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

Comparing the efficacy of dexamethasone implant and anti-VEGF for the treatment of macular edema: A systematic review and meta-analysis

OBJECTIVES

To evaluate the clinical efficacy of dexamethasone (DEX) implant, for the treatment of macular edema (ME) caused by retinal vein occlusion (RVO) and diabetic retinopathy (DR) through a systematic review and meta-analysis.

METHODS

The PubMed, Embase and Cochrane Library databases were comprehensively searched from inception to November 21, 2022, for studies evaluating the clinical efficacy of DEX implant for patients with retinal vein occlusion macular edema (RVO-ME) or diabetic macular edema (DME). Randomized controlled trials (RCTs) published in English were considered eligible. The Cochrane Collaboration tool was applied to assess the risk of bias in each study. Effect estimates with 95% confidence intervals (CIs) were pooled using the random effects model. We also conducted subgroup analyses to explore the sources of heterogeneity and the stability of the results.

RESULTS

This meta-analysis included 8 RCTs (RVO-ME [n = 2] and DME [n = 6]) assessing a total of 336 eyes. Compared with anti-VEGF therapy, DEX implant treatment achieved superior outcomes in terms of best corrected visual acuity (BCVA) (mean difference [MD] = -3.68 ([95% CI, -6.11 to -1.25], P = 0.003), and no heterogeneity was observed (P = 0.43, I2 = 0%). DEX implant treatment also significantly reduced central macular thickness (CMT) compared with anti-VEGF treatment (MD = -31.32 [95% CI, -57.92 to -4.72], P = 0.02), and there was a high level of heterogeneity between trials (P = 0.04, I2 = 54%). In terms of severe adverse events, DEX implant treatment had a higher risk of elevated intraocular pressure than anti-VEGF therapy (RR = 6.98; 95% CI: 2.16 to 22.50; P = 0.001), and there was no significant difference in cataract progression between the two groups (RR = 1.83; 95% CI: 0.63 to 5.27, P = 0.31).

CONCLUSIONS

Compared with anti-VEGF therapy, DEX implant treatment is more effective in improving BCVA and reducing ME. Additionally, DEX implant treatment has a higher risk of elevated intraocular pressure. Due to the small number of studies and the short follow-up period, the results should be interpreted with caution. The long-term effects of the two treatments need to be further determined.

TRIAL REGISTRATION

Prospero Registration Number CRD42021243185.

Comparing ranibizumab, dexamethasone implant, and combined therapy for macular edema secondary to branch retinal vein occlusion: a clinical trial

BACKGROUND

Macular edema (ME) is a common complication following branch retinal vein occlusion (BRVO) and is also the main reason for visual impairment. This study aimed to compare the efficacy and safety of intravitreal ranibizumab (IVR) or dexamethasone implant (IDI) monotherapy, as well as the combination of IVR and IDI injections, in patients with ME secondary to branch retinal vein occlusion (BRVO).

METHODS

This multicenter, prospective, and comparative study included 292 patients with unilateral ME involvement (total of 292 eyes) secondary to BRVO. The patients were randomly assigned to three groups and followed up for 12 months. Patients in group 1 (n = 96) were treated with 3-dose loading IVR injections followed by a pro re nata (PRN) regimen. Patients in group 2 (n = 98) received IVR combined with IDI injection, followed by IVR PRN regimen. Patients in group 3 (n = 98) were treated with IDI injection, followed by repeated IDI injection based on clinical necessity. Best corrected visual acuity (BCVA), central retinal thickness (CRT), complications, and frequency of injections were recorded and compared between the three groups.

RESULTS

At baseline, the three groups did not differ in age, gender, duration of ME, BCVA, IOP, and CRT (P > 0.05). Mean number of total injections per eye within 12 months were 7.1 ± 2.3 (range 4-9) in group 1, 3.7 ± 1.5 (range 2-6) in group 2, and 1.8 ± 0.4 (range 1-3) in group 3. There was a statistical difference in the number of injections between group 1 and group 2 (P = 0.037). Eyes in group 3 received fewer injections than those in group 2, but the difference was not statistically significant (P = 0.052). BCVA improvement and CRT reduction were achieved in all groups and there was no significant difference between the three groups at the end of the 12th month. However, IOP elevation and cataract progression were more frequent in group 3, especially in those patients who received repeated IDI injections.

CONCLUSION

Three therapeutic regimens had comparable efficacy in treating ME secondary to BRVO. Combination therapy had an advantage in maintaining good effect with fewer re-injections and complications.

TRIAL REGISTRATION INFORMATION

The study complied with the principles of the Declaration of Helsinki and was approved by Xi'an Aier Ancient City Eye Hospital, Xi'an Aier Eye Hospital, and Xianyang Aier Eye Hospital ethics committees (2022SF-367).

A prospective observation of influence of anti-VEGF on optic disc vasculature in nAMD patients

BACKGROUND

This study aims to investigate the short-term changes in relatively normal retinal vessels following anti-vascular endothelial growth factor (anti-VEGF) therapy in nAMD patients, an area that currently represents a research gap.

METHODS

In this prospective study, we enrolled patients newly diagnosed with neovascular age-related macular degeneration (nAMD) and received standardized monthly anti-VEGF therapy for three months. Follow-ups were conducted at baseline and 1-week, 1-month, 2-months and 3-months post first injection. Assessment indicators included radial peripapillary capillary vascular density (RPC-VD) and retinal nerve fiber layer (RNFL) thickness in different optic disk regions using optical coherence tomography angiography, as well as intraocular pressure (IOP).

RESULTS

68 nAMD patients (68 eyes) were included in this study. Significant reductions of RPC-VD and increases of RNFL thickness primarily in the nasal regions were observed 1-week post anti-VEGF (adjusted P < 0.05). Significant negative correlations were found between 1-week changes in RPC-VD and RNFL thickness in the nasal sectors (P < 0.05). From 1 to 3 months post-injection, RPC-VD and RNFL thickness essentially returned to baseline levels. Throughout the follow-up periods, IOP remained stable (P > 0.05).

CONCLUSION

Anti-VEGF treatments transiently influence the relatively normal retinal vessels, which might lead to nerve fiber edema, predominantly on the nasal side of the optic disk.

Characteristics of macular edema associated with retinal vein occlusion showing poor anatomic response to three loading anti-vascular endothelial growth factor injections: an optical coherence tomography analysis

PURPOSE

To analyze the clinical features of refractory cystoid macular edema related to retinal vein occlusion associated with the response to three consecutive loading doses of anti-vascular endothelial growth factor.

METHODS

A retrospective chart review was performed on retinal vein occlusion patients treated by three anti-vascular endothelial growth factor injections. They were divided into a group according to resolution of macular edema in optical coherence tomography (Group 1) and with persistent macular edema (Group 2). We analyzed qualitative and quantitative morphologic features of optical coherence tomography.

RESULTS

We enrolled a total of 120 eyes from 120 patients (Group 1: n = 54, Group 2: n = 66). The baseline choroidal thickness differed significantly between groups 1 and 2 (290.70 ± 19.58 μm and 311.06 ± 17.87 μm P < 0.001). The presence of Hyperreflective foci (16.70% vs. 36.40% P < 0.001), Disorganization of the retinal inner layers (14.80% vs. 87.90%) and external limiting membrane disruption (16.60% vs. 39.3% P < 0.001) differed significantly. Logistic regression analysis showed that the initial central macular thickness (B = 0.012; P = 0.006), baseline choroidal thickness (B = 0.232; P = 0.016) and presence of hyperreflective foci (B = 1.050; P = 0.019), disorganization of the retinal inner layers (B = 1.132; P = 0.001) and external limiting membrane disruption (B = 1.575; P = 0.012) significantly affected the anti-vascular endothelial growth factor treatment response.

