Intraretinal Hyper-Reflective Foci Are Almost Universally Present and Co-Localize With Intraretinal Fluid in Diabetic Macular Edema.

Purpose: In diabetic macular edema (DME), hyper-reflective foci (HRF) has been linked to disease severity and progression. Using an automated approach, we aimed to investigate the baseline distribution of HRF in DME and their co-localization with cystoid intraretinal fluid (IRF). Methods: Baseline spectral-domain optical coherence tomography (SD-OCT) volume scans (N = 1527) from phase III clinical trials YOSEMITE (NCT03622580) and RHINE (NCT03622593) were segmented using a deep-learning-based algorithm (developed using B-scans from BOULEVARD NCT02699450) to detect HRF. The HRF count and volume were assessed. HRF distributions were analyzed in relation to best-corrected visual acuity (BCVA), central subfield thickness (CST), and IRF volume in quartiles, and Diabetic Retinopathy Severity Scores (DRSS) in groups. Co-localization of HRF with IRF was calculated in the central 3-mm diameter using the en face projection. Results: HRF were present in most patients (up to 99.7%). Median (interquartile range [IQR]) HRF volume within the 3-mm diameter Early Treatment Diabetic Retinopathy Study ring was 1964.3 (3325.2) pL, and median count was 64.0 (IQR = 96.0). Median HRF volumes were greater with decreasing BCVA (nominal P = 0.0109), and increasing CST (nominal P < 0.0001), IRF (nominal P < 0.0001), and DRSS up to very severe nonproliferative diabetic retinopathy (nominal P < 0.0001). HRF co-localized with IRF in the en face projection. Conclusions: Using automated HRF segmentation of full SD-OCT volumes, we observed that HRF are a ubiquitous feature in DME and exhibit relationships with BCVA, CST, IRF, and DRSS, supporting a potential link to disease severity. The spatial distribution of HRF closely followed that of IRF.

Is Exudative Neovascular AMD a Chronic Disease? Analysis of Long-term Progression under Anti-VEGF Therapy. / Ist die exsudative neovaskuläre AMD eine chronische Erkrankung? Analyse von Langzeitverläufen unter einer Anti-VEGF-Therapie.

BACKGROUND: Anti-VEGF therapy is the standard treatment for exudative neovascular age-related macular degeneration (nAMD) caused by the development of macular neovascularisation (MNV) with associated fluid exudation. The therapeutic strategies (T&E or PRN) assumed a scarring transformation of the MNV and exit strategies and were formulated accordingly. The present study investigates this hypothesis as a real-life long-term analysis. PATIENTS: 150 eyes of 97 patients were continuously followed up over a mean period of 5.1 years (1 - 14 years) after initiation of anti-VEGF therapy between 2009 - 2017 until 2022. Treatment was based on the PRN regimen analogous to the IVAN study with ranibizumab, aflibercept or bevacizumab. The length and intensity of therapy were evaluated. RESULTS: Of these 150 eyes, 119 (79.3%) required ongoing anti-VEGF therapy, while in 18 eyes (12.0%) therapy could be discontinued due to stabilisation of the situation. In 13 eyes (8.7%), therapy was discontinued due to deterioration in visual acuity to < 0.05. With ongoing therapy, therapy was often protracted, with an indication for therapy at the last documented doctor's visit, while stabilisation was often achieved within the first 2 years of treatment. The treatment intensity increased to 7.7 - 8.0 injections/year, especially after 2013, with the introduction of OCT-based treatment criteria. Most eyes (74.8%) with ongoing therapy required 6 - 9 injections/year even in the last three years of treatment. CONCLUSION: The fact that in the present study there is a long-term and intensive need for therapy in the majority of patients (approx. 80%) with exudative nAMD, supports the assessment that nAMD should be regarded as a chronic disease. Therefore, a proactive treatment strategy with consistent therapy at any sign of lesion activity might be recommended. Particularly in view of the risk of irreversible loss of vision, long term adherence of patients is also crucial for the best possible long term therapeutic outcome.

