EVALUATION OF MACULAR ISCHEMIA IN EYES WITH CENTRAL RETINAL VEIN OCCLUSION: An Optical Coherence Tomography Angiography Study

Multimodal imaging to distinguish microvascular and morphological changes in retinal vein occlusion after intravitreal ranibizumab with or without triamcinolone acetonide injection

BACKGROUND

The study was designed to investigate microvascular and morphological changes in retinal vein occlusion (RVO) using multimodal imaging after intravitreal ranibizumab (IVR) with or without triamcinolone acetonide (IVTA) injections.

METHODS

This was a retrospective and observational study. Fifty patients (52 eyes) diagnosed with RVO were enrolled. Best corrected visual acuity (BCVA), ophthalmoscopy, fundus fluorescein angiography (FFA), spectral domain optical coherence tomography (SDOCT), and optical coherence tomography angiography (OCTA) were employed sequentially both before treatment and at the last visit after treatment.

RESULTS

The mean logMAR VAs in BRVO eyes decreased significantly after treatment (P = 0.029). OCTA showed there was a significant difference in foveal avascular zone (FAZ) in BRVO eyes (P = 0.024), superificial foveal vessel density in both CRVO (P = 0.0004) and BRVO eyes (P = 0.02155). OCT showed the foveal thickness had significant differences after treatment in both CRVO (P < 0.0001) and BRVO eyes (P = 0.0001). BCVA was associated most commonly with ellipsoid zone integrity (P = 0.022). The BCVA in eyes treated with IVR and IVTA was significantly decreased compared with IVR only in BRVO group (P = 0.021). However, the combination of IVR + IVTA significantly improved intraocular pressure (IOP) compared with IVR only in BRVO group (P = 0.037).

CONCLUSION

Both IVR and IVR + IVTA can significantly improve the central vision, macular structure, and functions in BRVO group. Simultaneous IVR with IVTA can significantly increase BCVA compared with IVR only in BRVO group.

Foveal Thickness Fluctuations in Anti-VEGF Treatment for Central Retinal Vein Occlusion

Purpose

The aim of this study was to examine the effects of foveal thickness (FT) fluctuation (FTF) on 2-year visual and morphological outcomes of eyes with central retinal vein occlusion (CRVO) undergoing anti-VEGF treatment for recurrent macular edema (ME) based on a pro re nata regimen.

Design

Retrospective, observational case series.

Participants

We analyzed 141 treatment-naive patients (141 eyes) with CRVO-ME at a multicenter retinal practice.

Methods

We assessed FT using OCT at each study visit. Patients were divided into groups 0, 1, 2, and 3 according to increasing FTF.

Main Outcome Measures

We evaluated the logarithm of the minimal angle of resolution (logMAR) best-corrected visual acuity (BCVA), the length of the foveal ellipsoid zone (EZ) band defect measured using OCT, and the association of FTF with VA and EZ band defect length.

Results

The mean baseline logMAR BCVA and FT were 0.65 ± 0.52 (Snellen equivalent range: 20/20-20/2000) and 661.1 ± 257.4 μm, respectively. The mean number of anti-VEGF injections administered was 5.6 ± 3.6. At the final examination, the mean logMAR BCVA and FT values were significantly improved relative to the baseline values (both P < 0.01). During the observation, BCVA longitudinally improved in Groups 0 and 1, remained unchanged in Group 2, and worsened in Group 3. Likewise, the length of the foveal EZ band defect did not increase in Group 0; however, it gradually increased in Groups 1, 2, and 3. Foveal thickness fluctuation was significantly and positively associated with the logMAR BCVA and length of the foveal EZ band defect at the final examination (P < 0.01). The final logMAR BCVA of patients developing neovascular complications was 1.27 ± 0.72 (Snellen equivalent range: 20/50-counting fingers), which was significantly poorer than that of patients without complications (P < 0.001). There was no significant difference in the neovascular complication rate among the FTF groups (P = 0.106, Fisher exact test).

Conclusions

In eyes receiving anti-VEGF treatment for CRVO-ME, FTF can longitudinally impair the visual acuity and foveal photoreceptor status during the observation period, thus influencing the final outcomes. However, neovascular complications, which would also lead to a poor visual prognosis, may not be associated with FTF.

Financial Disclosures

The authors have no proprietary or commercial interest in any materials discussed in this article.

Severe Macular Ischemia Is Associated with a Poor Visual Prognosis and Serious Complications in Eyes with Central Retinal Vein Occlusion

PURPOSE

This study aims to investigate the factors influencing post-treatment visual acuity (VA) in patients with central retinal vein occlusion (CRVO) with macular edema (ME).

