Mechanisms of vision loss in eyes with macular edema associated with retinal vein occlusion

Analyze of factors and prognosis of eyes lost to follow-up in retinal vein occlusive disease patients receiving anti-vascular endothelial growth factor therapy

BACKGROUND

Patients with macular edema (ME) secondary to retinal vein occlusion (RVO) who received at least one intravitreal injection of anti-vascular endothelial growth factor therapy (VEGF) and lost to follow-up (LTFU) for more than six months were analyzed to investigate the factors contributing to the LTFU and the prognosis.

METHOD

This was a retrospective, single-center study to analyze the causes and prognosis of LTFU over six months in RVO-ME patients treated with intravitreal anti-VEGF injections at our institution from January 2019 to August 2022 and to collect patients' baseline characteristics along with the number of injections before LTFU, primary disease, best corrected visual acuity (BCVA) before LTFU and after return visit, central macular thickness (CMT), months before LTFU and after LTFU, reasons for LTFU, and complications, to analyze the factors affecting visual outcome at a return visit.

RESULTS

This study included 125 patients with LTFU; 103 remained LTFU after six months, and 22 returned after LTFU. The common reason for LTFU was "no improvement in vision" (34.4%), followed by "transport inconvenience" (22.4%), 16 patients (12.8%) were unwilling to visit the clinic, 15 patients (12.0%) had already elected to seek treatment elsewhere, 12 patients (9.6%) were not seen in time due to the 2019-nCov epidemic, and 11 patients (8.8%) cannot do it due to financial reasons. The number of injections before LTFU was a risk factor for LTFU (P < 0.05). LogMAR at the initial visit (P < 0.001), CMT at the initial visit (P < 0.05), CMT before the LTFU (P < 0.001), and CMT after the return visit (P < 0.05) were influential factors for logMAR at the return visit.

CONCLUSION

Most RVO-ME patients were LTFU after anti-VEGF therapy. Long-term LTFU is greatly detrimental to the visual quality of patients; thus, the management of RVO-ME patients in follow-up should be considered.

Relationship between Diabetic Nephropathy and Development of Diabetic Macular Edema in Addition to Diabetic Retinopathy

This study aimed to examine the relationship between diabetic retinopathy (DR) and systemic factors. We evaluated 261 patients (143 men, 118 women, aged 70.1 ± 10.1 years) with type 2 diabetes. All participants underwent a fundus examination, fundus photography using spectral domain optical coherence tomography (SD-OCT), and blood tests. For glycated hemoglobin (HbA1c) levels, the average and highest values in the past were used. We observed DR in 127 (70 men and 57 women) of 261 patients. Logistic regression analyses revealed a significant correlation between DR development and the duration of diabetes (OR = 2.40; 95% CI: 1.50), average HbA1c level (OR = 5.57; 95% CI: 1.27, 24.4), highest HbA1c level (OR = 2.46; 95% CI: 1.12, 5.38), and grade of diabetic nephropathy (DN) (OR = 6.23; 95% CI: 2.70, 14.4). Regression analyses revealed a significant correlation between the severity of DR and duration of diabetes (t = -6.66; 95% CI: 0.21, 0.39), average HbA1c level (t = 2.59; 95% CI: 0.14, 1.02), and severity of DN (t = 6.10; 95% CI: 0.49, 0.97). Logistic regression analyses revealed a significant correlation between diabetic macular edema (DME) development and DN grade (OR = 2.22; 95% CI: 1.33, 3.69). DN grade correlates with the development of DR and DME, and decreased renal function predicts the onset of DR.

Visual Prognostic Factors in Eyes with Subretinal Fluid Associated with Branch Retinal Vein Occlusion

We investigated whether foveal ellipsoid zone (EZ) status affects visual prognosis in eyes with subretinal fluid (SRF) associated with branch retinal vein occlusion (BRVO). We included 38 eyes retrospectively and classified those with or without a continuous EZ on the SRF of the central foveola on the vertical optical coherence tomography (OCT) image at the initial visit as intact (n = 26) and disruptive EZ (n = 12) groups, respectively. In addition, we classified the intact EZ eyes into clear (n = 15) and blurred (n = 11) EZ groups according to whether EZ on the SRF was observed distinctly or not. Multiple regression analyses showed that baseline EZ status significantly correlated (p = 0.0028) with the 12-months logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA), indicating that baseline intact EZ significantly improves visual prognosis. The 12-months logMAR BCVA of the intact EZ group was significantly better (p < 0.001) than that of the disruptive EZ group, and did not differ significantly between the clear and blurred EZ groups. Thus, baseline foveal EZ status on vertical OCT images can be a novel biomarker for visual prognosis in eyes with SRF associated with BRVO.

