Predicting vision gains with anti-VEGF therapy in neovascular age-related macular degeneration patients by using low-luminance vision

Machine Learning to Predict Faricimab Treatment Outcome in Neovascular Age-Related Macular Degeneration

Purpose

To develop machine learning (ML) models to predict, at baseline, treatment outcomes at month 9 in patients with neovascular age-related macular degeneration (nAMD) receiving faricimab.

Design

Retrospective proof of concept study.

Participants

Patients enrolled in the phase II AVENUE trial (NCT02484690) of faricimab in nAMD.

Methods

Baseline characteristics and spectral domain-OCT (SD-OCT) image data from 185 faricimab-treated eyes were split into 80% training and 20% test sets at the patient level. Input variables were baseline age, sex, best-corrected visual acuity (BCVA), central subfield thickness (CST), low luminance deficit, treatment arm, and SD-OCT images. A regression problem (BCVA) and a binary classification problem (reduction of CST by 35%) were considered. Overall, 10 models were developed and tested for each problem. Benchmark classical ML models (linear, random forest, extreme gradient boosting) were trained on baseline characteristics; benchmark deep neural networks (DNNs) were trained on baseline SD-OCT B-scans. Baseline characteristics and SD-OCT data were merged using 2 approaches: model stacking (using DNN prediction as an input feature for classical ML models) and model averaging (which averaged predictions from the DNN using SD-OCT volume and from classical ML models using baseline characteristics).

Main Outcome Measures

Treatment outcomes were defined by 2 target variables: functional (BCVA letter score) and anatomical (percent decrease in CST from baseline) outcomes at month 9.

Results

The best-performing BCVA regression model with respect to the test coefficient of determination (R2) was the linear model in the model-stacking approach with R2 of 0.31. The best-performing CST classification model with respect to test area under receiver operating characteristics (AUROC) was the benchmark linear model with AUROC of 0.87. A post hoc analysis showed the baseline BCVA and the baseline CST had the most effect in the all-model prediction for BCVA regression and CST classification, respectively.

Conclusions

Promising signals for predicting treatment outcomes from baseline characteristics were detected; however, the predictive benefit of baseline images was unclear in this proof-of-concept study. Further testing and validation with larger, independent datasets is required to fully explore the predictive capacity of ML models using baseline imaging data.

Financial Disclosures

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

Honokiol Attenuates Choroidal Neovascularization by Inhibiting the Hypoxia-Inducible Factor-α/Vascular Endothelial Growth Factor Axis via Nuclear Transcription Factor-Kappa B Activation

PURPOSE

Honokiol is a lignan isolated from Magnolia officinalis and exhibits anti-angiogenic properties. This study was conducted to investigate the role of honokiol in choroidal neovascularization.

METHODS

C57BL/6 mice were treated with honokiol at 10-20 mg/kg by daily intraperitoneal injection from day 1 to 6 after laser photocoagulation. ARPE-19 cells were cultured under hypoxic conditions with or without the presence of honokiol. After laser photocoagulation and honokiol treatment, hematoxylin and eosin staining, immunofluorescence and fundus fluorescein angiography were used to analyze the effect of honokiol on choroidal neovascularization formation. Quantitative real-time PCR, western blot, enzyme-linked immunosorbent assay, immunofluorescence, luciferase assay, and chromatin immunoprecipitation were performed to explore the mechanism of honokiol in the pathological process of choroidal neovascularization. Finally, the role of honokiol on the human choroidal vascular endothelial cells was detected by using 5-ethynyl-20-deoxyuridine assay, Transwell and Tube formation assays.

RESULTS

The results of hematoxylin and eosin staining and immunofluorescence suggested that honokiol reduced the thickness, length, and area of choroidal neovascularization lesions in laser-induced choroidal neovascularization mouse model. Fundus fluorescein angiography showed that choroidal neovascularization leakage was reduced in honokiol group and the concentration of 20 mg/kg showed better effects. Mechanism studies have shown that honokiol exerted inhibitory effects on choroidal neovascularization by inactivating hypoxia-inducible factor-1α/vascular endothelial growth factor axis through the nuclear transcription factor-kappa B signaling pathway. The same results were obtained in ARPE-19 cells under hypoxic conditions. Furthermore, the conditional medium of retinal pigmented epithelial cells promoted the proliferation, migration, and tube formation of human choroidal vascular endothelial cells, while honokiol reversed these.