METHODS

The subjects of this study were patients who visited our clinic from May 2013 to July 2019 and who could be followed up with for at least 12 months. Cases with hemi CRVO were excluded from this study. Factors considered in the evaluation of visual prognosis at the 12 months included initial best-corrected VA, central subfoveal thickness, CRVO subtype (nonischemic, ischemic, or converted from nonischemic to ischemic), time taken for the first treatment, number of anti-vascular endothelial growth factor agent injections, structural changes in the inner and outer retinal layers, and the presence of macular ischemia in a multiple regression analysis.

RESULTS

There were 41 patients with 41 eyes, 27 males and 14 females. The mean age of the patients was 70.5 ± 12.2 (mean ± standard deviation) years. The mean VA was 0.544 ± 0.576, 0.456 ± 0.568, and 0.586 ± 0.665 at the initial visit, 12 months later, and time of last observation, respectively. There were no significant differences in VAs observed between the baseline, month 12, and final visit. Multiple regression analysis revealed that the external limiting membrane score at month 12 (p = 0.030), the VA at initial visit (p < 0.001), and the presence of severe macular ischemia (p < 0.001) were the key factors associated with VA at month 12. Moreover, severe macular ischemia was identified as the only factor affecting decimal VA less than 20/200 at the last observation (p = 0.0092).

CONCLUSIONS

Severe macular ischemia is strongly linked to a poor visual prognosis in patients with ME associated with CRVO.

The influence of retinal oxygen saturation and choroidal volume on postoperative outcomes in patients with epiretinal membrane

Purpose

To investigate the effects of vitrectomy (Vy) with or without same time cataract surgery and membrane plus internal limiting membrane peeling (MP+ILMP) on retinal oxygenation and choroidal volume and their role on postoperative outcome.

Methods

Thirty‐two eyes were included in this prospective clinical study. All patients received 23 gauge Vy+MP+ILMP without endotamponade. Additional cataract surgery was performed in 14 patients. Follow‐up visits were scheduled at day 1, week 1, month 1 and month 3. At each visit, best corrected visual acuity (BCVA) using ETDRS charts (except at day 1), oxygenation of retinal vessels using the Oxymap T1, and optical coherence tomography (OCT, Heidelberg Spectralis) was performed.

Results

Mean BCVA increased significantly from 73 ± 11 letters to 77 ± 7 letters at month 3 (p = 0.02). Mean central retinal thickness (CRT) decreased from 456 ± 84 µm at baseline to 418±58µm (p = 0.01 baseline versus month 3). In the cataract surgery group, CRT was higher at month 3 than in the group without (400 ± 58 µm versus 441 ± 51 µm; p = 0.007). There was no statistically significant difference in choroidal volume or oxygenation of retinal vessels between groups (additional cataract surgery versus vitrectomy alone). Oxygenation of retinal arteries tended to decrease at day 1 followed by an increase, but the changes did not reach the level of significance (p = 0.29 baseline versus month 3). Oxygenation of retinal veins increased significantly (p = 0.02 baseline versus month 1; p = 0.04 baseline versus month 3, accordingly). There was a significant negative correlation (Spearman correlation coefficient rs = −0.35, p = 0.047) between visual acuity and oxygenation of retinal veins at month 3. No statistically significant correlation was found between CRT and oxygenation of neither retinal arteries nor veins. Choroidal volume (CV) of the central mm did not change significantly during the study period (baseline: 0.203 ± 0.04 mm³, median: 0.206, month 3: 0.205 ± 0.04 mm³, p = 0.54). There was no statistically significant effect of choroidal volume at baseline on postoperative clinical outcomes (change in BCVA estimate [95% CI]: 7 [−76; 90], p = 0.86; change in CRT: 147 [−577; 871], p = 0.68).

Conclusion

Oxygen saturation may affect the visual acuity outcome but not the CRT in patients after vitrectomy for epiretinal membrane. Choroidal thickness had no statistically significant influence on the study outcomes. Further studies are needed to evaluate if the measurement of retinal oxygenation may be helpful in the decision for surgery.

Foveal Thickness Fluctuation in Anti-vascular Endothelial Growth Factor Treatment for Branch Retinal Vein Occlusion: A Long-term Study

OBJECTIVE OR PURPOSE

Branch retinal vein occlusion (BRVO) causes macular edema (ME) that can be controlled with anti-vascular endothelial growth factor (VEGF) treatments. However, these treatments are not curative, necessitating additional anti-VEGF treatments at recurrences. Long-term results, optimal anti-VEGF treatment regimens, and the comprehensive effects of ME recurrences are largely unknown. Thus, we aimed to examine the effects of foveal thickness (FT) fluctuation (FTF) on visual and morphologic outcomes following anti-VEGF treatments for BRVO-ME administered via a pro re nata regimen.

