ANALYSIS OF FLUID VOLUME AND ITS IMPACT ON VISUAL ACUITY IN THE FLUID STUDY AS QUANTIFIED WITH DEEP LEARNING

Impact of residual retinal fluid on treatment outcomes in neovascular age-related macular degeneration

Treatment decisions for neovascular age-related macular degeneration (nAMD) in the setting of individualised treatment regimens are adapted to disease activity. The main marker of disease activity and trigger for re-treatment with anti-vascular endothelial growth factor (anti-VEGF) agents is the presence of retinal fluid on optical coherence tomography (OCT). Recently, attention has focused on the impact of residual retinal fluid on nAMD management. Based on a literature review and the combined clinical experience of an international group of retinal specialists, this manuscript provides expert guidance on the treatment of nAMD according to fluid status and proposes an algorithm for determining when to administer anti-VEGF treatment according to residual fluid status. We explore the role of residual fluid in treatment decisions and outcomes in nAMD, taking into consideration fluid evaluation and, in particular, distinguishing between fluid in different anatomic compartments and at different stages during the treatment course. Current limitations to identifying and interpreting fluid on OCT, and the assumption that any residual retinal fluid reflects ongoing VEGF activity, are discussed.

Dynamics and patterns of recurrence in neovascular AMD during real-world management using automated fluid monitoring

In this retrospective longitudinal observational study, data from one site of the Fight Retinal Blindness! Registry (University of Zurich, Switzerland) was used to investigate the quantity and distribution of recurrent fluid in neovascular age-related macular degeneration (nAMD). Study eye eligibility required treatment-naïve nAMD, receiving at least three anti-vascular endothelial growth factor injections, followed by a treatment discontinuation of at least six months and subsequence fluid recurrence. To quantify fluid, a regulatory approved deep learning algorithm (Vienna Fluid Monitor, RetInSight, Vienna, Austria) was used. Fifty-six eyes of 56 patients with a mean age of 76.29 ± 6.58 years at baseline fulfilled the inclusion criteria. From baseline to the end of the first treatment-free interval, SRF volume had decreased significantly (58.0 nl (IQR 10-257 nl) to 8.73 nl (IQR 1-100 nl), p < 0.01). The quantitative increase in IRF volume from baseline to the end of the first treatment-free interval was not statistically significant (1.35 nl (IQR 0-107 nl) to 5.18 nl (IQR 0-24 nl), p = 0.13). PED also did not reach statistical significance (p = 0.71). At the end of the second treatment discontinuation there was quantitatively more IRF (17.3 nl) than SRF (3.74 nl). In conclusion, discontinuation of treatment with anti-VEGF therapy may change the fluid pattern in nAMD.

Impact of Prolonged Persisting Subretinal Fluid on the Outcome of Aflibercept Treatment in Neovascular Age-Related Macular Degeneration

Purpose: To evaluate the effect of prolonged residual subretinal fluid (SRF) on the outcomes of aflibercept treatment in neovascular age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV). Methods: This retrospective study included patients diagnosed with neovascular AMD or PCV who presented with fovea-involving residual SRF that persisted for a minimum of 6 months while undergoing aflibercept treatment. Changes in best-corrected visual acuity (BCVA) during persistent SRF were evaluated. The factors associated with the risk of visual deterioration during this period were also investigated. Results: In total, 135 patients were included in this study. During this period, the duration of the presence of residual SRF was 17.1 ± 10.3 months and mean injection interval was 2.6 ± 0.7 months. The mean BCVA was changed from 0.30 ± 0.23(Snellen equivalents, 20/39) to 0.36 ± 0.28 (20/45). In 18 (13.3%) patients, ≥2 lines of visual deterioration was noted. The duration of persisting SRF (P = 0.008) and mean height of SRF (P = 0.005) were significantly associated with a high risk of visual deterioration. Among the 80 patients with mean SRF height <100 μm, ≥2 lines of visual deterioration were noted in 4 (5.0%) patients. Among 41 patients with the mean SRF height ≥100 μm and <200 μm and 14 patients with the mean SRF height ≥200 μm, the visual deterioration was noted in 8 (19.5%) and 6 (42.9%) patients, respectively. Conclusions: In cases of neovascular AMD or PCV in which SRF persists without complete resolution during treatment, minimizing the duration of persistent SRF and mean height of SRF is recommended to mitigate the risk of visual deterioration. ClinicalTrials.gov Identifiers: NCT05662943 (https://clinicaltrials.gov/study/NCT05662943?cond=type%201%20macular%20neovascularization&rank=2).

