Abstract
Abstract: :
Introduction: Contact lens intolerance is more and more observed although lens quality is continuously improved. Contact lens multipurpose solutions (MPS) impregnated on lens during rinse could spread on the eye, and then we desmonstrated that multipurpose solution can induce cytotoxicity on conjonctival cells. Methods: Human conjunctival cells were incubated with the four main multipurpose solutions (OptifreeTM, SolocareTM, RenuTM, CompleteTM) compared to inert rinse products (NaCl 0.9%, sterile sea derivates: Serophta LensTM) associated with oxidative disinfectant (H2O2) for 15min–4h. Membrane integrity, reactive oxygen species and superoxide anion productions, oxidoreduction potential were assessed performing neutral red, DCFH–DA, dihydroethidium and alamar blue tests respectively. Apoptosis was then evaluated using P2X7 receptors opening (YOPRO–1 assay), chromatin condensation (Hoechst 33342 assay), and mitochondrial activity and mass (rhodamine 123 and NAO tests) with cold light cytofluorometer. Results: Cellular viability was significatively affected after 4h of incubation but chromatin condensation appeared after only 15min with some multipurpose solutions associated with a significant alteration of mitochondrial activity and oxidoreduction potential. These mechanisms of apoptonecrosis are not observed with inert rinse products used for oxidative molecules rinse. DISCUSSION. Rinse products impregnate lens and spread all day long. Multipurpose solutions containing preservatives are significatively cytotoxic and need to be rinsed by inert products (NaCl 0.9% or sterile sea derivates). Preservatives used in MultiPurpose Solutions could explain these cytotoxic effects, already observed with preserved antiglaucomatous intolerance. Conclusion: Contrary to NaCl 0.9% or sterile sea derivates, which are not cytotoxic, multipurpose solutions are significatively cytotoxic and then not adapted to final rinse of contact lens. They induce apoptosis and apoptonecrosis with mitochondrial alterations, which could explain contact lens intolerance. Oxidative products (H2O2) associated with inert rinse solutions could then be preferred for disinfection procedure and therefore limit late apoptotic cytotoxicity, probably at the origin of contact lens intolerance.
Keywords: conjunctiva • drug toxicity/drug effects • contact lens