CONCLUSION

We demonstrated that honokiol attenuated choroidal neovascularization formation by inactivating the hypoxia-inducible factor-1α/vascular endothelial growth factor axis through nuclear transcription factor-kappa B signaling pathway.

Clinical Effect of Tongmai Fuming Decoction on Neovascular Ophthalmopathy

Background

The incidence of neovascular eye disease is increasing year by year, seriously threatening human vision health and becoming an urgent public health problem. Tongmai fuming decoction as an experienced prescription can treat ischemic eye disease.

Objective

To investigate the therapeutic effect of Tongmai fuming decoction combined with anti-VEGF therapy on neovascular ophthalmopathy.

Methods

52 patients (62 eyes) with neovascular ophthalmopathy who met the inclusion criteria from January 2018 to July 2020 were randomly divided into the control and observation groups. The control group was given an intravitreal injection of antivascular endothelial growth factor (VEGF) drugs once a day combined with on-demand treatment. The observation group was treated with traditional Chinese medicine Tongmai fuming decoction in addition to the treatment of anti-VEGF drugs. The best-corrected visual acuity (BCVA) was examined before and after treatment, and optical coherence tomography angiography (OCTA) was used to examine the mean retinal thickness and neovascularization in the macular area. Patients were followed for one year and the number of anti-VEGF injections was recorded.

Results

After treatment, the average thickness of BCVA and macular retina in the two groups significantly improved. The BCVA of the control group was 0.59 ± 0.39 3 months after treatment, and that of the experimental group was 0.42 ± 0.25 3 months after treatment. The average thickness of the macular retina in the control group was 304.8 ± 79.7 3 months after treatment, and that in the experimental group was 267.7 ± 64.6 3 months after treatment; The average number of injections of anti-VEGF therapy in the control group was 2.32 ± 1.15 times, and that in the experimental group was 1.74 ± 0.76 times. There was a significant difference between the two groups.

Conclusion

Tongmai fuming decoction and anti-VEGF therapy have a synergistic effect in the treatment of neovascular ophthalmopathy, which can reduce the treatment times of anti-VEGF drugs.

Correlation of Optical Coherence Tomography Angiography Characteristics with Visual Function to Define Vision-Threatening Diabetic Macular Ischemia

The thresholds of macular microvasculature parameters associated with mild visual impairment in diabetic macular ischemia (DMI) patients are unclear. Therefore, this prospective observational study is aimed at demonstrating the optical coherence tomography angiography parameters that best correlate with mild visual impairment (<70 Early Treatment Diabetic Retinopathy Study (ETDRS) letters, Snellen equivalent 20/40) in DMI. The study was completed at the Moorfields Eye Hospital from December 2019 to August 2021. A total of 123 eyes of 87 patients with stable-treated proliferative diabetic retinopathy following panretinal photocoagulation were recruited. DMI was defined as an irregular foveal avascular zone (FAZ) area ≥ 0.5 mm2 or a smaller FAZ area with parafoveal capillary dropout in at least one quadrant. The analysis showed that the whole image deep vascular complex vessel density (DVC VD) in the 3 × 3 mm area had the best discriminatory ability to identify participants with mild visual impairment at 41.9% (area under the curve = 0.77, sensitivity 94%, specificity 54%, likelihood ratio [LR] = 2.04), and the FAZ area had the greatest post-test LR = 4.21 at 0.64 mm2. The 3 × 3 mm whole image DVC VD and FAZ area cutoffs are useful for screening vision-threatening DMI, but DVC VD has low specificity.

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.

