Choroidal thickness measurements with optical coherence tomography in branch retinal vein occlusion

Longitudinal Assessment of the Choroidal Vascularity Index in Eyes with Branch Retinal Vein Occlusion-Associated Cystoid Macular Edema

INTRODUCTION

Cystoid macular edema (CME) is the most common cause of central vision loss in eyes with branch retinal vein occlusion (BRVO eyes). In recent literature, choroidal vascularity index (CVI) has been proposed to be an enhanced depth imaging optical coherence tomography (EDI-OCT) metric that may help characterize choroidal vascular changes in the setting of retinal ischemia, and potentially prognose visual outcomes and treatment patterns for patients with BRVO-related CME. This study sought to further characterize choroidal vascular changes in BRVO by comparing the CVI, subfoveal choroidal thickness (SFCT), and central subfield thickness (CST) in BRVO eyes with CME compared to unaffected fellow eyes.

METHODS

This was a retrospective cohort study. Subjects included treatment-naïve BRVO eyes with CME diagnosed within 3 months of onset of symptoms and unaffected fellow eyes. EDI-OCT images were collected at baseline and at the 12-month follow-up visit. CVI, SFCT, and CST were measured. Demographics, treatment patterns, and best-corrected visual acuity (VA) were abstracted. Median CVI, SFCT, CST, and VA were compared between the two cohorts. Longitudinal relationships between these variables were analyzed.

RESULTS

A total of 52 treatment-naïve eyes with BRVO and CME and 48 unaffected fellow eyes were identified. Baseline CVI was lower in eyes with BRVO than in fellow eyes (64.7% vs. 66.4%, P = 0.003). At 12 months, there was no difference in CVI between BRVO eyes and fellow eyes (65.7% vs 65.8%, P = 0.536). In BRVO eyes, there was a strong correlation between reduced CST and improved VA over the 12-month study period (r = 0.671, P < 0.001).

CONCLUSION

There are differences in CVI in treatment-naïve BRVO eyes with CME at presentation compared to fellow eyes, but these differences resolve over time. Anatomic changes in macular thickness in BRVO eyes with CME may be correlated with VA outcomes.

Automatic Diagnosis of Different Types of Retinal Vein Occlusion Based on Fundus Images

Retinal vein occlusion (RVO) is the second common cause of blindness following diabetic retinopathy. The manual screening of fundus images to detect RVO is time consuming. Deep‐learning techniques have been used for screening RVO due to their outstanding performance in many applications. However, unlike other images, medical images have smaller lesions, which require a more elaborate approach. To provide patients with an accurate diagnosis, followed by timely and effective treatment, we developed an intelligent method for automatic RVO screening on fundus images. Swin Transformer learns the hierarchy of low‐to high‐level features like the convolutional neural network. However, Swin Transformer extracts features from fundus images through attention modules, which pay more attention to the interrelationship between the features and each other. The model is more universal, does not rely entirely on the data itself, and focuses not only on local information but has a diffusion mechanism from local to global. To suppress overfitting, we adopt a regularization strategy, label smoothing, which uses one‐hot to add noise to reduce the weight of the categories of true sample labels when calculating the loss function. The choice of different models using a 5‐fold cross‐validation on our own datasets indicates that Swin Transformer performs better. The accuracy of classifying all datasets is 98.75 ± 0.000, and the accuracy of identifying MRVO, CRVO, BRVO, and normal, using the method proposed in the paper, is 94.49 ± 0.094, 99.98 ± 0.015, 98.88 ± 0.08, and 99.42 ± 0.012, respectively. The method will be useful to diagnose RVO and help decide grade through fundus images, which has the potency to provide patients with further diagnosis and treatment.

Choroidal Vascularity Index in Central and Branch Retinal Vein Occlusion

(1) Background: we aimed to evaluate choroidal vascularity change in eyes with central and branch retinal vein occlusion (RVO). (2) Methods: in this retrospective cross-sectional study, we reviewed the records of 47 patients with recent-onset, naïve, unilateral retinal vein occlusion. Enhanced-depth imaging optical coherence tomography scans were binarized using the ImageJ software; luminal area (LA) and total choroidal area (TCA) were measured. The choroidal vascularity index (CVI) was calculated as the proportion of LA to TCA. Depending on the pattern of macular oedema, eyes were classified as having no macular oedema (nME), cystoid macular oedema (CME), cystoid macular oedema with serous retinal detachment (mixed). (3) Results: CVI, TCA and LA were greater in eyes with RVO than in fellow, unaffected eyes. No difference was found between central and branch RVO except for central macular thickness (CMT). When compared with controls, eyes with CME presented a significant increase in subfoveal choroidal thickness, CMT, TCA, LA and CVI; eyes with mixed macular oedema had greater CMT and CVI than contralateral eyes; no significant differences in any of the considered parameters were observed in eyes with nME. (4) Conclusions: The results suggest that RVO alters the vascularity of the choroid that varies according to the type of macular oedema.