Characteristics of Eyes With Neovascular Age-Related Macular Degeneration Requiring Frequent Anti-vascular Endothelial Growth Factor Injections

Objective In this study, we aimed to determine the characteristics of neovascular age-related macular degeneration (AMD) patients requiring frequent anti-vascular endothelial growth factor (VEGF) therapy. Methods This was a retrospective observational study involving the review of 32 eyes of 31 patients (25 men and six women, mean age: 74.3 years) treated with anti-VEGF injections for less than eight weeks and at least one year of follow-up. The subtype of macular neovascularization (MNV), follow-up duration, number of injections, visual acuity, and exudative changes during the study period were evaluated. Results Twenty-nine eyes (90.6%) had MNV under the retinal pigment epithelium (RPE), including 11 eyes with type 1 MNV and 18 eyes with polypoidal choroidal vasculopathy (PCV). Only three eyes had type 2 MNV (9.4%) above the RPE. The mean follow-up period was 28.7 ± 16.5 months, and the mean number of injections was 21.5 ± 11.8. The mean visual acuity [logarithm of the minimum angle of resolution (logMAR) units] was 0.19 ± 0.23 at the initial visit to our hospital, which decreased non-significantly to 0.24 ± 0.4 at the final visit (p=0.63). The exudation in four eyes (two with type 1 MNV and two with PCV) never resolved. The exudation remained in 27 eyes (84%) even after every four weeks of treatment, and it was present in five eyes (16%) in the treatment interval of eight weeks. Conclusions In the eyes receiving frequent anti-VEGF injections, the sub-RPE MNV might have affected the response to the treatment. Although patients requiring frequent anti-VEGF therapy did not have a significant decrease in their visual acuity, 84% of the eyes had exudations even with monthly injections.

Performance of retinal fluid monitoring in OCT imaging by automated deep learning versus human expert grading in neovascular AMD

PURPOSE

To evaluate the reliability of automated fluid detection in identifying retinal fluid activity in OCT scans of patients treated with anti-VEGF therapy for neovascular age-related macular degeneration by correlating human expert and automated measurements with central retinal subfield thickness (CSFT) and fluid volume values.

METHODS

We utilized an automated deep learning approach to quantify macular fluid in SD-OCT volumes (Cirrus, Spectralis, Topcon) from patients of HAWK and HARRIER Studies. Three-dimensional volumes for IRF and SRF were measured at baseline and under therapy in the central millimeter and compared to fluid gradings, CSFT and foveal centerpoint thickness (CPT) values measured by the Vienna Reading Center.

RESULTS

41.906 SD-OCT volume scans were included into the analysis. Concordance between human expert grading and automated algorithm performance reached AUC values of 0.93/0.85 for IRF and 0.87 for SRF in HARRIER/HAWK in the central millimeter. IRF volumes showed a moderate correlation with CSFT at baseline (HAWK: r = 0.54; HARRIER: r = 0.62) and weaker correlation under therapy (HAWK: r = 0.44; HARRIER: r = 0.34). SRF and CSFT correlations were low at baseline (HAWK: r = 0.29; HARRIER: r = 0.22) and under therapy (HAWK: r = 0.38; HARRIER: r = 0.45). The residual standard error (IRF: 75.90 µm; SRF: 95.26 µm) and marginal residual standard deviations (IRF: 46.35 µm; SRF: 44.19 µm) of fluid volume were high compared to the range of CSFT values.

CONCLUSION

Deep learning-based segmentation of retinal fluid performs reliably on OCT images. CSFT values are weak indicators for fluid activity in nAMD. Automated quantification of fluid types, highlight the potential of deep learning-based approaches to objectively monitor anti-VEGF therapy.

Long-term effect of fluid volumes during the maintenance phase in neovascular age-related macular degeneration: results from Fight Retinal Blindness!

OBJECTIVE

To investigate the effect of macular fluid volumes (subretinal fluid [SRF], intraretinal fluid [IRF], and pigment epithelium detachment [PED]) after initial treatment on functional and structural outcomes in neovascular age-related macular degeneration in a real-world cohort from Fight Retinal Blindness!

METHODS

Treatment-naive neovascular age-related macular degeneration patients from Fight Retinal Blindness! (Zürich, Switzerland) were included. Macular fluid on optical coherence tomography was automatically quantified using an approved artificial intelligence algorithm. Follow-up of macular fluid, number of anti-vascular endothelial growth factor treatments, effect of fluid volumes after initial treatment (high, top 25%; low, bottom 75%) on best-corrected visual acuity, and development of macular atrophy and fibrosis was investigated over 48 months.

