula of subjects enrolled in the Amish Eye Study with 2 years of follow-up were evaluated for the presence of iAMD and IHRF at baseline. The IHRF were counted in a series of 5 sequential en face slabs from outer to inner retina. The number of IHRF in each slab at baseline and the change in IHRF from baseline to year 2 were correlated with progression to late AMD at 2 years.

RESULTS

Among 120 eyes from 71 patients with iAMD, 52 eyes (43.3%) of 42 patients had evidence of both iAMD and IHRF at baseline. Twenty-three eyes (19.0%) showed progression to late AMD after 2 years. The total IHRF count increased from 243 at baseline to 604 at 2 years, with a significant increase in the IHRF number in each slab, except for the innermost slab 5 which had no IHRF at baseline or follow-up. The IHRF count increased from 121 to 340 in eyes that showed progression to late AMD. The presence of IHRF in the outermost retinal slabs 1 and 2 was independently associated with a significant risk of progression to late AMD. A greater increase in IHRF count over 2 years in these same slabs 1 and 2 was also associated with a higher risk of conversion to late AMD.

CONCLUSIONS

The risk of progression to late AMD appears to be significantly associated with the distribution and extent of IHRF in the outermost retinal layers. This observation may point to significant pathophysiologic differences of IHRF in inner versus outer layers of the retina.

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.

Clinical Use of Optical Coherence Tomography Angiography in Retinal Diseases

The advent of optical coherence tomography angiography (OCTA) is one of the cornerstones of fundus imaging. Essentially, its mechanism depends on the visualization of blood vessels by using the flow of erythrocytes as an intrinsic contrast agent. Although it has only recently come into clinical use, OCTA has become a non-invasive diagnostic tool for the diagnosis and follow-up of many retinal diseases, and the integration of OCTA in multimodal imaging has provided a better understanding of many retinal disorders. Here, we provide a detailed overview of the current applications of OCTA technology in the diagnosis and follow-up of various retinal disorders.

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.

CHORIOCAPILLARIS STRUCTURE IN THE FELLOW EYES OF PATIENTS WITH NEOVASCULAR AGE-RELATED MACULAR DEGENERATION: An OCT Angiography Image Averaging Study

PURPOSE

Histological choriocapillaris abnormalities have been reported in age-related macular degeneration (AMD). Averaging multiple en face optical coherence tomography angiography improves the quality of imaging of the choriocapillaris. This study used multiple en face swept source optical coherence tomography angiography image averaging to examine the structural changes in the choriocapillaris in the fellow eyes of patients with neovascular AMD.

METHODS

All patients underwent macular optical coherence tomography angiography imaging. One eye per subject was repeatedly imaged, and nine raster scan sets were obtained. Registered en face images were averaged, and area of flow voids and number of flow voids were measured using ImageJ software.

RESULTS

Forty-eight patients with neovascular AMD were recruited for analysis. Twenty-seven patients had polypoidal choroidal vasculopathy, and 22 eyes had soft drusen. Twenty-six eyes of 26 healthy individuals were included as age-matched normal controls. The choriocapillaris had a meshwork appearance in all eyes. The mean flow void area of the choriocapillaris was larger in patients with AMD than normal controls (1.14 ± 0.16 mm2 vs. 1.01 ± 0.12 mm2, P = 0.002). The mean size of each flow void was greater in patients with AMD than normal controls (729 ± 210 µm2 vs. 583 ± 120 µm2, P = 0.003). The mean flow void area of the choriocapillaris was larger in eyes with soft drusen than without soft drusen (1.2 ± 0.2 mm2 vs. 1.1 ± 0.1 mm2, P = 0.024).

CONCLUSION

Multiple en face image averaging revealed precise choriocapillaris structures in the fellow eyes of patients with neovascular AMD.

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.

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.

Do patients with unilateral macular neovascularization type 3 need AREDS supplements to slow the progression to advanced age-related macular degeneration?

Given the wide spectrum of unique characteristics of macular neovascularization type 3 (MNV3) compared with types 1 and 2, we suggest regrading the colour photography assessment of the AREDS study to verify the impact of AREDS supplements on eyes with MNV3.

