Authors' objectives:

To compare the technical features of viscoelastic solutions, implants and valves for glaucoma, orbital implants and other accessories for eye surgery (sponges, bands, rails, ropes, brackets, wheels, buttons, clips, meridional implants, hydrogel implants and hooks) specified on the marketing material of the products marketed by different dealers in Catalonia during the period 1994-95. To analyze, by means of the review of the scientific evidence, if the differences observed in the design of this type of products may influence in the clinical outcomes.

Authors' results and conclusions: 1. The use of viscoelastic solutions during eye surgery allows to keep the depth of the anterior chamber of the eye and to protect the ocular structures. 2. The implants, with and without valve, are used in case of glaucoma refractoryto other medical or surgical therapies. 3. Orbital implants are pieces that are placed in the orbit's muscular body after removing the eye. 4. The purpose of the other eye surgery accessories analyzed varies according to the type of pathology which has caused the intervention. 5. Six randomized controlled trials have been found which compare the efficacy of different kinds of viscoelastic solutions related to the different clinical measures and to ergonomic aspects. As regards the implants for glaucoma, two randomized controlled trials have been found which compare the Molteno single plate implant with the double plate implant, and the Molteno with the Schoket implant. No clinical studies have been found comparing the different liquid perfluorocarbonates. 6. Most studies identified, for all the analyzed eye surgery accessories, are observational type, most of them with a low quality design (retrospective, clinical series and case studies). No study has been identified comparing the relationship between cost and effectiveness of these health care products. 7. The materials of the most frequently described viscoelastic solutions are sodium hialuronate and hydroxypropylmetylcelulose. 8. As regards the sodium hialuronate solutions: a) the low molecular weight solutions provide a good level of safety pre and postsurgery (Healon , Bilon , Microvisc , Amvisc ); b) the high molecular weight solutions provide a better conservation of the anterior chamber depth and protect the eye structures better during the intervention; however, the risk of postsurgical complications (e. g. appearance of deposits in the posterior chamber and intraocular lens) is higher (Healon GV , Viscorneal P , Viscorneal P2 ). 9. The implants for glaucoma most frequently described in literature are the Molteno and the Baerveldt models. The double plate, double chamber and larger surface Molteno implants are the ones which offer a higher decrease of intraocular pressure (IOP). As for the Baerveldt implants, the larger surface implants provide a better control of IOP. However, in the election of the implant according to these features each individual patient's clinical characteristics should also be considered. 10. As regards the orbital implants, no study has been identified within each group of material showing significant differences regarding postimplantation clinical outcomes among the products analyzed. However, the implants which allow a better mobility and integration in the eye structures are the porous ones (hydroxyapatite and porous polypropylene). The silicone implants do also achieve an adequate mobility and are easily implanted in the eye. 11. As regards sponges, silicone implants and other accessories for eye surgery, and according to the characteristics of these types of materials, no conclusion can be made as regards the superiority of one specific product. 12. The main analysis parameter in the purchase of these implants should be the availability of a registration number for the product given by the Ministry of Health and Consumers. Other parameters of interest are discussed in theElements to consider in the purchase of complements for eye surgery' section of this document.

Project Status: Completed

URL for project: http://www.gencat.net/salut/depsan/units/aatrm/html/en/dir393/doc7921.ht ml

Year Published: 1996

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: Spain

Organisation Name: Agencia de Qualitat i Avaluacio Sanitries de Catalunya

Contact Address: Antoni Parada, CAHTA, Roc Boronat, 81-95 (2nd floor), 08005 Barcelona, Spain, Tel. +34 935 513 928, Fax: +34 935 517 510

Contact Name: direccio@aatrm.catsalut.net / aparada@aatrm.catsalut.net

Contact Email: direccio@aatrm.catsalut.net / aparada@aatrm.catsalut.net

Copyright: Catalan Agency for Health Technology Assessment and Research