RESULTS

A total of 209 eyes (mean age, 78.3 years) were included. Patients with high IRF volumes after initial treatment differed by -2.6 (p = 0.021) and -7.4 letters (p = 0.007) at months 12 and 48, respectively. Eyes with high IRF received significantly more treatments (+1.6 [p < 0.001] and +5.3 [p = 0.002] at months 12 and 48, respectively). Patients with high SRF or PED had comparable best-corrected visual acuity outcomes but received significantly more treatments for SRF (+2.4 [p < 0.001] and +11.4 [p < 0.001] at months 12 and 48, respectively) and PED (+1.2 [p = 0.001] and +7.8 [p < 0.001] at months 12 and 48, respectively).

DISCUSSION

Patients with high macular fluid after initial treatment are at risk of losing vision that may not be compensable with higher treatment frequency for IRF. Higher treatment frequency for SRF and PED may result in comparable treatment outcomes. Quantification of macular fluid in all compartments is essential to detect eyes at risk of aggressive disease.

Imaging Histology Correlations of Intraretinal Fluid in Neovascular Age-Related Macular Degeneration

Purpose

Fluid presence and dynamism is central to the diagnosis and management of neovascular age-related macular degeneration. On optical coherence tomography (OCT), some hyporeflective spaces arise through vascular permeability (exudation) and others arise through degeneration (transudation). Herein we determined whether the histological appearance of fluid manifested this heterogeneity.

Methods

Two eyes of a White woman in her 90s with anti-vascular endothelial growth factor treated bilateral type 3 neovascularization secondary to age-related macular degeneration were osmicated, prepared for submicrometer epoxy resin sections, and correlated to eye-tracked spectral domain OCT. Examples of intraretinal tissue fluid were sought among similarly prepared donor eyes with fibrovascular scars, in a web-based age-related macular degeneration histopathology resource. Fluid stain intensity was quantified in reference to Bruch's membrane and the empty glass slide.

Results

Exudative fluid by OCT was slightly reflective and dynamically responded to anti-vascular endothelial growth factor. On histology, this fluid stained moderately, possessed a smooth and homogenous texture, and contained blood cells and fibrin. Nonexudative fluid in degenerative cysts and in outer retinal tubulation was minimally reflective on OCT and did not respond to anti-vascular endothelial growth factor. By histology, this fluid stained lightly, possessed a finely granular texture, and contained mainly tissue debris. Quantification supported the qualitative impressions of fluid stain density. Cells containing retinal pigment epithelium organelles localized to both fluid types.

Conclusions

High-resolution histology of osmicated tissue can distinguish between exudative and nonexudative fluid, some of which is transudative.

Translational Relevance

OCT and histological features of different fluid types can inform clinical decision-making and assist in the interpretation of newly available automated fluid detection algorithms.

Therapeutic response in the HAWK and HARRIER trials using deep learning in retinal fluid volume and compartment analysis

OBJECTIVES

To assess the therapeutic response to brolucizumab and aflibercept by deep learning/OCT-based analysis of macular fluid volumes in neovascular age-related macular degeneration.

METHODS

In this post-hoc analysis of two phase III, randomised, multi-centre studies (HAWK/HARRIER), 1078 and 739 treatment-naive eyes receiving brolucizumab or aflibercept according to protocol-specified criteria in HAWK and HARRIER, respectively, were included. Macular fluid on 41,840 OCT scans was localised and quantified using a validated deep learning-based algorithm. Volumes of intraretinal fluid (IRF), subretinal fluid (SRF), pigment epithelial detachment (PED) for all central macular areas (1, 3 and 6 mm) in nanolitres (nL) and best corrected visual acuity (BCVA) change in ETDRS letters were associated using mixed models for repeated measures.

RESULTS

Baseline IRF volumes decreased by >92% following the first intravitreal injection and consistently remained low during follow-up. Baseline SRF volumes decreased by >74% following the first injection, while PED volume resolved by 68-79% of its baseline volume. Resolution of SRF and PED was dependent on the substance and regimen used. Larger residual post-loading IRF, SRF and PED volumes were all independently associated with progressive vision loss during maintenance, where the differences in mean BCVA change between high and low fluid volume subgroups for IRF, SRF and PED were 3.4 letters (p < 0.0001), 1.7 letters (p < 0.001) and 2.5 letters (p < 0.0001), respectively.

CONCLUSIONS

Deep-learning methods allow an accurate assessment of substance and regimen efficacy. Irrespectively, all fluid compartments were found to be important markers of disease activity and were relevant for visual outcomes.

