The impact of structural optical coherence tomography changes on visual function in retinal vein occlusion

Prevalence and Distribution of Macular Fluid with Central Retinal Artery Occlusion and Anterior Ischemic Optic Neuropathy

Purpose

To examine the prevalence and distribution of fluid within a cohort of eyes with acute central retinal artery occlusion (CRAO) and non-arteritic anterior ischemic optic neuropathy (AION) using optical coherence tomography (OCT).

Methods

A retrospective analysis of patient records and OCT imaging. Patients presenting with acute CRAO or AION who had available macular OCT imaging and no co-morbidities known to cause macular fluid were included in the analysis. Baseline characteristics, visual acuity (VA), and fluid presence and distribution among the retinal layers were recorded.

Results

In the 16 eyes with acute CRAO, fluid was noted in 5 eyes (31%), which was mainly subretinal (3 eyes) or intraretinal located within the outer retinal layers (3 eyes). Only one eye had inner retinal cysts. Of the 11 eyes with acute AION, fluid was present in 8 eyes (73%). Subretinal fluid was noted in 4 eyes and extended to the foveal area in 3 of them, and outer retinal versus inner retinal cysts were noted in 6 versus 3 eyes, respectively. None of the eyes showed hard exudate deposition. In the small subset of eyes with CRAO and macular fluid that were followed-up, VA improved, while in eyes with AION, VA remained stable.

Conclusion

Macular fluid on OCT is not an uncommon feature of acute CRAO and AION and is mainly distributed within the outer retinal layers or subretinal space. Fluid is an understudied feature of retinal and optic nerve head infarction and may have a role in predicting neuronal damage extent and visual outcome.

Rate and associations of inner retinal thinning in eyes with retinal vein occlusion and regressed macular oedema

PURPOSE

To investigate the associations between visual acuity (VA) and structural optical coherence tomography (OCT) features in retinal vein occlusion (RVO) eyes after cystoid macular oedema (CMO) regression and to assess whether inner retinal thinning is progressive.

METHODS

Retrospective observational study of RVO eyes with regressed CMO for at least 6 months. OCT scans at CMO regression were analysed, and features were correlated with VA at that visit. The inner retinal thickness was longitudinally compared between RVO and unaffected fellow eyes (controls) with linear mixed models. The rate of inner retinal thinning was obtained as the interaction term between disease status and time. Associations between inner retinal thinning and clinical characteristics were explored.

RESULTS

Thirty-six RVO eyes were followed for 34.2 ± 21.1 months after CMO regression. The presence of ellipsoid zone disruption (regression estimate[standard error(SE)] = 0.16[0.04] LogMAR vs. intact, p < 0.001) and lower inner retinal thickness (regression estimate[SE] = -0.25[0.12] LogMAR for 100-μm increase, p = 0.01) were associated with worse VA. The inner retinal thickness decreased faster in RVO than controls (rate of retinal thinning -0.27 ± 0.09 μm/month vs. -0.08 ± 0.11 μm/month, p = 0.01). Macular ischaemia was associated with a faster rate of retinal thinning (interaction term macular ischaemia*follow-up time, p = 0.04).

CONCLUSION

Inner retinal and photoreceptors' layers integrity are associated with better visual acuity once CMO resolves. RVO eyes undergo progressive inner retinal thinning after CMO regression, faster in eyes with macular ischaemia.

Long-Term Outcomes in Early versus Limited Response to Anti-VEGF Treatment for Retinal Vein Occlusion

OBJECTIVE

Macular edema secondary to retinal vein occlusion (RVO) is a sight-threatening condition. Previous studies showed that early responders (ERs) who respond well to anti-VEGF injections within 3 months of treatment have better outcomes, as measured by best visual acuity (BVA) and central subfield thickness (CST) at 12 months postinjection initiation compared with limited early responders (LERs). This study analyzed whether ER eyes continue to respond better than LER eyes over longer periods. This study also aimed to identify baseline comorbidities associated with response status.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Patients aged > 18 years with RVO-related macular edema treated with anti-VEGF injections.

METHODS

Patients were categorized as ERs or LERs. Limited early responder eyes were defined as having CST reduction < 10%, BVA gain < 5 ETDRS letters, or both at 3 months after anti-VEGF initiation. Best visual acuity and CST changes over the 24- and 36-month period after the first anti-VEGF treatment were compared between ERs and LERs. Patient characteristics and systemic comorbidities were identified by chart review. Statistical analysis involved the Levene test, Welch t test, and Welch analysis of variance.

MAIN OUTCOME MEASURES

Best visual acuity and CST changes over the initial 24-month and 36-month periods after treatment.