OCT angiography analysis of choriocapillaris vascular density in different stages of age-related macular degeneration

Objectives

To analyze the choriocapillaris vessel density (CVD) of eyes at different stages of Age-related Macular Degeneration (AMD) with Optical Coherence Tomography Angiography (OCTA).

Methods

This is a prospective observational cross-sectional study on 21 age-matched healthy eyes and 84 eyes with AMD (i.e., early AMD, late AMD, Geographic Atrophy [GA], and disciform scar AMD). OCTA was used to automatically measure the CVD (%), on both the whole macula and the foveal area, in a layer going from 9 µm above to 30 µm below the Bruch's membrane. Furthermore, in the GA subgroup, the extension of the Ellipsoid Zone (EZ) interruption and the area of macular chorio-retinal atrophy was analyzed.

Results

Macular CVD was significantly lower in the GA, late AMD and disciform scar AMD-subgroups compared to controls (respectively, p=0.0052; p<0.0001; p=0.0003), whereas it did not significantly vary in the early AMD group (p=0.86). A significant difference between the early AMD and both the late AMD and the disciform scar AMD subgroups was also found (p=0.0009 and 0.0095, respectively). When comparing the foveal CVD of healthy and AMD eyes, a significant difference was found with every AMD subgroup (early AMD, p=0.011; GA, p<0.0001; late AMD, p<0.0001; disciform scar AMD, p<0.0001). Furthermore, in the GA subgroup, the CVD had an inverse correlation with both the extension of the EZ-interruption (p=0.012) and with the calculated chorio-retinal atrophic area (p=0.009).

Conclusions

OCTA could play a crucial role in the categorization of AMD, allowing for the evaluation of gradual flow impairment at different stages of the disease. Moreover, the detection of a decreased macular and foveal CVD may shed light on the pathogenesis of AMD.

Choriocapillaris Flow Deficits Quantification in Hydroxychloroquine Retinopathy Using Swept-Source Optical Coherence Tomography Angiography

This study aims to quantitatively analyze choriocapillaris (CC) alterations using swept-source optical coherence tomography angiography (SS-OCTA) in eyes presenting with hydroxychloroquine (HCQ) toxic retinopathy and to compare it to patients under HCQ without toxic retinopathy and to healthy controls. For image analysis, CC en-face slabs were extracted from macular 6 × 6 mm SS-OCTA scans and a compensation method followed by the Phansalkar local thresholding was performed. Percentage of flow deficits (FD%) and other related biomarkers were computed for comparison. Fourteen eyes (7 patients) presenting with HCQ toxic retinopathy, sixty-two eyes (31 patients) under HCQ without signs of toxicity, and sixty eyes of 34 healthy controls were included. With regards to FD%, FD average size, and FD number there was a significant difference between the three groups (p < 0.05 with radius 4 and radius 8 pixels). Eyes presenting with HCQ toxicity had significantly higher FD% and average size, and a significantly lower number of FDs, with both radius 4 and 8 pixels. In conclusion, FD quantification demonstrates that CC involvement is present in HCQ toxic retinopathy, therefore giving pathophysiological insights with regards to the CC as being either the primary or secondary target of HCQ toxicity.

Topographical Analysis of the Choriocapillaris Reperfusion After Loading Anti-VEGF Therapy in Neovascular AMD

Purpose

The purpose of this study was to evaluate choriocapillaris vascular density changes around macular neovascularization (MNV) before and after anti-vascular endothelium growth factor (VEGF) injections by optical coherence tomography angiography (OCTA).

Methods

Treatment-naïve eyes with a diagnosis of exudative AMD and type 1 MNV were included. En face optical coherence tomography angiograms were analyzed for percentage of choriocapillaris (CC) flow deficit percentage (FD%), the FD average area (FDa), and the FD number (FDn) in 5 progressive 200-µm-wide concentric rings (R1, R2, R3, R4, and R5) surrounding the dark halo around the MNV. The OCTA acquisition was performed at the following visits: (i) before the loading phase of intravitreal injection of aflibercept or ranibizumab (T1), and (ii) 1 month after the last intravitreal injection of loading phase comprising 3 monthly injections (T2).