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

PURPOSE: To analyze the morphological changes of macular neovascularization (MNV) in exudative neovascular age-related macular degeneration under long-term intravitreal anti-vascular endothelial growth factor (VEGF) therapy in a retrospective cohort study. METHODS AND PATIENTS: We evaluated 143 nAMD eyes of 94 patients (31 male, 63 female; initial age 55-97 y, mean age 75.9 ± 7.5 y), who started anti-VEGF therapy (IVAN pro re nata (PRN) protocol) between 2009-2018 and received ongoing therapy until the last recorded visit (mean follow-up 5.3 ± 2.9 y, range 1-14 y). The mean total number of injections was 33.3 ± 19.8 with 7.0 ± 2.3 injections/year. MNV size and, if present, associated complete retinal pigment epithelium (RPE) and outer retina atrophy (cRORA) size were measured on optical coherence tomography (OCT) volume scans at the initial visit and for each year of follow-up. MNV and cRORA were identified on B-scans and their respective borders were manually transposed onto the en-face near infrared image and measured in mm2. RESULTS: MNV enlarged through follow-up, with a mean growth rate of 1.24 mm2 / year. The mean growth in MNV size was independent of initial MNV size, age, gender, MNV subtypes or number of injections per year. Nevertheless, a great interindividual variation in size and growth was observed. cRORA developed in association with increasing MNV size and its incidence increased linearly over follow-up. cRORA lesions also showed continuous growth by a rate of 1.22 mm2 / year. CONCLUSIONS: Despite frequent long-term anti-VEGF therapy, we observed ongoing MNV growth. This is consistent with the concept that the development of MNV may be a physiological biological repair mechanism to preserve RPE and photoreceptor function, provided hyperpermeability and fluid exudation are controlled. Whether recurring low VEGF levels or other factors are responsible for MNV growth remains controversial.

Hyperreflective Material Boundary Remodeling in Neovascular Age-Related Macular Degeneration: A Post Hoc Analysis of the AVENUE Trial.

OBJECTIVE: To describe the spatial and temporal characteristics of hyperreflective material (HRM) on spectral-domain OCT (SD-OCT) in neovascular age-related macular degeneration (nAMD) during antiangiogenic treatment and explore associations with best-corrected visual acuity (BCVA) and macular atrophy (MA). DESIGN: Retrospective regrading of SD-OCT-images from the multicenter, randomized controlled AVENUE trial (NCT02484690, conducted from August 2015 to September 2017). PARTICIPANTS: Treatment-naive nAMD patients enrolled from 50 sites in the US. METHODS: Retrospective regrading and secondary analysis. MAIN OUTCOME MEASURES: Spectral-domain OCT images from 207 study eyes that fit criteria for the present analysis were graded for HRM features, its evolution, and associated hypertransmission into choroid (HTC), a proxy for MA. The appearance of a well-defined hyperreflective inner boundary that separated persistent HRM from the neurosensory retina continuous with the adjacent retinal pigment epithelium layer was defined as hyperreflective material boundary remodeling (HRM-BR). Patterns of HRM composition/evolution were defined as follows: (1) no subretinal HRM at baseline, (2) fully resolved, (3) persistent with complete HRM-BR, or (4) partial/absent HRM-BR. Associations of HRM patterns with BCVA and HTC were analyzed. Predictive factors for complete HRM-BR were explored. RESULTS: Of 207 included eyes, subretinal HRM was present in 159 (76.8%) at baseline and persisted until month 9 in 118 (57.0%) eyes. Of these 118 eyes, 44.9% developed complete HRM-BR and had similar BCVA outcomes by month 9 compared with no/fully resolved subretinal HRM. Partial/absent HRM-BR had a strong negative association with BCVA outcome (-6.1 ETDRS letters; P = 0.016) and a higher frequency of intralesional HTC (69.2%) compared with eyes with complete HRM-BR (20.8%) at month 9. Older age (odds ratio [OR], 0.96; P = 0.054) and presence of intralesional HTC (OR, 0.06; P = 0.010) at baseline were associated with lower odds of complete HRM-BR at month 9. CONCLUSIONS: In nAMD eyes under antiangiogenic treatment, complete HRM-BR occurred frequently and was associated with better BCVA than when HRM-BR was only partial/absent. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Fibrosis in neovascular age-related macular degeneration: A review of definitions based on clinical imaging.