CONCLUSION

A thicker sub-fovea choroid and the presence of hyperreflective foci, disruption of the external limiting membrane and disorganization of the retinal inner layers associated with a poorer response to three loading anti-vascular endothelial growth factor injections in macular edema associated retinal vein occlusion.

An Analysis of Optical Coherence Tomography Angiography (OCT-A) Perfusion Density Maps in Patients Treated for Retinal Vein Occlusion with Intravitreal Aflibercept

AIM

The primary goal of this study was to evaluate the reduction in non-perfusion area and improvement in blood flow as well as the reduction in retinal edema on optical coherence tomography angiography (OCT-A) in patients with retinal vein occlusion treated with 2 mg intravitreal injections of aflibercept.

MATERIAL AND METHODS

Fifty eyes of nine patients with central retinal vein occlusion (CRVO) and sixteen patients with branch retinal vein occlusion (BRVO), aged 50 to 75 years, were collectively analyzed as retinal vein occlusion (RVO). The following parameters were analyzed: superficial vessel density (VDSF), deep vessel density (VDD), flow area in the outer retina (FAOR), choriocapillaris flow area (FACC), non-flow area (NFA) and the foveal avascular zone (FAZ).

RESULTS

OCT-A revealed a reduction in macular edema. The most significant change in central retinal thickness (CRT) was observed between measurement timepoint "5" and the baseline (46%). The non-flow area was also reduced. Following a significant decrease in superficial vessel density 30 days after the first dose of aflibercept, a non-significant increase was noted at the subsequent timepoints. An increase was also found in deep vessel density and choriocapillaris flow area. Improvements in the above OCT-A parameters resulted in increased retinal blood flow and improved visual acuity.

CONCLUSIONS

Patients with retinal vein occlusion treated with 2 mg aflibercept exhibited reduced macular edema and FAZ, increased vessel density, improved blood flow, and better visual acuity.

Tetrahedral framework nucleic acids inhibit pathological neovascularization and vaso-obliteration in ischaemic retinopathy via PI3K/AKT/mTOR signalling pathway

This study aimed to explore the effect and the molecular mechanism of tetrahedral framework nucleic acids (tFNAs), a novel self-assembled nanomaterial with excellent biocompatibility and superior endocytosis ability, in inhibition of pathological retinal neovascularization (RNV) and more importantly, in amelioration of vaso-obliteration (VO) in ischaemic retinopathy. tFNAs were synthesized from four single-stranded DNAs (ssDNAs). Cell proliferation, wound healing and tube formation assays were performed to explore cellular angiogenic functions in vitro. The effects of tFNAs on reducing angiogenesis and inhibiting VO were explored by oxygen-induced retinopathy (OIR) model in vivo. In vitro, tFNAs were capable to enter endothelial cells (ECs), inhibit cell proliferation, tube formation and migration under hypoxic conditions. In vivo, tFNAs successfully reduce RNV and inhibit VO in OIR model via the PI3K/AKT/mTOR/S6K pathway, while vascular endothelial growth factor fusion protein, Aflibercept, could reduce RNV but not inhibit VO. This study provides a theoretical basis for the further understanding of RNV and suggests that tFNAs might be a novel promising candidate for the treatment of blind-causing RNV.

Predictive value of retinal oximetry, optical coherence tomography angiography and microperimetry in patients with treatment-naïve branch retinal vein occlusion

Vascular endothelial growth factor inhibitors have substantially improved the visual outcomes in patients with macular edema (ME) caused by branch retinal vein occlusion (BRVO), but treatment outcomes are highly variable and early prediction of expected clinical outcome would be important for individualized treatment.As non-invasive metabolic, structural and functional retinal markers might act as early predictors of clinical outcomes, we performed a 12-month, prospective study aimed to evaluate if baseline retinal oximetry, optical coherence tomography angiography (OCT-A) or microperimetry were able to predict need of treatment, structural or functional outcome in patients with ME caused by treatment-näive BRVO.We evaluated 41 eyes of 41 patients with a mean age of 69.6 years and 56% females. We found a strong tendency towards a higher retinal arteriolar oxygen saturation in patients without a need of additional aflibercept treatment after the loading phase (99.8% vs. 92.3%, adjusted odds ratio 0.80 (95% confidence interval 0.64-1.00), adjusted p = 0.058), but otherwise, retinal oximetry, OCT-A or microperimetry were not able to predict need of treatment, structural nor functional outcomes. (Trial registration: clinicaltrials.gov, S-20,170,084. Registered 24 August 2014, https://clinicaltrials.gov/ct2/show/NCT03651011 ).

The Impact of Intraocular Treatment on Visual Acuity of Patients Diagnosed with Branch Retinal Vein Occlusions

Branch retinal vein occlusions are a significant cause of vision loss and present several ophthalmic and systemic risk factors, including age, hypertension, hyperlipidemia and glaucoma. Retinal vein occlusion is the second-most-common retinal vascular disease. This study evaluated the effects of Ozurdex in contrast to a combination therapy with anti-vascular endothelial growth factor (VEGF) and cortisone in treatment-naive branch retinal vein occlusions-macular edema (BRVO-ME) cases, at 4-month and 6-month follow-ups. Thirty eyes were included in the study, which were divided into two groups. The first group consisted of 15 eyes, and each received 1 injection of dexamethasone intravitreal implant Ozurdex (DEX). The second group of 15 eyes received 3 intravitreal injections, the first and second with the anti-vascular endothelial growth factor aflibercept and the third one with 4 mg of triamcinolone acetonide (Vitreal S), spaced at one month. The best corrected visual acuity (BCVA) results suggested that the peak efficacy was at 4 months for both groups, with mean values of 0.5 LogMAR and 0.4 LogMAR. Regarding macular edema, there were no significant changes between the 4- and 6-month follow-up periods, with mean values of 361 μm and 390 μm. Six patients experienced transient raised intraocular pressure at one week after treatment. This study highlights the benefits to visual acuity of the combination of anti-vascular endothelial growth factor and cortisone, which represents a viable solution with similar results to Ozurdex therapy.

Healing rate of macular edema secondary to branch retinal vein occlusion in two years after initiation of intravitreal ranibizumab later combined with other treatment as needed and characteristics of refractory cases

PURPOSE

To investigate the 2-year healing rate of macular edema (ME) secondary to branch retinal vein occlusion (BRVO) treated initially with intravitreal ranibizumab (IVR) and later combined with other treatment as needed, and the characteristics of refractory cases.

METHODS

130 patients (130 eyes) with BRVO-ME who received IVR initially were studied. Anti-vascular endothelial growth factor drug was additionally administered when ME relapsed or persisted. Photocoagulation was performed when the non-perfusion area (NPA) was ≥5 disc diameter (DD), and/or when ME relapsed due to microaneurysm. Patients were classified into a healed group [ME resolved in <2 years or mild ME remained without best-corrected visual acuity (BCVA) loss for ≥6 months] or refractory group (ME persisted for ≥2 years).

RESULTS

110 eyes were classified into the healed group, and 20 eyes into the refractory group. The healed group and refractory group had, respectively, mean follow-up periods of 21.2 and 37.4 months, and frequencies of NPA ≥5 DD of 55.5 and 25.0% (p = 0.015). In the healed group, mean BCVA (logMAR) improved significantly compared to baseline in all the periods until 24 months after treatment initiation and at the last visit (p<0.001). In the refractory group, mean BCVA improved significantly compared to baseline until 12 months after treatment initiation (p<0.05 for all periods), but was not significantly different at 18 or 24 months or at the last visit.

