“…SARS-CoV-2 Testing: On the surgery day, blood serum samples (1 ml) from 33 participants were collected, processed and stored at 4 °C at the State Key Laboratory of Ophthalmology of Zhongshan Ophthalmic Centre.Vitreous humor samples (0.2 ml) from 33 eyes were collected at the beginning of posterior pars plana vitrectomy (PPV) using the deep vitreous biopsy technique by the method previously described by Vivek Pravin Dave et al[ 10 ]. The samples were tested for SARS-CoV-2 RNA using the Real-time quantitative polymerase chain reaction (RT-PCR, qPCR) technique utilizing specifically designed primers targeting the ORF1ab and N genes of the SARS-CoV-2 and the primer sequences were listed in Table 1 .…”