A real-world study assessing the impact of retinal fluid on visual acuity outcomes in patients with neovascular age-related macular degeneration in Korea

To evaluate the real-world treatment outcomes in patients with neovascular age-related macular degeneration (nAMD) in Korea, focusing on retinal fluid resolution. This multi-institutional retrospective chart review study, analyzed medical records of patients with nAMD (age ≥ 50 years) who received their first anti-vascular endothelial growth factor (VEGF) treatment in ophthalmology clinics across South Korea between January 2017 and March 2019. The primary endpoint was the proportion of patients with retinal fluid after 12 months of anti-VEGF treatment. The association between fluid-free period and VA gains was also evaluated. A total of 600 patients were enrolled. At baseline, 97.16% of patients had retinal fluid; after 12 months of anti-VEGF treatment, 58.10% of patients had persistent retinal fluid. VA improvements were relatively better in patients with absence of retinal fluid compared with presence of retinal fluid (+ 12.29 letters vs. + 6.45 letters at month 12; P < .0001). Longer duration of absence of retinal fluid over first 12 months correlated with better VA gains at month 12 (P < .01). More than half of the study patients with nAMD had retinal fluid even after 12 months of treatment with their current anti-VEGF. Presence of retinal fluid was associated with relatively worse VA outcomes.

Artificial Intelligence Analysis of Biofluid Markers in Age-Related Macular Degeneration: A Systematic Review

This systematic review explores the use of artificial intelligence (AI) in the analysis of biofluid markers in age-related macular degeneration (AMD). We detail the accuracy and validity of AI in diagnostic and prognostic models and biofluid markers that provide insight into AMD pathogenesis and progression. This review was conducted in accordance with the Preferred Reporting Items for a Systematic Review and Meta-analysis guidelines. A comprehensive search was conducted across 5 electronic databases including Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, EMBASE, Medline, and Web of Science from inception to July 14, 2021. Studies pertaining to biofluid marker analysis using AI or bioinformatics in AMD were included. Identified studies were assessed for risk of bias and critically appraised using the Joanna Briggs Institute Critical Appraisal tools. A total of 10,264 articles were retrieved from all databases and 37 studies met the inclusion criteria, including 15 cross-sectional studies, 15 prospective cohort studies, five retrospective cohort studies, one randomized controlled trial, and one case–control study. The majority of studies had a general focus on AMD (58%), while neovascular AMD (nAMD) was the focus in 11 studies (30%), and geographic atrophy (GA) was highlighted by three studies. Fifteen studies examined disease characteristics, 15 studied risk factors, and seven guided treatment decisions. Altered lipid metabolism (HDL-cholesterol, total serum triglycerides), inflammation (c-reactive protein), oxidative stress, and protein digestion were implicated in AMD development and progression. AI tools were able to both accurately differentiate controls and AMD patients with accuracies as high as 87% and predict responsiveness to anti-VEGF therapy in nAMD patients. Use of AI models such as discriminant analysis could inform prognostic and diagnostic decision-making in a clinical setting. The identified pathways provide opportunity for future studies of AMD development and could be valuable in the advancement of novel treatments.

Personalized treatment supported by automated quantitative fluid analysis in active neovascular age-related macular degeneration (nAMD)-a phase III, prospective, multicentre, randomized study: design and methods

INTRODUCTION

In neovascular age-related macular degeneration (nAMD) the exact amount of fluid and its location on optical coherence tomography (OCT) have been defined as crucial biomarkers for disease activity and therapeutic decisions. Yet in the absence of quantitative evaluation tools, real-world care outcomes are disappointing. Artificial intelligence (AI) offers a practical option for clinicians to enhance point-of-care management by analysing OCT volumes in a short time. In this protocol we present the prospective implementation of an AI-algorithm providing automated real-time fluid quantifications in a clinical real-world setting.

METHODS

This is a prospective, multicentre, randomized (1:1) and double masked phase III clinical trial. Two-hundred-ninety patients with active nAMD will be randomized between a study arm using AI-supported fluid quantifications and another arm using conventional qualitative assessments, i.e. state-of-the-art disease management. The primary outcome is defined as the mean number of injections over 1 year. Change in BCVA is defined as a secondary outcome.

DISCUSSION

Automated measurement of fluid volumes in all retinal compartments such as intraretinal fluid (IRF), and subretinal fluid (SRF) will serve as an objective tool for clinical investigators on which to base retreatment decisions. Compared to qualitative fluid assessment, retreatment decisions will be plausible and less prone to error or large variability. The underlying hypothesis is that fluid should be treated, while residual persistent or stable amounts of fluid may not benefit from further therapy. Reducing injection numbers without diminishing the visual benefit will increase overall patient safety and relieve the burden for healthcare providers.