DESIGN

A retrospective, observational case series SUBJECTS, PARTICIPANTS AND/OR CONTROLS: This study analyzed 309 treatment-naïve patients (309 eyes) with BRVO-ME between 2012 and 2021 at a multi-center retinal practice.

METHODS, INTERVENTION, OR TESTING

FT was assessed via optical coherence tomography (OCT) at each study visit.

MAIN OUTCOME MEASURES

We evaluated the logarithm of the minimal angle of resolution best corrected visual acuity (logMAR BCVA) and the defect length of the foveal ellipsoid zone (EZ) band measured via OCT.

RESULTS

At baseline, the mean logMAR BCVA was 0.30±0.30 and the mean FT was 503±162 μm. The number of anti-VEGF injections for BRVO-ME was 5.8±4.6 during the mean follow-up period (50.6±22.2 months). At the final examination, the mean logMAR BCVA and FT values were significantly improved compared with the baseline. Multiple regression analyses showed that age, baseline logMAR BCVA, and FTF were significantly associated with the final logMAR BCVA (β=0.20, 0.35, and 0.30, respectively). FTF (divided into Groups 0-3 in ascending order of FTF) was significantly associated with the logMAR BCVA and the defect length of the foveal EZ band at the final examination. The defect lengths of the foveal EZ band were longitudinally shortened in Groups 0-1 and were slightly prolonged in Groups 2-3. The logMAR BCVA maintained improvements in Groups 0-1, and worsened slightly in Groups 2-3.

CONCLUSIONS

FTF was significantly associated with visual acuity and foveal photoreceptor status. Thus, may improve the morphologic and functional prognoses of eyes with BRVO by identifying the characteristics of eyes with a larger FTF, and consequently controlling the FTF more strictly.

Multimodal Imaging Characterization of Arteriolosclerotic Plaques in Retinal Vein Occlusion

BACKGROUND AND OBJECTIVES

To investigate the multimodal imaging features and the clinical associations of arteriolosclerotic plaques in patients with retinal vein occlusion (RVO).

MATERIALS AND METHODS

This was a retrospective case series of patients with RVO. Demographic and clinical characteristics were recorded at the time of RVO for each participant. Best-corrected visual acuity and central macular thickness were collected at baseline and observed for 1 year. Arteriolosclerotic plaques were identified on multimodal imaging, and their imaging features were summarized. Differences in demographic and clinical characteristics between eyes with arteriolosclerotic plaques and those with no arteriolosclerotic plaques were reported.

RESULTS

Seventy-five eyes of 75 patients (39 males; mean age, 72.5 years) were included. Arteriolosclerotic plaques were identified in nine eyes (12%) as segmental, yellow, ill-defined creamy lesions in the arterioles' walls. Baseline macular edema was worse in eyes with arteriolosclerotic plaques than in eyes with no plaques (716.5 μm vs 539.7 μm). Arteriolosclerotic plaques did not interfere with blood flow and regressed in three eyes (33%). Eyes with plaques had worse best-corrected visual acuity (P < .001) and lower central macular thickness (P = .02) at 12 months than did eyes with RVO and no plaques.

CONCLUSIONS

Arteriolosclerotic plaques suggest an ischemic or inflammatory involvement of the arteriolar branches in eyes with RVO and are associated with severe macular damage. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:650-657.].

Microvascular Structure Changes After Intravitreal Ranibizumab Injection in Retinal Vein Occlusion Patients With and Without Macular Ischemia

Purpose: To investigate the changes in the macular microvascular structure after anti-vascular endothelial growth factor (anti-VEGF) treatment in retinal vein occlusion (RVO) patients with and without macular ischemia.

Methods: A total of 39 patients were divided into the macular ischemia group (n = 22) and the nonischemia group (n = 17) at baseline. All the patients received an intravitreal injection of ranibizumab with a 3+ pro re nata (PRN) regimen. The foveal avascular zone (FAZ) areas, macular vessel density (VD), and macular ischemic index (ISI) were evaluated at baseline and 3 and 6 months after treatment.

Results: After treatment, some patients in the macular ischemia group achieved obvious reperfusion in macular nonperfusion areas. The VD and macular ISI improved in RVO patients, but the changes in VD and macular ISI were different in the two groups. The improvement of best corrected visual acuity (BCVA) was positively correlated with the improvement of macular perfusion status. Macular perfusion remained stable in most patients in RVO and only one patient had macular ischemia aggravation.