Results

A total of 30 eyes of 30 Caucasian patients with treatment naïve neurovascular AMD (nAMD) were included in the study. All rings showed a progressive FD% reduction at T2 in comparison to T1 values indicating gradual CC reperfusion of the peripheral rings. Furthermore, we found a progressive contraction of the FD average area in all the rings considered (P < 0.05). On the other hand, at T2, a significant increase in the FD number of the 5 rings was displayed, as compared to T1 (P < 0.05).

Conclusions

Our analysis showed topographical CC reperfusion after loading anti-VEGF therapy. CC flow deficits were greater around the associated dark halo before treatment, followed by a progressive recovery of CC flow after intravitreal therapy.

Translational Relevance

OCTA may be used to assess the development and progression of MNV but also in assessing response to intravitreal injections of anti-VEGF.

Computerized Texture Analysis of Optical Coherence Tomography Angiography of Choriocapillaris in Normal Eyes of Young and Healthy Subjects

Computerized texture analysis uses higher-order mathematics to identify patterns beyond what the naked eye can recognize. We tested its feasibility in optical coherence tomography angiography imaging of choriocapillaris. Our objective was to determine sets of parameters that provide coherent and consistent output when applied to a homogeneous, healthy group of patients. This observational cross-sectional study involved 19 eyes of 10 young and healthy Caucasian subjects. En-face macular optical coherence tomography angiography of superficial choriocapillaris was obtained by the RTVue-XR Avanti system. Various algorithms were used to extract texture features. The mean and standard deviation were used to assess the distribution and dispersion of data points in each metric among eyes, which included: average gray level, gray level yielding 70% threshold and 30% threshold, balance, skewness, energy, entropy, contrast, edge mean gradient, root-mean-square variation, and first moment of power spectrum, which was compared between images, showing a highly concordant homology between all eyes of participants. We conclude that computerized texture analysis for en-face optical coherence tomography angiography images of choriocapillaris is feasible and provides values that are coherent and tightly distributed around the mean in a homogenous, healthy group of patients. Homology of blob size among subjects may represent a “repeat pattern” in signal density and thus a perfusion in the superficial choriocapillaris of healthy young individuals of the same ethnic background.

The influence of retinal oxygen saturation and choroidal volume on postoperative outcomes in patients with epiretinal membrane

Purpose

To investigate the effects of vitrectomy (Vy) with or without same time cataract surgery and membrane plus internal limiting membrane peeling (MP+ILMP) on retinal oxygenation and choroidal volume and their role on postoperative outcome.

Methods

Thirty‐two eyes were included in this prospective clinical study. All patients received 23 gauge Vy+MP+ILMP without endotamponade. Additional cataract surgery was performed in 14 patients. Follow‐up visits were scheduled at day 1, week 1, month 1 and month 3. At each visit, best corrected visual acuity (BCVA) using ETDRS charts (except at day 1), oxygenation of retinal vessels using the Oxymap T1, and optical coherence tomography (OCT, Heidelberg Spectralis) was performed.

Results

Mean BCVA increased significantly from 73 ± 11 letters to 77 ± 7 letters at month 3 (p = 0.02). Mean central retinal thickness (CRT) decreased from 456 ± 84 µm at baseline to 418±58µm (p = 0.01 baseline versus month 3). In the cataract surgery group, CRT was higher at month 3 than in the group without (400 ± 58 µm versus 441 ± 51 µm; p = 0.007). There was no statistically significant difference in choroidal volume or oxygenation of retinal vessels between groups (additional cataract surgery versus vitrectomy alone). Oxygenation of retinal arteries tended to decrease at day 1 followed by an increase, but the changes did not reach the level of significance (p = 0.29 baseline versus month 3). Oxygenation of retinal veins increased significantly (p = 0.02 baseline versus month 1; p = 0.04 baseline versus month 3, accordingly). There was a significant negative correlation (Spearman correlation coefficient rs = −0.35, p = 0.047) between visual acuity and oxygenation of retinal veins at month 3. No statistically significant correlation was found between CRT and oxygenation of neither retinal arteries nor veins. Choroidal volume (CV) of the central mm did not change significantly during the study period (baseline: 0.203 ± 0.04 mm³, median: 0.206, month 3: 0.205 ± 0.04 mm³, p = 0.54). There was no statistically significant effect of choroidal volume at baseline on postoperative clinical outcomes (change in BCVA estimate [95% CI]: 7 [−76; 90], p = 0.86; change in CRT: 147 [−577; 871], p = 0.68).