TRIAL-REGISTRATION

EudraCT-Number: 2019-003133-42.

Efficacy and safety of brolucizumab versus aflibercept in eyes with early persistent retinal fluid: 96-week outcomes from the HAWK and HARRIER studies

OBJECTIVE

Post-hoc analysis to compare the outcomes of brolucizumab 6 mg vs. aflibercept 2 mg in neovascular age-related macular degeneration (nAMD) patients with early persistent retinal fluid in HAWK and HARRIER.

METHODS

After 3 monthly loading doses, brolucizumab-treated eyes (N = 730) received injections every 12 weeks (q12w) or q8w if disease activity was detected. Aflibercept-treated eyes (N = 729) received fixed q8w dosing. Early persistent fluid was defined as the presence of subretinal fluid and/or intraretinal fluid up to Week 12.

RESULTS

A lower proportion of brolucizumab patients had early persistent retinal fluid compared with aflibercept (11.2% (n = 82) vs. 19.2% (n = 140)). In these patients, 34.1% of the brolucizumab-treated group achieved a ≥ 15 ETDRS letter gain in best corrected visual acuity (BCVA) from baseline at Week 96 compared with 20.7% of the aflibercept-treated group. Brolucizumab achieved numerically better BCVA outcomes (Week 96: brolucizumab, +6.4 letters; aflibercept, +3.7 letters) and significantly greater central subfield thickness reductions versus aflibercept from baseline through Week 96 (Week 96: -202 µm vs. -145 µm; p = 0.0206). Brolucizumab demonstrated an overall favourable benefit/risk profile in this patient cohort. In their unmasked, post-hoc review, the Safety Review Committee identified two cases of retinal vasculitis and no cases of retinal vascular occlusion in the brolucizumab arm; no cases of retinal vasculitis or retinal vascular occlusion were identified in the aflibercept arm.

CONCLUSION

In this analysis, anatomical and visual outcomes were better with brolucizumab compared with aflibercept. Brolucizumab may therefore achieve greater disease control than aflibercept in nAMD patients with early persistent retinal fluid.

Neovascular age-related macular degeneration in which exudation predominantly occurs as a subretinal fluid during anti-vascular endothelial growth factor treatment

We investigated the characteristics of neovascular age-related macular degeneration (AMD) in which exudation predominantly occurs as a subretinal fluid (SRF) during anti-vascular endothelial growth factor (VEGF) treatment. A total of 509 treatment-naïve neovascular AMD patients treated with anti-VEGF for 24 months were retrospectively analyzed. The baseline characteristics to determine the odds of occurrence of SRF alone were evaluated using multivariate modeling. SRF was the sole manifestation of lesion activity in 209 (40.9%) eyes during follow-up. The visual outcome of eyes with only SRF occurrence during follow-up was comparable to that of eyes without exudative recurrence. In addition, the incidence of macular atrophy was significantly lower in eyes with only SRF occurrence (9.6%, 20 of 208 eyes) than in eyes without exudative recurrence (16.7%, 9 of 54 eyes, P = 0.018). Multivariate analysis revealed that better best-corrected visual acuity (BCVA) at baseline (odds ratio [OR], 0.306; P = 0.001), presence of SRF alone at baseline (OR, 5.256; P < 0.001), lower pigment epithelial detachment (PED) height (less than 100 µm; OR, 4.113; P = 0.025), and aneurysmal type 1 macular neovascularization (MNV) (OR, 2.594; P = 0.002) were associated with an increased likelihood of SRF occurrence during follow-up. In conclusion, the eyes with only SRF occurrence during anti-VEGF treatment showed more favorable visual outcomes and a lower incidence of macular atrophy. The baseline characteristics, including better baseline BCVA, presence of SRF alone at baseline, lower PED height, and MNV subtype, might influence the predominant development of SRF during anti-VEGF treatment.

Treatment Outcome of Wet Age-Related Macular Degeneration Management in Thailand: A Retrospective Real-World Study (TOWER Study)

INTRODUCTION

To present real-world outcomes of neovascular age-related macular degeneration (nAMD) management in Thailand.

METHODS

This multicenter retrospective study reviewed medical records of naive nAMD patients diagnosed from 1 January 2016 until 31 December 2018. The patients received at least one intravitreal anti-vascular endothelial growth factor (VEGF) treatment and had captured visual acuity (VA) at baseline and at month 12. Treatment outcomes were assessed at month 12, 24, and 36. The primary outcome was a mean change in VA from baseline to month 12.