Conclusion: The macular microvascular structures were stable in most RVO patients after anti-VEGF treatment. At the same time, some patients with macular ischemia presented reperfusion in macular nonperfusion areas, and still a few patients presented aggravated macular ischemia. Macular ISI is a good way to evaluate macular perfusion status in RVO compared to VD.

Outcomes of eyes with retinal vein occlusion that are lost to follow-up after antivascular endothelial growth factor therapy

BACKGROUND/AIMS

To evaluate the outcomes of eyes with macular oedema due to retinal vein occlusion (RVO) that are lost to follow-up (LTFU) after antivascular endothelial growth factor (VEGF) injections.

METHOD

A retrospective, single-centre, consecutive case series of RVO patients receiving injections who were LTFU >6 months was conducted. Data were collected from the visit before LTFU; return visit; 3 months, 6 months and 12 months after return; and the final visit.

RESULTS

Ninety eyes of 83 patients were included. Fifty (55.5%) eyes had branch RVO and 40 (44.5%) had central RVO. Mean LTFU duration was 277.8 days with additional mean follow-up for 748.1 days after return. Mean logarithm of the minimum angle of resolution visual acuity (VA) (Snellen) at the visit before LTFU was 0.72 (20/105) which worsened on return [1.04 (20/219), p<0.001) and remained worse at all timepoints after return: 0.92 (20/166) at 3 months (p<0.001), 0.97 (20/187) at 6 months (p<0.001), 0.94 (20/174) at 12 months (p<0.001) and 1.01 (20/205) at final visit (p<0.001). Mean central foveal thickness (CFT) increased from 252 µm at the visit before LTFU to 396 µm at the return visit (p<0.001). No difference in CFT was noted by 3 months (258 µm, p=0.71), 6 months (241 µm, p=0.54) or 12 months after return (250 µm, p=0.95). CFT was thinner at the final visit (215 µm, p=0.018).

CONCLUSION

RVO patients receiving anti-VEGF injections who were LTFU experienced a decline in VA that did not return to the levels seen before LTFU despite improvement in CFT after restarting therapy, underscoring the importance of ongoing treatment.

Assessing the Use of Incorrectly Scaled Optical Coherence Tomography Angiography Images in Peer-Reviewed Studies: A Systematic Review

Importance

Individual differences in axial length affect the lateral magnification of in vivo retinal images and as a result can affect the accuracy of quantitative measurements made from these images. As measurements from optical coherence tomography angiography (OCTA) images are becoming increasingly used in the diagnosis and monitoring of a wide range of diseases, evaluating which studies use correctly scaled images is crucial to their interpretation.

Objective

To perform a systematic literature review to assess the percentage of articles that report correcting the scale of their OCTA images for individual differences in retinal magnification.

Evidence Review

A PubMed (MEDLINE) search was conducted for articles on OCTA retinal imaging published between June 1, 2015, and June 1, 2018. Initial results included 7552 articles. Initial exclusion criteria removed studies of animal models, as well as reviews, letters, replies, comments, and image-based or photographic essays. Articles not written in English and those that required purchase from non-English language websites were excluded. Articles that did not use OCTA for imaging the retina were also excluded. Remaining articles were reviewed in detail to assess whether the OCTA measurements required correct lateral scaling, and if so, whether axial length was reported or used to scale the images. We also determined the number of articles that mentioned the lack of correct lateral scaling as a limitation of the study.

Findings

A total of 989 articles were included in the detailed review. Of these, 509 were determined to require correct image scaling for their analyses, but only 41 (8.0%) report measuring and using axial length to correct the lateral scale of their OCTA images. Furthermore, of the 468 articles that did not correctly scale their images, only 18 (3.8%) mentioned this as a limitation to their study.

Conclusions and Relevance

These findings suggest that most peer-reviewed articles in PubMed that use quantitative OCTA measurements use incorrectly scaled images. This could call into question the conclusions of such studies and warrants consideration by OCTA manufacturers, physicians, authors, journal reviewers, and journal editors.

Anatomic-Functional Correlates in Lesions of Retinal Vein Occlusion

Purpose

To evaluate anatomic–functional associations at sites of retinal lesions in retinal vein occlusion (RVO).