Conclusion

Oxygen saturation may affect the visual acuity outcome but not the CRT in patients after vitrectomy for epiretinal membrane. Choroidal thickness had no statistically significant influence on the study outcomes. Further studies are needed to evaluate if the measurement of retinal oxygenation may be helpful in the decision for surgery.

Quantitative Analysis of Choriocapillaris Using Swept-Source Optical Coherence Tomography Angiography in Eyes with Angioid Streaks

Purpose: to quantitatively analyze choriocapillaris perfusion using swept-source optical coherence tomography angiography (SS-OCTA) in eyes presenting with angioid streaks in comparison with control eyes. Methods: Macular 6 × 6 mm SS-OCTA scans were retrospectively analyzed in eyes with angioid streaks and in control eyes. En face choriocapillaris flow images were compensated with en face choriocapillaris structure images, followed by the Phansalkar local thresholding method (with a window radius of four and eight pixels). Quantitative analysis was performed in the four peripheral 1 × 1 mm corners of the 6 × 6 mm SS-OCTA image to include equidistant and comparable regions. The percentage of flow deficits (FD%), the number and size of the flow deficits (FDs) and the total area of FDs were then calculated. Results: 54 eyes of 31 patients were included in the study: 27 eyes diagnosed with angioid streaks and 27 controls. Analysis of the four 1 × 1 mm peripheral corners of the 6 × 6 mm SS-OCTA image showed that eyes with angioid streaks had a higher FD% compared to the control group (47.62 ± 8.06 versus 38.90 ± 6.38 using a radius of four pixels (p < 0.001); 48.37 ± 7.65 versus 39.66 ± 6.51 using a radius of eight pixels (p < 0.001). The average size of FDs as well as the total area size of the FDs were significantly higher in eyes with angioid streaks compared to control eyes (p < 0.001). Eyes with angioid streaks present reduced choriocapillaris flow compared to control eyes. Decreased choriocapillaris perfusion may contribute, among other factors, to the development of neovascularization and atrophy in patients with angioid streaks.

Optical coherence tomography angiography quantification of choriocapillaris blood-flow after half-fluence photodynamic therapy for chronic central serous chorioretinopathy

PURPOSE

To quantitatively analyze characteristics of choriocapillaris flow using spectral domain optical coherence tomography angiography (SD-OCTA) in eyes with chronic central serous chorioretinopathy (CSC) before and after treatment by photodynamic therapy (PDT).

METHODS

Retrospective interventional study. Macular 3X3 SD-OCT scans were analyzed in eyes diagnosed with chronic CSC before and after treatment with half-fluence PDT. The choriocapillaris en face slabs were extracted from the SD-OCTA device after manual segmentation. En face choriocapillaris flow images were compensated with en face choriocapillaris structure images. Phansalkar local thresholding method was then used with a radius of 4 and 8 pixels. Percentage of flow deficits (FD%), number, size, and total area of FDs were computed for comparison, before and after treatment by half-fluence PDT.

RESULTS

Mean choriocapillaris FD% before PDT was of 58.36 + / - 11.88 and of 60.82 + / - 11.08 after PDT using radius 4 pixels with no significant difference (p = 0.140). Mean choriocapillaris FD% was of 58.63 + / - 11.08 before PDT and of 60.87 + / - 10.36 after PDT using radius 8 pixels with no significant difference (p = 0.200). Similarly, no significative difference was found in number, size, and total area of FDs, before and after half-fluence PDT, using radius 4 and 8 pixels in patients with chronic CSC.

CONCLUSION

Using Phansalkar local thresholding method, quantitative analysis of choriocapillaris with SD-OCTA found no significant change in choriocapillaris flow deficits before and after successful half-fluence PDT in patients with chronic CSC. Therefore, it seems that half-fluence PDT may not alter choriocapillaris perfusion, at least on a relative short-term basis.

Functional Correlates of Outer Retina Remodeling in Intermediate Age-Related Macular Degeneration Using Microperimetry

Purpose

To assess the effect of drusen morphometric changes and choroidal vascular modifications on retinal sensitivity (RS) evaluated through microperimetry in intermediate age-related macular degeneration (iAMD).