CONCLUSION

In patients with BRVO-ME treated initially with IVR and later given additional treatments as needed, the healing rate was 84.6%. In eyes that healed within 2 years, BCVA improved relative to baseline throughout 24 months and at the last visit. In refractory eyes, BCVA improved only until 12 months, and thereafter deteriorated to baseline level at the last examination.

Quantitative Assessment Parameters of Peripapillary Regions with Branch Retinal Vein Occlusion by Using Optical Coherence Tomography Angiography

PURPOSE

To investigate the baseline parameters of peripapillary regions in both eyes of patients with unilateral branch retinal vein occlusion (BRVO) using optical coherence tomography angiography (OCTA) and their association with best-corrected visual acuity (BCVA).

METHODS

Forty-eight unilateral BRVO patients were enrolled. The 4.5 × 4.5 mm disc angiogram was acquired in the BRVO eyes and fellow eyes using the OCTA. Radial peripapillary capillary (RPC), whole vessel density, and retinal nerve fiber layer (RNFL) thickness in different regions and optic nerve head (ONH) analysis were automatically calculated. The partition includes the whole image, peripapillary, superior hemifield, inferior hemifield, eight equally divided sectors, and nine evenly divided square areas.

RESULTS

All vessel density and capillary vessel density in the whole and peripapillary regions of BRVO eyes were significantly lower than those in fellow eyes. The RNFL peripapillary thickness in BRVO eyes was significantly higher than those in fellow eyes. In eyes with supertemporal vein occlusion, all vessel density both in the superior hemifield and in the G12 region was significantly reduced compared with that in the fellow eyes. The capillary vessel density was significantly lower in the superior hemifield, superior temporal (ST), superior nasal (SN), and temporal superior (TS) areas than in the fellow eyes. The RNFL thickness in the NI, IN, TI, and TS sectors was significantly higher than in fellow eyes (all P < 0.05).

CONCLUSIONS

OCTA provided quantitative information on peripapillary vascular density and RNFL thickness changes in BRVO. Branch retinal vein occlusion not only affects the blood vessel density in the macular area but also decreases the radial peripapillary capillaries. The capillary density is mainly affected in the affected hemifield but not in the unaffected hemifield.

Structural and Visual Changes in Branch Retinal Vein Occlusion Patients with Retinal Atrophy

Background

To study the changes of retinal vascular density (VD), retinal thickness (RT), and their correlations with visual acuity (VA) in branch retinal vein occlusion (BRVO) patients with retinal atrophy after resolution of macular oedema (MO).

Methods

This is a retrospective study consisting of 46 patients diagnosed with BRVO at Beijing Hospital from 2015 to 2019. Patients' 46 affected eyes and 39 fellow eyes were included. The affected eyes were further divided into the atrophy group and the nonatrophy group. Optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) images obtained when MO completely resolved after treatment with ranibizumab were analyzed. We quantitatively measured foveal avascular zone (FAZ) parameters, the disruption extent of ellipsoid zone (EZ), RT, and VD of superficial vascular complex (SVC), and deep vascular complex (DVC) in central fovea and the minimal-VD quadrant. Paired t-tests, independent t-tests, Mann–Whitney U tests, Wilcoxon tests, Pearson correlation analyses, Spearman correlation analyses, and single and multiple linear regression models were adopted.

Results

Compared with nonatrophy eyes, the minimal-VD quadrantal (quadrantal for short) SVC-VD (25.76 ± 4.57% versus 36.21 ± 6.47%, P < 0.001) and quadrantal DVC-VD (27.72 (17.23) % versus 38.95 (11.05) %, P = 0.001) of atrophy eyes decreased significantly. Quadrantal SVC-VD and quadrantal DVC-VD were strongly correlated with quadrantal full RT (r = 0.763 and 0.698, both P < 0.001). The disruption length of EZ was significantly correlated with quadrantal full RT (r = −0.406, P = 0.005) and quadrantal SVC-VD (r = −0.298, P = 0.044). In multiple linear regression analysis, the disruption length of EZ and VA before treatment and age showed significant correlations with VA with complete resolution of MO (P = 0.020,  0.033,  and 0.002).

Conclusions

The retinal VD on the affected area correlates well with the corresponding full RT when BRVO-MO completely resolves, suggesting that VD may predict the final RT. Severe decrease in VD may result in retinal atrophy, which may cause VA loss indirectly with the intermediate influencing factor of EZ defects.

Wide-field swept-source OCT angiography of the periarterial capillary-free zone before and after anti-VEGF therapy for branch retinal vein occlusion

BACKGROUND

The aim of the study was to investigate the changes in the periarterial capillary-free zone (paCFZ) after anti-vascular endothelial growth factor (VEGF) therapy in patients with branch retinal vein occlusion (BRVO) by wide-field swept-source optical coherence tomography angiography (SS-OCTA) and assess their associations with clinical outcomes.

METHODS

In this retrospective observational study of 54 treatment-naïve BRVO patients with macular edema, we reviewed the findings of 12 × 12 mm² SS-OCTA at baseline, 3, 6, and 12 months after intravitreal ranibizumab injections. The paCFZ and major retinal artery areas were measured on SS-OCTA images. The paCFZ area to artery area (P/A) ratio was calculated.

RESULTS

The paCFZ areas and P/A ratios of first- and second-order arteries were significantly greater in BRVO eyes than in contralateral eyes (all P < 0.01), but there were no differences in the first- and second-order artery areas (P = 0.20 and 0.25, respectively). The paCFZ areas and P/A ratios decreased significantly at 3, 6, and 12 months after anti-VEGF therapy (all P < 0.01). The baseline P/A ratio was significantly correlated with the baseline best-corrected visual acuity (BCVA), central retinal thickness, and their improvements at 3, 6, and 12 months (all P < 0.05). Baseline BCVA and P/A ratios of first- and second-order arteries were independently associated with the final BCVA in multivariate linear regression.

CONCLUSIONS

Wide-field SS-OCTA shows that anti-VEGF therapy can lead to a significant improvement in the paCFZ parameters in BRVO. Smaller baseline P/A ratios on SS-OCTA tend to predict better visual outcomes at 12 months after anti-VEGF therapy.

Potential Prognostic Indicators for Patients With Retinal Vein Occlusion

The second most prevalent cause of retinal vascular disease is retinal vein occlusion (RVO). RVO raises intravascular pressure in the capillary and veins, triggering vessel barrier collapse and subsequent leaking of blood or plasma components into the tissue (edema). Macular edema (ME) is a major complication of RVO that results in significant visual impairment. Laser therapy, intravitreal steroid injections, and vascular endothelial growth factor (VEGF) inhibitors are the major therapeutic techniques. Different therapies reduce ME of RVO and improve visual activity. However, some people have no impact on the resolution of ME, while others have a poor visual prognosis despite full ME cure. There are many investigators who studied the relationship between indicators of various instruments with visual activity. However, a summary of those findings is currently lacking. Therefore, we will focus on the predictive factors of different studies associated with positive visual activity outcomes, which would be very useful and important to help address both treatment expectations and methods for patients with RVO.

The effect of branch retinal vein occlusion on the vascular structure of the choroid

OBJECTIVE

Our aim is to examine choroidal structural changes in eyes with branch retinal vein occlusion (BRVO).