Safety and Efficacy of Different Doses and Regimens of Faricimab vs Ranibizumab in Neovascular Age-Related Macular Degeneration: The AVENUE Phase 2 Randomized Clinical Trial

Question

What is the mean change in visual acuity in faricimab-treated participants with neovascular age-related macular degeneration across different treatment regimens compared with monthly ranibizumab through 36 weeks?

Findings

In this phase 2 randomized clinical trial, participants treated with faricimab every 4 or 8 weeks had a mean change in visual acuity that was neither superior nor inferior to that of participants receiving monthly ranibizumab. Faricimab showed no new or unexpected safety signals.

Meaning

These findings support pursuing faricimab in phase 3 trials as a potential alternative to monthly anti–vascular endothelial growth factor therapy.

Importance

Faricimab, the first bispecific antibody designed for intraocular use, simultaneously and independently binds and neutralizes angiopoietin 2 (Ang-2) and vascular endothelial growth factor A (VEGF-A).

Objective

To assess the efficacy and safety of different doses and regimens of faricimab vs ranibizumab in patients with neovascular age-related macular degeneration (nAMD).

Design, Setting, and Participants

AVENUE was a 36-week, multiple-dose–regimen, active comparator–controlled, double-masked, phase 2 randomized clinical study performed at 58 sites in the United States. Eligible participants were anti-VEGF treatment naive with choroidal neovascularization secondary to nAMD and best-corrected visual acuity (BCVA) Early Treatment Diabetic Retinopathy Study (ETDRS) letter score of 73 (Snellen equivalent, 20/40) to 24 (Snellen equivalent, 20/320). Data were collected from August 11, 2015, to January 12, 2017, with the final patient visit completed September 26, 2017. Data were analyzed from August 11, 2015, to October 4, 2019.

Interventions

Patients were randomized 3:2:2:2:3 to receive ranibizumab, 0.5 mg every 4 weeks (arm A [n = 68]); faricimab, 1.5 mg every 4 weeks (arm B [n = 47]); faricimab, 6.0 mg every 4 weeks (arm C [n = 42]); faricimab, 6.0 mg every 4 weeks until week 12, then faricimab, 6.0 mg every 8 weeks (arm D [n = 47]); and ranibizumab, 0.5 mg every 4 weeks until week 8, then faricimab, 6.0 mg every 4 weeks (arm E [n = 69]).

Main Outcomes and Measures

Mean change in BCVA from baseline to week 36, proportion of participants gaining at least 15 letters, BCVA of 20/40 or better or 20/200 or worse, and ocular coherence tomographic outcomes in anti-VEGF treatment-naive participants (arms A, B, C, D) and from weeks 12 to 36 in those with incomplete response (participants in arms A and E with week 12 BCVA ETDRS letter score of ≤68 [Snellen equivalent, 20/50 or worse]).

Results

A total of 263 participants were included in the analysis (172 [65.4%] female; 258 [98.1%] white; mean [SD] age, 78.3 [8.7] years). At week 36, adjusted mean change in BCVA vs ranibizumab was 1.6 (80% CI, −1.6 to 4.7) letters for arm B (P = .52), −1.6 (80% CI, −4.9 to 1.7) letters for arm C (P = .53), and −1.5 (80% CI, −4.6 to 1.6) letters for arm D (P = .53). For arm E, adjusted mean change from week 12 was –1.7 (80% CI, −3.8 to 0.4) letters (P = .30).

Conclusions and Relevance

AVENUE did not meet its primary end point of superiority of faricimab over ranibizumab in BCVA at week 36. Although not superior to monthly ranibizumab as given in this trial, overall visual and anatomical gains noted with faricimab support pursuing phase 3 trials for a potential alternative to monthly anti-VEGF therapy. Faricimab showed no new or unexpected safety signals.