Role of the choroidal vascularity index in branch retinal vein occlusion (BRVO) with macular edema

Purpose

To assess choroidal vasculature changes in eyes with branch retinal vein occlusion (BRVO) and macular edema (ME) using the choroidal vascularity index (CVI) and evaluate the effectiveness of CVI as a prognostic biomarker.

Methods

35 patients with monocular BRVO and ME were analyzed retrospectively. Luminal and stromal areas in choroids of swept-source optical coherence tomography were calculated using the image binarization technique. The CVI was calculated as the ratio of the luminal to total choroidal area. The CVI of BRVO and ME eyes were compared with that of the unaffected fellow and post anti-vascular endothelial growth factor (VEGF) injected eyes. A regression analysis was performed on the choroidal parameters, logMAR visual acuity (VA) two years post disease onset and central macula thickness (CMT).

Results

The CVI of BRVO and ME eyes was significantly lower than the fellow and post-injected eyes (p<0.05). The regression analysis showed a strong association between two years after logMAR VA and the CVI of fellow eyes (R² = 0.433, p<0.001). Remarkable correlations were observed in the CVI and subfoveal choroidal thickness of BRVO and ME eyes (R² = 0.189, 0.155, respectively, p<0.05). The CMT of diseased eyes were also significantly associated with the CVI of unaffected fellow eyes (R² = 0.113, p<0.05).

Conclusions

The alteration of CVI in BRVO and ME suggests that choroidal vasculature might be affected by extracellular fluid shift and VEGF changes. The fellow eye CVI could be a useful supplementary prognostic biomarker.

Treatment Results of Bevacizumab for Macular Edema Secondary to Branch Retinal Vein Occlusion

Purpose: To evaluate the results of treatment according to the method of intravitreal injection of bevacizumab for macular edema due to branch retinal vein occlusion (BRVO). Methods: The clinical records of macular edema patients were analyzed retrospectively for a total of 62 eyes of 62 patients who were injected with bevacizumab into the vitreous as the first treatment for BRVO. Best-corrected visual acuity (BCVA), the findings of spectral-domain optical coherence tomography before and after injection, and prognosis-related factors were evaluated for 21 eyes that received the initial three monthly loading treatments and the 41 eyes that did not. Results: Significant improvement in BCVA was observed in the group having received the initial three injections compared with the group who did not receive the injections at 3, 6, and 12 months (<i>p</i> = 0.025, <i>p</i> = 0.019, and <i>p</i> = 0.008, respectively). The central macular thickness (CMT) showed greater improvement in the initial three injections group than the group without at 6 months (<i>p</i> = 0.034). Multivariate regression showed that the duration from the onset, the three loadings, BCVA, disorganization of the retinal inner layer (DRIL), and choroidal thickness were predictors related to visual gain (<i>p</i> = 0.044, <i>p</i> = 0.047, <i>p</i> = 0.004, <i>p</i> = 0.045, and <i>p</i> = 0.034, respectively). Age, three loadings, BCVA, and DRIL were predictors related to final visual acuity (<i>p</i> = 0.045, <i>p</i> = 0.046, <i>p</i> = 0.002, and <i>p</i> = 0.034, respectively). Duration from the onset, CMT, and choroidal thickness were predictors related to CMT improvement (<i>p</i> = 0.042, <i>p</i> = 0.009, and <i>p</i> = 0.015, respectively). Conclusions: In macular edema of BRVO, the initial three monthly intravitreal injections of bevacizumab provided superior treatment outcomes regarding short-term functional and anatomical improvements and long-term functional improvement, compared with methods that did not treat with the initial three monthly injections.

Short-term effects of intravitreal Conbercept injection combined with laser photocoagulation on macular edema secondary to ischemic retinal vein occlusion

AIM

To observe changes in the best-corrected visual acuity (BCVA), central macular thickness (CMT), and central choroidal thickness (CCT) of patients with macular edema (ME) secondary to ischemic retinal vein occlusion (iRVO) following intravitreal Conbercept injection.

METHODS

This retrospective study included 33 eyes from 33 patients who received intravitreal injections of Conbercept for ME secondary to iRVO. Treatments were performed on a 3+pro re nata (3+PRN) basis. All of the patients were examined by fundus fluorescein angiography and spectral domain optical coherence tomography at the first visit. Laser photocoagulation was performed in the nonperfusion area of the retina of all eyes after the first injection. BCVA, CMT, and CCT were observed before and after 6mo of treatment. The number of injections necessary to achieve improved vision was also noted.