Foveal photoreceptor disruption in ocular diseases: An optical coherence tomography-based differential diagnosis

Fovea centralis, located at the center of the macula, is packed with cone photoreceptors and is responsible for central visual acuity. Isolated foveal photoreceptor disruption may occur in a variety of hereditary, degenerative, traumatic, and toxic chorioretinal diseases. These have been known previously by multiple synonyms including macular microhole, foveal spot, and outer foveal microdefects. A common clinical feature underlying these conditions is the presence of apparently normal fovea or subtle hypopigmented lesion at the foveal or juxtafoveal area. A detailed history along with high-resolution optical coherence tomography is often helpful to derive a conclusive diagnosis in majority of these cases. Focal photoreceptor disruption usually involves loss or rarefaction of ellipsoid/interdigitation zone, either in isolation or associated with external limiting membrane or retinal pigment epithelium disruption in the fovea. Vitreomacular interface (VMI) disorders including vitreomacular traction, posterior vitreous detachment, epiretinal membrane, and impending macular hole possibly remain the most common cause. Retinal dystrophies such as cone dystrophy, occult macular dystrophy, and achromatopsia may present with diminution of vision and normal appearing fundus in a younger age group. Other causes include photic retinopathy (e.g., from a history of sun gazing, or laser pointer exposure), blunt trauma, drug exposure (e.g., poppers maculopathy or tamoxifen retinopathy), and acute retinal pigment epitheliopathy (ARPE). Visual prognosis depends on the underlying etiology with complete recovery common in the subset of patients with VMI, and ARPE, whereas persistent outer retinal defects are the rule in other conditions. We discuss the differential diagnoses that lead to isolated foveal photoreceptor defects. Identifying and understanding the underlying disease processes that cause foveal photoreceptor disruption may help predict visual prognosis.

Visual Acuity in Patients Requiring Intravitreal Injections: Short-Term and Long-Term Effects of Delay in Care

Purpose: To assess the short-term and long-term effects of a delay in care on visual acuity (VA) in patients requiring intravitreal injections. Methods: This retrospective cohort study comprised patients with neovascular age-related macular degeneration (nAMD), diabetic macular edema (DME), or retinal vein occlusion (RVO) receiving intravitreal injections. The visual and anatomic outcomes at the next completed visit and at the 1-year follow-up were studied. Results: Of 1172 patients, 38% had a delay in care (mean 5.7 weeks). Compared with baseline, these patients lost VA (Early Treatment Diabetic Retinopathy Study letters) (mean −2.13 ± 0.49 SE) in the short-term ( P = .0003) and had a thicker central subfield. Patients with no delay in care had a net VA gain (0.97 ± 0.39) ( P = .0067). There was no difference in VA between 1 year and the baseline in either group. Long term, patients with nAMD in both groups had VA loss (no delay in care: −1.76 ± 0.60; delayed care: −2.44 ± 0.78) ( P = .0005 and P = .0114, respectively). Patients with DME and no delay in care maintained gains in vision (4.68 ± 1.86) but those with delayed care did not (1.72 ± 2.24) ( P = .0202 and P = .3756, respectively). In both groups, patients with RVO had no significant difference in vision from baseline. Conclusions: In patients requiring intravitreal injections, a delay in care of 5.7 weeks affected vision outcomes in the short term but not the long term.

Comparison of hyperreflective foci in macular edema secondary to multiple etiologies with spectral-domain optical coherence tomography: An observational study

Background

Hyperreflective foci (HRF) features in macular edema associated with different etiologies may indicate the disease pathogenesis and help to choose proper treatment. The goal of this study is to investigate the retinal microstructural features of macular edema (ME) secondary to multiple etiologies with spectral-domain optical coherence tomography (SD-OCT) and analyze the origin of HRF in ME.

Methods

This was a retrospective study. SD-OCT images were reviewed to investigate macular microstructural features such as the number and distribution of HRF and hard exudates and the internal reflectivity of the cysts. The differences in microstructural features between groups and the correlations between the number of HRF and other parameters were analyzed.

Results

A total of 101 eyes with ME from 86 diabetic (diabetic macular edema, DME) patients, 51 eyes from 51 patients with ME secondary to branch retinal vein occlusion (branch retinal vein occlusion-macular edema, BRVO-ME), 59 eyes from 58 central retinal vein occlusion (central retinal vein occlusion-macular edema, CRVO-ME) patients, and 26 eyes from 22 uveitis (uveitic macular edema, UME) patients were included in this study. The number of HRF, the frequency of hard exudates and the enhanced internal reflectivity of the cysts were significantly different among the groups. The number of HRF in the DME group was significantly higher than that in the other groups (all P < 0.05). The frequency of hard exudates and enhanced internal reflectivity of the cysts in the DME group were significantly higher than ME secondary to other etiologies (all P < 0.001). Within the DME group, the number of HRF in the patients with hard exudates was significantly higher than that in the patients without hard exudates (P < 0.001).