Trial Registration

ClinicalTrials.gov Identifier: NCT02484690

Low Luminance Visual Acuity and Low Luminance Deficit in Choroideremia and RPGR-Associated Retinitis Pigmentosa

Introduction

Choroideremia and RPGR-associated retinitis pigmentosa (RP) are two distinct inherited rod-cone degenerations, where good visual acuity (VA) is maintained until late disease stages, limiting its usefulness as a disease marker. Low luminance VA and low luminance deficit (standard VA minus low luminance VA) may be more sensitive visual function measures.

Methods

Standard VA was obtained using Early Treatment Diabetic Retinopathy Study letter charts (Precision Vision, Bloomington, IL, USA). Low luminance VA was assessed using a 2.0-log unit neutral density filter, with the same chart setup, without formal dark adaptation. Mean central retinal sensitivity was assessed using MAIA microperimetry (Centervue SpA, Padova, Italy). Optical coherence tomography imaging was attained with Heidelberg Eye Explorer software (Heidelberg Engineering, Heidelberg, Germany).

Results

Twenty-four male participants with confirmed pathogenic RPGR mutations, 44 male participants with confirmed pathogenic CHM mutations, and 62 age-matched controls underwent clinical assessment prior to clinical trial recruitment. Low luminance VA was significantly reduced in both disease groups compared to controls. The low luminance deficit correlated with microperimetry retinal sensitivity and ellipsoid zone width. Eleven participants with moderate VA had poor low luminance VA (subsequently a large low luminance deficit), no detectable microperimetry sensitivity, and severely constricted ellipsoid zone widths.

Conclusions

Low luminance VA and subsequently low luminance deficit are useful markers of central macular visual function in both choroideremia and RPGR-associated RP, when standard VA is preserved.

Translational Relevance

Low luminance visual acuity and low luminance deficit are useful vision measures in two distinct rod-cone degenerations and may be useful in other retinal degenerations.

Low luminance visual acuity as a clinical measure and clinical trial outcome measure: a scoping review

PURPOSE

The measurement of standard visual acuity (VA) is the most well-known part of any ophthalmic examination to indicate visual function. Despite this, it is insensitive in detecting early disease changes. Therefore, other visual function tests have been developed including low luminance VA (LLVA) and low luminance deficit (LLD). This scoping literature review aims to summarise the current published applications of LLVA and LLD assessments to evaluate their utility as clinical markers and research outcome measures in a variety of ophthalmic conditions.

RECENT FINDINGS

Sixty-five peer-reviewed publications were included. LLVA was pioneered for use in geographic atrophy, a subtype of age-related macular degeneration, which remains the mainstay of its clinical application. However, other studies have reported additional useful applications in inherited retinal diseases including rare maculopathies and rod-cone dystrophies. Although there are some variations in testing methodology, use of the standard Early Treatment Diabetic Retinopathy Study (ETDRS) chart with a 2.0 log unit neutral density filter is the most popular approach. The optimal testing luminance is still to be defined.

SUMMARY

Overall, LLVA is an earlier clinical marker of change in central retinal function than standard VA. It has been shown to be a risk factor for disease progression and a better indicator of a patient's level of everyday visual function. It is inexpensive and simple to implement using readily available standard ophthalmic equipment.

Contrast sensitivity and binocular reading speed best correlating with near distance vision-related quality of life in bilateral nAMD

Purpose

Bilateral neovascular age‐related macular degeneration (nAMD) causes difficulties in daily life, especially with regard to near‐vision tasks, despite well preserved Early Treatment of Diabetic Retinopathy Study (ETDRS) best corrected visual acuity (BCVA) at distance. Therefore, alternative visual function measures were evaluated in terms of their correlation with vision‐related quality of life scores (QoL).

Methods

A prospective cross‐sectional pilot study including patients with a diagnosis of bilateral nAMD having lesions within the central 1 mm ETDRS grid subfield. Standardised testing included a vision‐related QoL assessment (NEI‐VFQ25), best corrected visual acuity (BCVA), low luminance visual acuity (LLVA), Radner maximum reading speed and Pelli‐Robson contrast sensitivity (CS).

