An Independent GLP Evaluation of a New Glaucoma Drain, the Midi

Abstract

 

Purpose:

 

To assess the safety and biocompatibility of the Bascom Palmer Eye Institute– InnFocus glaucoma drainage device in a Good Laboratory Practice (GLP) setting (NAMSA, Northwood, OH).

 

Methods:

 

Eleven New Zealand White healthy rabbits were included in this ongoing six months study. Identical glaucoma drainage devices made of poly(styrene–b–isobutylene–b–styrene) ("SIBS") preloaded in an injector were used (InnFocus LLC, Miami, FL). The device was implanted into the anterior chamber via a track made 2mm below the limbus with the distal end of the device placed in a delaminated conjunctival pocket which was securely sutured at the end of the procedure. The animals were examined preop, in immediate postop and postoperatively at days 2, 14, 28 and 90 by slit–lamp biomicroscopy and indirect ophthalmoscopy. IOP readings were taken with a TonoPen. The anterior segment status was graded using NAMSA’s modified McDonald–Shadduck score system.

 

Results:

 

The device was found easy to implant, average surgical time: was 13.5 ±4.6 min. Very few intraoperative difficulties were observed. The cornea, iris, lens and retina remained normal. No extrusion occurred in any of the animals. The intraocular pressure difference between the operated and non–operated contralateral eye expressed as a ratio was: preoperatively 0.08 ± 0.25, at POD2 –0.34±2.44, at POD7 –0.09 ± 0.18, at POD14 –0.13±0.12, at POD28 0.05±0.13 and at POD90 0.00±0.12. POD180 results will be shown.  

 

Conclusions:

 

The MiDi device was found easy to implant, safe and biocompatible.

 

Keywords: aqueous • intraocular pressure • wound healing