RESULTS

Five hundred seventy-two (572) eyes were included in this study and of these eyes, 222 and 96 had 2- and 3-year follow-up periods, respectively. At month 12, the mean improvement of VA (ETDRS letter) was six letters (P < 0.0001), and central retinal thickness (CRT) decreased on average by 104 microns (P < 0.0001). However, visual improvement by 0.1 letters at month 36 did not show statistical significance. The presence of fluid was found in approximately half of patients throughout the study period (45.98%, 48.85%, and 50.91% at month 12, 24, and 36, respectively). Mean number of injections (SD) was 6.06 (3.00), 3.44 (2.94), and 2.71 (3.07) for years 1, 2, and 3, respectively. The mean number of visits (SD) in year 1 was 9.01 (2.60) and declined to 5.67 (2.69) in year 2 and 4.93 (2.49) in year 3. Patients who had an average injection interval of ≤ 8 weeks were 74.46% in year 1, 51.28% in year 2, and 45.24 in year 3; 35.31% of patients were lost to follow-up.

CONCLUSIONS

This analysis reflects real-world nAMD management with significant improvement of outcomes. At the same time, the study reveals unmet needs in anti-VEGF therapy in nAMD including persistent disease activities, inadequacy of available treatment, and lack of treatment adherence leading to visual deterioration in the long-term.

Intravitreal Aflibercept Therapy and Treatment Outcomes of Eyes with Neovascular Age-Related Macular Degeneration in a Real-Life Setting: A Five-Year Follow-Up Investigation

Introduction

We aimed to evaluate visual and anatomical outcomes among eyes with neovascular age-related macular degeneration (nAMD) that were persistent to intravitreal aflibercept therapy compared to those that were nonpersistent to therapy.

Methods

We audited 648 treatment-naïve eyes of 559 patients regarding visual acuity (VA) given as the logarithm of the minimum angle of resolution (logMAR) and anatomic outcomes at baseline and at each subsequent follow-up visit for up to 5 years. Nonpersistence was defined as a visit-free interval of > 6 months.

Results

Among the enrolled eyes, 405 were persistent to the therapy and 243 (37%) were nonpersistent, of which 161 (66%) eyes returned for further therapy after a gap of clinical care. In the nonpersistent group, we observed a decline from 0.58 ± 0.35 to 0.92 ± 0.57 logMAR (p = 0.01) after 60 months. Compared with the persistent group, the nonpersistent group had worse visual outcomes at their 33-month (p = 0.03), 42-month (p = 0.01), 51-month (p = 0.001) and 60-month (p = 0.01) visits. Additionally, 5/405 (1.2%) eyes in the persistent group and 8/161 (5.0%) eyes in the nonpersistent group developed an end-stage disease with a subfoveal fibrosis during the observational period (p = 0.013).

Conclusion

We found that eyes with nAMD that were nonpersistent to intravitreal aflibercept therapy experienced statistically significantly worse VA compared to eyes persistent to therapy within 3 years. Moreover, eyes in the nonpersistent group had a four-fold higher risk of developing a fovea-involving fibrosis. Considering the potential irreversible deterioration with respect to best-corrected VA within nAMD, strategies need to be developed for patients at risk of nonpersistence to therapy.

Optimal approaches and criteria to treat-and-extend regimen implementation for Neovascular age-related macular degeneration: experts consensus in Taiwan

The management of neovascular age-related macular degeneration (nAMD) has taken a major stride forward with the advent of anti-VEGF agents. The treat-and-extend (T&E) approach is a refined management strategy, tailoring to the individual patient’s disease course and treatment outcome. To provide guidance to implementing anti-VEGF T&E regimens for nAMD in resource-limited health care systems, an advisory board was held to discuss and generate expert consensus, based on local and international guidelines, current evidence, as well as local experience and reimbursement policies. In the experts’ opinion, treatment of nAMD should aim to maximize and maintain visual acuity benefits while minimizing treatment burden. Based on current evidence, treatment could be initiated with 3 consecutive monthly injections. After the initial period, treatment interval may be extended by 2 or 4 weeks each time for the qualified patients (i.e. no BCVA loss ≥5 ETDRS letters and dry retina), and a maximum interval of 16 weeks is permitted. For patients meeting the shortening criteria (i.e. any increased fluid with BCVA loss ≥5 ETDRS letters, or presence of new macular hemorrhage or new neovascularization), the treatment interval should be reduced by 2 or 4 weeks each time, with a minimal interval of 4 weeks. Discontinuation of anti-VEGF may be considered for those who have received 2–3 consecutive injections spaced 16 weeks apart and present with stable disease. For these individuals, regular monitoring (e.g. 3–4 months) is recommended and monthly injections should be reinstated upon signs of disease recurrence.