Despite the success of antiangiogenic therapy in controlling exudation in neovascular age-related macular degeneration (nAMD), the involvement of the outer retina in fibrosis results in gradual vision loss over time. The development of drugs that prevent or ameliorate fibrosis in nAMD requires that it is accurately detected and quantified with reliable endpoints and identification of robust biomarkers. Achievement of such an aim is currently challenging due to the lack of a consensus definition of fibrosis in nAMD. As a first step towards the establishment of a clear definition of fibrosis, we provide an extensive overview of the imaging modalities and criteria used to characterize fibrosis in nAMD. We observed variety in the selection of individual and combinations of imaging modalities, and criteria for detection. We also observed heterogeneity in classification systems and severity scales for fibrosis. The most commonly used imaging modalities were color fundus photography, fluorescein angiography and optical coherence tomography (OCT). A multimodal approach was frequently utilized. Our review suggests that OCT offers a more detailed, objective and sensitive characterization than color fundus photography/fluorescein angiography. Thus, we recommend it as a primary modality for fibrosis evaluation. This review provides a basis for future discussions to reach a consensus definition using standardized terms based on a detailed characterization of fibrosis, its presence and evolution, and taking into consideration impact on visual function. Achieving this goal is of paramount importance for the development of antifibrotic therapies.

Macular Telangiectasia Type 2: A Classification System Using MultiModal Imaging MacTel Project Report Number 10.

Purpose: To develop a severity classification for macular telangiectasia type 2 (MacTel) disease using multimodal imaging. Design: An algorithm was used on data from a prospective natural history study of MacTel for classification development. Subjects: A total of 1733 participants enrolled in an international natural history study of MacTel. Methods: The Classification and Regression Trees (CART), a predictive nonparametric algorithm used in machine learning, analyzed the features of the multimodal imaging important for the development of a classification, including reading center gradings of the following digital images: stereoscopic color and red-free fundus photographs, fluorescein angiographic images, fundus autofluorescence images, and spectral-domain (SD)-OCT images. Regression models that used least square method created a decision tree using features of the ocular images into different categories of disease severity. Main Outcome Measures: The primary target of interest for the algorithm development by CART was the change in best-corrected visual acuity (BCVA) at baseline for the right and left eyes. These analyses using the algorithm were repeated for the BCVA obtained at the last study visit of the natural history study for the right and left eyes. Results: The CART analyses demonstrated 3 important features from the multimodal imaging for the classification: OCT hyper-reflectivity, pigment, and ellipsoid zone loss. By combining these 3 features (as absent, present, noncentral involvement, and central involvement of the macula), a 7-step scale was created, ranging from excellent to poor visual acuity. At grade 0, 3 features are not present. At the most severe grade, pigment and exudative neovascularization are present. To further validate the classification, using the Generalized Estimating Equation regression models, analyses for the annual relative risk of progression over a period of 5 years for vision loss and for progression along the scale were performed. Conclusions: This analysis using the data from current imaging modalities in participants followed in the MacTel natural history study informed a classification for MacTel disease severity featuring variables from SD-OCT. This classification is designed to provide better communications to other clinicians, researchers, and patients. Financial Disclosures: Proprietary or commercial disclosure may be found after the references.

Association of lipid-lowering drugs and antidiabetic drugs with age-related macular degeneration: a meta-analysis in Europeans.

BACKGROUND/AIMS: To investigate the association of commonly used systemic medications with prevalent age-related macular degeneration (AMD) in the general population. METHODS: We included 38 694 adults from 14 population-based and hospital-based studies from the European Eye Epidemiology consortium. We examined associations between the use of systemic medications and any prevalent AMD as well as any late AMD using multivariable logistic regression modelling per study and pooled results using random effects meta-analysis. RESULTS: Between studies, mean age ranged from 61.5±7.1 to 82.6±3.8 years and prevalence ranged from 12.1% to 64.5% and from 0.5% to 35.5% for any and late AMD, respectively. In the meta-analysis of fully adjusted multivariable models, lipid-lowering drugs (LLD) and antidiabetic drugs were associated with lower prevalent any AMD (OR 0.85, 95% CI=0.79 to 0.91 and OR 0.78, 95% CI=0.66 to 0.91). We found no association with late AMD or with any other medication. CONCLUSION: Our study indicates a potential beneficial effect of LLD and antidiabetic drug use on prevalence of AMD across multiple European cohorts. Our findings support the importance of metabolic processes in the multifactorial aetiology of AMD.