Conclusion

HRF detected with SD-OCT were more frequent in DME patients than in BRVO-ME, CRVO-ME, or UME patients. The occurrence of HRF was correlated with the frequency of hard exudates. HRF may result from the deposition of macromolecular exudates in the retina, which is speculated to be a precursor of hard exudates.

Foveal Intraretinal Fluid Localization Affects the Visual Prognosis of Branch Retinal Vein Occlusion

We investigated whether baseline foveal intraretinal fluid (IRF) localization affects the visual prognosis of branch retinal vein occlusion (BRVO). Fifty eyes from 50 patients were included in this retrospective study. We classified the eyes with IRF involving and not involving the central foveola on the vertical optical coherence tomography (OCT) image at the initial visit into both-sides (n = 17) and one-side IRF (n = 33) groups, respectively. Multiple regression analyses demonstrated that not only the baseline logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA) but also the IRF localization significantly correlated with the 12-month logMAR BCVA (p = 0.04 and p = 0.001, respectively), indicating that eyes with better baseline logMAR BCVA and one-side IRF have a significantly better visual prognosis in BRVO. The foveal ellipsoid zone band was significantly more disrupted (p < 0.001) in the both-sides IRF (47.1%) group than in the one-side IRF (3.0%) group. No eyes with decimal BCVA less than 0.5 were detected in the one-side IRF group at 12 months. Thus, baseline foveal IRF localization on vertical OCT images can be considered a novel biomarker for the visual prognosis of BRVO.

Predictors of vision-related quality of life in patients with macular oedema receiving intra-vitreal anti-VEGF treatment

PURPOSE

To determine which demographic and clinical characteristics are predictive of vision-related quality of life (VrQoL) and quality of life (QoL) in patients with macular oedema receiving intravitreal anti-vascular endothelial growth factor (VEGF) treatment.

METHODS

Vision-related quality of life (VrQoL) and quality of life (QoL) were measured in 712 patients with retinal exudative disease receiving anti-VEGF treatment at baseline, 6 and 12 months. VrQoL was measured using an item-response theory based 47-question item bank (EyeQ), whereas QoL was measured using the EuroQol Five Dimensions (EQ-5D) questionnaire. The EQ-5D score was dichotomized into a perfect score of 1 and a suboptimal score of <1. Demographic and clinical patient characteristics were considered as possible predictors of (Vr)QoL. Prediction models for (Vr)QoL were created with linear mixed models and generalised estimating equations, using a forward selection procedure.

RESULTS

A worse VrQoL was predicted by poorer LogMAR visual acuity of the better eye, female sex, single civil status, older age, longer length of anti-VEGF treatment at baseline and the presence of non-ocular and ocular comorbidities. Suboptimal EQ-5D scores were predicted by poorer LogMAR visual acuity of the better eye, female sex, single civil status, older age, the presence of non-ocular comorbidities and a lower educational background.

CONCLUSIONS

Along with visual acuity of the better eye, which is the main factor used in clinical decision making, other patient characteristics should also be considered for the risk assessment of (Vr)QoL, such as sex, age, civil status, comorbidities and length of anti-VEGF treatment.

Altered White Matter Integrity in Patients with Retinal Vein Occlusion: A Diffusion Tensor Imaging and Tract-Based Spatial Statistics Study

Background

To investigate microstructural alterations of white matter in retinal vein occlusion (RVO) patients by tract-based spatial statistics (TBSS) and diffusion tensor imaging (DTI). Material/Methods. DTI was performed on 14 RVO patients and 14 normal controls (HCs). We measured and recorded fractional anisotropy (FA) and radial diffusivity (RD) of white matter fibers and classified them through the receiver operating characteristic (ROC) curve and correlation analysis, respectively.

Results

The mean FA value of white matter in RVO patients is lower than the HCs, and the mean RD value in RVO patients increased, especially in the bilateral posterior thalamic, bilateral sagittal stratum, body of corpus callosum, cingulum, and fornix. The ROC curve of different brain regions showed high accuracy. Moreover, the mean FA and RD values were significantly correlated with visual and psychological disorders.

Conclusion

TBSS could be regarded as an important method to reveal the alterations of white matter in RVO patients, indicating the underlying neurological mechanism of the RVO.

Intravital Imaging of Circulating Red Blood Cells in the Retinal Vasculature of Growing Mice

Purpose

To establish a custom-built, high-speed 90 frame-per-second laser-scanning confocal microscope for real-time in vivo retinal imaging of individual flowing red blood cells (RBCs) in retinal vasculature of live mouse model.

Methods

Fluorescently labeled RBCs were injected into mice of different ages (3 to 62 weeks old). Anti-CD31 antibody conjugated with Alexa Fluor 647 was injected to visualize retinal endothelial cells (ECs). Longitudinal and cross-sectional intravital retinal imaging of flowing RBCs and ECs was performed in two strains (C57BL/6 and Balb/c) by using the custom-built confocal microscope.