Methods

This pilot, prospective, observational study was conducted at the Northern Ireland Clinical Research Facility (NICRF) of Queen's University and the Belfast Health and Social Care Trust, Northern Ireland, between August 1, 2018, and September 30, 2019. The study included 10 treatment-naïve patients with RVO (10 RVO eyes and 10 fellow eyes). There were 81 points/sites assessed for each eye at baseline; six patients were re-assessed 6 months after anti-vascular endothelial growth factor therapy at the same locations. We investigated associations between retinal sensitivity and presence of structural RVO lesions, including retinal ischemia, hemorrhages, intraretinal fluid (IRF) and subretinal fluid outside the foveal/parafoveal regions. Comparisons were made between RVO eyes and fellow eyes at baseline, and between RVO eyes at baseline and at 6 months after treatment. Regression models were used to investigate anatomic–functional associations.

Results

At baseline, strong associations were found between reduced retinal sensitivity and presence of ischemia (estimate = −2.08 dB; P < 0.001), intraretinal fluid (estimate = −7.82 dB; P < 0.001), and subretinal fluid (estimate = −8.66 dB; P < 0.001). Resolution of subretinal fluid but not intraretinal fluid was associated with improved function (estimate = 2.40 dB [P = 0.022]; estimate = 1.16 dB [P = 0.228], respectively). However, reperfusion of ischemic retina, observed in 31 of 486 points (6%) 6 months after anti-vascular endothelial growth factor therapy, was associated with a further decrease in retinal sensitivity (estimate = −2.34 dB; P = 0.035).

Conclusions

Retinal sensitivity was decreased at sites of RVO lesions. Decreased function at sites of retinal ischemia did not recover after treatment, even when reperfusion occurred.

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.

Non-dipping pattern of nocturnal blood pressure as a risk factor for macular ischemia in branch retinal vein occlusion

Branch retinal vein occlusion (BRVO) is ocular vascular disease affecting approximately 14 million people worldwide, and is closely associated with high blood pressure (BP). Although macular ischemia is a critical factor in the visual prognosis of BRVO, the relationship between macular ischemia and different patterns of nocturnal BP is unknown. Here, we investigated whether a dipping pattern of nocturnal BP is associated with the development of macular ischemia in patients with BRVO. A total of 273 patients were reviewed; of these, 86 (86 eyes) patients were included. All recruited patients had a macular thickness map by optical coherence tomography and underwent 24-h ambulatory BP monitoring. According to their dipping patterns, the participants were divided into dipper and non-dipper groups. The non-dipper group had worse visual outcomes at the initial and 6-month visits (P = 0.014 and P = 0.003, respectively). Five of 32 eyes (15.6%) in the dipper group and 32 of 54 (59.3%) in the non-dipper group had macular ischemia. In a multivariate analysis, the night-to-day systolic BP ratio was associated with the degree of macular ischemia (β = − 0.313, P = 0.004). Thus, a non-dipping pattern may be a risk factor for macular ischemia in patients with BRVO.

Structural and Functional Imaging of the Retina in Central Retinal Artery Occlusion - Current Approaches and Future Directions

Central retinal artery occlusion (CRAO) is a form of acute ischemic stroke which affects the retina. Intravenous thrombolysis is emerging as a compelling therapeutic approach. However, it is not known which patients may benefit from this therapy because there are no imaging modalities that adequately distinguish viable retina from irreversibly infarcted retina. The inner retina receives arterial supply from the central retinal artery and there is robust collateralization between this circulation and the outer retinal circulation, provided by the posterior ciliary circulation. Fundus photography can show canonical changes associated with CRAO including a cherry-red spot, arteriolar boxcarring and retinal pallor. Fluorescein angiography provides 2-dimensional imaging of the retinal circulation and can distinguish a complete from a partial CRAO as well as central versus peripheral retinal non-perfusion. Transorbital ultrasonography may assay flow through the central retinal artery and is useful in the exclusion of other orbital pathology that can mimic CRAO. Optical coherence tomography provides structural information on the different layers of the retina and exploratory work has described its utility in determining the time since onset of ischemia. Two experimental techniques are discussed. 1) Retinal functional imaging permits generation of capillary perfusion maps and can assay retinal oxygenation and blood flow velocity. 2) Photoacoustic imaging combines the principles of optical excitation and ultrasonic detection and - in animal studies - has been used to determine the retinal oxygen metabolic rate. Future techniques to determine retinal viability in clinical practice will require rapid, easily used, and reproducible methods that can be deployed in the emergency setting.

ASSESSING THE ABILITY OF PREOPERATIVE QUANTITATIVE SPECTRAL-DOMAIN OPTICAL COHERENCE TOMOGRAPHY CHARACTERISTICS TO PREDICT VISUAL OUTCOME IN IDIOPATHIC MACULAR HOLE SURGERY

PURPOSE

To determine which spectral domain optical coherence tomography biomarkers of idiopathic macular hole (MH) correlate with the postoperative best-corrected visual acuity (BCVA) in anatomically closed MH.