Quantitative assessment of retinal fluid in neovascular age-related macular degeneration under anti-VEGF therapy

The retinal world has been revolutionized by optical coherence tomography (OCT) and anti-vascular endothelial growth factor (VEGF) therapy. The numbers of intravitreal injections are on a constant rise and management in neovascular age-related macular degeneration (nAMD) is mainly driven by the qualitative assessment of macular fluid as detected on OCT scans. The presence of macular fluid, particularly subretinal fluid (SRF) and intraretinal fluid (IRF), has been used to trigger re-treatments in clinical trials and the real world. However, large discrepancies can be found between the evaluations of different readers or experts and especially small amounts of macular fluid might be missed during this process. Pixel-wise detection of macular fluid uses an entire OCT volume to calculate exact volumes of retinal fluid. While manual annotations of such pixel-wise fluid detection are unfeasible in a clinical setting, artificial intelligence (AI) is able to overcome this hurdle by providing real-time results of macular fluid in different retinal compartments. Quantitative fluid assessments have been used for various post hoc analyses of randomized controlled trials, providing novel insights into anti-VEGF treatment regimens. Nonetheless, the application of AI-algorithms in a prospective patient care setting is still limited. In this review, we discuss the use of quantitative fluid assessment in nAMD during anti-VEGF therapy and provide an outlook to novel forms of patient care with the support of AI quantifications.

Impact of intra- and subretinal fluid on vision based on volume quantification in the HARBOR trial

PURPOSE

To investigate the functional associations of intra- and subretinal fluid volumes at baseline, after the loading dose as well as fluid change after the first injection with best corrected visual acuity (BCVA) in patients with neovascular AMD (nAMD) who received an anti-VEGF treatment over 24 months.

DESIGN

Post-hoc analysis of a phase III, randomized, multicenter trial, in which ranibizumab was administered monthly or in a PRN regimen (HARBOR).

PARTICIPANTS

Study eyes of 1094 treatment-naïve nAMD patients.

METHODS

Intraretinal (IRF) and subretinal (SRF) fluid volumes were segmented automatically on monthly SD-OCT images. Fluid volumes and changes thereof were included as covariates into longitudinal mixed effects models, modeling BCVA trajectories.

MAIN OUTCOME MEASURES

BCVA estimates corresponding to baseline, follow-up and persistent IRF/SRF volumes following the loading dose; BCVA estimates of change in fluid volumes following the first injection; marginal and conditional R2.

RESULTS

Analysis of 22,494 volumetric scans revealed that foveal IRF consistently shows a negative correlation with BCVA at baseline and subsequent visits (-3.23 and -4.32 letters/100nl). After the first injection, BCVA increased by +2.13 letters/100nl decrease of foveal IRF. Persistent IRF was associated with lower baseline BCVA and less improvement. Foveal SRF correlated with better BCVA at baseline and subsequent visits (+6.52 and +1.42 letters/100nl). After the first injection, SRF decrease was associated with significant vision gain (+5.88 letters/100nl). Foveal fluid correlated more with BCVA than parafoveal IRF/SRF.

CONCLUSION

While IRF consistently correlates with decreased function and recovery throughout therapy, SRF is associated with a more pronounced functional improvement. Moreover, SRF resolution provides increased benefit. Fluid-function correlation represents an essential base for the development of personalized treatment regimens, optimizing functional outcomes and reducing treatment burden.

Artificial intelligence-based predictions in neovascular age-related macular degeneration

PURPOSE OF REVIEW

Predicting treatment response and optimizing treatment regimen in patients with neovascular age-related macular degeneration (nAMD) remains challenging. Artificial intelligence-based tools have the potential to increase confidence in clinical development of new therapeutics, facilitate individual prognostic predictions, and ultimately inform treatment decisions in clinical practice.

RECENT FINDINGS

To date, most advances in applying artificial intelligence to nAMD have focused on facilitating image analysis, particularly for automated segmentation, extraction, and quantification of imaging-based features from optical coherence tomography (OCT) images. No studies in our literature search evaluated whether artificial intelligence could predict the treatment regimen required for an optimal visual response for an individual patient. Challenges identified for developing artificial intelligence-based models for nAMD include the limited number of large datasets with high-quality OCT data, limiting the patient populations included in model development; lack of counterfactual data to inform how individual patients may have fared with an alternative treatment strategy; and absence of OCT data standards, impairing the development of models usable across devices.

