[Retinal vein occlusion : Epidemiology, classification and clinical findings]

Retinal Vascular Occlusion and Underlying Generalized Vascular Diseases

Retinal vascular occlusion not only threatens vision loss but is also associated with other systemic risk factors and vascular diseases. Interdisciplinary cooperation is of great importance in these patients. The risk factors hardly differ between arterial and venous retinal occlusions, which is due to the special anatomy of retinal vessels. Major underlying conditions associated with retinal vascular occlusion include arterial hypertension, diabetes mellitus, dyslipidemia, cardiac disease, particularly atrial fibrillation, or vasculitis of large- and middle-sized arteries. Every new diagnosed retinal vascular occlusion should therefore be taken as an occasion to search for risk factors and possibly adjust an already existing therapy in order to prevent further vascular events.

Evaluation of Automated Measurement of Macular Ischemic Changes in Retinal Vein Occlusion With Optical Coherence Tomography Angiography

OBJECTIVE

The foveal avascular zone (FAZ) is altered in patients with retinal vein occlusion (RVO) and correlates inversely with visual acuity. Optical coherence tomography angiography (OCTA) is an imaging tool to visualize FAZ safely and easily. Automated measurements can facilitate interpretation of OCTA images. In this comparative cross-sectional study, we compare the results of manual measurement of the FAZ with automated measurement by built-in application (Metrix).

METHODS

The study included patients with RVO who underwent OCTA. Manual measurement was compared with automated evaluation by Metrix in 3 mm x 3 mm and 6 mm x 6 mm scan sizes and correlations of the circularity, circumference, and size of the FAZ were calculated.

RESULTS

Forty-seven eyes were included in the study. A reliable measurement result in both Metrix 3 mm x 3 mm and 6 mm x 6 mm was found in only 25 of 47 eyes. The mean FAZ in these eyes by manual measurement was 0.50 mm2 compared with 0.20 mm2 and 0.24 mm2, respectively, by automated measurement. A statistically significant inverse correlation was found in both the automated 3 mm x 3 mm and 6 mm x 6 mm measurements for FAZ circumference with FAZ circularity but not FAZ area.

CONCLUSION

The two automated measurements showed no significant bias regarding the size of the FAZ, but the plausibility of the data should be checked on a case-by-case basis. The manual measurements were higher, indicating limited agreement of manual and automated measurements. The information on circularity can point to ischemic maculopathy early in the course of the disease. [Ophthalmic Surg Lasers Imaging Retina 2023;54:462-469.].

[Asymmetric dimethylarginine (ADMA) in retinal vein occlusion-Results from the Gutenberg RVO study]

BACKGROUND

Asymmetric dimethylarginine (ADMA) is considered an independent cardiovascular risk factor (cvRF) and thus represents a potential new biomarker for retinal vein occlusion (RVO).

METHODS

Overall, 92 patients with RVO and the same number of matched controls were included in the Gutenberg RVO study. All patients underwent a standardized examination for cvRF at the study center of the population-based Gutenberg health study (GHS) as well as ophthalmological examinations and intensive laboratory tests. This article presents a substudy of patients (≤65 years old) and the controls in whom ADMA was additionally determined by high performance liquid chromatography (HPLC) at baseline and 4-6 weeks later.

RESULTS

Out of 44 patients with RVO 22 had central retinal vein occlusion (CRVO), 15 had branch retinal vein occlusion (BRVO) and 7 had hemiretinal vein occlusion (hemi-RVO). The ADMA levels were 0.383 ± 0.094 µM (mean ± standard deviation) in RVO patients at baseline and 0.380 ± 0.093 µM (p = 0.514, initial vs. follow-up) after the follow-up period versus 0.360 ± 0.077 µM (p = 0.175, controls vs. RVO) in controls (n = 44). Arterial hypertension was the most prevalent risk factor in 22 (50%) of the patients and in 11 (25%) of the controls (odds ratio, OR 2.77, 95% confidence interval, CI 0.97-7.95; p = 0.058). The ADMA values above the 95th percentile (>0.530 µM) were detected in 4 patients with RVO (9.1%) but not in any of the controls (p = 0.041, RVO vs. controls).

CONCLUSION

Hypertension is the most important risk factor for RVO. Due to the high number of hypertensive patients in the cohort, the relevance of ADMA as an independent risk factor could neither be confirmed nor disproved.

Intravitreal injection of conbercept combined with retinal photocoagulation on macular edema secondary to branch retinal vein occlusion

Effects of Conbercept combined with retinal photocoagulation on macular edema secondary to branch retinal vein occlusion (BRVO) were investigated. A total of 98 patients (98 eyes) with macular edema secondary to BRVO were collected. The central macular thickness (CMT), incidence rate of complications after treatment and best corrected visual acuity (BCVA) were recorded. Also the factors affecting visual recovery of patients were analyzed. At 1 week, 1 month, 3 months and 6 months after treatment, the BCVA in both groups was significantly superior to that before treatment (P<0.05). In the combination group and laser group, the logarithm of the minimum angle of resolution (logMAR) of BCVA increased from 0.84±0.47 to 0.34±0.10 and from 0.89±0.49 to 0.45±0.14, and CMT declined from 559.5±152.7 to 267.8±19.8 µm and from 570.3±172.6 to 314.7±18.4 µm. It was observed that at 1 week, 1 month, 3 months and 6 months after treatment, the BCVA in combination group was obviously better than that in laser group (P=0.008, P<0.001, P=0.004, P<0.001, respectively), while CMT in combination group was obviously smaller than that in laser group (P=0.009, P=0.002, P<0.001, P<0.001). Conbercept with retinal photocoagulation can effectively improve the visual acuity and reduce the CMT. The visual recovery of patients after treatment is related to the BCVA before treatment, decreased value of CMT at 1 month after treatment and integrity of external limiting membrane (ELM).

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.

Comparison of foveal avascular zone between optical coherence tomography angiography and fluorescein angiography in patients with retinal vein occlusion

OBJECTIVE

To compare area of foveal avascular zone (FAZ) in different retinal vascular layers in optical coherence tomography angiography (OCTA) and fluorescein angiography (FA) in patients with retinal vein occlusion (RVO).

DESIGN AND METHODS

Prospective cross-sectional comparative study in 47 eyes of 47 patients. FA was recorded with the Zeiss FF450plusIR camera and OCTA was obtained with the Zeiss Cirrus 5000 equipped with the AngioPlex module. Area of FAZ was graded by two independent investigators and calculated with Adobe Photoshop. Analysis for the total study population as well as subgroup analysis for branch retinal vein occlusion (BRVO), central retinal vein occlusion (CRVO) and patients with and without macular edema (ME) was performed.

RESULTS

For all patients, FAZ was 0.449 mm2 in FA, 0.496 mm2 in OCTA superficial capillary layer (SCL) and 3.168 in OCTA deep capillary layer (DCL). In patients without ME FAZ was 0.288 mm2 in FA, 0.342 mm2 in OCTA SCL and 1.384 mm2 in OCTA DCL. FAZ area measurement in patients with ME revealed 0.482 mm2 in FA, 0.527 mm2 in OCTA SCL and 3.554 mm2 in OCTA DCL.

CONCLUSIONS

Especially the SCL of OCTA shows a good agreement to FA in measurement of FAZ in all patients with low limits of variation in patients without ME. There were no considerable differences in BRVO and CRVO. OCTA could replace FA in FAZ area measurement in patients with RVO, especially in those without ME, achieving similar measurements whilst being non-invasive.