Predictors of persistent disease activity following anti-VEGF loading dose for nAMD patients in Singapore: the DIALS study

Factors Affecting Disease Stability After Intravitreal Brolucizumab Injection for Refractory Neovascular Age-Related Macular Degeneration

INTRODUCTION

The purpose of this study is to identify the factors affecting neovascular age-related macular degeneration (nAMD) disease stability after brolucizumab treatment.

METHODS

We retrospectively analyzed the medical records of 31 patients (31 eyes) with recalcitrant nAMD who were switched to brolucizumab after conventional anti-vascular endothelial growth factor (VEGF) treatment. We divided patients into two groups by treatment extension (TE) period: group 1 with TE < 12 weeks (N = 16) and group 2 with TE ≥ 12 weeks (N = 15). We compared outcomes between the groups at 2, 4, 8, and 12 weeks, including morphological characteristics of choroidal neovascularization (CNV). Logistic regression analysis identified factors associated with TE ≥ 12 weeks.

RESULTS

Group 2 had a significantly greater proportion of patients with dry macula (subretinal and intraretinal fluids absent) than group 1 (60 vs. 12.5%) at 2 weeks (P < 0.05). Best-corrected visual acuity (BCVA) and subfoveal choroidal thickness (SFCT) did not differ significantly between groups at all timepoints. Central subfield retinal thickness (CST) was significantly lower in group 2 at 2 (237.1 vs. 280.8 μm; P < 0.05), 4 (224.0 vs. 262.9 μm; P < 0.05), and 8 weeks (216.8 vs. 331.1 μm; P < 0.05). Group 2 had less vessel area (0.63 vs. 1.27 mm2; P < 0.05) and total vessel length (0.22 vs. 0.42 mm; P < 0.05). Choriocapillaris flow deficit (CCFd) was significantly lower in group 2 (42.7 vs. 48.2%; P < 0.05). Dry macula at 2 weeks (odds ratio [OR] = 8.3; P < 0.05) and a lower CCFd (OR = 0.73; P < 0.05) were associated with TE ≥ 12 weeks.

CONCLUSIONS

Early fluid-free status after switching to brolucizumab and choriocapillary function around CNV were prognostic factors for disease stability in nAMD refractory to anti-VEGF treatment.

Efficacy of Aflibercept as initial treatment for neovascular age-related macular degeneration in an Iraqi patient sample

Age-related macular degeneration (AMD) is a progressive degenerative eye disorder that primarily affects individuals over 50. It causes gradual loss of central vision and can lead to irreversible severe visual loss if left untreated. AMD is a leading cause of blindness in the developed world. This study aimed to investigate the effects of a loading dosage of intravitreal Aflibercept on functional and morphological responses in neovascular AMD, considering demographic characteristics and the link between AMD-related retinal symptoms at presentations. A prospective interventional study was conducted from November 2021 to September 2022 on a sample of Iraqi patients with neovascular AMD who had active choroidal neovascularization (CNV) lesions confirmed by OCT-A and received intravitreal Aflibercept 2mg injection as initial therapy (3 loading doses). Best-corrected visual acuity (BCVA) was used to measure functional responses, and central macular thickness (CMT) and maximum area of the retinal thickness (MART) (by SD-OCT) were used to measure morphological responses. The study included 48 patients (57 eyes) with active neovascular AMD. The mean difference of BCVA in log MAR (0.2 ± 0.7) significantly improved from 1.3±0.7 at baseline to 1.1±0.8 after loading Aflibercept (P=0.034). The mean difference in CMT 113.6 ± 125.9 was statistically significant (P<0.0001). Also, the mean change in MART significantly decreased from 444.2 ± 127.1 µm at baseline to 348.7±74.5 µm (p < 0.0001) after loading Aflibercept. This study demonstrated that Aflibercept is a functionally and anatomically successful treatment for neovascular AMD.

Automatic quantification of retinal photoreceptor integrity to predict persistent disease activity in neovascular age-related macular degeneration using deep learning

Purpose

Using deep learning (DL)-based technique, we identify risk factors and create a prediction model for refractory neovascular age-related macular degeneration (nAMD) characterized by persistent disease activity (PDA) in spectral domain optical coherence tomography (SD-OCT) images.

Materials and methods

A total of 671 typical B-scans were collected from 186 eyes of 186 patients with nAMD. Spectral domain optical coherence tomography images were analyzed using a classification convolutional neural network (CNN) and a fully convolutional network (FCN) algorithm to extract six features involved in nAMD, including ellipsoid zone (EZ), external limiting membrane (ELM), intraretinal fluid (IRF), subretinal fluid (SRF), pigment epithelium detachment (PED), and subretinal hyperreflective material (SHRM). Random forest models were probed to predict 1-year disease activity (stable, PDA, and cured) based on the quantitative features computed from automated segmentation and evaluated with cross-validation.

Results

The algorithm to segment six SD-OCT features achieved the mean accuracy of 0.930 (95% CI: 0.916–0.943), dice coefficients of 0.873 (95% CI: 0.847–0.899), a sensitivity of 0.873 (95% CI: 0.844–0.910), and a specificity of 0.922 (95% CI: 0.905–0.940). The six-metric model including EZ and ELM achieved the optimal performance to predict 1-year disease activity, with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.980, the accuracy of 0.930, the sensitivity of 0.920, and the specificity of 0.962. The integrity of EZ and ELM significantly improved the performance of the six-metric model than that of the four-metric model.

Conclusion

The prediction model reveals the potential to predict PDA in nAMD eyes. The integrity of EZ and ELM constituted the strongest predictive factor for PDA in nAMD eyes in real-world clinical practice. The results of this study are a significant step toward image-guided prediction of long-term disease activity in the management of nAMD and highlight the importance of the automatic identification of photoreceptor layers.