RESULTS

Following Conbercept treatment, the mean BCVA significantly improved from 0.81±0.39 at baseline to 0.41±0.25 and 0.43±0.29 logMAR in the third and sixth months, respectively (both P=0.000). The CMT of the patients at baseline was 556.75±98.57 µm; 304.78±68.53 and 306.85±76.77 µm 3 and 6mo after treatment, respectively (both P=0.000 vs baseline). The CCTs of the patients at baseline, 3 and 6mo after treatment were 304.63±57.83, 271.31±45.53, and 272.29±39.93 µm, respectively (P=0.026 and 0.035 vs baseline). No severe adverse event relevant to the therapy was noted, and the average number of injections delivered was 3.35.

CONCLUSION

Intravitreal Conbercept injection combined with laser photocoagulation appears to be a safe and effective treatment for ME secondary to iRVO in the short-term.

Choroidal thickening in retinal vein occlusion patients with serous retinal detachment

PURPOSE

To evaluate choroid thickness and macular retinal metrics in treatment naïve retinal vein occlusion (RVO) patients with serous retinal detachment (SRD) before and after intravitreal anti-vascular endothelial cell growth factor (VEGF) injection and to elucidate the possible role of choroid in the development of SRD and the potential role of SRD as a prognostic parameter.

METHODS

This is a retrospective study involving 85 RVO patients, 41 central retinal vein occlusion (CRVO), and 44 branch retinal vein occlusion (BRVO), with macular edema: 21 central retinal vein occlusion and 22 branch retinal vein occlusion with SRD and the rest without SRD. Patients were evaluated with ophthalmic examinations and swept-source optical coherence tomography (SS-OCT) both before and 4-6 weeks after intravitreal anti-VEGF treatment. Choroid thickness and retinal metrics were measured and compared between SRD and non-SRD groups within each RVO subtype.

RESULTS

In both CRVO and BRVO patients, the mean central subfield foveal thickness (CSFT) and central subfoveal choroid thickness (CSCT) of the SRD groups were thicker than those in the non-SRD groups (p < 0.05) at onset. After one anti-VEGF injection, CSFT and FNRT decreased in all groups (p < 0.05). The CSCTs were thicker in the SRD groups compared with the non-SRD groups (p < 0.05). The mean changes of CSFT were more remarkable in the SRD groups (p < 0.05).

CONCLUSION

Thicker choroid was a feature of naïve RVO patients with SRD and SRD may be an indicator of better anatomical recovery of retina in RVO patients after a single dose of anti-VEGF treatment.

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.

10-year fundus tessellation progression and retinal vein occlusion

AIM

To access the 10-year fundus tessellation progression in patients with retinal vein occlusion.

METHODS

The Beijing Eye Study 2001/2011 is a population-based longitudinal study. The study participants underwent a detailed physical and ophthalmic examination. Degree of fundus tessellation was graded by using fundus photographs of the macula and optic disc. Progression of fundus tessellation was calculated by fundus tessellation degree of 2011 minus degree of 2001. Fundus photographs were used for assessment of retinal vein occlusion.

RESULTS

The Beijing Eye Study included 4403 subjects in 2001, 3468 subjects was repeated in 2011. Assessment of retinal vein obstruction and fundus tessellation progression were available for 2462 subjects (71.0%), with 66 subjects fulfilled the diagnosis of retinal vein occlusion. Of the 66 participants, 59 participants with unilateral branch retinal vein occlusion, 5 participants with unilateral central retinal vein occlusion, 1 participant with bilateral branch retinal vein occlusion, and 1 participant with branch retinal vein occlusion in one eye and central retinal vein occlusion in the other eye. Mean degree of peripapillary fundus tessellation progression were significantly higher in the whole retinal vein occlusion group (0.33±0.39, P<0.001), central retinal vein occlusion group (0.71±0.8, P=0.025) and branch retinal vein occlusion group (0.29±0.34, P=0.006) than the control group (0.20±0.26). After adjustment for age, prevalence of tilted disc, change of best corrected visual acuity, axial length, progression of peripapillary fundus tessellation was associated with the presence of retinal vein occlusion (P=0.004; regression coefficient B, 0.094; 95%CI, 0.029, 0.158; standardized coefficient B, 0.056). As a corollary, after adjusting for smoking duration, systolic blood pressure, anterior corneal curvature, prevalence of RVO was associated with more peripapillary fundus tessellation progression (P<0.001; regression coefficient B: 1.257; OR: 3.517; 95%CI: 1.777, 6.958).

CONCLUSION

Peripapillary fundus tessellation progresses faster in individuals with retinal vein occlusion. This may reflect the thinning and hypoperfusion of choroid in patients with retinal vein occlusion.