Optic neuropathies, including glaucoma, are a group of neurodegenerative diseases, characterized by the progressive loss of retinal ganglion cells (RGCs), leading to irreversible vision loss. While previous studies demonstrated the potential to replace RGCs with primary neurons from developing mouse retinas, their use is limited clinically. We demonstrate successful transplantation of mouse induced pluripotent stem cell (miPSC)/mouse embryonic stem cell (mESC)-derived RGCs into healthy and glaucomatous mouse retinas, at a success rate exceeding 65% and a donor cell survival window of up to 12 months. Transplanted Thy1-GFP+ RGCs were able to polarize within the host retina and formed axonal processes that followed host axons along the retinal surface and entered the optic nerve head. RNA sequencing of donor RGCs re-isolated from host retinas at 24 h and 1 week post-transplantation showed upregulation of cellular pathways mediating axonal outgrowth, extension, and guidance. Additionally, we provide evidence of subtype-specific diversity within miPSC-derived RGCs prior to transplantation.

Racemose hemangioma with focal macular involvement may lead to a progressive reduction in visual acuity because of exudation. Further studies need to be conducted to confirm the efficacy of bevacizumab injections to treat vascular malformation; however, this form of management does seem promising.

To test conjunctival swabs from patients with laboratory-confirmed severe forms of coronavirus disease 2019 for the presence of SARS-CoV-2 on real-time reverse-transcription polymerase chain reaction (rRT-PCR). METHODS: Fifty conjunctival swabs were collected from 50 in-patients with laboratory-confirmed severe forms of COVID-19 at the largest teaching hospital and referral center in Brazil (HCFMUSP, Sã o Paulo, SP). The samples were tested for SARS-CoV-2 on rRT-PCR with the primers and probes described in the CDC protocol which amplify the region of the nucleocapsid N gene (2019_nCoV_N1 and 2019_nCoV_N2) of SARS-CoV-2 RNA and compared with naso/oropharyngeal swabs collected within 24 hours of the conjunctival swabs. RESULTS: Five conjunctival samples (10%) tested positive (amplification of the N1 and N2 primer/probe sets) while two conjunctival samples (4%) yielded inconclusive results (amplification of the N1 primer/probe set only). The naso/oropharyngeal swabs were positive for SARS-CoV-2 on rRT-PCR in 34 patients (68%), negative in 14 (28%) and inconclusive in 2 (4%). The 5 patients with positive conjunctival swabs had positive (n=2), negative (n=2) or inconclusive (n=1) naso/oropharyngeal swabs on rRT-PCR. Patients with negative or inconclusive naso/ oropharyngeal swabs had the diagnosis of COVID-19 confirmed by previous positive rRT-PCR results or by serology. CONCLUSION: This is the first study to present conjunctival swab rRT-PCR results for SARS-CoV-2 in a Brazilian population. In our sample of 50 patients with severe forms of COVID-19, 10% had positive conjunctival swabs, most of which were correlated with positive naso/oropharyngeal rRT-PCR results.