Results

N = 54. The mean better eye (range) BCVA was 79 (55–96) letters, median (range) LLVA 79.5 (58–97) letters and median (range) CS 1.35 (0–1.65) log units. Mean binocular maximum reading speed was 117.33 ± 28.42 wpm. The best correlations with the near subscale score were found for CS followed by binocular maximum reading speed (r = 0.59, p = 0.0001; r = 0.36, p = 0.008, respectively). A weaker correlation was observed for the BCVA in the better eye (r = 0.33, p = 0.02). The correlation between the NEI‐VFQ25 distance subscale and BCVA was weaker (r = 0.37, p = 0.005) than the correlations with CS (r = 0.67, p = 0.0001) and LLVA (r = 0.40, p = 0.003).

Conclusions

For patients with a bilateral centre‐involving nAMD, the best correlation with near QoL was the better eye CS followed by maximum binocular reading speed. These measures could be valuable in quantifying vision‐related QoL outcomes in AMD clinical trials.

Treatment regimens for administration of anti-vascular endothelial growth factor agents for neovascular age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is one of the leading causes of permanent blindness worldwide. The current mainstay of treatment for neovascular AMD (nAMD) is intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) agents: aflibercept, ranibizumab, and off-label bevacizumab. Injections can be given monthly, every two or three months ('extended-fixed'), or as needed (pro re nata (PRN)). A variant of PRN is 'treat-and-extend' whereby injections are resumed if recurrence is detected and then delivered with increasing intervals. Currently, injection frequency varies among practitioners, which underscores the need to characterize an optimized approach to nAMD management.

OBJECTIVES

To investigate the effects of monthly versus non-monthly intravitreous injection of an anti-VEGF agent in people with newly diagnosed nAMD.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, LILACS, and three trials registers from 2004 to October 2019; checked references; handsearched conference abstracts; and contacted pharmaceutical companies to identify additional studies.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared different treatment regimens for anti-VEGF agents in people with newly diagnosed nAMD. We considered standard doses only (ranibizumab 0.5 mg, bevacizumab 1.25 mg, aflibercept 2.0 mg, or a combination of these).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods for trial selection, data extraction, and analysis.