Methods

A retrospective review of 18 iAMD patients (18 eyes) with a 12-month follow-up was performed. Eye-tracked spectral-domain optical coherence tomography was obtained, with automatic segmentation of the outer retinal layer (ORL) delineating the drusen area from the external limiting membrane to Bruch's membrane and outer nuclear layer (ONL) thickness maps adjusted manually, as needed. Advanced retinal pigment epithelium analysis was also performed with a ZEISS PLEX Elite 900. Microperimetry obtained under mesopic conditions was overlaid with the corresponding thickness maps with Fiji software. The choroidal vascularity index (CVI) was calculated in the subfoveal b-scan and volumetric in the central 1-mm subfield.

Results

A reduced central ONL thickness was strongly associated with RS decline at the same region (r = 0.69, P = 0.002) and globally (r = 0.80, P < 0.001) at baseline, but also at 1 year in the central subfield (central: r = 0.70, P = 0.001). One-year subfoveal CVI variation, differently from volumetric CVI, directly influenced the central (r = 0.64, P = 0.004) and global RS (r = 0.59, P = 0.009), indicating that a CVI reduction negatively affected RS. A greater volumetric CVI within central 1-mm was associated with ORL thickening at 1 year (r = 0.61, P = 0.008).

Conclusions

Progressive degeneration of the ONL is related to irreversible photoreceptor dysfunction in iAMD. Likewise, choroidal vascular modifications are associated with a significant functional decline in the central region and diffusely.

An Update on the Hemodynamic Model of Age-Related Macular Degeneration

PURPOSE

To provide an update on the hemodynamic model of age-related macular degeneration (AMD).

DESIGN

Evidence-based perspective.

METHODS

Review of the literature and experience of the authors.

RESULTS

Choroidal hemodynamics are not the primary cause of AMD as proposed by Ephraim Friedman in 1997. However, evidence is accumulating to suggest that choroidal perfusion is an important environmental influence that contributes to our understanding of disease progression in this complex genetic disorder. Although early and intermediate AMD seem to be influenced to a large extent by the underlying genetics, the asymmetry of disease progression to the later stages of AMD cannot be explained by genetics alone. The progression of disease and the asymmetry of this progression seem to correlate with abnormalities in choroidal perfusion that can be documented by optical coherence tomography. These perfusion abnormalities in the setting of a thickened Bruch's membrane are thought to exacerbate the impaired nutritional exchange between the retinal pigment epithelium and the choriocapillaris. We propose that the genetic susceptibility to develop AMD combined with age-related changes in macular choroidal hemodynamics, such as increasing choriocapillaris perfusion deficits and decreasing choroidal vascular densities, play an important role in disease progression and may help to explain the asymmetry between eyes, particularly in the later stages of AMD.

CONCLUSIONS

This updated hemodynamic model of AMD focuses on disease progression and highlights the importance of age-related changes in the choroidal circulation as a major environmental influence on disease severity in eyes that are genetically susceptible to develop AMD.

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.

Intraocular Cytokine Changes in Patients with Polypoidal Choroidal Vasculopathy Treated with Ranibizumab

Purpose: To investigate the changes in intraocular cytokines after ranibizumab treatment in patients with polypoidal choroidal vasculopathy (PCV).Methods: This multicenter, prospective study enrolled patients with PCV treated with three monthly ranibizumab followed by a pro re nata regimen for 24 weeks. Best corrected visual acuity, slit lamp examination, fundus photography, and optical coherence tomography were performed every 4 weeks. Aqueous humor was collected to measure intraocular cytokines at baseline, week 8, and the time of recurrence or week 20. The association of changes in intraocular cytokines with visual acuity, central macular thickness, central choroidal thickness, area of abnormal vessels, and polyp closure was assessed.Results: This study included 25 eyes. The mean patient age was 70.3 ± 6.1 years. The vascular endothelial growth factor (VEGF) concentration decreased at week 8, but only interferon (IFN)-γ, tissue inhibitors of matrix metalloproteinases (TIMP)-2, and monocyte chemoattractant protein (MCP)-2 decreased at the time of recurrence. The recurrence interval was positively associated with the baseline epithelial-neutrophil activating peptide (ENA)-78, interleukin (IL)-17, leptin, and transforming growth factor-β1, and baseline central macular thickness was positively correlated with the baseline fibroblast growth factor-4 and IL-10. Thick central choroidal thickness was associated with a low basic fibroblast growth factor and high IFN-γ at baseline. The MCP-3 and Tie-2 levels decreased in two eyes with polyp closure.Conclusions: Ranibizumab significantly reduced intraocular VEGF concentrations and consequently improved PCV. However, the cytokines IFN-γ, TIMP-2, and MCP-2, rather than VEGF, were associated with PCV recurrence. Further studies of intraocular cytokines involved in neovascularization in PCV are needed.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Short-term changes in retinal and choroidal relative flow volume after anti-VEGF treatment for neovascular age-related macular degeneration

