Relative strength of photodynamic biologic tissue glue in penetrating keratoplasty in cadaver eyes

Purpose: To compare the relative strength of photodynamic biologic tissue g lue (PBTG) with that of 10-0 nylon sutures in closing penetrating keratopla sty (PKP) wounds in cadaver eyes. Setting: Corneal Research Laboratory, University of Chicago, Chicago, Illin ois, USE. Methods: A 7 mm central corneal trephination was performed on 8 recently en ucleated human eyes. Each corneal button was removed and then resutured in its original position, using 4 interrupted 10-0 nylon cardinal sutures and PBTG (n = 7) or 16 interrupted 10-0 nylon sutures (n = 1). Wound leak and i ncisional bursting pressures were determined. Results: The average pressure at which wound leak and iris prolapse occurre d was 124 mm Hg (range 70 to 180)and 185 mm Hg (range 90 to 300), respectiv ely. The pressure required to create wound leak increased as the time betwe en glue application and pressurization of the globe lengthened (mean 22 min utes, range 5 to 60 minutes), indicating that the bonding and stability of the adhesive increased with time. In contrast, the control eye developed wo und leak at 70 mm Hg and iris prolapse at 800 mm Hg. Conclusions: Photodynamic biologic tissue glue was comparable to sutures in providing adequate corneal wound strength in PKP in a cadaver eye model. W ound closure with PBTG may reduce the number of sutures required in corneal transplantation and decrease the incidence of suture-related complications and allograft rejection.