Prediction of post-treatment retinal sensitivity by baseline retinal perfusion density measurements in eyes with branch retinal vein occlusion

Visual Acuity and Retinal Thickness and Sensitivity after Intravitreal Ranibizumab Injection for Macular Edema in Branch Retinal Vein Occlusion

Background/Objectives: To investigate changes in visual acuity and retinal sensitivity and thickness after intravitreal ranibizumab injection (IRI) for macular edema in branch retinal vein occlusion (BRVO) patients. Methods: This study evaluated 34 patients with treatment-naïve BRVO and at least 6 months' follow-up after pro re nata IRI. Best-corrected visual acuity (BCVA) was determined as the logarithm of the minimum angle of resolution (logMAR). In nine retinal regions, retinal sensitivity was calculated by MP-3 microperimetry; and in nine macular subfields, retinal thickness was measured by optical coherence tomography (OCT); evaluations were performed before IRI and then monthly for 6 months. Results: IRI significantly improved visual acuity and retinal sensitivity and thickness. In patients with good improvement in BCVA (change in logMAR > 0.2), IRI significantly improved retinal sensitivity in eight of nine regions, i.e., in all except the outer non-occluded region, and in patients with poor improvement in BCVA (change in logMAR < 0.2), in six of nine regions, i.e., not in the inner, outer non-occluded, and outer temporal regions. We found significant differences in the trend profile in the foveal, outer occluded, and inner nasal regions between patients with good and poor improvement in BCVA. Conclusions: The findings suggest that IRI improves visual acuity and retinal sensitivity and thickness and that retinal effects may vary between patients with good and poor visual improvement.

Caspase-9 inhibition confers stronger neuronal and vascular protection compared to VEGF neutralization in a mouse model of retinal vein occlusion

Purpose

Retinal vein occlusion (RVO) is a sight-threatening condition typically treated with intravitreal injection of vascular endothelial growth factor (VEGF) antagonists. Treatment response to anti-VEGF therapies is highly variable, with poor visual outcomes and treatment response in patients with significant retinal nonperfusion following RVO. Recently, caspase-9 has been identified as a potent regulator of edema, gliosis, and neuronal dysfunction during acute retinal hypoxia. The purpose of this study was to compare the therapeutic effect of caspase-9 inhibition against VEGF-neutralization in an established mouse model of RVO.

Methods

Adult male C57Bl/6 J mice were randomized to induction of RVO and treatment with either vehicle, intravitreal injection of anti-VEGF antibody, topical administration of a selective caspase-9 inhibitor (Pen1-XBir3), or a combination therapy. Animals were followed on days 1, 2, and 8 after RVO with fundus retinal imaging, and with optical coherence tomography (OCT) to capture retinal swelling, capillary nonperfusion (measured by disorganization of retinal inner layers, DRIL), hyperreflective foci (HRF), and retinal atrophy. Focal electroretinography (ERG) measurements were performed on day 7. Histology was performed on retinal sections from day 8.

Results

Both VEGF neutralization and caspase-9 inhibition showed significant retinal protection from RVO compared to vehicle treatment arm. Retinal reperfusion of occluded veins was accelerated in eyes receiving caspase-9 inhibitor, but not significantly different from vehicle in the anti-VEGF group. Retinal edema was suppressed in all treatment groups, with approximately 2-fold greater edema reduction with caspase-9 inhibition compared to VEGF neutralization. HRF were reduced similarly across all treatment groups compared to vehicle. Retinal detachment was reduced only in eyes treated with caspase-9 inhibitor monotherapy. Caspase-9 inhibition reduced retinal atrophy and preserved ERG response; VEGF neutralization did not prevent neurodegeneration following RVO.

Conclusion

Caspase-9 inhibition confers stronger neuronal and vascular protection compared to VEGF neutralization in the mouse laser-induced model of RVO.

Two-Week Central Macular Thickness Reduction Rate >37% Predicts the Long-Term Efficacy of Anti-vascular Endothelial Growth Factor Treatment for Macular Edema Secondary to Retinal Vein Occlusion

Objective

To determine if the early response assessments can predict the long-term efficacy of anti-vascular endothelial growth factor (VEGF) treatment for macular edema secondary to retinal vein occlusion (RVO-ME).

