Genetically predicted retinal vascular occlusion in relation to cardiovascular diseases: A bidirectional two-sample Mendelian randomization analysis.

INTRODUCTION: Increasing evidence implicates retinal vascular occlusions as a susceptibility factor for cardiovascular diseases (CVDs), whereas inconsistent results on the relationship were reported in previous observational studies. This research using a bidirectional two-sample Mendelian randomization (MR) analysis aimed to investigate the potential association between genetically determined central/branch retinal artery and retinal vein occlusions (CRAO/BRAO/RVO) and the risk of CVD. METHODS: Summary statistics of retinal vascular occlusions from the largest available genome-wide association study of European descent were used to investigate their relationship with CVDs, and vice versa. Primary analyses were conducted using the common inverse-variance weighted approach. Several complementary sensitivity analyses were performed to verify the reliability of our results. RESULTS: Inverse variance weighted method showed suggestive effects of genetically determined RVO on ischemic stroke (IS) (odds ratio [OR] = 1.021, 95% confidence [CI] = 1.004-1.037, p = 0.012), a genetic liability to CRAO increased the risk of myocardial infarction (MI) (OR = 1.014, 95% CI = 1.006-1.023, p = 7.0 × 10-4). In addition, genetic predisposition to BRAO had a positive effect on stroke (OR = 1.008, 95% CI = 1.002-1.013, p = 0.011), IS (OR = 1.007, 95% CI = 1.001-1.014, p = 0.022), and cardioembolic stroke (CES) (OR = 1.018, 95% CI = 1.006-1.031, p = 0.004). The point estimates from sensitivity analyses were in the same direction. Reverse MR analyses found no significant evidence for the effect of CVDs on retinal vascular occlusions. CONCLUSION: Our MR study provides potential evidence that retinal vascular occlusions are causally linked to increased risk of CVDs including IS, MI, stroke, and CES. This supports the need for clinical CVD screening in individuals with retinal vascular occlusions. Further investigations are warranted to clarify the effects of CVDs on ocular comorbidities.

SARS-CoV-2 neurovascular invasion supported by Mendelian randomization.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is known to affect vessels and nerves and can be easily visualized in the retina. However, the effect of SARS-CoV-2 on retinal morphology remains controversial. In the present research, we applied Mendelian randomization (MR) analysis to estimate the association between SARS-CoV-2 and changes in the thickness of the inner retina. METHODS: Two-sample MR analysis was conducted using summary-level data from 3 open genome-wide association study databases concerning COVID-19 infection (2,942,817 participants) and COVID-19 hospitalization (2,401,372 participants); moreover, the dataset of inner retina thickness, including the macular retinal nerve fiber layer (mRNFL) and macular ganglion cell-inner plexiform layer (mGCIPL), included 31,434 optical coherence tomography (OCT) images derived from healthy UK Biobank participants. All the participants were of European ancestry. The inverse variance weighted (IVW) meta-analysis was used as our primary method. Various complementary MR approaches were established to provide robust causal estimates under different assumptions. RESULTS: According to our MR analysis, genetically predicted COVID-19 infection was associated with an increased risk of mRNFL and mGCIPL thickness (OR = 1.74, 95% CI 1.20-2.52, P = 3.58 × 10-3; OR = 2.43, 95% CI 1.49-3.96, P = 3.6 × 10-4). The other MR methods produced consistent results. However, genetically predicted COVID-19 hospitalization did not affect the thickness of the inner retina (OR = 1.11, 95% CI 0.90-1.37, P = 0.32; OR = 1.28, 95% CI 0.88-1.85, P = 0.19). CONCLUSION: This work provides the first genetically predictive causal evidence between COVID-19 infection and inner retinal thickness in a European population. These findings will contribute to further understanding of the pathogenesis of COVID-19 and stimulate improvements in treatment modalities.

Resveratrol Ameliorates Retinal Ischemia-Reperfusion Injury by Modulating the NLRP3 Inflammasome and Keap1/Nrf2/HO-1 Signaling Pathway.

Glaucoma, as an ischemia-reperfusion (I/R) injury disease, leading irreversible blindness through the loss of retinal ganglion cells (RGCs), mediated by various pathways. Resveratrol (Res) is a polyphenolic compound that exerts protective effects against I/R injury in many tissues. This article aimed to expound the underlying mechanisms through which Res protects RGCs and reduces visual dysfunction in vivo. An experimental glaucoma model was created using 6-8-week wild-type male C57BL/6J mice. Res was injected intraperitoneally for 5 days. The mice were then grouped according to the number of days after surgery and whether Res treatment was administered. We applied the Brn3a-labeled immunofluorescence staining and flash electroretinography (ERG) to assess the survival of RGCs and visual function. The expression of components of the NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome, the interleukin-1-beta (IL-1ß), and vital indicators of kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2)/heme-oxygenase 1 (HO-1) pathway at the protein and RNA levels were detected respectively. The survival of RGCs was reduced after surgery compared to controls, whereas Res application rescued RGCs and improved visual dysfunction. In conclusion, our results discovered that Res administration showed neuroprotective effects through inhibition of the NLRP3 inflammasome pathway and activation of Keap1/Nrf2/HO-1 pathway. Thus, we further elucidated the potential of Res in glaucoma therapy.

Posterior choroidal leiomyoma: new findings from a case and literature review.

Posterior choroidal leiomyoma is a sporadic, rare benign tumor that is always confused with anaplastic melanoma. Here we report a case and provide a review. Most of the preoperative findings in our case were suggestive of malignant choroidal melanoma. However, the contrast enhanced ultrasound (CEUS) suggested a benign hemangioma. In summary, the posterior choroidal leiomyomas were yellowish-white in color and most commonly located in the temporal quadrant of the fundus (11/15). They were more frequent in Asians (13/16), the prevalence was almost equal in males and females (9:7), with a mean age of 35y. Microscopically, the tumor typically showed spindle cell bundles and nonmitotic ovoid nuclei arranged in intersecting fascicles. Vitrectomy is now a popular treatment option and definitive diagnosis can be made after immunohistochemistry. Finally, some summarized features of this tumor differ from those previously described. These may help in the diagnosis of posterior choroidal leiomyoma and differentiation from malignant melanoma.