Rationale.  Contact Lenses (CLs) have had a massive diffusion; a 2005 survey estimates that there are up to 140 million of CLs wearers worldwide. CLs are used in the most different conditions. External factors, physical (pollution, micro-environment, air conditioning etc) and biological (bacterial contamination) interact with the tear film, whose composition changes according to endogenous factors (diet, hydratation etc). To deal with this complex and dynamic environment, the ideal Lens Care Product (LCP) should have a number of characteristics: a) excellent antimicrobial activity, including action on sporae and protozoa  b) ability to remove deposits on the lens surface and in the macromolecular web of the lens (proteins, fatty acids, PMx, etc.) c) absence of hymmunogenic or cyto-toxic effect  d) respect of the lens structure. Manufacturers have tried different ways to obtain the best balance of the above characteristics.

Aim.   To compare the scientific evidence supporting the different  LCPs  developed

Methods. The Authors reviewed the recent scientific literature in international databases (PubMed ; Cochrane). Only indexed journals and masked studies have been considered in the analysis.

Results.  There is no evidence that any class of LCPs meets all the main requisites better than others, yet each class of LCPs is different in terms of main properties. Therefore, the choice of the LCP should be done according the profile of the lens wearer. Manufacturers have to apply more effort on LCP formulation with the aim to reduce the risk of long term effect due to risk factors analyzed.
 
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Lipéner (2008). Arq. Bras. Oftalmol. 71, S0
Robertson (2008) Inv.Ophthalmol. Vis. Sci. 49, 7-15