MATERIAL AND METHOD

This retrospective, comparative study included 34 newly diagnosed unilateral BRVO patients and 40 healthy controls. Subfoveal choroidal thickness (SFCT) measurement was performed with enhanced depth imaging optical coherence tomography (EDI-OCT). The images were binarized using the ImageJ software program. Total choroidal area (TCA), stromal area (SA), and luminal area (LA) were calculated from the 1500 µm area. The choroidal vascular index (CVI) was determined as the LA/TCA ratio. All parameter values were compared between the BRVO eye and the fellow eye, and the control group eyes.

RESULTS

Eyes with BRVO had a greater SA compared to both fellow and control eyes; hence, the CVI was lower (p < 0.001). LA did not differ between eyes. TCA, although not statistically significant, was larger in eyes with BRVO than in both fellow and control eyes. SFCT was also greater in eyes with BRVO. No correlation was observed between CVI and SFCT and best-corrected visual acuity (BCVA).

CONCLUSION

BRVO affects the stromal part of the choroid rather than its vascular structure. SA increases due to choroidal exudation that occurs in response to retinal ischemia, and CVI decreases accordingly.

Effect of anti-VEGF treatment on nonperfusion areas in ischemic retinopathy

In recent years, retinal ischemia such as that which occurs in diabetic retinopathy (DR) and retinal vein occlusion (RVO) has become a hotspot of ischemic retinopathy research. High levels of vascular endothelial growth factor (VEGF) are recognized as a major cause of macular edema (ME) in DR and RVO. High concentrations of VEGF in the vitreous can lead to serious retinal ischemia and hypoxia and form retinal nonperfusion areas (NPAs). Different levels of retinal ischemia can represent disease severity and progression. Anti-VEGF therapy as the first-line treatment for ME has been found to be effective in improving vision, but there are still disputes about whether anti-VEGF therapy could improve retinal ischemia and achieve reperfusion of previously developed retinal NPAs. Here, we review and summarize studies of the effects of anti-VEGF drugs on retinal ischemia, especially NPAs.

Optical-coherence tomography angiography and ultrawide-field angiography findings in eyes with refractory macular edema secondary to retinal vein occlusion switched to aflibercept: A subanalysis from a 48-week prospective study

PURPOSE:

To evaluate anatomical changes on ultra-wide-field fluorescein-angiography and optical coherence angiography (OCT-A) among a cohort with treatment-resistant macular edema secondary to retinal vein occlusions (RVO) switched to aflibercept.

MATERIALS AND METHODS:

Patients with persistent macular edema despite previous bevacizumab and/or ranibizumab were switched to aflibercept in a 48-week prospective trial. Ultra-wide-field fluorescein angiography (UWFFA) and OCT-A were performed at baseline, week-24 and week-48. The ischemic index was calculated from UWFFA and the areas of vascular perfusion. The foveal avascular zone (FAZ) were quantitatively evaluated on OCT-A.

RESULTS:

Eighteen patients (mean age, 70.3±8.6 years) were recruited. Mean central macular thickness (CMT) was significantly reduced at 48-weeks compared to baseline (-87.6±48.8 μm, P < 0.001 and -191.0±128.3μm, P < 0.001 among BRVO and CRVO eyes, respectively). The mean baseline ischemic index as measured on Optos wide-field angiography was 10.9%±8.3 and decreased to 5.7%±4.2 (P = 0.028), at week 48. The mean FAZ areas of the SCP and DCP reduced by -0.06 ± 0.12 mm 2 and -0.17± 0.45 mm 2 , respectively. FAZ area on OCT-A was stable in eyes with stable or improved vision but increased in size in eyes with baseline macular ischemia and those with lower gains in BCVA at week 48 (R 2 =0.719, P = 0.05 and R 2 =0.516, P = 0.01).

CONCLUSION:

There was a reduction in macular edema measured on OCT at 48-weeks in eyes switched to aflibercept with chronic macular edema due to retinal vein occlusion. There was also a reduction in retinal ischemia as measured using UWFFA.

Evaluation of retinal sensitivity and microstructure in areas of capillary nonperfusion of eyes with branch retinal vein occlusion

Background

To evaluate macular microstructure alterations in the parafoveal nonperfusion areas of eyes with branch retinal vein occlusions (BRVO), and to investigate their impact on retinal sensitivity.

Methods

This was a cross-sectional study including thirteen BRVO patients with parafoveal capillary nonperfusion areas (NPA). Multiple modalities including microperimetry, optical coherence tomography angiography, and optical coherence tomography were performed to measure retinal sensitivity and thickness, and to identify the microstructure changes and perfusion status.

Results

The retinal sensitivity and thickness in the NPA were significantly lower than those in the perfusion areas (PA) (P = 0.001, P = 0.003). Microstructure changes, including disorganization of the retinal inner layers (DRIL), disruption of the outer retinal layers, and cysts were more frequently observed in NPA (P = 0.002, P = 0.018, P = 0.068). Within NPA, the retinal sensitivity of areas with DRIL, and outer retinal layers disruption was significantly lower than that of the areas without DRIL (P = 0.016), and with intact outer retinal layers (P < 0.001), respectively. 1dB increase in retinal sensitivity was correlated with 2.2 μm (95 % confidence interval, 1.71–2.7) increase of the thickness (P < 0.001). The retinal sensitivity was significantly lower at points with both DRIL and outer retinal layers disruption than at the points with DRIL or outer retina layers disruption alone (P = 0.001, P = 0.001).

Conclusions

Alterations in the macular microstructure are associated with ischemia, especially DRIL. DRIL and outer retinal layers disruption are imaging features that have important implications for local retinal sensitivity in the ischemic areas, and where the microstructure of both inner and outer retinal layers is disrupted the function is further destructed.

Bilateral Retinal Vein Occlusion-Simulated Coats' Disease

Retinal vein occlusion (RVO) is a differential diagnosis for Coats' disease due to retinal arterial Leber's aneurysms. Occasionally, RVO shows a Coats-like appearance. The differential diagnosis between Coats' disease and RVO is essential for clinical therapy, especially for those obsolete RVOs with collateral vessels and without retinal hemorrhage. In this case report, we describe and discuss the imaging characteristics of bilateral RVO-simulated Coats' disease with tortuous retinal arterioles and its prognosis after anti-vascular endothelial growth factor therapy, which will be beneficial for its definite diagnosis and aid further investigation.

Changes in Macular Microvascular Structure in Macular Edema Secondary to Branch Retinal Vein Occlusion Treated with Antivascular Endothelial Growth Factor for One Year

Purpose

To observe the changes in macular microvascular structure and the correlation between anatomy and visual function in patients with macular edema secondary to branch retinal vein occlusion (BRVO) treated with antivascular endothelial growth factor for one year.

Methods

This prospective study enrolled 39 patients (one eye per patient) who received intravitreal injections of ranibizumab for macular edema secondary to BRVO. All patients received a minimum of 3 initial monthly ranibizumab injections and criteria-driven pro re nata (PRN) dosing thereafter for visual acuity (VA) and central retinal thickness (CRT) stabilization. The follow-up period of this study was one year. The vascular density (VD) of the superficial retinal capillary plexus (SCP) and deep retinal capillary plexus (DCP), the foveal avascular zone (FAZ) area, the FAZ perimeter, the VD within a 300 μm wide ring surrounding the FAZ (FD-300), and the acircularity index (AI) were measured automatically by optical coherence tomography angiography (OCTA) at baseline, month 6, and month 12.

