Abstract
Purpose: :
To assess biocompatibility of an absorbable cross linked hyaluronic acid (cSHA) implant for non penetrating deep sclerectomy (NPDS) procedure
Methods: :
24 NZW rabbits underwent NPDS procedure with intrascleral implantation of cSHA implant in one eye while the other served as control in a 9 months study After peritomy 2 hours wide, a 1/3 thickness limbal scleral flap dissection was done up to 1 mm into the cornea, a secondary 1/3 thickness scleral flap was dissected, Schlemm’s canal was unroofed, aqueous humor percolating through the remaining trabeculo-Descemet membrane was observed, secondary flap was excised and the implant was inserted in the scleral bed, scleral flap was repositioned and sutured with 10-0 nylon. Conjunctiva was closed with 10-0 nylon; Clinical evaluation included: Biomicroscopy, tonometry, gonioscopy, funduscopy and UBM in pre and postop at days 1, 3, weeks 1, 2, 4, 6, 8 and then monthly
Results: :
23 rabbits stayed healthy and increased weight. No intraoperative difficulties except 1 inadvertent Descemet perforation, 1 died spontaneously at POD7; at 3 months follow-up period 10 were euthanized for histology, no implant extruded, no conjunctival erosion or intraocular infection was observed, no clinical changes in iris, lens, vitreous and retina.Scleral flap thinning was present in all animals after POD7. Displacement of the implant was observed in 4 animals at POD7; 5 implants protruded partially at POD7 and 3 at POD14 that required minimal excision, Minimal anterior blebs were observed in 5 animals at POD7, in 3 at POD60 and in 1 at POD150. Biodegradation started at POD28; at POD90 there was no observable implant in 7 animals; the size of the implants was variable at all time points depending of swelling process. Data at POD 270 and histology analysis will be shown
Conclusions: :
New cSHA implant is easy to place, safe and biocompatible. Clinical exam and UBM showed biodegradation starting at POD28. Clinical implications of the results require further studies
Keywords: aqueous • trabecular meshwork • anterior chamber