The effects of anti-vascular endothelial growth factor (anti-VEGF) agents on the native ocular vasculature are poorly understood. This pilot study aimed to assess short-term changes in retinal and choroidal perfusion after anti-VEGF treatment for neovascular exudative age-related macular degeneration (nAMD) using the relative flow volume (RFV) parameter derived from laser speckle flowgraphy. Ten treatment-naïve nAMD patients underwent measurements of mean, maximum, minimum, and differential RFV within a retinal arteriolar segment and a choroidal vessel segment outside the neovascular area. Measurement of retinal RFV (rRFV), choroidal RFV (cRFV), and subfoveal choroidal thickness (SCT) was repeated 9 and 35 days after a single anti-VEGF injection. The treatment caused a statistically significant decrease in the mean rRFV, mean cRFV, and SCT during the follow-up (p < 0.05). At the intermediate visit, the mean cRFV and SCT were − 17.6% and − 6.4% compared to baseline, respectively. However, at the final measurement, the mean cRFV was not different from the baseline value, which indicated waning of the anti-VEGF effect. In conclusion, a single anti-VEGF injection in treatment-naïve nAMD resulted in a decrease in retinal arteriolar and choroidal perfusion, according to the RFV parameter, which is a promising tool to simultaneously assess retinal and choroidal perfusion changes in response to anti-VEGF therapy.

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.

Optical coherence tomography (OCT) angiolytics: a review of OCT angiography quantitative biomarkers

Optical coherence tomography angiography (OCTA) provides a non-invasive method to obtain angiography of the chorioretinal vasculature leading to its recent widespread adoption. With a growing number of studies exploring the use of OCTA, various biomarkers quantifying the vascular characteristics have come to light. In the current report, we summarize the biomarkers currently described for retinal and choroidal vasculature using OCTA systems and the methods used to obtain them. Further, we present a critical review of these methods and key findings in common retinal diseases and appraise future directions, including applications of artificial intelligence in OCTA .

The Development of Macular Atrophy in Patients with Wet Age-Related Macular Degeneration Receiving Anti-VEGF Treatment

Age-related macular degeneration (AMD) is a leading cause of blindness. Late AMD can be classified into exudative (commonly known as wet AMD [wAMD]) or dry AMD, both of which may progress to macular atrophy (MA). MA causes irreversible vision loss and currently has no approved pharmacological treatment. The standard of care for wAMD is treatment with anti-vascular endothelial growth factors (VEGF). However, recent evidence suggests that anti-VEGF treatment may play a role in the development of MA. Therefore, it is important to identify risk factors for the development of MA in patients with wAMD. For example, excessive blockade of VEGF through intense use of anti-VEGF agents may accelerate the development of MA. Patients with type III macular neovascularisation (retinal angiomatous proliferation) have a particularly high risk of MA. These patients are characterised as having a pre-existing thin choroid (age-related choroidopathy), suggesting that the choroidal circulation is unable to respond to increased VEGF expression. Evidence suggests that subretinal fluid (possibly indicative of residual VEGF activity) may play a protective role. Patients receiving anti-VEGF agents must be assessed for overall risk of MA and there is an unmet medical need to prevent the development of MA without undertreating wAMD.

