EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/78788
August 2012 10-year experience of CAD by Svetlana Y. Anisimova, M.D., Sergei I. Anisimov, M.D., and Elena Vialova, M.D. S urgical treatment of glaucoma is still a com- mon treatment approach. Its effectiveness often de- pends on the application of additional devices that prevent scarring of the newly created outflow pathways. More than 10 years ago, the Russian Ministry of Health gave permission for surgeons to use a collagen antiglaucomatous drainage device (CAD) that was produced from osteal non-absorbable collagen type I Xenoplast material (Figure 1). Its structure resembles the normal ultrastructure of the human trabecu- lar meshwork (Figure 2). A porous material, Xenoplast was invented in Russia 15 years ago. Thorough studies with the im- plant were conducted in vitro and in vivo for 5 years. Preliminary studies have shown the unique properties of CAD, which can maintain an opti- mal amount of decompression and a filtering bleb with non-penetrating deep sclerectomy (NPDS). It can also provide an adequate outflow of in- traocular fluid from the eye in pene- trating interventions. The CAD does not encapsulate in the tissues of the eye. Its contact with uveal tissue, iris, conjunctiva, and the sclera causes no harm. CAD results We have analyzed the results with the CAD in 12 clinics (2-5 years of follow-up) in Russia and the Ukraine. We collected results from 3,379 operations. Ninety-one per- cent of patients had advanced glau- coma with significant deterioration of the optic disc and visual fields. The IOP ranged from 20-45 mm Hg pre-op. The average number of med- ications used per day was 3.1±0.9. The main types of surgeries per- formed on the patients were trabeculectomy, NPDS, CAD implan- tation ab interno into the anterior chamber angle during trabeculec- tomy, and inserting the drainage de- vice between the anterior chamber and suprachoroidal space ab externo (Figures 3 and 4). The softness and plasticity of CAD's material allowed surgeons to use Xenoplast in these different surgical situations. Post-op, flat, well-vascularized filtration blebs were seen (Figure 5). There have been no cases of rejec- tion, loss in the anterior chamber, or external protrusions of the CAD. There were no cases where the de- vice needed to be removed. In the case of tight contact with the tissues of the eye, degenerative changes were not marked in the conjunctiva (Figure 5) or in the iris (Figure 6). At reoperation, the device can be implanted without removing the previous one (Figure 6). Figure 1. The CAD next to a small paper clip Figure 2. The ultrastructure of the material is almost identical to the ultrastructure of the normal trabecular meshwork Figure 3. Some variants of the CAD implant Figure 4. Fixation in the scleral bed of CAD during NPDS