Hybrid deep learning models for the screening of Diabetic Macular Edema in optical coherence tomography volumes.

Several studies published so far used highly selective image datasets from unclear sources to train computer vision models and that may lead to overestimated results, while those studies conducted in real-life remain scarce. To avoid image selection bias, we stacked convolutional and recurrent neural networks (CNN-RNN) to analyze complete optical coherence tomography (OCT) cubes in a row and predict diabetic macular edema (DME), in a real-world diabetic retinopathy screening program. A retrospective cohort study was carried out. Throughout 4-years, 5314 OCT cubes from 4408 subjects who attended to the diabetic retinopathy (DR) screening program were included. We arranged twenty-two (22) pre-trained CNNs in parallel with a bidirectional RNN layer stacked at the bottom, allowing the model to make a prediction for the whole OCT cube. The staff of retina experts built a ground truth of DME later used to train a set of these CNN-RNN models with different configurations. For each trained CNN-RNN model, we performed threshold tuning to find the optimal cut-off point for binary classification of DME. Finally, the best models were selected according to sensitivity, specificity, and area under the receiver operating characteristics curve (AUROC) with their 95% confidence intervals (95%CI). An ensemble of the best models was also explored. 5188 cubes were non-DME and 126 were DME. Three models achieved an AUROC of 0.94. Among these, sensitivity, and specificity (95%CI) ranged from 84.1-90.5 and 89.7-93.3, respectively, at threshold 1, from 89.7-92.1 and 80-83.1 at threshold 2, and from 80.2-81 and 93.8-97, at threshold 3. The ensemble model improved these results, and lower specificity was observed among subjects with sight-threatening DR. Analysis by age, gender, or grade of DME did not vary the performance of the models. CNN-RNN models showed high diagnostic accuracy for detecting DME in a real-world setting. This engine allowed us to detect extra-foveal DMEs commonly overlooked in other studies, and showed potential for application as the first filter of non-referable patients in an outpatient center within a population-based DR screening program, otherwise ended up in specialized care.

Initial response and 12-month outcomes after commencing dexamethasone or vascular endothelial growth factor inhibitors for retinal vein occlusion in the FRB registry.

To compare baseline characteristics, initial response and 12-month efficacy and safety outcomes in eyes with branch and central retinal vein occlusion (BRVO and CRVO) treated with dexamethasone implants (DEX) or anti-vascular endothelial growth factor (anti-VEGF) we performed a multi-centre, retrospective and observational study using Fight Retinal Blindness! Registry. Of 725 eligible eyes, 10% received DEX initially with very frequent adjunctive anti-VEGF (BRVO-DEX 49%, CRVO-DEX 60%). The primary outcome of mean adjusted change in VA at 12 months with DEX and anti-VEGF initiated groups were not statistically significantly different (BRVO: DEX + 6.7, anti-VEGF + 10.6 letters; CRVO: DEX + 2.8, anti-VEGF + 6.8 letters). DEX initiated eyes had fewer injections and visits than anti-VEGF initiated eyes. The BRVO-DEX eyes had greater initial mean changes in VA and central subfield thickness (CST) and achieved inactivity sooner than BRVO-anti-VEGF eyes. The mean CST after the first three months was above 350 µm in all but the BRVO-anti-VEGF group, suggesting undertreatment. In routine care DEX is uncommonly used when available as initial treatment of BRVO and CRVO requiring supplemental anti-VEGF within the first year. The 12-month outcomes were similar, but DEX initiated eyes had fewer injections and visits but more episodes of raised IOP Vs those starting anti-VEGF.

Quantitative Microvascular Change Analysis Using a Semi-Automated Software in Macula-off Rhegmatogenous Retinal Detachment Assessed by Swept-Source Optical Coherence Tomography Angiography.

Objective: To analyze the performance of custom semi-automated software for quantitative analysis of retinal capillaries in eyes with macula-off rhegmatogenous retinal detachment (RRD) and the role of these microvascular measures as potential biomarkers of postoperative visual outcomes. Methods: A prospective, observational, and single-center study was conducted on consecutive patients who underwent 25G pars-plana vitrectomy for primary uncomplicated macula-off RRD. Optical coherence tomography angiography (OCTA) was performed in the fellow and RRD eyes before surgery and in months 1, 3, and 6 after surgery. The preoperative values of the fellow eyes were used as surrogates of macula-off ones. The primary endpoints were the mean vessel diameter index (VDI); vessel area density (VAD); and vessel skeleton density (VSD) at month 6. Results: Forty-four eyes (44 patients) were included in the study. Considering the fellow eyes as a surrogate of preoperative values of macula-off eyes, VDI in superficial (SCP) and deep (DCP) capillary plexuses was significantly reduced at month 6 (p = 0.0087 and p = 0.0402, respectively); whereas VSD in SCP increased significantly from preoperative values (p = 0.0278). OCTA built-in software parameters were significantly reduced from month 1 to month 6 in both SCP and DCP (p values ranged between 0.0235 and <0.0001). At month 6, 25 (56.8%) eyes achieved a best-corrected visual acuity BCVA ≥ 0.3 (LogMAR). The greater the preoperative BCVA, the greater the probability of achieving good visual outcomes (Odds ratio: 11.06; p = 0.0037). However, none of the OCTA parameters were associated with the probability of achieving a BCVA improvement ≥ 0.3. Conclusions: Quantitative evaluation of capillary density and morphology through OCTA and semi-automated software represents a valuable tool for clinical assessment and managing the disease comprehensively.