Results

Compared with those before treatment, the VD of the SCP significantly decreased 6 months after treatment (P < 0.05), while the area and perimeter of the FAZ increased significantly (P < 0.01). After 12 months of treatment, the area and perimeter of the FAZ increased significantly (P < 0.01). There was no significant difference in any parameters between 12 months and 6 months after treatment (P > 0.05). The change in BCVA was negatively correlated with the VD of the SCP at 12 months (P=0.0447, r = -0.3233). There was a relationship between the DBP and AI, and CRT was related to VD of DCP at baseline (P=0.028,  0.0209; r = 0.383, -0.384). The PERIM and AI at 12 months were significantly associated with the recurrence of macular edema, and the changes in vascular density in the SCP and PERIM were significantly associated with the number of injections within 12 months (P < 0.05).

Conclusions

One year after ranibizumab treatment, the area and perimeter of the FAZ were enlarged, while the VD of the SCP and DCP remained stable, which indicated that ranibizumab treatment did not improve macular blood supply and macular ischemia in BRVO patients.

Correlation of Retinal Thickness and Swept-Source Optical Coherence Tomography Angiography Derived Vascular Changes in Patients with Neovascular Age-Related Macular Degeneration

Purpose: The aim of this study was to investigate whether structural OCT changes, in specific retinal thickness, is associated with the vascular response within the nAMD CNV lesion. In other words, whether SSOCTA derived parameters may prove suitable to assess CNV activity in future.Methods: During the first 3 months patients were prospectively followed with visits at days 7, and 14 after each anti-VEGF treatment up to day 90. At baseline, day 30 and 60 Aflibercept was administered. OCT-derrived retinal thickness (RT) and OCTA-derived CNV lesion parameters (vessel area [VA]), total vessel length [TVL], total number of junctions [TNJ], junction density [JD]) were determined. Parameters were exported from SSOCT/A (PlexElite, Zeiss) images using the semi-automated AngioTool software. Additionally, the superficial and deep vascular plexus fractal dimension of the para- and perifoveal region were identified. Consequently, all OCTA derived parameters were correlated with RT.Results: 16 consecutive patients presenting with treatment-naïve, SSOCTA-positive CNV lesions were included. A weak to moderate statistically significant correlation was found between the mean RT of the inner as well as the outer ETDRS ring with the SSOCTA-derived vascular markers vessel area (VA; r² = -0.38, p < .001; r² = -0.47, p < .001, respectively), total vessel length, (TVL; r² = -0.38, p < .001; r² = -0.48, p < .001, respectively) and total number of junctions (TNJ; r² = -0.35, p < .001; r² = -0.44, p < .001, respectively). Junctions density (JD), and all variables based on fractal dimension (FD) did not show statistically significant correlations with retinal thickness measurements.Conclusions: In summary, we could confirm a moderate, however, statistically significant correlation between mean para- and perifoveal retinal thickness and the SSOCTA derived vascular parameters VA, TVL, and TNJ. This leads us to the conclusion that an SSOCTA-based activity analysis of the CNV complex is not yet a substitute for retinal thickness or in-depth fluid analysis in patients with nAMD.

Macular Microvascular Changes and Their Correlation With Peripheral Nonperfusion in Branch Retinal Vein Occlusion

PURPOSE

To investigate the correlation between macular microvascular alterations on optical coherence tomography angiography (OCTA) and retinal ischemia on ultra-widefield fluorescein angiography (UWF FA) in eyes with branch retinal vein occlusion (BRVO).

DESIGN

Cross-sectional study.

METHODS

This prospective study was performed from September 2019 to June 2020 at Yeungnam University Medical Center. We included 60 patients with treatment-naïve BRVO. Two independent, masked graders analyzed OCTA parameters, including vessel density, skeletal density, and fractal dimension (FD), and UWF FA parameters, including retinal nonperfusion area (NPA) and ischemic index (ISI), from various concentric regions (perimacular region, 0.5-3 mm radius; near-peripheral region, 3-10 mm; midperipheral region, 10-15 mm; far-peripheral region, >15 mm). A repeated-measures analysis of variance test and a paired t test were performed for inter-visit and inter-regional comparisons, and Pearson correlation coefficient and multivariate regression analyses were performed to examine the correlation between UWF FA and OCTA parameters.

RESULTS

The OCTA parameters from both the superficial and deep capillary plexuses (DCP) were significantly correlated with NPA and ISI in all concentric regions. Even after adjusting for several covariates, all OCTA parameters revealed a significant association with ISI on UWF FA. Moreover, OCTA parameters from DCP were significantly correlated with concentrations of placental growth factor and vascular endothelial growth factor. Although all OCTA parameters achieved excellent results of area under the curve (AUC) > 0.9 for detecting severe retinal ischemia, defined as ISI >10%, FD reduction in DCP was the most reliable parameter (AUC = 0.948, P < .001), and 5.39% was the best cut-off point for predicting ISI > 10%.

CONCLUSIONS

OCTA is a useful noninvasive tool not only for evaluation of macular microvasculature but for supposition of peripheral nonperfusion in eyes with BRVO.

The Structural and Comparative Analysis of Intravitreal Dexamethasone Implant (Ozurdex) and Anti-VEGF Injection in Branched Retinal Vein Occlusion Patients by Optical Coherence Tomography Angiography Images Quantitation

Background and Objective: To evaluate and compare the structural changes of retinal vasculature after intravitreal dexamethasone implant (Ozurdex) insertion and antivascular endothelial growth factor (anti-VEGF) injection in patients with branched retinal vein occlusion (BRVO) using optical coherence tomography angiography (OCTA).Study Design/Materials and Methods: We retrospectively analyzed 39 patients with unilateral BRVO. Subjects were divided into two groups according to treatment agent: Ozurdex (n = 18) and anti-VEGF (n = 21). Swept Source (SS) OCT and OCTA were performed and images were analyzed quantitatively using ImageJ (National Institutes of Health) software. Intravitreal implant and anti-VEGF injections were performed following a prn regimen. The specific anti-VEGF agent used was chosen among bevacizumab, ranibizumab and aflibercept.Results: Of the 39 patients (mean ± SD age, 70.0 ± 8.9 years [range, 48-89 years]; 20 men [51.0%]) with unilateral BRVO, in an independent two-sample t test, there was greater vascular reperfusion of the choriocapillaris slab in the intravitreal Ozurdex implant group than in the anti-VEGF group using the angiography mode (P = .013). Increased number of particles was more prominent in intravitreal anti-VEGF injection group than intravitreal Ozurdex implant group in outer retina slab of En-face mode (P = .039). There was no statistically significant difference between the 2 treatment groups in relation to the Early Treatment Diabetic Retinopathy Study (ETDRS) density map and other angiography slabs; and the superficial, deep, and outer retina.Conclusions: Results of a quantitative analysis of OCTA images using ImageJ software suggest that the intravitreal Ozurdex implant induced increased retinal vascular perfusion compared with anti-VEGF injection for the treatment of BRVO.

Microvascular comparison in younger and older patients with retinal vein occlusion analyzed by OCT angiography

Background

To compare changes in retinal microvasculature of young and elderly patients with retinal vein occlusion (RVO) after anti-VEGF treatment.

Methods

RVO patients who underwent anti-VEGF treatment were retrospectively reviewed and categorized into two groups based on age. The OCT angiography images were obtained during each visit. Best corrected visual acuity (BCVA), vessel density (VD) and foveal avascular zone (FAZ) were measured and compared between the two groups. Vision improvements and retinal microvasculature changes were also correlated.

Results

Twenty patients with 20 eyes were enrolled in the younger group and 46 patients with 46 eyes were enrolled in the older group. Younger patients demonstrated better BCVA, higher VD and smaller FAZ than older patients at 12 months after the first anti-VEGF treatment. The improvement of VD was observed only in the younger group. A positive correlation between vision improvement and VD increase was noted.