SUMMARY

Artificial intelligence has the potential to enable powerful prognostic tools for a complex nAMD treatment landscape; however, additional work remains before these tools are applicable to informing treatment decisions for nAMD in clinical practice.

Predictors of Visual Acuity After Treatment of Neovascular Age-Related Macular Degeneration - Current Perspectives

Visual acuity is a key outcome measure in the treatment of neovascular age-related macular degeneration (nAMD) using anti-vascular endothelial growth factor agents. Large variations in visual responses between individuals within clinical trials and real-world studies may relate to underlying differences in patient and treatment factors. Most notably, a better baseline visual acuity, younger age and smaller choroidal neovascularization lesion size have been strongly associated with achieving better visual outcomes. In addition, there is emerging evidence for other roles including genetic factors and anatomical variables such as fluid status. Apart from patient-related factors, treatments that favor a higher number of injections tend to provide better visual outcomes. Overall, the identification of predictive factors does not currently play an essential role in the clinical management of patients with nAMD. However, they have allowed for the understanding that early detection, timely management and close monitoring of the disease are required to achieve optimal visual outcomes. Further investigation into predictive factors alongside the development of novel therapeutic agents may one day provide a means to accurately predict patient outcomes. Treatment regimens that offer flexible dosing patterns such as the treat-and-extend strategy currently provide a degree of personalization during treatment.

Aflibercept therapy for exudative age-related macular degeneration resistant to bevacizumab and ranibizumab

Background

Despite the good outcomes achieved with intravitreal angiogenic therapy, a subset of neovascular age-related macular degeneration (AMD) patients experience resistance to therapy after repeated injections. Switching drugs could offer benefit to this group of patients.

Purpose

To determine visual and anatomical outcomes in a cohort of neovascular AMD patients resistant to repeated injections of bevacizumab/ranibizumab after switching to aflibercept therapy.

Methods

This was a retrospective chart review of patients who had a diagnosis of neovascular AMD and persistent intraretinal (IRF) and/or subretinal fluid (SRF) on optical coherence tomography (OCT) for at least 3 months despite monthly bevacizumab and/or ranibizumab injections prior to transition to aflibercept. We reviewed patients’ records and OCT images obtained at baseline, 1, 3, 6 and 12 months after transition to aflibercept. Data collected included demographics, best-corrected visual acuity (BCVA), number of injections received and the occurrence of any adverse events. Studied OCT parameters included central macular thickness (CMT) values and the presence or absence of SRF, IRF and/or pigment epithelial detachment (PED) at each visit.

Results

We included 53 eyes of 48 patients. Mean change in BCVA from baseline was 0.05 ± 0.13 (P = 0.01) at M1, 0.04 ± 0.16 (P = 0.08) at M3, 0.01 ± 0.22 (P = 0.9) at M6, and 0.02 ± 0.28 (P = 1) at M12, while the mean change in CMT from baseline was 64 ± 75 μm (P < 0.0001) at M1, 42 ± 85 μm (P = 0.002) at M3, 47 ± 69 μm (P < 0.0001) at M6, and 46 ± 99 μm (P = 0.001) at M12. The percentage of eyes with SRF decreased from 77.4% at baseline to 39.6% at M1, then increased to 47.2% at M3, then decreased to 43.4% at M6, and to 41.5% at M12 (All p < 0.001, compared to baseline). Compared to baseline, there was a statistically significant decrease in the percentage of eyes having IRF from 47.2 to 20.8% at M1 (p < 0.001), 30.2% at M3, 24.5% at M6 and 26.4% at M12 (p < 0.01, each). The number of bevacizumab and/or ranibizumab injections (7.36 ± 1.85) was significantly higher than that of aflibercept (6.47 ± 2.45, p = 0.001). A significant direct relationship between CMT reduction and BCVA improvement was demonstrated at M1 (p = 0.01, r = 0.36), M3 (p = 0.03, r = 0.30) and M12 (p = 0.03, r = 0.30). Eyes with IRF had significantly poorer BCVA than eyes without IRF at baseline (p = 0.02) and M3 (p = 0.04).

Conclusion

Switching to intravitreal aflibercept therapy in a cohort of neovascular AMD patients resistant to chronic bevacizumab and/or ranibizumab injections can lead to significant visual improvement in the short term and sustained reduction of central macular thickness over 1 year of followup.