METHODS

Retrospective analysis of spectral domain optical coherence tomography scans of 44 patients presenting with MH followed for a mean of 17 months. Widths of MH aperture, base, and ellipsoid zone disruption were calculated from presenting foveal spectral domain optical coherence tomography B-scans. Macular hole base area and ellipsoid zone disruption area were calculated through the custom in-house software.

RESULTS

Poorer postoperative BCVA correlated with increased preoperative choroidal hypertransmission (r = 0.503, P = 0.0005), minimum diameter (r = 0.491, P = 0.0007), and base diameter (r = 0.319, P = 0.0348), but not with preoperative ellipsoid zone width (r = 0.199, P = 0.2001). Applying en-face analysis, the BCVA correlated weakly with preoperative ellipsoid zone loss area (r = 0.380, P = 0.013), but not with preoperative MH base area (r = 0.253, P = 0.1058).

CONCLUSION

Increased MH minimum diameter, base diameter, base area, and choroidal hypertransmission are correlated with a poorer postoperative BCVA. Ellipsoid zone loss measurements were not consistently correlated with a BCVA. Choroidal hypertransmission width may be an easy-to-visualize predictive imaging biomarker in MH surgery.

Factors associated with extremely poor visual outcomes in patients with central retinal vein occlusion

Here, we examined prognostic factors for extremely poor visual outcomes in patients with central retinal vein occlusion (CRVO) in actual practices. We included 150 consecutive eyes with treatment-naïve acute CRVO from four different facilities and observed them for over 24 months. Macular edema (ME) was treated with one or three monthly anti-vascular endothelial growth factor injections (1 or 3 + pro re nata). According to the final Snellen visual acuity (VA), we divided the patients into very poor VA (< 20/200) and control (≥ 20/200) groups and examined risk factors for poor final visual outcomes. The baseline Snellen VA was hand motion to 20/13. The mean number of anti-VEGF injections for ME was 5.3 ± 3.7 during the follow-up period. In total, 49 (32.7%) patients exhibited a very poor final VA; this group comprised significantly older patients with a significantly poorer baseline VA (P < 0.01 for both) than the control group. Comorbid internal carotid artery disease and diabetic retinopathy were significantly associated with a poor final VA. In actual clinical practice, visual outcomes may be extremely poor despite ME treatment in certain patients with CRVO, with advanced age, poor baseline VA, and comorbid internal carotid artery disease and diabetic retinopathy being significant risk factors.

Identification of microvascular and morphological alterations in eyes with central retinal non-perfusion

Purpose

To evaluate the characteristics and morphological alterations in central retinal ischemia caused by diabetic retinopathy (DR) or retinal vein occlusion (RVO) as seen in optical coherence tomography angiography (OCTA) and their relationship to visual acuity.

Methods

Swept-source optical coherence tomography (SSOCT) and OCTA (Topcon, Triton) data of patients with central involving retinal ischemia were analyzed in this cross-sectional study. The following parameters were evaluated: vessel parameters, foveal avascular zone (FAZ), intraretinal cysts (IRC), microaneurysms (MA), vascular collaterals in the superficial (SCP) and deep plexuses (DCP), hyperreflective foci (HRF), epiretinal membrane (ERM), external limiting membrane (ELM) and ellipsoid zone (EZ) disruption, as well as the disorganization of retinal inner layers (DRIL). Best-corrected visual acuity (BCVA), age, gender, disease duration and ocular history were also recorded.

Results

44 eyes of 44 patients (22 with RVO, 22 with DR) were analyzed. The mean age was 60.55 ± 11.38 years and mean BCVA 0.86 ± 0.36 (Snellen, 6m). No significant difference was found between DR subgroups (non proliferative vs. proliferative). Between RVO subgroups (CRVO vs. BRVO) a significant difference was found in term of collateral vessel of the DCP (p = 0.014). A pooled DR and RVO group were created and compared. Significantly more MAs (p = 0.007) and ERM (p = 0.007) were found in the DR group. Statistically significant negative correlation was demonstrated between FAZ and BCVA (p = 0.45) when analyzing all patients with retinal ischemia.

Conclusion

This study has shown that the best predictor of visual outcome in center involved ischemic diseases is the size of FAZ. Besides the presence of MAs and ERM, all other OCT and OCTA parameters were present in a similar extent in DR and RVO group despite the completely different disease origins. Our results suggest that as soon as retinal ischemia in the macular region is present, it has a similar appearance and visual outcome independently of the underlying disease.

