Retinal function after intravitreal injection of autologous bone marrow-derived mesenchymal stromal cells in advanced glaucoma.

PURPOSE: To report electroretinographic (ERG) findings in advanced glaucoma treated with a single intravitreal injection of bone marrow-derived mesenchymal stem cells (MSCs). METHODS: Intravitreal injection of autologous MSCs (1 × 106 cells) was performed in 2 eyes from 2 patients with open-angle glaucoma in advanced stage of optic neuropathy (ClinicalTrials.gov, NCT02330978, 01.05.2015): cup/disk ratio worse than 0.9, visual field mean deviation index lower than - 15 dB, visual acuity of light perception, but controlled intraocular pressure. ERG tests were recorded at baseline and week 1, 4 and 48 after injection, using DTL electrodes following the ISCEV standard: After dark adaptation, ERG was elicited using white flashes of 0.01 cd.s/m2 and 3.0 cd.s/m2, followed by 10-min light adaptation (30 cd/m2) and stimuli of 3.0 cd.s/m2 and 30 Hz flicker. RESULTS: Patients did not show improvement on visual acuity or visual field after treatment. At baseline, ERG responses showed typical findings for advanced glaucoma, with a- and b-wave amplitude and latency within normative range, but reduced photopic negative responses. No noteworthy changes were observed on ERG responses for both cases up to 1 week after treatment, but at day 15, one patient showed retinal detachment with proliferative vitreoretinopathy and was removed from the trial. The other patient kept ERG responses stable throughout study period. CONCLUSION: Although no ERG response changes were observed after MSCs injection in one case, the complication observed on the second one, along with the lack of visual function improvement, warrants further studies involving modified MSCs to treat ocular disorders, including glaucoma. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02330978- missed in pdf.

Ex vivo evaluation of intravitreal mesenchymal stromal cell viability using bioluminescence imaging.

BACKGROUND: Bone marrow-derived mesenchymal stromal cell (MSC) therapy is a promising treatment for several degenerative ocular diseases; however, no reproducible method of monitoring these cells into the eye has been established. The aim of this study was to describe successful bioluminescence imaging (BLI) to detect viable luciferase-expressing MSC in the eye. METHODS: Human donor MSC in culture were transduced with 50 µl luciferase lentiviral vector (three viral particles/cell) prior to intraocular injection. Twenty-one right eyes of 21 rabbits were evaluated through BLI after receiving 1 × 106 luciferase-expressing MSC intravitreally. Contralateral eyes were injected with vehicle (phosphate-buffered saline (PBS)) and were used as controls. At seven different time points (1 h to 60 days), D-luciferin (40 mg/ml, 300 µl PBS) was injected in subsets of six enucleated eyes for evaluation of radiance decay through BLI analysis. CD90 and CD73 immunofluorescence was studied in selected eyes. RESULTS: Eyes injected with MSC showed high BLI radiance immediately after D-luciferin injection and progressive decay until 60 days. Mean BLI radiance measures from eyes with luciferase-expressing MSC were significantly higher than controls from 8 h to 30 days. At the thirtieth day, positive CD90- and CD73-expressing cells were observed only in the vitreous cavity of eyes injected with MSC. CONCLUSIONS: Viable MSC were identified in the vitreous cavity 1 month after a single injection. Our results confirmed BLI as a useful and reliable method to detect MSC injected into the eye globe.