HYALURONIC-ACID - A REVIEW OF ITS PHARMACOLOGY AND USE AS A SURGICAL AID IN OPHTHALMOLOGY, AND ITS THERAPEUTIC POTENTIAL IN JOINT DISEASE AND WOUND-HEALING

Hyaluronic acid is a naturally occurring polysaccharide with distinct physicochemical properties which underlie its application as a viscoel astic tool in ophthalmological surgery. In cataract surgery the role o f hyaluronic acid in facilitating procedures and protecting the cornea l endothelium is well established. Some benefit has also been gained w ith the use of hyaluronic acid in penetrating keratoplasty, trabeculec tomy, retinal reattachment and trauma surgery, although its efficacy i n these indications is less well-defined in the published literature. In addition to its lubricating and cushioning properties, demonstratio n of some in vitro anti-inflammatory activity and a possible disease-m odifying effect for hyaluronic acid in animals has prompted its invest igation as a treatment in osteoarthritis and, to a much lesser extent, in rheumatoid arthritis. Hyaluronic acid 20mg, as weekly intra-articu lar injections for 3 to 7 weeks, improved knee pain and joint motion i n patients with osteoarthritis. Although this occurred to a greater de gree than with placebo in most comparisons, the effects of hyaluronic hyaluronic acid was similar to those of placebo in the largest trial. In the few available comparisons with other agents, hyaluronic acid ap peared equivalent to methylprednisolone 40mg (for 3 weeks) and to a si ngle injection of triamcinolone 40mg. Hyaluronic acid was distinguishe d from other therapies by providing a sustained effect after treatment discontinuation. Together with its very good tolerability profile, th ese properties justify further study of hyaluronic acid in patients wi th osteoarthritis. Some limited evidence of improvement in patients wi th rheumatoid arthritis, and a possible healing effect of hyaluronic a cid on tympanic membrane perforations, represent additional areas of i nterest for future investigation. In summary, hyaluronic acid is a wel l-established adjunct to cataract surgery and may prove to be a promis ing option in the treatment of patients with osteoarthritis. Its very good tolerability provides further impetus for examination of its pote ntial role in an extended scope of arthritic and ophthalmological indi cations, and in wound healing.