Correction: Díaz-Aljaro et al. Quantitative Microvascular Change Analysis Using a Semi-Automated Algorithm in Macula-on Rhegmatogenous Retinal Detachment Assessed by Swept-Source Optical Coherence Tomography Angiography. Diagnostics 2024, 14, 750.

In the original publication [...].

Quantitative Microvascular Change Analysis Using a Semi-Automated Algorithm in Macula-on Rhegmatogenous Retinal Detachment Assessed by Swept-Source Optical Coherence Tomography Angiography.

PURPOSE: The purpose of this study was to objectively evaluate the longitudinal changes observed in the retinal capillaries in eyes with macula-on rhegmatogenous retinal detachment (RRD), assessed with optical coherence tomography angiography (OCTA), and to assess the role of these microvascular measures as potential biomarkers of postoperative visual outcomes. METHODS: This was a prospective, longitudinal study conducted on consecutive patients who underwent 25 G pars plana vitrectomy for primary RRD. The vessel area density (VAD), vessel skeleton density (VSD), and vessel diameter index (VDI) were assessed in the superficial (SCP) and deep (DCP) capillary plexuses. RESULTS: Twenty-three eyes with macula-on RRD were included in the study. The mean preoperative VDI, VAD, and VSD of the RRD eye were 18.6 ± 1.1, 0.43 ± 0.02, and 0.17 ± 0.01 in the SCP; and 18.6 ± 0.6, 0.38 ± 0.03, and 0.15 ± 0.01 in the DCP, respectively. At month 6, eight (34.8%) eyes achieved a best-corrected visual acuity (BCVA) gain ≥ 0.1 LogMAR. A preoperative VDI > 17.80, VSD > 0.170, and VDI-change > -0.395 in the SCP; and VDI > 18.11 and VDI change > -0.039 in the DCP were predictors of achieving a BCVA-gain ≥ 0.1 LogMAR. CONCLUSIONS: The preoperative VDI in SCP and DCP, the preoperative VSD in SCP, and their changes from preoperative values were predictors of visual outcomes. A quantitative OCTA analysis of capillary density and morphology may represent a potential predictive tool for surgical outcomes in RRD. The results reported in this study suggest that OCTA is a useful ancillary test for clinical disease management.

Three-Year Outcomes of VEGF Inhibitors in Naive Branch Retinal Vein Occlusion: Fight Retinal Blindness!

PURPOSE: To evaluate the 3-year outcomes of VEGF inhibitors in the treatment of cystoid macular edema due to branch retinal vein occlusion (BRVO) in an international multicenter cohort of eyes. DESIGN: Multicenter, international, BRVO database study. SUBJECTS: Seven hundred forty-seven patients (760 eyes) undergoing intravitreal therapy for BRVO for 3 years in a multicenter international setting. METHODS: Demographics, visual acuity (VA) in logarithm of the minimum angle of resolution letters, central subfield thickness (CST), treatments, number of injections, and visits data was collected using a validated web-based tool. MAIN OUTCOME MEASURES: Visual acuity gain at 3 years in logarithm of the minimum angle of resolution letters. Secondary outcome measures included anatomical results, treatment pattern, and percentage of completers. A subgroup analysis by study drug was conducted for clinical outcomes. RESULTS: Mean adjusted VA change was +11 letters (95% confidence interval 9-13), mean adjusted change in CST was -176 µm (-193, -159). Median number of injections/visits was 16 of 24 at 3 years of follow-up. Most eyes received VEGF inhibitors exclusively (89%, n = 677) and as a monotherapy in 71% (n = 538). Few eyes were switched to steroids (11%, n = 83). Suspensions in treatment >180 days occurred in 26% of study eyes. Aflibercept showed greater CST reductions (-147 vs. -128 vs. -114 µm; P < 0.001) and significantly lower switching rates (14% vs. 38% vs. 33%; P < 0.001) compared with ranibizumab and bevacizumab, respectively. CONCLUSIONS: This international study of 3-year BRVO outcomes after starting treatment with VEGF inhibitors found adequate visual and anatomical results in routine clinical care. Visual outcomes were similar among the different initiating VEGF inhibitors, although eyes starting with aflibercept had better anatomical outcomes and a lower switching rate. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

European Unmet Needs in the Management of Neovascular Age-Related Macular Degeneration in Daily Practice: Data from the Fight Retinal Blindness! Registry.

