Variations in clinical manifestations of post-fever retinitis during the COVID-19 pandemic

Dear Editor, We conducted a retrospective study to examine the impact of the COVID-19 pandemic on the clinical presentation and treatment outcomes of post-fever retinitis (PFR). We included all consecutive patients diagnosed as PFR during two study periods: April 2019–March 2020 (pre-COVID-19 group) and April 2020–March 2021 (post-COVID-19 group). The study included 19 patients in the pre-covid and 25 patients in the post-covid groups with a mean age of 36.58 years. We observed a male preponderance in the pre-COVID group (73.7%), while the gender distribution was more uniform in the post-COVID group (56% males vs. 44% females). Notably, we observed increased rates of vitritis (87.5% vs. 44.8%), disc edema (62.5% vs. 37.9%), macular involvement (85% vs. 58.6%), and vasculitis (30% vs. 6.9%) in the post-COVID group. Similarly, fundus fluorescein angiography (FFA) revealed more frequent disc hyperfluorescence (75% vs. 27.6%) and four cases of retinal neovascularization in the post-COVID group. Optical coherence tomography (OCT) also showed a higher prevalence of cystoid macular edema (85% vs. 58.6%) in the post-COVID group. Although routine uveitis investigations showed no significant differences, a higher proportion of positive Weil-Felix tests was noted in the post-COVID group (84% vs. 47.4%). Treatment protocols included oral steroids for all patients and doxycycline for 84% of the post-COVID group vs. 47.4% of the pre-COVID group. Intravitreal anti-VEGF was administered to one patient with extensive neovascularization in the post-COVID group. Complete resolution of retinitis was achieved in both groups, with the post-COVID group demonstrating a significantly shorter mean time to resolution (35.15 ± 17.63 days vs. 59.47 ± 44.65 days). Final visual acuity improvements were similar between groups (BCVA: 0.47 ± 0.47 vs. 0.62 ± 0.56). Based on our experience of treating a large number of cases with PFR,[1] we noted a change in the clinical presentation of PFR during the COVID-19 pandemic, including an increased frequency of vitreous inflammation, disc leakage, and retinal neovascularization. This is more likely due to the delay in presentation rather than a real change in the pattern of presentation. Additionally, the more balanced gender distribution in the post-COVID group, compared to the male predominance in the pre-COVID group, might reflect changes in vector exposure patterns due to lockdowns, with more individuals, including males, staying indoors, and thus being equally exposed to vectors within domestic environments. Surprisingly, a higher rate of positive Weil-Felix tests was noted in the post-COVID group, indicating a possible shift toward rickettsial infections in our region during the pandemic. Alternatively, this could be due to antigen cross-reactivity influenced by concurrent COVID-19 infection or immune responses.[2] Our findings are consistent with recent studies, suggesting that while the COVID-19 pandemic did not directly cause PFR, it influenced the clinical presentation and management of the condition due to external factors such as healthcare access and vector exposure.[3] Financial support and sponsorship: Nil. Conflicts of interest: There are no conflicts of interest.