Does real-time artificial intelligence-based visual pathology enhancement of three-dimensional optical coherence tomography scans optimise treatment decision in patients with nAMD? Rationale and design of the RAZORBILL study.

BACKGROUND/RATIONALE: Artificial intelligence (AI)-based clinical decision support tools, being developed across multiple fields in medicine, need to be evaluated for their impact on the treatment and outcomes of patients as well as optimisation of the clinical workflow. The RAZORBILL study will investigate the impact of advanced AI segmentation algorithms on the disease activity assessment in patients with neovascular age-related macular degeneration (nAMD) by enriching three-dimensional (3D) retinal optical coherence tomography (OCT) scans with automated fluid and layer quantification measurements. METHODS: RAZORBILL is an observational, multicentre, multinational, open-label study, comprising two phases: (a) clinical data collection (phase I): an observational study design, which enforces neither strict visit schedule nor mandated treatment regimen was chosen as an appropriate design to collect data in a real-world clinical setting to enable evaluation in phase II and (b) OCT enrichment analysis (phase II): de-identified 3D OCT scans will be evaluated for disease activity. Within this evaluation, investigators will review the scans once enriched with segmentation results (i.e., highlighted and quantified pathological fluid volumes) and once in its original (i.e., non-enriched) state. This review will be performed using an integrated crossover design, where investigators are used as their own controls allowing the analysis to account for differences in expertise and individual disease activity definitions. CONCLUSIONS: In order to apply novel AI tools to routine clinical care, their benefit as well as operational feasibility need to be carefully investigated. RAZORBILL will inform on the value of AI-based clinical decision support tools. It will clarify if these can be implemented in clinical treatment of patients with nAMD and whether it allows for optimisation of individualised treatment in routine clinical care.

Vascular Analysis of Type 1, 2, and 3 Macular Neovascularization in Age-Related Macular Degeneration Using Swept-Source Optical Coherence Tomography Angiography Shows New Insights into Differences of Pathologic Vasculature and May Lead to a More Personalized Understanding.

Background: The clinical appearance of macular neovascularization (MNV) in age-related macular degeneration (nAMD) varies widely, but so far, this has had no relevance in terms of therapeutic approaches or prognosis. Therefore, our purpose was to investigate if and which differences exist in the vascular architecture of MNV and to quantify them. Methods: In 90 patients with newly diagnosed nAMD, MNV was identified by means of optical coherence tomography angiography (OCTA), and automated quantitative vascular analysis was carried out. The analyzed vascular parameters were area, flow, fractal dimension (FD), total vascular length (sumL), number of vascular nodes (numN), flow, and average vessel caliber (avgW). The current classification of MNVs divides them according to their localization into type 1 (grown from the choroid below the RPE), type 2 (grown from the choroid through RPE), and type 3 (grown from the retina toward the RPE). We compared the analyzed vascular parameters of each of the three MNV types. Kruskal−Wallis test was applied, Dunn test was performed for post hoc analysis, and for pairwise comparison, p-values were adjusted using Bonferroni comparison. Results: Regarding the MNV area, there was no significant difference between types 1 and 2, but type 3 was significantly smaller than types 1 and 2 (p < 0.00001). For FD, types 1 and 2 did not differ significantly, but again, type 3 was lower than type 1 and 2 (p < 0.00001). The numN were significantly higher in types 1 and 3 than in 2 (p < 0.005), but not between types 1 and 3. No significant differences were found between MNV types for flow. As for sumL, types 1 and 2 did not differ significantly, but type 3 was significantly lower than types 1 and 2 (p < 0.00001). For avgW, there was no significant difference between types 1 and 2 or between types 2 and 3, but type 3 was significantly larger than type 1 (p < 0.05). Conclusions OCTA yields detailed information on the vascular morphology of MNV in patients with nAMD and is able to show differences among types 1, 2, and 3. Especially comparing types 1 and 2 with type 3 reveals significant differences in area, FD, sumL, and numN. One explanation could be the similar pathogenesis of types 1 and 2 with their origin in the choroid and their growth towards the retinal pigment epithelium (RPE), whereas type 3 originates in the deep capillary plexus. Between types 1 and 2, however, only the numN differ significantly, which could be due to the fact that type 1 spreads horizontally below the RPE and, thus, display more vascular branching, while type 2 grows more vertically through the RPE and under the neurosensory retina. Detailed information about the pathologic vasculature is important for proper monitoring of the disease and to assess the efficacy of medication, especially with regard to new substances. This should be taken into consideration in future studies.