PURPOSE: To evaluate the proportion, predictors, and outcomes of patients with neovascular age-related macular degeneration (nAMD) treated with a high burden of VEGF inhibitor intravitreal (IVT) injections after 2 years in routine clinical practice. DESIGN: Retrospective analysis of data from a prospectively designed observational outcomes registry, the Fight Retinal Blindness! Project, of patients treated in European centers. PARTICIPANTS: Treatment-naïve eyes (1 eye per patient) starting VEGF inhibitors for nAMD from January 2017 to March 2020 with 24 months of follow-up. We analyzed the following 3 treatment-burden groups defined by the mean interval of the 3 closest injections to the 24-month visit: (1) those with a high-treatment burden had injection intervals ≤ 42 days, (2) those with a low-treatment burden had injection intervals between 43 and 83 days; and (3) those with tolerable treatment burden had injection intervals between 84 and 365 days. METHODS: Multinomial regression was used to evaluate baseline risk predictors of patients requiring a high-treatment burden. MAIN OUTCOME MEASURES: The proportion of patients that experienced a high-treatment burden at 2 years and its predictors. RESULTS: We identified 2038 eligible patients completing 2 years of treatment (2038/3943 patients [60%]) with a median (quartile 1, quartile 3) of 13 (10, 17) injections. The proportion of patients with a high-treatment burden was 25% (516 patients) at 2 years. Younger patients (odds ratio [OR], 0.97; 95% confidence interval [CI], 0.96-0.99; P < 0.01) were more likely to have high-treatment burden, whereas eyes with type 3 choroidal neovascular lesions at baseline were significantly less likely (OR, 0.26; 95% CI, 0.13-0.52; P < 0.01). Regarding type of fluid, patients with subretinal fluid only at baseline (OR, 3.85; 95% CI, 1.34-11.01; P = 0.01) and persistent active intraretinal (OR, 1.56; 95% CI, 1.18-2.06; P < 0.01) or subretinal fluid only (OR, 2.21; 95% CI, 1.52-3.21; P < 0.01) after the loading phase had a higher risk of high treatment burden at 2 years. CONCLUSIONS: High treatment burden is a common issue in routine clinical practice in Europe, with a quarter of patients requiring injections of conventional VEGF inhibitors every 6 weeks at 2 years and 40% discontinuing treatment within 2 years. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Retinal vessel volume reference database derived from volume-rendered optical coherence tomography angiography.

Optical coherence tomography angiography (OCTA) enables three-dimensional reconstruction of the functional blood vessels in the retina. Therefore, it enables the quantification of 3D retinal vessel parameters such as surface area and vessel volume. In spite of the widespread use of OCTA, no representative volume-rendered vessel volume (VV) data are published to date. In this study, OCTA 3 × 3 mm macular cubes were processed with volume-rendering techniques to measure VV in 203 eyes from 107 healthy volunteers. Generalized linear models (GLM) were constructed to assess the impact of age, gender, visual acuity (VA), spherical equivalent (SE), and axial length (AL) on VV. Overall mean VV was 0.23 ± 0.05mm3. Age and axial length showed a negative correlation with VV. However, GLM model analysis found that AL exerted the most pronounced influence on VV. No statistically significant associations were identified between gender or between left and right eyes. This is the first study to assess 3D OCTA VV and its naturally occurring variations in a large series of healthy subjects. It offers novel insights into the characterization of normal retinal vascular anatomy in healthy individuals, contributing to a valuable reference for future research in this field.

C-reactive protein-complement factor H axis as a biomarker of activity in early and intermediate age-related macular degeneration.

Purpose: To determine and compare the serum levels of complement Factor H (FH), monomeric C-Reactive Protein (mCRP) and pentameric C-Reactive protein (pCRP) in patients with age-related macular degeneration (AMD) and to correlate them with clinical, structural and functional parameters. Methods: Cross-sectional observational study. One hundred thirty-nine individuals (88 patients and 51 healthy controls) from two referral centers were included and classified into three groups: early or intermediate AMD (n=33), advanced AMD (n=55), and age and sex matched healthy controls (n=51). Serum levels of FH, mCRP, and pCRP were determined and correlated with clinical and imaging parameters. Results: Patients with intermediate AMD presented FH levels significantly lower than controls [186.5 (72.1-931.8) µg/mL vs 415.2 (106.1-1962.2) µg/mL; p=0.039] and FH levels <200 µg/mL were associated with the presence of drusen and pigmentary changes in the fundoscopy (p=0.002). While no differences were observed in pCRP and mCRP levels, and mCRP was only detected in less than 15% of the included participants, women had a significantly higher detection rate of mCRP than men (21.0% vs. 3.8%, p=0.045). In addition, the ratio mCRP/FH (log) was significantly lower in the control group compared to intermediate AMD (p=0.031). Visual acuity (p<0.001), macular volume (p<0.001), and foveal thickness (p=0.034) were significantly lower in the advanced AMD group, and choroidal thickness was significantly lower in advanced AMD compared to early/intermediate AMD (p=0.023). Conclusion: Intermediate AMD was associated in our cohort with decreased serum FH levels together with increased serum mCRP/FH ratio. All these objective serum biomarkers may suggest an underlying systemic inflammatory process in early/intermediate AMD patients.