Conclusions

Young patients with RVO can achieve rapid rehabilitation of deep retinal vasculature which lead to a better visual outcome.

Longitudinal Changes on Optical Coherence Tomography Angiography in Retinal Vein Occlusion

Background: To evaluate the longitudinal changes on optical coherence tomography angiography (OCTA) in retinal vein occlusion (RVO). Methods: Retrospective study of patients with RVO treated with intravitreal anti-vascular endothelial growth factors (VEGF) for macular edema. Foveal avascular zone (FAZ) area, vessel density (VD), vessel length density (VLD), and adjusted flow index (AFI) were calculated. The unaffected eye of each participant was used as a control. Results: Twelve RVO eyes were included, receiving 6 ± 3 anti-VEGF injections over a follow-up of 10.4 ± 3.1 months. Compared to fellow eyes, RVO eyes had lower VD and VLD at inclusion (p = 0.07 and p = 0.04) and last visit (p = 0.002 and p < 0.001). VD, AFI, and VLD did not change over time, while FAZ area increased in RVO eyes (+0.016 ± 0.024 mm², p = 0.04). AFI correlated with duration of disease (r = 0.63, p = 0.02). Visual acuity was inversely related to VD and VLD over the follow-up. Conclusions: OCTA parameters remained stable with sustained anti-VEGF treatment in RVO, while changes in the FAZ area may suggest capillary remodeling after RVO.

Retinal nonperfusion in optical coherence tomography angiography

BACKGROUND

Retinal nonperfusion (NP) is a biomarker for assessment of the severity of diabetic retinopathy and retinal vein occlusion. However, various conditions mimic the retinal NP flow void signals that are observed in optical coherence tomography angiography (OCTA).

METHODS

In this review, the possible mechanisms for these similar void flow signals in OCTA were summarized, and the discrepancies between the evaluations of retinal NP with fluorescein angiography and OCTA were also investigated and evaluated in terms of size and morphology.

RESULTS AND CONCLUSION

Vascular occlusion, resulting in retinal ischemia, leads to a flow void signal, indicating retinal NP in OCTA images. In addition, displacement of retinal vessels secondary to cystoid macular edema presents a false NP signal and produces a flow void signal similar to that of retinal NP in OCTA. Finally, various pathological conditions can coexist in the same retinal disease, with one of these factors playing a major role. Understanding the various causes of retinal NP in OCTA will be beneficial in conducting appropriate pathological investigations and making appropriate treatment and management choices.

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.

Ocular microcirculation changes, measured with laser speckle flowgraphy and optical coherence tomography angiography, in branch retinal vein occlusion with macular edema treated by ranibizumab

PURPOSE

This study searched for early predictive vascular biomarkers for visual outcomes in eyes with macular edema caused by branch retinal vein occlusion (BRVOME).

METHODS

Twenty-four eyes of 24 subjects with BRVOME were treated with the intravitreal injection of ranibizumab (IVR) for at least 6 months. We measured mean blur rate (MBR) in the optic nerve head (ONH) and vessel density (VD) in the macula with laser speckle flowgraphy and optical coherence tomography angiography, respectively.

RESULTS

Six-month post-IVR best-corrected visual acuity (BCVA) was correlated positively with age, pre-IVR BCVA, 1-month post-IVR BCVA, 3-month post-IVR BCVA and pre-IVR systolic blood pressure (P < 0.001, P < 0.001, P < 0.001, P < 0.001 and P = 0.02, respectively) and negatively with pre-IVR overall MBR, 1-month post-IVR overall MBR, 6-month post-IVR overall MBR, 3-month post-IVR deep retinal capillary plexus (DCP) VD and 6-month post-IVR DCP VD (P = 0.03, P = 0.03, P = 0.02, P = 0.01 and P = 0.005, respectively). Furthermore, a multiple regression analysis showed that pre-IVR overall MBR (β =  - 0.67, P = 0.009) was among independent prognostic factors predicting 6-month post-IVR BCVA. Six-month post-IVR DCP VD was also correlated with overall MBR at all time points.

CONCLUSION

ONH blood flow may be a pre-IVR biomarker of both visual outcomes and post-IVR deep macular microcirculation in eyes with BRVOME.

Association of retinal vessel density with retinal sensitivity in surgery for idiopathic epiretinal membrane

PURPOSE

The success of surgical treatment for idiopathic epiretinal membrane (ERM) is measured by postoperative best-corrected visual acuity (BCVA), metamorphopsia, and foveal retinal sensitivity (RS).This study searched for predictive biomarkers of surgical success by determining the association between foveal RS and various aspects of vessel density (VD) in the fovea of patients with ERM.

METHODS

The study examined 25 eyes of 25 patients with ERM who underwent 27-gauge microincision vitrectomy surgery (MIVS). RS was measured with microperimetry (MP-3; NIDEK) at four central points in the fovea with an interpoint distance of 2°. VD was measured with SD-OCT (RS 3000; NIDEK) within the 1-mm² square defined by the 4 RS points at various depths, including the superficial and deep retinal capillary plexus (SCP and DCP, respectively).

RESULTS

Though VD did not change throughout the follow-up period, BCVA and RS significantly improved 1 and 3 months after surgery, respectively (both P < 0.0017). Postoperative RS at 6 months was positively correlated with postoperative DCP VD at 1, 3, and 6 months (r = 0.62, P = 0.001; r = 0.40, P = 0.049; r = 0.53, P = 0.007, respectively), but not with SCP VD at any time point. Multiple regression analysis confirmed that postoperative RS at 6 months was associated with postoperative DCP VD at 1 month (P = 0.03).

CONCLUSION

Higher postoperative DCP VD at 1 month contributed to better postoperative foveal RS at 6 months. Early postoperative VD in the fovea might be a useful predictive biomarker of late postoperative RS in the fovea in ERM patients.

Comparison between Ozurdex and intravitreal anti-vascular endothelial growth factor treatment for retinal vein occlusion-related macular edema: A systematic review and meta-analysis of randomized controlled trials

This systematic review aimed to evaluate the effectiveness and safety of intravitreal dexamethasone (DEX) implant and intravitreal anti-vascular endothelial growth factor (VEGF) treatments for macular edema (ME) secondary to retinal vein occlusion (RVO), central retinal vein occlusion (CRVO), and branch retinal vein occlusion (BRVO). The electronic databases comprehensively searched for the studies that compared DEX with anti-VEGF treatments in patients suffering from RVO-related ME. The effectiveness was estimated using best-corrected visual acuity (BCVA), central retinal thickness (CRT), and intraocular pressure (IOP). All data were analyzed by Review Manager (RevMan) 5.3. According to the meta-analysis from five randomized control trials, both DEX implant and anti-VEGF agent treatments were effective, but no significant differences in BCVA and CRT were observed between these two treatments. Novartis’ two studies indicated that anti-VEGF agents significantly reduced the CRT compared with DEX implant at 6 months [weighted mean difference: 158.53 μm, 95% confidence interval (CI): (71.09, 245.96), P = 0.0004]. Furthermore, anti-VEGF agents showed some advantages on cataract formation [risk ratio (RR): 3.43, 95% CI: (1.35, 8.71), P = 0.009] and other adverse events [RR: 1.19, 95% CI: (1.09, 1.31), P = 0.0002] without heterogeneity (P = 0.20, I² = 35%). Anti-VEGF agents were also effective treatments for cataract formation or less adverse events for RVO-related ME. In contrast, DEX implant had higher risk for IOP elevation and lower cataract incidence than anti-VEGF agents. Hence, complementary and alternative treatments are expected.