RESULTS

The 24-month cohort included 68 ERs and 39 LERs, and the 36-month cohort included 58 ERs and 33 LERs. At the 24-month time point, there were significant differences in BVA and CST gains between ERs (+19.8 letters, -221.2 um) and LERs (-2.4 letters, -90.1 um; P < 0.001, P < 0.01). Similarly, at 36 months, there were significant differences in BVA and CST gains between ERs (+17.7 letters, -229.3 um) and LERs (+1.3 letters, -128 um; P < 0.001, P < 0.05). After controlling for differences in baseline BVA and CST, only the 24-month change in BVA remained significant (P < 0.001). There were no significant associations between response status and cardiopulmonary, endocrine, and oncologic comorbidities.

CONCLUSIONS

Early responder eyes with branched retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO) have better functional responses to anti-VEGF injections at 24 months compared with LER eyes, even after controlling for baseline differences. Early identification of eyes as ERs or LERs in BRVO and CRVO may predict long-term functional prognoses.

FINANCIAL DISCLOSURE(S)

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

A systematic evaluation of human expert agreement on optical coherence tomography biomarkers using multiple devices

OBJECTIVES

To assess the agreement in evaluating optical coherence tomography (OCT) variables in the leading macular diseases such as neovascular age-related macular degeneration (nAMD), diabetic macular oedema (DMO) and retinal vein occlusion (RVO) among OCT-certified graders.

METHODS

SD-OCT volume scans of 356 eyes were graded by seven graders. The grading included presence of intra- and subretinal fluid (IRF, SRF), pigment epithelial detachment (PED), epiretinal membrane (ERM), conditions of the vitreomacular interface (VMI), central retinal thickness (CRT) at the foveal centre-point (CP) and central millimetre (CMM), as well as height and location of IRF/SRF/PED. Kappa statistics (κ) and intraclass correlation coefficient (ICC) were used to report categorical grading and measurement agreement.

RESULTS

The overall agreement on the presence of IRF/SRF/PED was κ = 0.82/0.85/0.81; κ of VMI condition was 0.77, that of ERM presence 0.37. ICC for CRT measurements at CP and CMM was excellent with an ICC of 1.00. Height measurements of IRF/SRF/PED showed robust consistency with ICC = 0.85-0.93. There was substantial to almost perfect agreement in locating IRF/SRF/PED with κ = 0.67-0.86. Between diseases, κ of IRF/SRF presence was 0.69/0.80 for nAMD, 0.64/0.83 for DMO and 0.86/0.89 for RVO.

CONCLUSION

Even in the optimized setting, featuring certified graders, standardized image acquisition and the use of a professional reading platform, there is a disease dependent variability in biomarker evaluation that is most pronounced for IRF in nAMD as well as DMO. Our findings highlight the variability in the performance of human expert OCT grading and the need for AI-based automated feature analyses.

[Biomarkers in the treatment of retinal vein occlusion]

BACKGROUND

Retinal vein occlusion, subdivided into central retinal and branch retinal vein occlusion, is one of the most frequent vascular diseases of the retina. Biomarkers of optical coherence tomography (OCT), OCT-angiography and (ultra-widefield) fluorescein angiography are of exceptional importance in the initial diagnosis and also in the treatment of complications associated with retinal vascular occlusion, particularly macular edema.

METHODS

A systematic literature review was carried out in PubMed with the keywords central retinal vein occlusion, branch retinal vein occlusion, biomarker, OCT, OCT angiography, ultra-widefield fluorescein angiography with prioritization of the most important aspects.

RESULTS

Relevant biomarkers in OCT include central retinal thickness (CRT), macular fluid, the integrity of the photoreceptor bands (external limiting membrane and ellipsoid zone), disorganization of retinal inner layers (DRIL), hyperreflective foci, choroidal thickness and signs of ischemia, such as a prominent middle limiting membrane (p-MLM), paracentral acute middle maculopathy (PAMM) as well as hyperreflectivity of inner retinal layers (HIRL). The importance of OCT-angiography lies particularly in the assessment of microvascular alterations, especially vessel density in the deep retinal vascular plexus, the foveal avascular zone and of areas with no capillary perfusion. Biomarkers of ultra-widefield angiography, such as peripheral ischemia (ischemic index) and neovascularízation are essential with respect to treatment decisions for retinal laser.

CONCLUSION

A multitude of simple and complex biomarkers currently enable an effective individualized evaluation of treatment and prognosis in retinal vein occlusion. A shift from invasive to noninvasive biomarkers can be observed.

Prognostic Factor Study of Macular Edema Recurrence in Retinal Vein Occlusion after Conbercept Treatment: A Post Hoc Analysis of the FALCON Study

Objective

The study was aimed at exploring the potential predictive factors associated with the recurrence of macular edema (ME) secondary to vein occlusion (RVO) after intravitreal antivascular endothelial growth factor (VEGF) loading treatment in the FALCON study.

Methods

This is a post hoc analysis of 30 patients with central RVO and 30 patients with branch RVO. All patients received a monthly administration of intravitreal conbercept during the 3-month loading phase and pro re nata (PRN) treatment during the 6-month follow-up period. Based on the recurrence of ME at the first follow-up visit, patients were classified into the recurrence group or nonrecurrence group. The primary endpoint was to explore the risk factors for recurrence among baseline characteristics, fluorescein angiography (FA) patterns, and optical coherence tomography (OCT).

