Abstract
Purpose: :
To assess biocompatibility, safety and efficacy of 4 different new models of this Glaucoma Drainage Device implant MIDI Ray made of SIBS
Methods: :
15 normotensive NZW rabbits in 4 groups were used in this ongoing 6 months study: 3 received implant with tube outer diameter (od) 350 um, inner diameter (id) 100um and plate’s thickness of 400 um sutured at the equator of the plate (A), 3 received an implant od 300 um, id 100um and plate’s thickness of 500 um sutured at the equator of the plate (B); 3 received an implant od 400 um, id 100um and plate’s thickness of 400 um sutured at anterior region of the plate (C) and 6 received an implant od 350 um, id 100um and plate’s thickness of 350 um sutured at anterior region of the plate(D)The same surgeon implanted MIDI Ray in one eye, the other served as control, the tube was placed into the anterior chamber via a track made 2mm below the limbus, the plate was sutured at 4 mm (A) and 6 mm (B,C,D) from limbus and covered with conjunctivaIOP measurements were obtained pre and postoperatively with a Perkins and pneumatonometer, Slit lamp biomicroscopy follow-up, gonioscopy and funduscopy was done in pre and postop and at POD 1, 7, 14, 21, 28, 60, 90 (current), and monthly up to 6 mo.Continuous variables were analyzed with general linear models; dichotomous variables were analyzed with Chi-square
Results: :
The study included 15 NZW rabbits with a mean preoperative weight of 2.64 (±0.48). The device showed excellent biocompatibility, with few intraoperative difficulties, No device extruded or eroded through the conjunctivaNo animal developed choroidal effusion, suprachoroidal hemorrhage or intraocular infectionSignificant differences in IOP changes occurred in surgery groups as measured with the Perkins (p= .041) and Pneumotonometer (p= .003). Operated eyes demostrated thicker CCT than control eyes by pachymetry (p= .021) irrespective of device. Bleb were present in all groups at day 7 but, group D developed blebs earlier during the first week (days 1, 3, p=0.024, 0.083). Subsquently, results were comparable in all groups. The local tissue reaction consisted of an enveloping, very thin capsule surrounded the plate of the devices at pod 60Long-term data and histology after 180 days follow-up will be presented
Conclusions: :
All 4 models of MIDI Rays were found easy to implant, safe and biocompatibleAll groups developed postoperative comparable blebs until POD 90MIDI Ray resulted in minimal clinical capsular reaction in rabbits
Keywords: aqueous • intraocular pressure • anterior chamber