Quantitative optical coherence tomography angiography: A review

As a new optical coherence tomography (OCT) modality, OCT angiography (OCTA) provides a noninvasive method to detect microvascular distortions correlated with eye conditions. By providing unparalleled capability to differentiate individual plexus layers in the retina, OCTA has demonstrated its excellence in clinical management of diabetic retinopathy, glaucoma, sickle cell retinopathy, diabetic macular edema, and other eye diseases. Quantitative OCTA analysis of retinal and choroidal vasculatures is essential to standardize objective interpretations of clinical outcome. Quantitative features, including blood vessel tortuosity, blood vessel caliber, blood vessel density, vessel perimeter index, fovea avascular zone area, fovea avascular zone contour irregularity, vessel branching coefficient, vessel branching angle, branching width ratio, and choroidal vascular analysis have been established for objective OCTA assessment. Moreover, differential artery–vein analysis has been recently demonstrated to improve OCTA performance for objective detection and classification of eye diseases. In this review, technical rationales and clinical applications of these quantitative OCTA features are summarized, and future prospects for using these quantitative OCTA features for artificial intelligence classification of eye conditions are discussed.

Higher aqueous levels of matrix metalloproteinases indicated visual impairment in patients with retina vein occlusion after anti-VEGF therapy

PURPOSE

To investigate the levels of matrix metalloproteinases (MMPs) in aqueous humour of patients with retinal vein occlusion (RVO) and the relationship between intraocular MMP levels and retinal lesion and visual prognosis.

MATERIALS AND METHODS

52 RVO patients, including 23 with central retinal vein occlusion (CRVO) and 29 with branch retinal vein occlusion (BRVO) and 20 participants with senile cataract were enrolled in this study. Retinal lesions were examined by fundus colour photography, fluorescein fundus angiography and optical coherence tomographic angiography. Sixty microliters of aqueous humour were collected during intravitreal anti-Vascular Endothelial Growth Factor (VEGF) injection or cataract surgery. The aqueous levels of MMP-1, MMP-2, MMP-7, MMP-9 and MMP-10 were measured using the Luminex xMAP multiplex assay. The relationship between MMP levels and clinical presentations was analysed by Pearson correlation test.

RESULTS

The aqueous humour levels of MMP-1, MMP-2, MMP-7 and MMP-9, but not MMP10 in RVO patients were significantly higher than those in people with cataract after adjusting for age. Further analysis of RVO subgroups showed that the aqueous humour level of MMP2 in CRVO was significantly higher than that in BRVO. The aqueous humour levels of MMP-1 and MMP-2 were positively correlated with superficial capillary plexus vessel density (SVD), whereas the aqueous humour levels of MMP-1 and MMP-7 were negatively correlated with visual improvement following treatment. No correlation between aqueous humour levels of MMP and disease duration and central retinal thickness was observed.

CONCLUSIONS

RVO eyes had significantly higher intraocular levels of MMP-1, MMP-2, MMP-7 and MMP-9 than cataract eyes and the level of MMP2 appears to be related to the area of occlusion. Intraocular levels of MMP may positively affect SVD and negatively impact visual function in RVO.

Papillary Vessel Density Changes After Intravitreal Anti-VEGF Injections in Hypertensive Patients with Central Retinal Vein Occlusion: An Angio-OCT Study

PURPOSE

To investigate papillary microvascular changes in patients affected by macular edema due to Central Retinal Vein Occlusions (CRVO) after anti-Vascular Endothelial Growth Factor (VEGF) therapy.

METHODS

Prospective analysis of papillary and peripapillary vessel density (VD) changes in 18 eyes of 18 hypertensive patients affected by CRVO before and after the loading-phase of intravitreal Ranibizumab (IVR) injections. Data were quantitatively measured by optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) before as well as 1 month and 4 months after injections. The correlation between post-treatment best-corrected visual acuity (BCVA) and changes in the retinal microvasculature evaluated by OCTA was assessed. Results: 18 eyes of 18 consecutive patients with a known history of arterial hypertension and affected by an acute CRVO episode were enrolled. Central macular thickness (CMT) was significantly reduced after IVR injections (p < 0.001), while mean BCVA improved from 0.70 ± 0.26 logarithm of the minimal angle of resolution (logMAR) units at baseline to 0.25 ± 0.18 logMAR units after 4 months (p < 0.001). VD inside disc and peripapillary significantly increased (p < 0.001 and p = 0.01, respectively) after treatment.

CONCLUSIONS

OCTA showed VD increase in the papillary area in patients affected by CRVO after anti-VEGF therapy. This area could represent a new region of interest to study microvasculature changes concomitant with severe macular edema.

A Novel Automatic Method to Estimate Visual Acuity and Analyze the Retinal Vasculature in Retinal Vein Occlusion Using Swept Source Optical Coherence Tomography Angiography

The assessment of vascular biomarkers and their correlation with visual acuity is one of the most important issues in the diagnosis and follow-up of retinal vein occlusions (RVOs). The high workloads of clinical practice make it necessary to have a fast, objective, and automatic method to analyze image features and correlate them with visual function. The aim of this study is to propose a fully automatic system which is capable of estimating visual acuity (VA) in RVO eyes, based only on information obtained from macular optical coherence tomography angiography (OCTA) images. We also propose an automatic methodology to rapidly measure the foveal avascular zone (FAZ) area and the vascular density (VD) in the superficial and deep capillary plexuses in swept-source OCTA images centered on the fovea. The proposed methodology is validated using a representative sample of 133 visits of 50 RVO patients. Our methodology estimates VA with very high precision and is even more accurate when we integrate depth information, providing a high correlation index of 0.869 with the real VA, which outperforms the correlation index of 0.855 obtained when estimating VA from the data obtained by the semiautomatic existing method. In conclusion, the proposed method is the first computational system able to estimate VA in RVO, with the additional benefits of being automatic, less time-consuming, objective and more accurate. Furthermore, the proposed method is able to integrate depth information, a feature which is lacking in the existing method.

Vitrectomy for macular edema due to retinal vein occlusion

Purpose: To determine the long-term outcomes of vitrectomy for the macular edema associated with a retinal vein occlusion (RVO).

Methods: This was a retrospective, consecutive, interventional case series. The intraoperative procedures included internal limiting membrane peeling, arteriovenous sheathotomy, radial optic neurotomy, and intravitreal triamcinolone acetonide injection at the end of the surgery. The main outcome was the best-corrected visual acuity (BCVA).

Results: Eight hundred and fifty-four eyes of 854 patients were studied. The eyes consisted of 602 with branch RVO (BRVO), 74 with hemi-central RVO (hemi-CRVO), 87 with nonischemic central retinal vein occlusion (CRVO), and 91 with ischemic CRVO. The mean follow-up period was 68.6 months with a range of 12 to 262 months. The mean BCVA was significantly improved at the final visit (P<0.0001 to 0.0016). The final BCVA improved in 74.4% of the BRVO eyes, in 58.1% of the hemi-CRVO eyes, in 57.4% of the nonischemic CRVO eyes, and in 51.6% of the ischemic CRVO eyes. Multiple regression analysis showed there was no significant relationship between the intraoperative combined procedures and the final BCVA.

Conclusions: The results indicate that the type of RVO is significantly associated with the final BCVA, and vitrectomy is a treatment option to improve and maintain BCVA for a long term.

[Foveal avascular zone and OCT angiography. An overview of current knowledge]

BACKGROUND

The foveal avascular zone (FAZ) has often been analyzed under different aspects in the last decades, mainly by fluorescence angiography (FA); however, the novel technology of optical coherence tomography angiography (OCTA) enables a non-invasive examination, visualization and quantitative analysis of the FAZ, which has recently led to many new findings, especially in a multidisciplinary manner. This article provides an overview of the investigation of the FAZ using OCTA and the new findings that have been obtained using OCTA in recent years.