Choriocapillaris Vascular Density Changes: Healthy vs. Advanced Exudative Age-Related Macular Degeneration Previously Treated with Multiple Anti-VEGF Intravitreal Injections

Purpose: To assess choriocapillaris vascular density (VD) in healthy and advanced exudative age-related macular degeneration (ae-AMD) patients by new full-range optical coherence tomography angiography (OCT-A). Method: In this observational, cross-sectional study, 21 healthy and 21 ae-AMD eyes, already treated with anti-VEGF, were enrolled. Angio-View retina patterns centered on fovea (6.4 × 6.4 mm) were acquired for all participants using Solix full-range OCT (Optovue Inc., Freemont, CA, USA). The main outcome was to compare choriocapillaris VD between healthy and ae-AMD eyes. Automated measurements of whole image choriocapillaris VD (%) and fovea grid-based (%) were collected for the analysis. Angio-View patterns were used to assess the flow area (mm²) of macular neovascularization (MNV) by contour flow measure algorithm. Best-corrected visual acuity (BCVA) of both groups was also used for the statistical analysis. Results: The mean age was 60.9 (±8.3) in healthy and 73.33 (±15.05) in ae-AMD eyes. The mean BCVA (ETDRS letters) was 98.47 (±1.50) in healthy and 7.04 (±5.96) in ae-AMD eyes. The Mann–Whitney test comparing choriocapillaries VD for whole and fovea healthy and ae-AMD eyes showed statistical significance (p < 0.0001 (t = 4.91; df = 40) and p < 0.0001 (t = 6.84; df = 40), respectively). Regarding, the correlation between MNV and VD of choriocapillaries, neither whole nor fovea areas were statistically significant (F = 0.38 (R² = 0.01) and 1.68 (R² = 0.08), respectively). Conclusions: Choriocapillaris VD showed a statistically significant reduction in comparison to healthy eyes in ae-AMD eyes. Choriocapillaris impairment can be seen in the early phase of MNV pathogenesis.

THE RAP STUDY, REPORT TWO: The Regional Distribution of Macular Neovascularization Type 3, a Novel Insight Into Its Etiology

PURPOSE

To explore the regional distribution of macular neovascularization type 3 (MNV3).

METHODS

Seventy-eight eyes of 78 patients were reviewed. We defined the location of each lesion after applying a modified ETDRS grid and the incidence of simultaneous MNV1 or 2. Also, we investigated the distribution of MNV3 at the outline of the foveal avascular zone and when the diameter of foveal avascular zone was less than 325 µm.

RESULTS

The distribution of MNV3 was 4 lesions (5%) from the center to 500 µm, 72 (92%) from 500 µm to 1500 µm, and 2 (3%) from 1,500 µm to 3000 µm. The distribution in respect of the ETDRS fields was 7 (9%) nasal, 16 (20%) superior, 32 (40%) temporal, and 23 (31%) inferior. No additional MNV1 or 2 were found elsewhere. Most lesions tended to distribute along straight bands radiating from the perifoveal area, mainly in the temporal half (72%). None of the cases had MNV3 at the boundary of the foveal avascular zone. Only five cases had foveal avascular zone diameter of less than 325 µm, the closest lesion was 425 µm away from the center.

CONCLUSION

MNV3 lesions are most likely neither symmetrical nor uniformly distributed. They have a higher affinity to distribute radially in the temporal perifoveal area.

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.

Choroidal structural changes determined by the binarization method after intravitreal aflibercept treatment in neovascular age-related macular degeneration

AIM

To assess the choroidal structural alterations after intravitreal injection of aflibercept in neovascular age-related macular degeneration (nAMD).

METHODS

Fifty eyes with treatment-naïve nAMD were evaluated at baseline, 3^rd, and 12^th month. Fifty eyes of 50 healthy subjects were also included as controls. Choroidal thickness (CT) was measured in the subfoveal region. Total circumscribed choroidal area (CA), luminal area (LA), stromal area (SA), and choroidal vascularity index (CVI) was calculated using Image J.

RESULTS

At baseline, subfoveal CT was increased in nAMD patients compared to controls (P=0.321). Eyes with nAMD had a significantly increased total circumscribed CA and SA (P=0.041, 0.005, respectively). The CVI was decreased (P=0.038). In the 3^rd month, the subfoveal CT, LA, and CVI revealed a decrease (P=0.005, P=0.039, 0.043, respectively). In the 12^th month, subfoveal CT, LA, and CVI were decreased in comparison to baseline measures (P<0.001, 0.006, 0.010, respectively).