Results

Simultaneous tracking of the routes of many fluorescently labeled individual RBCs flowing from a large artery and vein to a single capillary in the retina of live mice was achieved, which enabled in vivo measurement of retinal RBC flow velocities in each vessel type in growing mice from 3 to 62 weeks after birth. Average RBC flow velocities were gradually increased during growing from 3 to 14 weeks by more than two times. Then the average RBC flow velocity was maintained at about 20 mm/s in artery and 16 mm/s in vein until 62 weeks.

Conclusions

Our study successfully established a custom-built high-speed 90-Hz retinal confocal microscope for measuring RBC flow velocity at the single cell level. It could be a useful tool to investigate the pathophysiology of various retinal diseases associated with blood flow impairment.

Translational Relevance

This technological method could be a valuable assessment tool to help the development of novel therapeutics for retinal diseases.

Assessment of spontaneous brain activity patterns in patients with iridocyclitis: a resting-state study

Several studies demonstrated that patients with iridocyclitis were associated with vision loss and cognitive decline, whereas alterations in spontaneous brain activity occur in iridocyclitis patients remains unknown. The study aimed to explore spontaneous brain activity changes in iridocyclitis patients. Twenty-six patients with iridocyclitis and 26 healthy controls were finally included in our study. Resting-state MRI (rs-MRI) scan was conducted on both groups and the whole brain amplitude of low-frequency fluctuations (ALFFs) value was collected to assess differences in spontaneous brain activity. A receiver operating characteristic (ROC) curve was analyzed to distinguish between the fMRI data of patients with iridocyclitis and healthy controls. Patients with iridocyclitis showed significantly lower ALFF values in the right inferior parietal lobule, right calcarine, right superior temporal gyrus and right precentral gyrus compared to healthy controls and significantly higher ALFF values in the left superior frontal gyrus (P < 0.01, false discovery rate correction). The ROC curve analysis of different brain areas showed that the accuracies of ALFF value specificity between the iridocyclitis and healthy controls of the area under the curve were over 0.8. Our study highlighted an altered spontaneous activity in multiple brain regions, including the visual cortex, default-mode network, auditory area and sensorimotor areas in iridocyclitis. This may provide valuable information about underlying pathogenic mechanisms of iridocyclitis. These findings also indicate that rs-fMRI serves as a potential tool in the disease detection and evaluation of neurologic impairment in iridocyclitis.

Relative Retinal Blood Flow: A Novel and Informative Measure of Unilateral Retinal Vein Occlusion Severity

Purpose

This study quantifies retinal vascular blood flow affected by unilateral central or branch retinal vein occlusion (CRVO or BRVO). We created a new, unitless metric for the severity of these diseases—relative blood flow (RBF)—and contextualized it with subject demographics, ocular presentation, and systemic conditions. Finally, we explored its efficacy as a predictor of future outcomes.

Methods

Data were collected from 20 control subjects and 32 clinically diagnosed CRVO (n = 15) or BRVO (n = 17) patients. We used laser speckle flowgraphy to quantify blood flow as mean blur rate and present RBF as the ratio between the blood flow in a subject's diseased and undiseased eyes. Because of our demonstration that blood flow has high intrapatient (between eyes and over time) but low interpatient correlation in eyes of healthy subjects, any differences between eyes can be attributed to the disease. These data were correlated with subject demographics and disease characteristics.

Results

In CRVO and BRVO eyes, average blood flow decreased by 26% and 7%, respectively. In CRVO, occlusion duration, central macular thickness, intraocular pressure, diabetes, previous laser and injection treatments, and injection within three months after measurement were significantly associated with RBF. In BRVO, no significant associations with RBF were found.

Conclusions

Blood flow in CRVO and BRVO was reduced compared to the unaffected fellow eye in most patients. RBF was useful in determining the severity of RVOs and predicting future treatment needs.

Translational Relevance

RBF is a promising new and informative metric for quantifying the severity of unilateral RVOs.

Wide-Field Swept-Source Optical Coherence Tomography Angiography Analysis of the Periarterial Capillary-Free Zone in Branch Retinal Vein Occlusion

Purpose

To investigate the characteristics of the retinal periarterial capillary-free zone (paCFZ) with wide-field swept-source optical coherence tomography angiography (SS-OCTA) in eyes with branch retinal vein occlusion (BRVO).

Methods

Seventy treatment-naïve eyes with BRVO and 35 healthy eyes were included. The paCFZ areas, artery calibers, and areas of the major arteries in the unaffected quadrants of BRVO eyes were measured in 12 × 12-mm SS-OCTA images and compared with those of the contralateral eyes and healthy eyes. Other multimodal imaging data were collected.

Results

There were no significant differences in the unaffected artery caliber or area among the three groups (all P > 0.05). The unaffected paCFZ areas and the ratios of the unaffected paCFZ area to the counterpart artery area (paCFZ/artery area) of the major arteries were significantly larger than those in the contralateral or healthy eyes (all P < 0.05). Subgroup analysis revealed that the paCFZ/artery area value differed significantly between ischemic and nonischemic BRVO eyes (P < 0.01). The paCFZ/artery area value was positively correlated with logMAR best-corrected visual acuity, symptom duration, central macular thickness, and retinal nonperfusion area in BRVO.