METHODS

This article is based on a comprehensive literature review.

RESULTS

In many studies a good reproducibility and repeatability of the FAZ measurements by OCTA could be proven, also by comparing different OCTA devices. In patients with ocular pathologies and systemic diseases, e. g. after retinal vein occlusion or retinal surgery and in patients with diabetes mellitus without diabetic retinopathy, differences to healthy control groups and correlations to visual function could be shown. Moreover, in patients with neurological diseases, such as Alzheimer's dementia, changes of the FAZ could be identified.

CONCLUSION

The OCTA is a non-invasive technology, which enables a reliable visualization and reproducible quantification of the FAZ. The size of the FAZ seems to be altered in different retinal and systemic diseases, which also may correlate with visual function; however, long-term studies evaluating the diagnostic value of these changes in the course of the disease are currently lacking.

Longitudinal vasculature changes in branch retinal vein occlusion with projection-resolved optical coherence tomography angiography

PURPOSE

To analyze vascular changes in branch retinal vein occlusion (BRVO) using projection-resolved optical coherence tomography angiography (PR-OCTA).

METHODS

We reviewed 30 consecutive eyes of 30 cases with BRVO retrospectively. PR-OCTA was performed during the acute, intermediate, and remission phases when anti-vascular endothelial growth factor drugs suppress cystic changes. The main outcome measures were vessel density (VD) and retinal thickness changes in the superficial capillary plexus (SCP), intermediate capillary plexus (ICP), and deep capillary plexus (DCP).

RESULTS

The VDs did not change longitudinally in the SCP and DCP during the follow-up period. The VD was significantly (p = 0.0105) greater in the ICP during remission than the acute phase. The full retinal thickness (internal limiting membrane [ILM] to retinal pigment epithelium [RPE]) and inner retinal thickness (ILM to inner plexiform layer [IPL]) decreased significantly (p = 0.0002 and p = 0.0014, respectively) during the follow-up period. When the inner retina was thinner than 117 μm, the VD in the ICP increased significantly (p = 0.045) during the follow-up period. When the inner retinal layer did not become thinner, the VD in the ICP remained unchanged.

CONCLUSION

PR-OCTA showed the three distinct vascular plexuses in BRVO. The VDs remained unchanged during the follow-up period in the SCP and DCP but increased significantly in the ICP during remission. Inner retinal thinning might cause increases in the VD in the ICP because of projection artifacts and segmentation errors despite using PR-OCTA.

Quantitative Analysis of Retinal Microvascular Changes after Conbercept Therapy in Branch Retinal Vein Occlusion Using Optical Coherence Tomography Angiography

PURPOSE

To quantitatively evaluate microvascular changes in eyes with macular oedema due to branch retinal vein occlusion (BRVO) using optical coherence tomography angiography (OCTA) before and after intravitreal conbercept injection and the correlation of such changes with best-corrected visual acuity (BCVA) and retinal thickness.

METHODS

Twenty-eight eyes of 28 patients treated with a single intravitreal injection of conbercept for macular oedema due to BRVO were included in this study. The automatically measured values of the vessel density in the superficial (SCP) and deep retinal capillary plexus (DCP), the foveal avascular zone (FAZ) area, the FAZ perimeter, the vessel density within a 300 μm wide ring surrounding the FAZ (FD-300), the acircularity index (AI), the choriocapillaris flow area and the retinal thickness were obtained via OCTA before and at 1 month after initial injection and compared with those of age- and sex- matched healthy subjects.

RESULTS

In BRVO eyes, the vascular density in the SCP and DCP, the FD-300 and the flow area of choriocapillaris were significantly lower than those in healthy eyes, while the AI and the retinal thickness were significantly increased. After treatment, the retinal thickness in eyes with BRVO was significantly decreased in all quadrants, and the mean BCVA dramatically increased from 20/162 to 20/78 (p = 0.0017). The mean flow area of choriocapillaris significantly improved after treatment. Moreover, negative correlations between the logMAR BCVA and the whole vascular density in the SCP and DCP as well as the flow area of choriocapillaris were observed.

CONCLUSION

OCTA enables non-invasive, layer-specific and quantitative assessment of microvascular changes in eyes with BRVO before and after treatment, and it can be used as a valuable imaging tool for the evaluation of the follow-up in BRVO patients.

Microvascular changes after conbercept therapy in central retinal vein occlusion analyzed by optical coherence tomography angiography

AIM

To investigate microvascular changes in eyes with central retinal vein occlusion (CRVO) complicated by macular edema before and after intravitreal conbercept injection and evaluate correlations between these changes and best-corrected visual acuity (BCVA) and retinal thickness.

METHODS

Twenty-eight eyes of 28 patients with macular edema caused by CRVO were included in this retrospective study. All patients received a single intravitreal conbercept injection to treat macular edema. BCVA and the results of optical coherence tomography angiography (OCTA) automatic measurements of the vessel density in the superficial (SCP) and deep retinal capillary plexus (DCP), the foveal avascular zone (FAZ) area, the FAZ perimeter (PERIM), the vessel density within a 300-µm wide ring surrounding the FAZ (FD-300), the acircularity index (AI), the choriocapillaris flow area, and retinal thickness were recorded before and at one month after treatment and compared with the results observed in age- and sex-matched healthy subjects.

RESULTS

The vessel density in the SCP and DCP, the FD-300, and the flow area of the choriocapillaris were all significantly lower in CRVO eyes than in healthy eyes, while the AI and retinal thickness were significantly higher (all P<0.05). After treatment, retinal thickness was significantly decreased, and the mean BCVA had markedly improved from 20/167 to 20/65 (P=0.0092). The flow area of the choriocapillaris was also significantly improved, which may result from the reduction of shadowing effect caused by the attenuation of macular edema. However, there were no significant changes in SCP and DCP vessel density after treatment. The flow area of the choriocapillaris at baseline was negatively correlated with retinal thickness.

CONCLUSION

OCTA enables the non-invasive, layer-specific and quantitative assessment of microvascular changes both before and after treatment, and can therefore be used as a valuable imaging tool for the evaluation of the follow-up in CRVO patients.

Five-year outcomes of retinal vein occlusion treated with vascular endothelial growth factor inhibitors

Purpose

Report 5-year outcomes of patients receiving anti-vascular endothelial growth factor (VEGF) for the treatment of macular oedema secondary to retinal vein occlusion (RVO.

Methods

Retrospective review of eyes with RVO which initiated anti-VEGF treatment. Data including age, gender, visual acuity (VA) and injection numbers were obtained from medical records. Optical coherence tomography scans were graded for presence or absence of macular oedema and central foveal thickness (CFT). Macular perfusion was assessed on fundus fluorescein angiography by masked graders.

Results

68 eyes (31 branch RVO, BRVO; 35 central RVO, CRVO and 2 hemi-RVO) with 5 years of follow-up after initiation of anti-VEGF treatment. Mean change in VA at 5 years was + 9.6 ± 21.6 letters among CRVO eyes and + 14.2 ± 15.6 letters among eyes with BRVO (p=0.001). Vision of 20/40 or better was achieved in 65 % of treated eyes. The proportion of eyes with a three-line improvement of vision (15 letters) at 5 years was 22 %. Mean CFT decreased by 257.6 ± 249.8 µm in eyes with CRVO and 145.6 ± 143.3 µm in eyes with BRVO.

Conclusion

The results confirm good long-term outcomes can be achieved with anti-VEGF therapy for RVO.