Methods

A retrospective study of patients with diagnosis of RVO-ME and intravitreal anti-VEGF treatment was conducted. Clinical characteristics including age, gender, disease subtype and disease duration were recorded at baseline. The best corrected visual acuity (BCVA and logMAR), intraocular pressure (IOP), and central macular thickness (CMT) were recorded at baseline, 2 weeks, and every month (months 1–6) after injection. Further, we compared the early response assessments between the cured group (6-month CMT ≤ 250 μm) and the uncured group (6-month CMT &gt; 250 μm).

Results

A total of 164 eyes in 164 patients (77 male and 87 female) were included. At each post-injection time point, both BCVA and CMT are significantly decreased from baseline (all P &lt; 0.001). Spearman’s test showed that 2-week CMT reduction rate after the first injection was negatively correlated with BCVA at 6 months (r = −0.359, P &lt; 0.001). Compared with the uncured group (47 cases), the cured group (117 cases) was younger (59.53 ± 11.68 vs. 65.19 ± 13.10 years old, P &lt; 0.01), had more BRVO patients (76.1% vs. 44.7%, P &lt; 0.01), a shorter disease duration (1.92 ± 2.43 vs. 5.05 ± 4.32 months, P &lt; 0.01), lower baseline CMT (527.09 ± 154.95 vs. 768.96 ± 287.75 μm, P &lt; 0.01), and lower baseline BCVA (0.86 ± 0.44 vs. 1.31 ± 0.51, P &lt; 0.01). At each post-injection time point, the cured group had lower CMT and BCVA values when compared to the uncured group (all P &lt; 0.01), and the 2-week CMT reduction rate was identified as the earliest response time to predict the long-term treatment efficacy. Moreover, ROC curve analysis indicated that a 2-week CMT reduction rate &gt;37% yielded the best cut-off point for predicting the long-term cure of anti-VEGF treatment at 6 months (P &lt; 0.001). Multivariable logistic regression confirmed that the 2-week CMT reduction rate &gt;37% was independently associated with the 6-month cured rate (OR = 9.639, 95% Cl = 1.030–90.227, P = 0.047).

Conclusion

Age, disease duration, baseline CMT, and baseline BCVA are associated with visual outcomes at 6-month of anti-VEGF treatment for RVO-ME. The “2-week CMT reduction rate &gt;37%” after the first injection is an independent factor to predict better long-term outcomes.

Macular Ischemia Quantification Using Deep-Learning Denoised Optical Coherence Tomography Angiography in Branch Retinal Vein Occlusion

Purpose

To examine whether deep-learning denoised optical coherence tomography angiography (OCTA) images could enhance automated macular ischemia quantification in branch retinal vein occlusion (BRVO).

Methods

This retrospective, single-center, cross-sectional study enrolled 74 patients with BRVO and 46 age-matched healthy subjects. The severity of macular ischemia was graded as mild, moderate, or severe. Denoised OCTA images were produced using a neural network model. Quantitative parameters derived from denoised images, including vessel density and nonperfusion area, were compared with those derived from the OCTA machine. The main outcome measures were correlations between quantitative parameters, and areas under receiver operating characteristic curves (AUCs) in classifying the severity of the macular ischemia.

Results

The vessel density and nonperfusion area from denoised images were correlated strongly with the corresponding parameters from machine-derived images in control eyes and BRVO eyes with mild or moderate macular ischemia (all P < 0.001). However, no such correlation was found in eyes with severe macular ischemia. The vessel density and nonperfusion area from denoised images had significantly larger area under receiver operating characteristic curve than those derived from the original images in classifying moderate versus severe macular ischemia (0.927 vs 0.802 [P = 0.042] and 0.946 vs 0.797, [P = 0.022], respectively). There were no significant differences in the areas under receiver operating characteristic curve between the denoised images and the machine-derived parameters in classifying control versus BRVO, and mild versus moderate macular ischemia.

Conclusions

A neural network model is useful for removing speckle noise on OCTA images and facilitating the automated grading of macular ischemia in eyes with BRVO.

Translational Relevance

Deep-learning denoised optical coherence tomography angiography images could enhance automated macular ischemia quantification.