MAIN RESULTS

We included 15 RCTs. The total number of participants was 7732, ranging from 37 to 2457 in each trial. The trials were conducted worldwide. Of these, six trials exclusively took place in the US, and three included centers from more than one country. Eight trials were at high risk of bias for at least one domain and all trials had at least one domain at unclear risk of bias. Seven trials (3525 participants) compared a PRN regimen with a monthly injection regimen, of which five trials delivered four to eight injections using standard PRN and three delivered nine or 10 injections using a treat-and-extend regimen in the first year. The overall mean change in best-corrected visual acuity (BCVA) at one year was +8.8 letters in the monthly injection group. Compared to the monthly injection, there was moderate-certainty evidence that the mean difference (MD) in BCVA change at one year for the standard PRN subgroup was -1.7 letters (95% confidence interval (CI) -2.8 to -0.6; 4 trials, 2299 participants), favoring monthly injections. There was low-certainty evidence of a similar BCVA change with the treat-and-extend subgroup (0.5 letters, 95% CI -3.1 to 4.2; 3 trials, 1226 participants). Compared to monthly injection, there was low-certainty evidence that fewer participants gained 15 or more lines of vision with standard PRN treatment at one year (risk ratio (RR) 0.87, 95% CI 0.76 to 0.99; 4 trials, 2299 participants) and low-certainty evidence of a similar gain with treat-and-extend versus monthly regimens (RR 1.11, 95% CI 0.91 to 1.36; 3 trials, 1169 participants). The mean change in central retinal thickness was a decrease of -166 μm in the monthly injection group; the MD compared with standard PRN was 21 μm (95% CI 6 to 32; 4 trials, 2215 participants; moderate-certainty evidence) and with treat-and extend was 22 μm (95% CI 37 to -81 μm; 2 trials, 635 participants; low-certainty evidence), in favor of monthly injection. Only one trial (498 participants) measured quality of life and reported no evidence of a difference between regimens, but data could not be extracted (low-certainty evidence). Both PRN regimens (standard and 'treat-and-extend') used fewer injections than monthly regimens (standard PRN: MD -4.6 injections, 95% CI -5.4 to -3.8; 4 trials, 2336 participants; treat-and-extend: -2.4 injections, 95% CI -2.7 to -2.1 injections; moderate-certainty evidence for both comparisons). Two trials provided cost data (1105 participants, trials conducted in the US and the UK). They found that cost differences between regimens were reduced if bevacizumab rather than aflibercept or ranibizumab were used, since bevacizumab was less costly (low-certainty evidence). PRN regimens were associated with a reduced risk of endophthalmitis compared with monthly injections (Peto odds ratio (OR) 0.13, 95% CI 0.04 to 0.46; 6 RCTs, 3175 participants; moderate-certainty evidence). Using data from all trials included in this review, we estimated the risk of endophthalmitis with monthly injections to be 8 in every 1000 people per year. The corresponding risk for people receiving PRN regimens was 1 in every 1000 people per year (95% CI 0 to 4). Three trials (1439 participants) compared an extended-fixed regimen (number of injections reported in only one large trial: 7.5 in one year) with monthly injections. There was moderate-certainty evidence that BCVA at one year was similar for extended-fixed and monthly injections (MD in BCVA change compared to extended-fixed group: -1.3 letters, 95% CI -3.9 to 1.3; RR of gaining 15 letters or more: 0.94, 95% CI 0.80 to 1.10). The change in central retinal thickness was a decrease of 137 μm in the monthly group; the MD with the extended-fixed group was 8 μm (95% CI -11 to 27; low-certainty evidence). The frequency of endophthalmitis was lower in the extended-fixed regimen compared to the monthly group, but this estimate was imprecise (RR 0.19, 95% CI 0.03 to 1.11; low-certainty evidence). If we assumed a risk of 8 cases of endophthalmitis in 1000 people receiving monthly injections over one year, then the corresponding risk with extended-fixed regimen was 2 in 1000 people (95% CI 0 to 9). Other evidence comparing different extended-fixed or PRN regimens yielded inconclusive results.

AUTHORS' CONCLUSIONS

We found that, at one year, monthly regimens are probably more effective than PRN regimens using seven or eight injections in the first year, but the difference is small and clinically insignificant. Endophthalmitis is probably more common with monthly injections and differences in costs between regimens are higher if aflibercept or ranibizumab are used compared to bevacizumab. This evidence only applies to settings in which regimens are implemented as described in the trials, whereas undertreatment is likely to be common in real-world settings. There are no data from RCTs on long-term effects of different treatment regimens.

Clinical pharmacology of intravitreal anti-VEGF drugs

Clinical efficacy of intravitreal anti-VEGF drugs has been widely demonstrated in several angiogenesis-driven eye diseases including diabetic macular edema and the neovascular form of age-related macular degeneration. Pegaptanib, ranibizumab, and aflibercept have been approved for use in the eye, whereas bevacizumab is widely used by ophthalmologists to treat patients "off-label". These drugs are active in the nanomolar to picomolar range; however, caution is required when establishing the rank order of affinity and potency due to in vitro inter-experimental variation. Despite the small doses used for eye diseases and the intravitreal route of administration may limit systemic side effects, these drugs can penetrate into blood circulation and alter systemic VEGF with unknown clinical consequences, particularly in vulnerable groups of patients. Clinical pharmacokinetics of ocular anti-VEGF agents should therefore be taken into account when choosing the right drug for the individual patient. The gaps in current understanding that leave open important questions are as follows: (i) uncertainty about which drug should be given first, (ii) how long these drugs can be used safely, and (iii) the choice of the best pharmacological strategy after first-line treatment failure. The current review article, based on the information published in peer-reviewed published papers relevant to anti-VEGF treatments and available on the PubMed database, describes in detail the clinical pharmacology of this class of drugs to provide a sound pharmacological basis for their proper use in ophthalmology clinical practice.