Impact of local COVID-19 alert levels on rhegmatogenous retinal detachment

PURPOSE: To investigate the impact of the local alert levels regarding coronavirus disease 2019 (COVID-19) on the clinical patterns of rhegmatogenous retinal detachment (RRD) in Japan. STUDY DESIGN: Retrospective, single-center, consecutive case series. METHODS: We compared two groups of RRD patients, a COVID-19 pandemic group and a control group. Based on the local alert levels in Nagano, five periods during the COVID-19 pandemic were further analyzed: epidemic 1 (state of emergency), inter-epidemic 1, epidemic 2 (second epidemic duration), inter-epidemic 2, and epidemic 3 (third epidemic duration). Patients’ characteristics, including symptoms’ duration before visiting our hospital, macula status, and retinal detachment (RD) recurrence rate in each period, were compared with those in a control group. RESULTS: There were 78 patients in the pandemic group and 208 in the control group. The pandemic group had a longer duration of symptoms than the control group (12.0 ± 13.5 days vs. 8.9 ± 14.7 days, P = 0.0045). During the epidemic 1 period, patients had a higher rate of macula-off RRD (71.4% vs. 48.6%) and RD recurrence (28.6% vs. 4.8%) than the control group. This period also demonstrated the highest rates compared to all other periods in the pandemic group. CONCLUSION: During the COVID-19 pandemic, RRD patients significantly delayed visiting a surgical facility. They showed a higher rate of macula-off and recurrence compared to the control group during the state of emergency than during other periods of the COVID-19 pandemic, although the difference was not statistically significant due to the small sample size. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10384-023-00980-1.