Can Digital Instruments Like the Macula-App Support AMD Therapy? / Können digitale Instrumente wie die Makula-App die AMD-Therapie unterstützen?

BACKGROUND: A long lasting and continuous anti VEGF-therapy represents a gold standard in nAMD treatment to maintain and stabilize vision in the individual patient. Disease Management represents a daily life challenge for patients and relatives and "Real-life" clinical outcomes of patients treated with IVOM therapy are often inferior to results from randomized clinical trials. After their diagnosis, AMD-patients undergo individualized long-term therapeutic approaches. An important success factor is, that this care is patient centered and provided continuously. This study aimed at evaluating, whether digital tools, such as Makula-App 1.0 developed by the AMD-Netz can support AMD patients. PATIENTS AND METHODS: The results of a user survey integrated in the Makula-App 1.0 (n = 110) as well as the results of an additional survey on the topic of "Digital appointment management in IVOM therapy" by ophthalmologists (n = 54) and patients (n = 60) were analysed with respect to use and acceptance of the Makula-App. RESULTS: The survey revealed: 79% of Makula-App user rely on the information presented, 71% perceive the device helpful for their daily life and 80% would recommend the device. 52% of ophthalmologists and 65% of patients regard clear benefits of future digital tools for patient adherence. A digital appointment management function is rated as important by 82% of ophthalmologists. CONCLUSIONS: User perceived Makula-App 1.0 as well as its future development options as beneficial especially for the management of appointment arrangements but also as information tool. Ophthalmologists confirm the importance and usefulness of devices such as Makula-App 1.0 with respect to an optimized management of appointments and an improved patient adherence. These promising results support the future development of a Makula-App 2.0 platform, providing interfaces for an information exchange between patient and treating ophthalmologist.

Axial Stretching of Vessels in the Retinal Vascular Plexus With 3D OCT-Angiography.

PURPOSE: The purpose of this study is to describe and quantify the nonpathological axial stretching in the retinal vascular plexus in three-dimensional (3D) optical coherence tomography angiography (OCTA) images. METHODS: The 3D vascular network underneath the inner limiting membrane of OCTA volumes was labeled as ground truth (GT) data. To analyze the cross-section area of the vessels the width and depth of the vessels in the GT data were computed and an elliptical quotient was proposed to quantify the axial stretching. RESULTS: A total of 21 3D OCTA volumes were labeled. It was found that the vessels in 3D OCTA images are stretched in the direction of the A-Scan by a factor of 2.46 ± 1.82 with a median of 2.24. Furthermore, a larger cross-section area leads to higher axial stretching. CONCLUSIONS: The elliptical shape of the cross-section area of the vessel does not match with the expected pathology of the vascular network in the human eye. Therefore a correction of the volume data before a 3D analysis is recommended. TRANSLATIONAL RELEVANCE: This work gives a systematic insight to the stretched shape of vessels in 3D OCTA images and is relevant for further clinical research analyzing the 3D vascular network.

Clinically applicable deep learning-based decision aids for treatment of neovascular AMD.

