Year: 2020, European Eye Bank Association (EEBA)

Authors: D’Amato Tothova J.; Ferrari B.; Giurgola L.; Gatto C.

Purpose
To develop a quantitative method to assess the toxicity of intraocular endotamponades using human retina ex-vivo model. The study aimed at determination of retina viability, positive and negative controls, method accuracy and repeatability.

Methods
Human donor eye globes for research use were transported to FBOV and stored in DMEM/F-12 medium at 4°C for a maximum of 48 hours. 2-mm and 3-mm retina samples were evaluated for viability using TOX-1 In Vitro Toxicology Assay Kit (Sigma-Aldrich, Italy) immediately (T0) and 24 h, 48 h, 72 h and 7 days after retina extraction. Sodium Dodecyl Sulfate (SDS) concentrations of 0.25 mg/ml, 0.50 mg/ml and 1 mg/ml were tested as positive (cytotoxic) controls. DMEM/F-12 medium was used as a negative control. The toxicity of perfluorooctane samples (PFO) and the same PFO containing toxic residues (1H-PFO and PFOA, positive controls) was assessed in a comparison between donor retina ex vivo model and cytotoxicity test in vitro model using ARPE-19 cell line.

Results
Retina extracted within 24 and 48 hours post mortem showed optimal viability at T0. Incubation of the samples with 0.25, 0.50 mg/ml and 1 mg/ml SDS (cytotoxic control) induced 75.3 ± 4 %, 98.6 ± 2 % and 98.5 ± 2 % mortality at T0, respectively. In average 53 ± 2 samples with 3-mm diameter were prepared from one donor retina. 3-mm sample size was suitable to allow good method repeatability. Both donor retina ex vivo and cell line models showed comparable cytotoxic results; not cytotoxic samples resulted in similar % of cell viability corresponding to 92 ± 3 % and 97 ± 1 % for donor retina ex vivo and cell line models respectively. Cytotoxic samples induced higher mortality in donor retina ex vivo model compared to the cytotoxicity test in vitro in cell line model.

Conclusion
A quantitative method to assess the toxicity of intraocular liquid devices in human retina ex-vivo model was standardized with high sensibility and repeatability.