Toxicity of an endotamponade made by a mixture of perfluorooctane and perfluorohexyloctane evaluated by a new cytotoxicity method.

Abstract

Purpose : Acute retinal toxicity caused by some perfluorocarbon liquids used during surgery has been reported recently. A batch of Bio Octane Plus^®, a mixture of 90% perfluorooctane (PFO) and 10% perfluorohexyloctane was suspect to produce some cases. Batch was certified non-toxic (CE marked), by a test using agarose overlay method following UNE EN ISO 10993 - 5 & 12 : 2009 standard. This study evaluates the suspected batch using a new direct contact cytotoxicity evaluation method designed for testing volatile substances.

Methods : Cultures of retinal pigment epithelial cells (ARPE-19 cell line) were grown on a seeding density of 1 x 10⁴ per well in standard culture conditions to reach an OD₅₇₀ ≥ 0.2. Then cultures were exposed for 60 minutes directly to suspected batch of Bio Octane Plus^® by blocking its evaporation. Cultures were grown for 24 and 72 hours and cytotoxicity were measured by MTT^® assay. A batch of Bio Octane Plus^® with no report of producing toxicity in patients, a batch of perfluorooctane (PFO) already tested as a safe substance and cell culture medium were used as controls for comparison. Experiments were performed following ISO 10993 standard and under GLP guidelines and repeated three times in triplicate (n=9).

Results : ARPE-19 cell cultures grew well and achieved standards required by ISO 10993. Viability of cell cultures exposed to suspected batch was 0% (≤70%) confirming it is a toxic batch. Viability of cell cultures exposed to the controls was ≥70% in all cases.

Conclusions : New direct contact method confirmed toxic the suspected batch of Bio Octane Plus^®, a correlation with clinical cases of acute retinal toxicity. The suspected batch was previously certified non toxic using ISO recommended agarose overlay method, thus confirming the failure of this method to detect a toxic batch. An adequate cytotoxicity method including the protocol steps is crucial to certify a medical device containing volatile substances to avoid incidence of retinal toxicity.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.