PURPOSE: Anti-vascular endothelial growth factor (Anti-VEGF) therapy is currently seen as the standard for treatment of neovascular AMD (nAMD). However, while treatments are highly effective, decisions for initial treatment and retreatment are often challenging for non-retina specialists. The purpose of this study is to develop convolutional neural networks (CNN) that can differentiate treatment indicated presentations of nAMD for referral to treatment centre based solely on SD-OCT. This provides the basis for developing an applicable medical decision support system subsequently. METHODS: SD-OCT volumes of a consecutive real-life cohort of 1503 nAMD patients were analysed and two experiments were carried out. To differentiate between no treatment class vs. initial treatment nAMD class and stabilised nAMD vs. active nAMD, two novel CNNs, based on SD-OCT volume scans, were developed and tested for robustness and performance. In a step towards explainable artificial intelligence (AI), saliency maps of the SD-OCT volume scans of 24 initial indication decisions with a predicted probability of > 97.5% were analysed (score 0-2 in respect to staining intensity). An AI benchmark against retina specialists was performed. RESULTS: At the first experiment, the area under curve (AUC) of the receiver-operating characteristic (ROC) for the differentiation of patients for the initial analysis was 0.927 (standard deviation (SD): 0.018), for the second experiment (retreatment analysis) 0.865 (SD: 0.027). The results were robust to downsampling (» of the original resolution) and cross-validation (tenfold). In addition, there was a high correlation between the AI analysis and expert opinion in a sample of 102 cases for differentiation of patients needing treatment (κ = 0.824). On saliency maps, the relevant structures for individual initial indication decisions were the retina/vitreous interface, subretinal space, intraretinal cysts, subretinal pigment epithelium space, and the choroid. CONCLUSION: The developed AI algorithms can define and differentiate presentations of AMD, which should be referred for treatment or retreatment with anti-VEGF therapy. This may support non-retina specialists to interpret SD-OCT on expert opinion level. The individual decision of the algorithm can be supervised by saliency maps.

Correlation of retinal alterations with vascular structure of macular neovascularisation in swept-source optical coherence tomography angiography in age-related macular degeneration.

PURPOSE: The aim of this study was to find out whether the vascular architecture of untreated macular neovascularisations (MNV) in neovascular age-related macular degeneration (nAMD) as visualised with optic coherence tomography angiography (OCTA) is associated with functional and known morphological alterations of the retina in optic coherence tomography (SD-OCT). METHODS: The study design was retrospective with consecutive patient inclusion. In 107 patients with newly diagnosed nAMD, MNV were detected by means of OCTA and automated quantitative vascular analysis was performed. The MNV characteristics measured were area, flow density, total vascular length (sumL), density of vascular nodes (numN), fractal dimension (FD) and average vascular width (avgW). These parameters were assessed for associations with vision (BCVA), central retinal thickness (CRT), fluid distribution, the elevation of any pigment epithelial detachment (PED), the occurrence of subretinal haemorrhage and atrophy. RESULTS: BCVA was significantly worse with greater MNV area and sumL. Fluid distribution differed significantly in relation to area (p < 0.005), sumL (p < 0.005) and FD (p = 0.001). Greater PED height was significantly associated with higher numN (p < 0.05) and lower avgW (p < 0.05). Atrophy was present significantly more often in MNV with larger area (p < 0.05), higher sumL (p < 0.05) and higher flow density (p = 0.002). None of the MNV parameters had a significant association with CRT or the occurrence of haemorrhage. CONCLUSION: OCTA is not restricted to evaluation of secondary changes but offers the opportunity to analyse the vascular structure of MNV in detail. Differences in vascular morphology are associated with certain secondary changes in retinal morphology. There are thus grounds for optimism that further research may identify and classify OCTA-based markers to permit more individualised treatment of nAMD.

Quantification of Early and Intermediate Age-related Macular Degeneration Using OCT "en face" Presentation. / Quantifizierung der frühen und intermediären altersabhängigen Makuladegeneration mittels OCT-"en-face"-Darstellung.