Angiographic Risk Features of Branch Retinal Vein Occlusion Onset as Determined by Optical Coherence Tomography Angiography

Purpose

Examine associations between the vasculature at arteriovenous (AV) crossings and the onset of branch retinal vein occlusion (BRVO).

Methods

We included 78 patients with major BRVO, 35 patients with macular BRVO, and 110 controls without BRVO and determined the vessel positions at AV crossings, where the first- or second-order branches of the retinal veins associate, using a viewing angle of 12 × 12 mm² in optical coherence tomography angiography (OCTA).

Results

We reviewed 1349 and 1276 AV crossings in BRVO patients and control subjects, respectively. The proportions of venous overcrossing were 26.5%, 28.6%, and 26.8% at non-causative crossings in BRVO eyes, non-BRVO fellow eyes, and unaffected control eyes, respectively; however, the rate of venous overcrossings at the causative crossings was 45.1%. In OCTA analyses, we divided the branches into macular- or non-macular veins. The rate of venous overcrossing was 52.5% at causative crossings in major BRVO but was 28.6% in macular BRVO. Odds ratios for whether venous overcrossing was a risk factor for BRVO were 3.09 (95% confidence interval [CI], 1.96–4.88) and 0.94 (95% CI, 0.44–2.00) for non-macular veins and macular veins, respectively. The patients with major BRVO caused by venous overcrossing were younger than patients for whom the cause was arterial overcrossing (P < 0.001). The onset of macular BRVO did not differ between crossing patterns at causative crossings (P = 0.60).

Conclusions

In eyes with BRVO, venous overcrossing was a common angiographic feature at causative crossings and might be a risk factor for major BRVO onset.

Use of OCTA Capillary Perfusion Density Measurements to Detect and Grade Macular Ischemia

BACKGROUND AND OBJECTIVE

To compare optical coherence tomography angiography (OCTA) capillary perfusion density (CPD) measurements of normal eyes and eyes with macular ischemia (MI).

PATIENTS AND METHODS

AVATAR is an institutional review board-approved, prospective, observational imaging study using the Avanti RTVue XR HD. OCTA reports were reviewed for the presence of MI. Qualitative MI grading was performed, and CPD metrics in the superficial and deep fovea and parafovea were analyzed. A normal eye cohort was identified for comparative assessment.

RESULTS

The MI and normal cohorts included 55 and 58 eyes, respectively. Compared to normal eyes, eyes with MI had significantly lower CPD values in all regions. There was a statistically significant correlation between qualitative MI grade and VA in the superficial (P = .003) and deep plexuses (P = .029). Only deep parafoveal CPD values demonstrated correlation with VA (P = .043).

CONCLUSIONS

Eyes with MI determined by masked qualitative OCTA grading demonstrated significantly reduced CPD values compared to normal eyes. Categorical assessment of MI severity correlated with VA. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:S30-S36.].

Guidelines for the Management of Retinal Vein Occlusion by the European Society of Retina Specialists (EURETINA)

The high prevalence of cardiovascular disease particularly in the elderly population is associated with retinal vascular disease. Retinal vein occlusions represent severe disturbances of the hypoxia-sensitive neurosensory retina. Acute and excessive leakage leads to the diagnostic hallmarks of retinal hemorrhage and edema with substantial retinal thickening. Advanced diagnostic tools such as OCT angiography allow to evaluate retinal ischemia and identify the risk for late complications and will soon reach clinical routine besides fluorescein angiography. Accordingly, the duration of non-perfusion is a crucial prognostic factor requiring timely therapeutic intervention. With immediate inhibition of vascular leakage, anti-VEGF substances excel as treatment of choice. Multiple clinical trials with optimal potential for functional benefit or a lesser regenerative spectrum have evaluated aflibercept, ranibizumab, and bevacizumab. As retinal vein occlusion is a chronic disease, long-term monitoring should be individualized to combine maintenance with practicability. While steroids may be considered in patients with systemic cardiovascular risk, surgery remains advisable only for very few patients. Destructive laser treatment is an option if reliable monitoring is not feasible. Ophthalmologists are also advised to perform a basic systemic workup to recognize systemic concomitants. The current edition of the EURETINA guidelines highlights the state-of-the-art recommendations based on the literature and expert opinions in retinal vein occlusion.

