A newly designed glaucoma drainage implant made of poly(styrene-b-isobutylene-b-styrene): biocompatibility and function in normal rabbit eyes.
OBJECTIVE
To report clinical evaluation, flow patency, and histopathological findings of a novel glaucoma drainage implant (GDI) made of poly(styrene-b-isobutylene-b-styrene) (SIBS) in rabbits.


METHODS
In 16 normal eyes, the proximal end of the SIBS GDI was inserted into the anterior chamber while the distal end was placed in the subconjunctival space. A control group underwent implantation of a similarly designed silicone GDI. Slitlamp follow-up and intraocular pressure measurements were recorded. Flow patency was evaluated by injecting 0.01% fluorescein into the anterior chamber. Immunostaining against collagen IV, macrophages, and alpha smooth muscle actin was performed.


RESULTS
Slitlamp examination suggested adequate biocompatibility. A low and diffuse bleb was observed in the SIBS group. All SIBS tubes were patent 6 months after insertion. Immunostaining demonstrated noncontinuous collagen deposition. No macrophages or myofibroblasts were visible around the SIBS tubes. In contrast, silicone induced collagen deposition and myofibroblast differentiation.


CONCLUSIONS
This new GDI is clinically biocompatible in the rabbit and maintained 100% patency at 6 months. A remarkable difference was the absence of myofibroblasts in the surrounding tissue in the SIBS group.


CONCLUSIONS
This novel GDI made of SIBS would prevent the feared complication of hypotony and will decrease the amount of subconjunctival fibrosis.
Acosta
Ana C
AC
Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, FL 33136, USA.
Espana
Edgar M
EM
Yamamoto
Hideo
H
Davis
Stewart
S
Pinchuk
Leonard
L
Weber
Bruce A
BA
Orozco
Marcia
M
Dubovy
Sander
S
Fantes
Francisco
F
Parel
Jean-Marie
JM
D000199:Actins / Q000032:analysis; D000818:Animals; D000867:Anterior Chamber / Q000737:chemistry / Q000601:surgery*; D001082:Aqueous Humor / Q000378:metabolism*; D001672:Biocompatible Materials; D024141:Collagen Type IV / Q000032:analysis; D005260:Female; D015590:Fluorophotometry; D020327:Glaucoma Drainage Implants; D007429:Intraocular Pressure; D008264:Macrophages / Q000166:cytology; D008422:Materials Testing; D011474:Prosthesis Design; D019919:Prosthesis Implantation; D011817:Rabbits; D013343:Styrenes
D000199:Actins; D001672:Biocompatible Materials; D024141:Collagen Type IV; D013343:Styrenes; C500040:poly(styrene-b-isobutylene-b-styrene)