Outcomes of Shunt Tube Coverage With Glycerol Preserved Cornea Versus Pericardium

Abstract

Pericardium is a biomaterial widely used for covering the outflow tubes of glaucoma drainage devices. Recently, glycerol preserved cornea has been introduced as an alternative that offers durability and improved cosmesis because of its clarity. We retrospectively reviewed 262 patients in the University of Alabama Birmingham Glaucoma Service who underwent shunt procedures using either cornea tissue or pericardium to cover the tube. The primary outcome measure was the number of erosions of the covering material. Nine out of 101 (8.9%) patients in the pericardium covered group experienced an erosion compared with 3 out of 161 (1.9%) in the cornea covered group. A significant difference was reached with P=0.0125. Median follow-up was 440 days for the cornea group and 331 days for the pericardium group. The type of glaucoma (primary open-angle glaucoma vs. secondary glaucoma) was not associated with the risk of erosion (odds ratio, 0.501; 95% confidence interval, 0.204-1.234). The median time to exposure was 252 days in the pericardium group and 440 days in the cornea group (P=0.0017).

Heterologous, Fresh, Human Donor Sclera as Patch Graft Material in Glaucoma Drainage Device Surgery

“…Follow-up in our study is probably adequate, and is substantially longer compared with a previous report in the Chinese literature, 13 as the median and mean time to exposure has been determined between 8.3 to 14.4 months and 23 to 31 months in the previous studies. 10,21 In our cohort the single case of tube/plate exposure was discovered at the 1-month postoperative visit. A large meta-analysis determined a 2.0 ± 2.6% incidence of tube exposure after an average follow-up of 26.1 ± 3.3 months.…”

“…This has been demonstrated in a retrospective case-control study investigating single-layer versus doublelayer pericardium 20 and in another comparing cornea versus pericardium. 21 In both the studies the thicker material provided an advantage with respect to the risk of exposure. Follow-up in our study is probably adequate, and is substantially longer compared with a previous report in the Chinese literature, 13 as the median and mean time to exposure has been determined between 8.3 to 14.4 months and 23 to 31 months in the previous studies.…”

“…39 Glycerin-cryopreserved corneal tissue is another option that has become available as a patch graft material in GDD surgery. 21 Resistant microorganisms, such as Bacillus cereus can survive in both ethanol and glycerin-preserved sclera for at least 2 weeks. 40 The use of preserved sclera is consequently not without risk with respect to viral transmission despite donor screening.…”

Clinical outcomes of gamma-irradiated sterile cornea in aqueous drainage device surgery: a multicenter retrospective study

“…In the study by Wigton et al 9 the glycerol-preserved cornea group presented a significantly lower PGF rate (1.9%, mean follow-up of 14.5 months) compared with the pericardium group (8.9%, mean follow-up of 11.0 months). As Table 3 shows, GISC is likely to have a comparable PGF rate and time interval until the occurrence of PGF, comparing to glycerol-preserved cornea, 9 which might be primarily due to preserved stromal structure in GISC. The study on glycerolpreserved cornea 9 has much in common with that on optisol-stored fresh cornea, 8 indicating that the dense, regular collagenous structure of corneal tissue might be particularly suitable for tectonic support of the ocular wall and more resistant to melting than other loosely structured tissues, such as pericardium and sclera.…”

“…Therefore, a variety of materials, including sclera, 3 dura mater, 4 fresh cornea, 5,6 fascia lata, 7 pericardium, 8 and glycerol-preserved cornea, 9 have been used to cover the portion of the tube lying underneath the conjunctiva to prevent erosion. Each of these materials has at least some disadvantages, including potential transmission of infectious disease, graft melting, opaqueness, and difficulty in surgical manipulation.…”