Midi-Ray Glaucoma Drain With Drug Release Potential; A Rabbit Pilot Study

Abstract

 

Purpose:

 

To assess efficacy, safety and biocompatibility of a novel SIBSimplant consisting to a 250µm outer and 100µm innerdiameter tube fused to a 6mm diameter 50µm thick shieldand the feasibility of impregnating the shield with an antimetabolite.

 

Methods:

 

7 NZW rabbits were used in this ongoing 6 months study: 3 receiveda bare implant (A) and 4 received an implant with its shieldloaded with 250µg paclitaxel (B). Same surgeon implantedMIDI Ray in one eye, the other being a control, the tube wasplaced into the anterior chamber via a track made 2mm belowthe limbus, the distal shield was placed under conjunctiva.Slit lamp biomicroscopy, Perkins tonometer readings, gonioscopyand funduscopy was done in pre- and postop and at POD 1, 7,14, 21, 28, 60 (current), and monthly up to 6 mo and gradedusing a modified McDonald-Shadduck score system.

 

Results:

 

The device was easy to implant, showed excellent biocompatibilityand few intraoperative difficulties were noted. No significantchange in average pachymetry, no extrusion, and 5 of 7 had ableb present at POD 60. The implants were not sutured and 2of 6 folded. Hypotony and cataract occurred with paclitaxeldevices only, suggesting that high dosage of Paclitaxel wasused but cornea and retina remained normal. (Table 1)IOP remainedlower in the implanted eye (-35% at POD 28). IOP differenceratio between operated and non-operated contralateral eye isshown in Table 2.

 

Conclusions:

 

Bare MIDI Rays were found easy to implant, safe and biocompatible.The Paclitaxel dose will be reduced in the Phase II of thisstudy. 

 

 

Keywords: aqueous • anterior chamber • conjunctiva