that the local supply of exogenous ha has distinct therapeutic and protective benefits in a great variety of pathological conditions of connective and epithelial tissues such as particularly appreciated is the possibility provided by the visco elastic nature of ha to coat the tissues exposed to risk of damage during surgical manipulation according to all the surgeons who have used ha the presence of a viscous layer of exogenous ha on the tissues which are most exposed to traumatizing accidental contacts such as the cornea exerts an efficient protective influence which is reflected to a very positive degree in the successful outcome of the operation the protective effect and the facilitatory influence on tissue repair exerted by exogenous ha on the cornea has been shown both in experimental animals miller et al use of na hyaluronate during intraocular lens implantation in rabbits ophthalmic surgery 8 6 58 61 1977 miller et al use of na hyaluronate in autocorneal transplantation in rabbits ophthalmic surgery 11 1 19 21 1980 graue et al the protective effect of na hyaluronate to corneal endothelium exp eye res 31 119 127 1980 ozaki et al protective effect of healon coated intraocular lens on the corneal endothelium folia ophthalmologica japonica 32 1301 1305 1981 and in man norm preoperative protection of cornea and conjunctiva acta ophthalmologica 59 587 594 1981 polack f m et al sodium hyaluronate healon in keratoplasty and iol implantation ophthalmology 88 425 431 1981 during eye surgery hyaluronic acid provides effective protection to exposed tissues such as the corneal endothelium and permits the reconstruction of the anatomical form of the operation site exogenous hyaluronic.