CONCLUSION

Significant structural alterations are found after intravitreal aflibercept treatment during the 12-month follow-up, in particular at the third month, in eyes with nAMD.

Visualising the choriocapillaris: Histology, imaging modalities and clinical research - A review

The choriocapillaris plays a considerable role in the normal physiology of the eye as well as in various diseases. Assessing the changes in the choriocapillaris can therefore provide important information about normal ageing and pathogenesis of visual impairment, and even some systemic diseases. In vivo imaging of the choriocapillaris has evolved from non-depth resolved, dye-based angiography to advanced, high-resolution optical coherence tomography angiography (OCTA). However, the intricate microvascular networks within the choriocapillaris are still beyond the resolving limits of most OCTA instruments. Knowledge of histology, meticulous image acquisition methods, recognition of artefact and post-acquisition processing techniques are necessary for optimising OCTA choriocapillaris images. Qualitative and quantitative analyses of the choriocapillaris provide clinical information in age-related macular degeneration (AMD), diabetic retinopathy (DR), pathologic myopia and central serous chorioretinopathy (CSC). Furthermore, studies have revealed choriocapillaris changes in posterior uveitis that are correlated with treatment outcome and have important prognostic significance. In addition to retinal diseases, choriocapillaris changes have been observed in systemic vascular diseases and complications associated with pregnancy.

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.

Integrative analysis of the choroid by quantifying Haller vessel and choriocapillaris parameters in different drusen subtypes

This study aimed to quantify the Haller vessel and choriocapillaris (CC) parameters in drusen subtypes in nonexudative age-related macular degeneration (AMD) and pachydrusen. Ninety-five eyes of 80 patients and 28 control eyes were categorized into soft drusen, subretinal drusenoid deposit (SDD), soft drusen plus SDD, pachydrusen, and control groups. The diameter, length and intersections of Haller vessels and the total area, size and number of CC flow voids were quantified using en face optical coherence tomography (OCT) or OCT angiography. The pachydrusen group showed the largest Haller vessel area and diameter and shortest total length but similar CC parameters to those in the control group. The soft drusen plus SDD group showed the largest CC flow void area and size, while the Haller parameters were similar to those in the control group. The area and size of the flow voids in the SDD group were smaller than those in the soft drusen plus SDD group. Based on unsupervised machine learning, the eyes were classified into 4 clusters—the control, pachydrusen, soft drusen plus SDD and soft drusen plus SDD groups. Cluster 3 showed a larger diameter and shorter total length of the Haller vessels than cluster 4.

PREDICTIVE ACTIVATION BIOMARKERS OF TREATMENT-NAIVE ASYMPTOMATIC CHOROIDAL NEOVASCULARIZATION IN AGE-RELATED MACULAR DEGENERATION

PURPOSE

To assess the long-term evolution of treatment-naive quiescent choroidal neovascularization (CNV), in age-related macular degeneration (AMD), to identify predictive activation biomarkers.

METHODS

Patients with quiescent CNV underwent a comprehensive ophthalmological examination, including fluorescein and indocyanine green angiographies, structural optical coherence tomography (OCT), and OCT angiography. Qualitative and quantitative analyses of structural OCT and OCT angiography images were performed during the study period. At the last follow-up evaluation, the enrolled eyes were divided into two groups: eyes with quiescent CNV converting to exudative AMD (eAMD) and those not progressing to eAMD.

RESULTS

Sixty-eight eyes of 68 patients were enrolled in the study. Mean follow-up duration was 40 ± 28 months using multimodal imaging and 22 ± 13 months using OCT angiography. On structural OCT, quiescent CNV not converting to eAMD showed a preferential growth of the pigment epithelium detachment greatest linear diameter (P = 0.009), whereas the eAMD group presented a preferential growth of the pigment epithelium detachment maximal height (P < 0.0001) during the study period. Quantitative analysis of choriocapillaris OCT angiograms confirmed the CNV area growth during follow-up (from 4.18 ± 4.77 mm at baseline to 5.10 ± 5.06 mm at the last follow-up visit; P = 0.02).

CONCLUSION

A close follow-up is recommended to early identify predictive activation biomarkers of treatment-naive quiescent CNV.