Retinal vascular occlusions in COVID-19 infection and vaccination: a literature review.

PURPOSE: Abnormal hypercoagulability and increased thromboembolic risk are common in patients with coronavirus disease (COVID-19). COVID-19 has been suggested to cause retinal vascular damage, with several studies on COVID-19 patients with retinal vascular occlusions. We reviewed and investigated studies on retinal vascular occlusions in patients diagnosed with COVID-19 and in those vaccinated for COVID-19. METHODS: Studies that reported retinal vascular occlusion in COVID-19 patients or in vaccinated people were identified using the terms "retinal occlusion," together with "severe acute respiratory syndrome coronavirus 2", "SARS-CoV-2," "COVID-19," "coronavirus," and "vaccine," through systematic searches of PubMed and Google Scholar databases until January 7, 2022. RESULTS: Thirteen cases of retinal artery occlusion (RAO) and 14 cases of retinal vein occlusion (RVO) were identified among patients diagnosed with COVID-19. Half of the patients with RAO or RVO revealed no systemic disorders except current or past COVID-19, and ocular symptoms were the initial presentation in five cases. Among patients with RAO, most presented with central RAO at 1-14 days of COVID-19 diagnosis, with abnormal coagulation and inflammatory markers. Among those with RVO, two-thirds presented with central RVO and one-third with RVO. Eleven cases with acute macular neuroretinopathy (AMN) and/or paracentral acute middle maculopathy (PAMM) were reported among patients with COVID-19, presenting scotoma resolved spontaneously in most cases. Among the 26 cases vaccinated with either mRNA or adenoviral vector vaccines for COVID-19 and presenting retinal vascular occlusions, there were more RVO cases than RAO cases, and ocular symptoms mostly occurred within 3 weeks after vaccination. One case presented bilateral AMN and PAMM after COVID-19 vaccination. CONCLUSION: Retinal vascular occlusions might be a manifestation of COVID-19, although rare, especially in patients at risk of systemic hypercoagulability and thromboembolism. For COVID-19 vaccines, the causal relationship is controversial because there are few case reports of retinal vascular occlusions after COVID-19 vaccination.

Is gas/air tamponade essential for eyes with small peripheral retinal breaks without detachment during vitrectomy?

BACKGROUND: To investigate the safety of vitrectomy with laser photocoagulation in eyes with small peripheral retinal breaks without air or gas tamponade. METHODS: Among patients who underwent vitrectomy for various retinal disorders, those with small peripheral retinal breaks treated by laser photocoagulation without air or gas tamponade were included in this study. Their medical records were assessed retrospectively, and we investigated the characteristics of small peripheral retinal breaks and the incidence of postoperative retinal detachment (RD). RESULTS: Thirty-one eyes of 31 patients who presented with small peripheral retinal breaks requiring endolaser photocoagulation during vitrectomy were included in this analysis. There were two cases of iatrogenic retinal breaks that occurred during vitrectomy, while others were preexisting lesions, including retinal tears, atrophic retinal holes, and retinal holes with lattice degeneration. There were no cases of RD during the follow-up period of at least 6 months. CONCLUSIONS: Adequate laser treatment without gas or air tamponade may be sufficient during vitrectomy in cases with small peripheral retinal breaks without concurrent RD, along with complete removal of vitreoretinal traction.