Conclusions

Quantitative SS-OCTA measurements confirmed enlarged paCFZs along the unaffected major retinal arteries in BRVO eyes. The paCFZ parameters were correlated with symptom duration, retinal ischemia, and visual function.

Translational Relevance

Retinal periarterial capillary-free zones in BRVO can be non-invasively measured by SS-OCTA, assisting in clinically identifying retinal ischemia and evaluating visual function.

The laser combined with intravitreal injection of ranibizumab for treatment of macular edema secondary to branch retinal vein occlusion: A protocol for systematic review and meta-analysis

BACKGROUND

At present, laser is regarded as an effective treatment for macular edema secondary to branch retinal vein occlusion. With the breakthrough of anti-vascular endothelial growth factor drugs in ophthalmology clinical research, the intravitreal injection of ranibizumab is widely applied, but both methods have their limitations, so some clinical studies have combined and applied them together. However, the clinical results are inconsistent and controversial, and there is no relevant system evaluation for the laser combined with intravitreal injection of ranibizumab for treatment of macular edema secondary to branch retinal vein occlusion now.

OBJECTIVE

Meta analysis is used to analyze and evaluate the effectiveness and safety of the laser combined with intravitreal injection of ranibizumab for treatment of macular edema secondary to branch retinal vein occlusion.

METHOD

CNKI, VIP, WANFANG, China Biology Medicine disc, Web of Science, PubMed, Embase, Cochrane Library have used random controlled clinical trial of laser combined with intravitreal injection of ranibizumab for treatment of macular edema secondary to branch retinal vein occlusion from the establishment of the database to October 2020. Two researchers conducted independent screening, quality assessment and data extraction for the literatures, and used RevMan5.3 to conduct Meta analysis for the included literatures.

RESULT

The research has evaluated the effectiveness and safety of the laser combined with intravitreal injection of ranibizumab for treatment of macular edema secondary to branch retinal vein occlusion through the aspects of the best corrected visual acuity 6 months after operation, macular center thickness and the incidence of adverse reactions such as elevated intraocular pressure, endophthalmitis, vitreous hemorrhage and cataract.

CONCLUSION

Laser combined with intravitreal injection of ranibizumab for treatment of macular edema secondary to branch retinal vein occlusion has good effect, and the research has provided reliable evidence for the use of clinical treatment of the laser combined with intravitreal injection of ranibizumab for treatment of macular edema secondary to branch retinal vein occlusion.

Comparative efficacy of intravitreal pharmacotherapy for macular edema secondary to retinal vein occlusion: A protocol for the systematic review and network meta-analysis

BACKGROUND

Multiple intravitreal pharmacotherapies including different anti-vascular endothelial growth factors (VEGF), intravitreal steroids, and combined therapy with anti-VEGF and steroids are available for patients with macular edema secondary to retinal vein occlusion (RVO). However, the recommendation of multiple therapies remains unknown. This study aims to evaluate the efficacy and safety of multiple intravitreal pharmacotherapies in patients with macular edema secondary to RVO.

METHODS

We will systematically search the PubMed, Embase, and the Cochrane library for eligible studies. Randomized controlled trials (RCTs) with intravitreal pharmacotherapies for patients with macular edema secondary to RVO will be included. The Cochrane Collaboration's tool will be used to assess the risk of bias in the randomized trial. The primary outcome is the mean change in BCVA from baseline. The secondary outcomes are the proportion of patients who gained ≥15 letters in BCVA from baseline, the mean change in central retinal thickness from baseline and the number of serious adverse events.

RESULTS

The result will obtain a comprehensive treatment recommendation for macular edema secondary to RVO.

CONCLUSION

The results of the network meta-analysis will be submitted in a peer-reviewed journal for publication.

ETHICAL STATEMENT

This article does not contain any studies with human or animal subjects performed by any of the authors.

Dexamethasone Intravitreal Implant (Ozurdex) in Paediatric Patients with Non-infectious Intermediate Uveitis and Related Cystoid Macular Oedema: Evaluation of Macular Morphology and Function with Six-month Follow-up; a Deeper Role of MfERG?

PURPOSE

To evaluate the efficacy of Ozurdex implant by analyzing macular morphology and function in pediatric uveitis and related cystoid macular edema (CMO).

METHODS

Main outcomes were visual acuity, mfERG and photopic ERG response, and central macular thickness. Mean values recorded at each time-point were compared to baseline and correlations between functional and anatomical parameters were evaluated.