BACKGROUND: Early and intermediate age-related macular degeneration (AMD) results in drusen deposits under the retinal pigment epithelium (RPE). These early stages of AMD exhibit different risks of progressing to late AMD. To date, early AMD has been classified and quantified by fundus photography. This does not appear to be sensitive enough for clinical trials studying the impact on drusen. SD-OCT with two-dimensional rendering of the segmented slices analysed allows for en face imaging of the drusen. The present trial studied the potential of quantifying early and intermediate AMD by en-face optical coherence tomography (OCT). MATERIAL AND METHODS: Thirty-one eyes of 29 patients in different stages of early and intermediate AMD were studied. To this end, fundus photographs (Kowa VX-10i, Kowa, Tokyo, Japan) and en-face OCT images (RTVue XR Avanti, Optovue, Inc., Fremont, CA, USA) were taken. First, different segmentation levels (6 µm underneath the RPE, on the RPE, 6 µm and 9 µm above the RPE) and different layer thicknesses (5 µm, 10 µm, 20 µm and 30 µm) were analysed to determine the best segmentation for visualising drusen. Drusen were marked manually and their number and surface area calculated. This analysis was then compared with the standardised drusen analyses on fundus photography. Additional changes in early and intermediate AMD such as pigment epithelial detachments (PEDs) and subretinal drusenoid deposits (SDD) as well as small atrophies were also documented and compared. OUTCOMES: The best segmentation for delineating the drusen on the en-face OCT images was found to be a segmentation 6 µm underneath the RPE with a slice thickness of 20 µm. Comparison of drusen quantification on en-face OCT images with the standardised drusen analysis on fundus photography revealed particularly good similarity. Other changes in early and intermediate AMD, such as PEDs, SDD and small atrophies, were easier to assess on the en-face OCT images. CONCLUSIONS: The analysis and quantification of drusen from en-face OCT images with 20 µm segmentation at 6 µm underneath the RPE allows differentiated quantification of various drusen characteristics. Moreover, other changes in early and intermediate AMD can also be analysed. In future observational and clinical trials, this could help quantify drusen.

Imaging endpoints for clinical trials in MacTel type 2.

INTRODUCTION: Macular Telangiectasia type 2 (MacTel) is a bilateral neurodegenerative disease associated with dysfunction in the serine and lipid metabolism resulting in loss of Muller cells and photoreceptors. Typical structural changes include vascular abnormalities, loss of retinal transparency, redistribution of macular pigment and thinning of the central retina with photoreceptor loss. The presence and extent of photoreceptor loss, as visible on Optical Coherence Tomography (OCT) ("disease severity scale"), correlate with functional loss and the limitation of photoreceptor loss appears to be the most promising therapeutic approach. Ongoing clinical trials of ciliary neurotrophic factor (CNTF) implants for the treatment of MacTel are using this outcome to evaluate efficacy. An ideal outcome measure provides the ability to quantify the extent of the disease progression with precision and reproducibility. METHODS: This review describes the changes and findings on different imaging techniques including fluorescein- and OCT angiography, blue light reflectance, 1- and 2-wavelength autofluorescence and OCT. RESULTS: The possibilities of objective quantification of the severity of MacTel and correlation with functional characteristics such as best-corrected visual acuity (BCVA) and microperimetry and their applications as quantitative imaging endpoints for clinical treatment trials are discussed. OCT and especially en face OCT could be demonstrated as precise and reproducible methods to quantify the area of photoreceptor loss, which correlated highly significantly with functional loss in microperimetry. CONCLUSION: The analysis of the area of photoreceptor loss on en face OCT is the most reliable imaging endpoint for treatment trials in MacTel. This method is already being used in ongoing randomized trials.

Fundus Autofluorescence Imaging in Macular Telangiectasia Type 2: MacTel Study Report Number 9.

PURPOSE: To investigate the role of fundus autofluorescence (FAF) imaging in the diagnosis of macular telangiectasia type 2 (MacTel) and to describe disease-associated FAF patterns and their origin. DESIGN: Cross-sectional multicenter study METHODS: FAF images were collected from the multicenter MacTel Natural History Observation and Registry Study. In a first qualitative approach, common FAF phenotypes were defined and correlated with multimodal imaging. We then evaluated how many eyes showed FAF changes, and temporal vs nasal asymmetry of FAF changes was graded. Finally, 100 eyes of MacTel patients and 100 control eyes (50 normal eyes and 50 eyes with other macular diseases) were combined and 2 masked graders assessed the presence of MacTel based on FAF images alone. RESULTS: The study included 807 eyes of 420 patients (33 eyes were excluded owing to poor image quality). Loss of macular pigment, cystoid spaces, pigment plaques, neovascular membranes, and ectatic vascular changes commonly caused characteristic changes on FAF images. All MacTel patients had macular FAF changes in at least 1 eye. In 95% of eyes, these changes were more pronounced temporally than nasally. Common FAF patterns were increased (60%) and mixed/decreased FAF (38%) and/or visibility of vascular changes such as blunted vessels or ectatic capillaries (79%). Based on those features, high diagnostic performance was achieved for detection of the disease based on FAF alone (Youden index up to 0.91). CONCLUSIONS: The study demonstrates that MacTel is consistently associated with disease-specific changes on FAF imaging. Those changes are typically more pronounced in the temporal parafovea.