Arteriovenous crossing associated with branch retinal vein occlusion

Branch retinal vein occlusion (BRVO) is defined as the focal occlusion of a first or second-order branch of retinal vein, which occurs most frequently at an arteriovenous (AV) crossing. Direct ophthalmoscopy, color fundus photography, and fluorescein angiography facilitate observation of AV crossings parallel to the retinal plane. Optical coherence tomography (OCT), with its high-depth resolution, enables observation of retinal lesions perpendicular to the retinal plane. OCT angiography (OCTA) provides depth-resolved images of the retinal vasculature by segmenting three-dimensional data. In this review, we discuss novel findings related to affected AV crossings associated with BRVO obtained via OCT and OCTA. The high-depth resolution of OCT or OCTA is useful for observation of the narrowed vein and determination of the vessel position of the affected AV crossing. Studies using OCT and OCTA have shown that BRVO caused by a venous overcrossing is more prevalent than previously reported, and that venous narrowing was significantly greater in instances caused by a venous overcrossing than in those caused by an arterial overcrossing. Moreover, OCTA also revealed that the retinal nonperfusion area size was larger in eyes with BRVO caused by a venous overcrossing than in those with BRVO caused by an arterial overcrossing. This contrasts with earlier findings obtained by conventional imaging modalities predating OCT, which showed that an arterial overcrossing was more common than a venous overcrossing at the causative venous occlusion site in eyes with BRVO. This review discusses these findings and their significance in the study of AV crossing associated with BRVO.

Changes in Retinal Microvasculature and Visual Acuity After Antivascular Endothelial Growth Factor Therapy in Retinal Vein Occlusion

Purpose

To investigate the changes in the retinal microvasculature during the course of anti-VEGF therapy in eyes with macular edema due to retinal vein occlusion (RVO) and their association with visual outcomes.

Methods

The vessel density (VD) and foveal avascular zone (FAZ) area in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were quantitatively measured by optical coherence tomography angiography (OCTA) in 48 consecutive eyes with RVO before and 1, 3, 6, 9, and 12 months after anti-VEGF therapy. Anti-VEGF therapy was performed either with ranibizumab or aflibercept following a pro re nata (PRN) regimen. The correlation between post-treatment best-corrected visual acuity (BCVA) and changes in the retinal microvasculature evaluated by OCTA were assessed.

Results

The BCVA improved significantly at 12 months (P < 0.001). Better BCVA at 12 months was significantly associated with a better VD in the SCP and DCP both at baseline (R2 = 0.524, P < 0.001 and R2 = 0.457, P < 0.001, respectively) and at 12 months (R2 = 0.521, P < 0.001 and R2 = 0.662, P < 0.001, respectively). Overall, both VD and FAZ did not change significantly during the 12 months. However, the progression of nonperfusion was observed in the SCP in 6 (13%) eyes and in the DCP in 10 (21%) eyes. The number of macular edema recurrence was significantly associated with a decrease in the VD (P = 0.006 [SCP] and P < 0.001 [DCP]) and less visual gain (P = 0.02) after treatment.

Conclusions

Anti-VEGF therapy maintains retinal perfusion in most patients with RVO. Preserving retinal perfusion is crucial for better visual outcomes.

OCT Angiography: A Technique for the Assessment of Retinal and Optic Nerve Diseases in the Pediatric Population

Optical coherence tomography angiography (OCT-A) is a novel, rapidly evolving, non-invasive imaging technique that allows images of the retinal vasculature to be obtained in a few seconds. Blood vessels of different retinal vascular plexuses and the foveal avascular zone (FAZ) can be examined without the administration of any contrast or dye. Due to these characteristics, OCT-A could be an excellent complementary test to study retinal vascularization in children. Until now, most of the studies with OCT-A have been conducted in adults and only a few have been carried out in children. In this review, we describe the principles and advantages of OCT-A over traditional imaging methods and provide a summary of the OCT-A findings in retinopathy of prematurity and other retinal and optic disc pathologies in children. In view of the promising results from studies, the advantages of a relatively rapid and non-invasive method to assess the retinal vasculature makes OCT-A a tool of which applications in the field of pediatric ophthalmology will be expanded in the near future for patient diagnosis and follow-up in every day clinical practice.

Advances in Retinal Optical Imaging

Retinal imaging has undergone a revolution in the past 50 years to allow for better understanding of the eye in health and disease. Significant improvements have occurred both in hardware such as lasers and optics in addition to software image analysis. Optical imaging modalities include optical coherence tomography (OCT), OCT angiography (OCTA), photoacoustic microscopy (PAM), scanning laser ophthalmoscopy (SLO), adaptive optics (AO), fundus autofluorescence (FAF), and molecular imaging (MI). These imaging modalities have enabled improved visualization of retinal pathophysiology and have had a substantial impact on basic and translational medical research. These improvements in technology have translated into early disease detection, more accurate diagnosis, and improved management of numerous chorioretinal diseases. This article summarizes recent advances and applications of retinal optical imaging techniques, discusses current clinical challenges, and predicts future directions in retinal optical imaging.