RESULTS

Resolution of intraocular inflammation and CMO was achieved in all eyes 1 month after implant without procedure or drug-related complications. Mean visual acuity and mfERG amplitude improved showing a statistically significant difference to baseline values for the first 4 months. Mean central macular thickness showed a statistically significant reduction for all follow-up time. Photopic ERG did not vary significantly. Statistically significant correlation was found between trends of visual acuity, central macular thickness, and mfERG responses.

CONCLUSION

Correlation found between macular morphology and function confirms the efficacy of Ozurdex in pediatric uveitis.

Real-World Visual and Neovascularisation Outcomes from anti-VEGF in Central Retinal Vein Occlusion

PURPOSE

Central retinal vein occlusion (CRVO) can be complicated by macular oedema, requiring intravitreal injection (IVI) of anti-vascular endothelial growth factor (VEGF). CRVO can cause neovascularisation, potentially causing persistent pain if not identified early. Whilst clinical trial data describe visual and anti-neovascular benefit from anti-VEGF there are limited real-world data.

METHODS

A retrospective cohort study of a consecutive series of patients found from a review of the electronic medical record at a single UK centre. Visual acuity, macula status, number of IVIs and neovascular status were extracted at standardised timepoints.

RESULTS

In total, 231 eyes from 231 patients were identified with 6-48 months of follow up. Twenty-four months after treatment initiation, 81 eyes (53.3%) had no remaining macula oedema and mean visual acuity gained was 8.9 (SD 19.0) Early Treatment of Diabetic Retinopathy Study (ETDRS) letters following a mean of 10.1 (3.9) IVIs. Of 222 eyes that had no initial neovascularisation, 11 went on to develop it, with iris involvement in 10 eyes. Median time from treatment initiation to neovascularisation was 17.2 (range 5.0-44.1) months, and the median time from latest IVI to neovascularisation was 9.6 (2.9-27.6) months after a median of 4 (3-10) IVIs.

CONCLUSIONS

Visual acuity in CRVO complicated by macular oedema improves following anti-VEGF treatment but real-world gains are more modest than those from clinical trials. Neovascularisation following CRVO can be substantially delayed by anti-VEGF treatment and so if individuals who have received IVIs are to be effectively screened for neovascularisation long-term surveillance is necessary.

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

In this study, we investigated the longitudinal correlation between macular sensitivity and perfusion density (PD) in retinas affected by branch retinal vein occlusion. Retinal sensitivity was measured using microperimetry and PD was measured by optical coherence tomography angiography. We also investigated the possibility that the PD, 1 month after anti-vascular endothelial growth factor (VEGF) treatment, is a predictor of retinal sensitivity after 1 year of successful macular oedema management with anti-VEGF. The correlation between measurements of retinal sensitivity and PD at baseline (1 M) and at 6 and 12 months were investigated. There was a significant positive correlation between retinal sensitivity and PD at all time points (baseline (1 M), r = 0.67, P < 0.0001; 6 months, r = 0.59, P < 0.0001; 12 months, r = 0.62, P < 0.0001) and between the PD at 1 month and retinal sensitivity at 12 months (r = 0.63, P < 0.0001). Unlike in areas that showed a mild to moderate decline in PD, retinal sensitivity in areas where the decrease in PD was severe at baseline did not show significant improvement with treatment over time. These findings suggest that the PD value measured using optical coherence tomography angiography at or soon after the baseline can predict retinal sensitivity after 1 year of anti-VEGF treatment.

Assessment of cerebral low-frequency oscillations in patients with retinal vein occlusion: a preliminary functional MRI study

BACKGROUND

There is increasing evidence that patients with retinal vein occlusion exhibit cerebral vascular changes and are at an increased risk of stroke. However, it remains unknown whether patients with retinal vein occlusion exhibit changes in intrinsic brain activity.

PURPOSE

This study investigated intrinsic brain activity changes in patients with retinal vein occlusion by assessing the amplitude of low-frequency fluctuations.

MATERIAL AND METHODS

Forty-five patients with retinal vein occlusion (22 men, 23 women, mean age 56.55 ± 6.97 years) and 43 healthy controls (13 men, 30 women; mean age 53.53 ± 8.19 years) closely matched in age, sex, and education level underwent resting-state MRI scans. The amplitude of low-frequency fluctuation method was used to compare intrinsic brain activity between the two groups.

RESULTS

Compared with healthy controls, patients with retinal vein occlusion exhibited significantly lower amplitude of low-frequency fluctuation values in the left middle occipital gyrus, right middle occipital gyrus, and right calcarine. However, patients with retinal vein occlusion showed significantly higher amplitude of low-frequency fluctuations in the bilateral cerebellum 6, right hippocampus, left insula, and left fusiform (voxel-level P < 0.01, Gaussian random field correction, cluster-level P < 0.05).

CONCLUSION

Our results demonstrated that patients with retinal vein occlusion showed abnormal spontaneous neural activities in the visual cortices, cerebellum, and Papez circuit, which might indicate impaired vision, cognition, and emotional function in patients with retinal vein occlusion. These findings offer important insights into the neural mechanism of retinal vein occlusion.