Incidence and phenotypical variation of outer retina-associated hyperreflectivity in macular telangiectasia type 2.

BACKGROUND: Macular telangiectasia type 2 (MacTel) is a neurodegenerative disease resulting in photoreceptor loss. Optical coherence tomography (OCT) reveals outer retina-associated hyperreflectivity (ORaH) as part of this process. The purpose of this study was to describe the incidence and phenotypical variation of ORaH. METHODS: Different parameters of ORaH were analysed: OCT characteristics (Spectralis SD-OCT), correlation with vascular changes (OCT angiography; OCTA 3×3 mm Optovue) and correlation with hyperpigmentation (autofluorescence/fundus images). ORaH was also evaluated regarding the grade of severity of photoreceptor loss (Disease Severity Scale). RESULTS: Of 220 eyes with MacTel type 2, 106 demonstrated ORaH. On OCT, the size, the extension into the inner retina and the contact with retinal pigment epithelium (RPE) of the ORaH were variable. On OCTA neovascularisation (NV) in the outer retina (OR) was present at the location of the ORaH in 97.6%. Increasing size of NV correlated with progressive photoreceptor loss. In 86.6% with NV, the flow signals were visible between the OR and the choriocapillaris. In 85.7%, the ORaH was associated with hyperpigmentation on autofluorescence and fundus colour images. CONCLUSIONS: The presence of ORaH is associated with increasing photoreceptor loss and disease severity. In these more advanced cases of the present study, a variable presentation of ORaH in respect to size and form was seen, but in most cases, ORaH was in contact to the RPE. Additionally, ORaH was associated with hyperpigmentation and OR NV on OCTA. These results are consistent with the concept of ORaH representing fibrovascular OR-NV with RPE proliferation after contact with the RPE.

[Fibrovascular transformation of CNV in nAMD after long-term anti-VEGF therapy : Methodological evaluation of quantifying morphological changes]. / Die fibrovaskuläre Umwandlung der CNV bei nAMD unter lang andauernder Anti-VEGF-Therapie : Methodenevaluation zur Quantifizierung morphologischer Veränderungen.

BACKGROUND: Under long-term anti-VEGF therapy neovascular age-related macular degeneration (nAMD) may result in fibrovascular transformation of choroidal neovascularization (CNV). So far there is a lack of definitions on how a differentiated quantification of the associated morphological changes can best be carried out. This pilot study aimed to define the most appropriate imaging modalities. PATIENTS AND METHODS: In 56 eyes with fibrotic CNV after at least 2 years of anti-VEGF therapy and at least 12 intravitreal anti-VEGF injections, the following imaging modalities were investigated with respect to the delimitation of vascular and fibrous portions of CNV as well as associated atrophy of retinal pigment epithelium (RPE) and disruption of the ellipsoid zone (EZ): multicolor imaging (MC), fundus autofluorescence (FAF), fluorescein angiography (FA) and indocyanine green angiography (ICGA), spectral domain optical coherence tomography (SD-OCT) and OCT angiography (OCTA). RESULTS: The vascular portion of fibrotic CNV was best visualized by OCTA, the fibrous portion by SD-OCT. The RPE atrophy was best delimitated by FAF, but differentiation was also possible by MC and ICGA. Disruption of the EZ could be delineated by SD-OCT b­scan. CONCLUSION: The use of MC is suitable for visualization of RPE atrophy and the fibrous portion of fibrotic CNV and FAF is suitable for differentiation of RPE atrophy. The SD-OCT can be used to quantify the fibrous portion of CNV; the EZ interruption is delimitable in the b­scan but not in the transverse structure-scan. The vascular part can best be detected by OCTA.