Results

In general, 38 patients (64.4%) experienced ME recurrence at the first follow-up visit (3 months), regardless of disease type (p = 0.32). Significant improvements in VA were noted in both the nonrecurrence and recurrence groups (p < 0.001), however, without significant between-group differences (p = 0.1). A significant reduction in CRT in both groups (p < 0.001) was identified, and patients without recurrence showed a greater reduction in CRT compared with those with recurrence (p < 0.001). In addition, logistic regression analyses indicated the corrections of ME recurrence with baseline macular volume and the disruption of the outer limiting membrane at the fovea.

Conclusion

This study suggested that OCT parameters, including baseline macular volume and outer limiting membrane disruption, and reduction in CRT after loading therapy were more predictive of ME recurrence than FA patterns or visual changes following conbercept loading therapy.

The Quantification and Impact of Persistent Retinal Fluid Compartments on Best-Corrected Visual Acuity of Patients With Retinal Vein Occlusion

BACKGROUND AND OBJECTIVES

To evaluate the impact of persistent intraretinal fluid (IRF) and subretinal fluid (SRF) on best visual acuity (BVA) of patients with retinal vein occlusions (RVOs).

PATIENTS AND METHODS

This retrospective cohort study observed 92 treatment-naïve patients with RVO during 12 months of treatment with anti-vascular endothelial growth factor agents. Deep learning was used to quantify IRF and SRF volumes, and linear mixed effects regression modeled the impact on BVA.

RESULTS

Average IRF volume declined -923.1 ± 2,382.5 nL from baseline to 12 months (P < .001). Average SRF volume declined -35.4 ± 223.4 nL from baseline to 12 months (P = .139). linear mixed effects regression modeling disclosed IRF≥ 1,616 nL at all time points predicted a -10.38 letter loss at 12 months (95% CI, -14.58 to -5.9 letters; P < .001). A similar relationship was not found for SRF.

CONCLUSION

Persistent IRF may be an important prognostic biomarker for BVA outcomes in real-world patients with RVO. [Ophthalmic Surg Lasers Imaging Retina. 2022;53:139-147.].

Significance of Hyperreflective Foci as an Optical Coherence Tomography Biomarker in Retinal Diseases: Characterization and Clinical Implications

Hyperreflective foci (HRF) is a term coined to depict hyperreflective dots or roundish lesions within retinal layers visualized through optical coherence tomography (OCT). Histopathological correlates of HRF are not univocal, spacing from migrating retinal pigment epithelium cells, lipid-laden macrophages, microglial cells, and extravasated proteinaceous or lipid material. Despite this, HRF can be considered OCT biomarkers for disease progression, treatment response, and prognosis in several retinal diseases, including diabetic macular edema, age-related macular degeneration (AMD), retinal vascular occlusions, and inherited retinal dystrophies. The structural features and topographic location of HRF guide the interpretation of their significance in different pathological conditions. The presence of HRF less than 30 μm with reflectivity comparable to the retinal nerve fiber layer in the absence of posterior shadowing in diabetic macular edema indicates an inflammatory phenotype with a better response to steroidal treatment. In AMD, HRF overlying drusen are associated with the development of macular neovascularization, while parafoveal drusen and HRF predispose to macular atrophy. Thus, HRF can be considered a key biomarker in several common retinal diseases. Their recognition and critical interpretation via multimodal imaging are vital to support clinical strategies and management.

Total venous nature of retinal deep capillary plexus inferred by continuity of prominent middle limiting membrane sign in optical coherence tomography

This study aimed to theoretically identify the vascular nature of the deep capillary plexus (DCP) by examining patients presenting with both paracentral acute middle maculopathy (PAMM) and prominent middle limiting membrane (p-MLM) sign and p-MLM sign alone in spectral-domain optical coherence tomography (SD-OCT). A retrospective review of the medical records of patients with retinal vein or artery occlusion from two tertiary medical centers was performed. Consecutive patients with a clinical diagnosis of all categories of retinal artery occlusion (RAO) and retinal vein occlusion (RVO) (branch or central and ischemic or non-ischemic) who had undergone SD-OCT imaging from January 2015 to May 2020 were recruited and their p-MLM signs and PAMM lesions were assessed. We included 118 patients who presented with p-MLM sign with or without PAMM lesions. Amon them, 40 were female and 78 were male, with a mean age of 61.1 years. Of the 109 patients with both p-MLM sign and PAMM lesions, 23 had branch RAO, two had branch RVO, 67 had central RAO, 13 had central RVO, and four had a combination of central RAO and central RVO. All nine patients with the p-MLM sign alone had central RVO accompanied by cystoid macular edema. In all the enrolled patients, the hyperreflective lines of the p-MLM sign were continuous, regardless of the type of PAMM lesions. In conclusion, when PAMM and p-MLM sign are examined together, further proof regarding the possible complete venous nature of the vasculature of the retinal DCP might be speculated.