Combined Administration of Preoperative Intravitreal and Intraoperative Subretinal Recombinant Tissue Plasminogen Activator in Acute Hemorrhagic Age-related Macular Degeneration

Purpose

To evaluate the efficacy of combining pre-operative intravitreal administration of recombinant tissue plasminogen activator (rTPA) followed by 23G pars plana vitrectomy with the subretinal administration of rTPA in the management of acute submacular hemorrhage (SMH) secondary to neovascular age-related macular degeneration (AMD).

Methods

This is a single-center case series report that included 14 patients with SMH secondary to neovascular AMD. All of them received preoperative intravitreal injection of 0.05 ml (50 µg) rTPA, followed on the next day by 23G pars plana vitrectomy with subretinal 0.1 ml (10 µg) rTPA administration and air tamponade.

Results

There was a significant (p=0.01) overall improvement in the visual acuity post-treatment (from 1.4±0.5 log MAR to 0.9±0.4). The mean overall change in the visual acuity post-treatment was 0.5±0.3 log MAR (mean % change=31.7±15.1). There was a significant (p=0.03) overall reduction in the central macular thickness post-treatment (896±608.1 µm to 497.2±196.0 µm). The mean overall change in the central macular thickness post-treatment was 398.8±458.1 µm (mean % change=38.1±18.1).

Conclusion

Combined treatment of 24 hours of preoperative administration of intravitreal rTPA followed the next day by vitrectomy and the administration of subretinal rTPA with air tamponade appeared to be effective as a prompt intervention in managing acute SMH secondary to neovascular AMD. However, similar studies with larger sample size and a control comparative group are warranted to further confirm these findings.

Ranibizumab and aflibercept intravitreal injection for treatment naïve and refractory macular oedema in branch retinal vein occlusion

BACKGROUND

Branch retinal vein occlusion complicated by macular oedema is a common disease treated with intravitreal injection of anti-vascular endothelial growth factor. Controversy exists surrounding anti-vascular endothelial growth factor selection for both treatment naïve and refractory cases.

METHODS

A retrospective electronic medical record review at a single UK centre generated a cohort of 259 treatment naïve eyes from 258 patients receiving ranibizumab, aflibercept or a combination (n = 83, 97 and 79, respectively) from 2013 to 2018 with ⩾6 months follow-up. Number of intravitreal injections, visual acuity and macular oedema presence were noted at 3, 6, 12, 24, 36 and 48 months. A subgroup analysis examined refractory cases switched from ranibizumab to aflibercept (n = 77) or maintained on ranibizumab (n = 35).

RESULTS

Eyes receiving ranibizumab or aflibercept had equivocal vision gain at 1 year, 8.0 (95% CI 5.0-11.0) and 9.6 (7.2-12.1) Early Treatment of Diabetic Retinopathy Study letters, respectively. About 35.6% had no macular oedema at 12 months with ranibizumab compared with 50.0% with aflibercept (p = 0.07) following 5.1 (4.7-5.6) and 6.0 (5.6-6.4) intravitreal injections, respectively. Visual prognosis declined significantly as treatment delay extended (p = 0.003) which was only apparent with ⩾3 months delay. Eyes with refractory macular oedema also had equivocal functional and anatomical outcomes whether they were maintained on ranibizumab or switched to aflibercept.

CONCLUSION

These real world data demonstrate more modest clinical improvements from anti-vascular endothelial growth factor treatment than reported in clinical trials. The functional outcomes of ranibizumab and aflibercept in both treatment naïve and refractory cases were equivocal while the anatomical outcomes of aflibercept may be superior.

Retinal oximetry in branch retinal vein occlusion

PURPOSE

To measure retinal oxygen saturation (SO₂ ) in eyes with branch retinal vein occlusion (BRVO).

METHODS

Retinal oximetry was performed using the Oxymap T1 retinal oximeter in 50 eyes (50 patients) with resolved BRVO. SO₂ was calculated in each major retinal artery and vein in four quadrants. The superior or inferior hemisphere with BRVO was categorized as the affected hemisphere and the other as the unaffected hemisphere.

RESULTS

Oxymap T1 allowed us to measure SO₂ in major retinal vessels. Both arterial and venous SO₂ in the affected hemisphere were significantly higher than those in the unaffected hemisphere. However, there was no significant difference in arteriovenous (A-V) difference in SO₂ between the affected and unaffected hemispheres. Of the 50 included eyes, 32 had non-ischemic BRVO and 18 had ischemic BRVO. In the affected hemisphere, arterial SO₂ was significantly higher in ischemic BRVO (106.9 ± 8.8%) than in non-ischemic BRVO (101.3 ± 9.2%, p = 0.044). There were no significant differences in venous SO₂ between non-ischemic and ischemic BRVO. Consequently, the A-V difference in SO₂ was significantly higher in ischemic BRVO (51.9 ± 13.9%) than in non-ischemic BRVO (43.4 ± 11.5%, p = 0.028). In multiple regression analysis, the type of perfusion (non-ischemic or ischemic) had associations with arterial SO₂ (β = 0.365, p = 0.013) and with A-V differences in SO₂ in the affected hemisphere (β = 0.406, p = 0.006).

