Impact of COVID-19 on a rare disease (uveal melanoma) in a national reference unit of intraocular tumors in Spain.

Objective: To analyse the impact of the COVID-19 pandemic on the diagnosis and management of uveal melanoma (a tumour included in the Orphanet catalogue of rare diseases) in a Spanish national reference unit for intraocular tumours during the first year of the pandemic.

Method: An observational retrospective study of patients with uveal melanoma in the National Reference Unit for Adult Intraocular Tumors of the Hospital Clínico Universitario de Valladolid (Spain) was performed, analysing the pre- and post-COVID-19 periods: from March 15, 2019 to March 15, 2020 and from March 16, 2020 to March 16, 2021. Demographic data, diagnostic delay, tumour size, extraocular extension, treatment and evolution were collected. A multivariable logistic regression model was used to identify factors that were associated with the variable: enucleation.

Results: Eighty-two patients with uveal melanoma were included, of which 42 (51.21%) belonged to the pre-COVID-19 period and 40(40.78%) to the post-COVID-19 period. An increase in tumour size at diagnosis and in the number of enucleations was observed during the post-COVID-19 period (p < 0.05). Multivariable logistic regression demonstrated that both medium-large tumour size and patients diagnosed in the post-COVID-19 period were independently related to an increased risk of enucleation (OR 250, 95%CI, 27.69-2256.37; p < 0.01 and OR 10; 95%CI, 1.10-90.25; p = 0.04, respectively).

Conclusions: The increase in tumour size observed in uveal melanomas diagnosed during the first year of the COVID-19 pandemic may have favored the increase in the number of enucleations performed during that period.