CONCLUSION

In ischemic BRVO, arterial SO₂ and the A-V difference in SO₂ in the affected hemisphere were significantly higher than in non-ischemic BRVO.

Comparison of subfoveal choroidal thickness in eyes with CRVO and BRVO

BACKGROUND

To evaluate the subfoveal choroidal thickness (SFCT) in eyes with macular edema (ME) secondary to retinal vein occlusion(RVO), and to investigate the short term response after a single intravitreal ranibizumab (IVR) injection. What is more, to compare SFCT and SFCT change between central RVO (CRVO) and branch RVO (BRVO).

METHODS

In the retrospective study, we had collected 36-six treatment-naïve patients with unilateral ME secondary to RVO (including 19 CRVO and 17 BRVO). All patients had received IVR injection after newly diagnosed. The SFCT was measured at the onset and after 2 weeks of IVR injection. Paired t test was performed to compare the SFCT of RVO eyes and fellow eyes, as well as the SFCT of pre-injection and post-injection. In further, independent t test was used to compare SFCT and SFCT change between CRVO eyes and BRVO eyes.

RESULTS

The mean SFCT at the onset was 326.03 ± 30.86 μm in CRVO eyes, which was significantly thicker than that in contralateral fellow eyes (p < 0.01, paired t test), and reduced to 294.15 ± 30.83 μm rapidly after 2 weeks of IVR injection (p < 0.01, paired t test). Similarly, the SFCT in BRVO eyes was significantly thicker than that in contralateral eyes at the onset, and decreased significantly after IVR injection. However, our findings showed that there was no statistically significant difference in SFCT and SFCT reduction after IVR injection between CRVO eyes and BRVO eyes.

CONCLUSIONS

The SFCT in eyes with ME secondary to CRVO and BRVO was significantly thicker than that in fellow eyes, and decreased significantly within a short time in response to a single IVR injection. In further, the study showed that SFCT and SFCT change had no correlation with RVO subtypes.

Interleukin-17: The Role for Pathological Angiogenesis in Ocular Neovascular Diseases

Ocular neovascular diseases are featured by abnormal angiogenesis in the eye, and they seriously threaten the human visual health. These diseases include proliferative diabetic retinopathy (PDR), age-related macular degeneration (AMD), retinopathy of prematurity (ROP), and retinal vein occlusion (RVO). In fact, ocular neovascular diseases represent the leading causes of vision impairment and blindness worldwide. Ocular neovascularization, the process of pathological vessel formation in eye, underlies ocular neovascular diseases. Cytokines have important regulatory roles in neovascularization through immunological networks. Interleukin (IL)-17, the signature cytokine produced by T helper 17 (Th17) cells, has proven to be involved in ocular neovascularization. However, roles of IL-17 in ocular neovascular diseases still remain controversial. This review provides an overview of the functional roles of IL-17 in ocular neovascular diseases from basic research to clinical evidence by focusing on PDR, AMD, ROP, and RVO. The possible roles of IL-17 in neovascularization are achieved through a regulatory network of cytoskeleton remodeling, vascular endothelial growth factor (VEGF), VEGF-related cytokines, and complement components. Current applications as well as potential therapies targeting IL-17 with genome editing systems are also outlined and discussed. Targeting IL-17 might be a promising therapeutic strategy against ocular neovascular diseases.

Short-term effect of intravitreal conbercept injection on major and macular branch retinal vein occlusion

OBJECTIVE

To evaluate the effectiveness of intravitreal conbercept injection on major and macular branch retinal vein occlusion (BRVO).

METHODS

This retrospective analysis involved 43 patients with BRVO (major BRVO n = 24; macular BRVO, n = 19) who were diagnosed by fluorescein fundus angiography (FFA) and injected with intravitreal conbercept. The following outcomes were measured at baseline and follow-up (1-6 months): best-corrected visual acuity (BCVA), central foveal thickness (CFT), total retinal volume in a 6-mm diameter section of the macula, choroidal thickness under the central fovea of the macula, relative area of retinal hemorrhage, complications, and times when repeated injection was performed.

RESULTS

There were significant differences between the two groups in terms of BCVA, CFT, and total retinal volume in a 6-mm diameter section of the macula at 6 months after treatment. Choroidal thickness under the central fovea of the macula and relative area of retinal hemorrhage showed no significant differences between the two groups at 6 months after treatment; however, they significantly differed from baseline measurements.

CONCLUSION

In general, intravitreal injection of conbercept may have a better short-term effect in patients with macular BRVO than in patients with major BRVO.