Abstract
Purpose: :
To assess the biocompatibility of synthetic corneal inlays over a 18 month period in humans.
Methods: :
Porous perfluropolyether corneal inlays (LD: 4.3mm ct: 80 microns) were placed under a microkeratome flap (180 microns thickness) without sutures in the unsighted eye of 5 patients. Three patients, aged from 58 to 68 years, were unsighted in one eye as a result of optic atrophy, whilst a further 2 patients, aged 24 and 38 years, were unsighted in one eye as a result of traumatic optic neuropathy and central retinal artery occlusion. The contralateral eye had "good" vision (20/20–20/40). A microkeratome flap without implantation was performed on the unsighted eye of a patient aged 50 years. This patient served as a control. The patients undergoing surgery were assessed at baseline, immediately post–op, at 7 days, 1 month and every month thereafter for 12 months and then at least at 3 monthly intervals. Confocal microscopy has been performed at 3 monthly intervals.
Results: :
Surgery was uneventful and no episodes of inflammation, significant vascular in–growth or other adverse reactions reported. The inlay was removed from one patient at 5 months possibly due to epithelial and stromal breakdown, possibly consistent with a retrospective diagnosis of forme fuste keratoconus. In all other patients, the corneal tissue surrounding the inlays remained unaffected, except for some mild haze surrounding the inlays in 2 cases. Confocal microscopy has indicated normal posterior stroma and endothelium appearance. Changes observed in the epithelium, anterior stroma and interface were consistent with those observed in animal models and were less marked from 12 months onwards. Inlay position remained stable throughout, but clarity decreased slightly over the first 3 months before stablilizing thereafter.
Conclusions: :
Corneal inlays made from perfluoropolyether are biocompatible with corneal tissue in the long term and offer a safe and biologically acceptable alternative to other forms of refractive surgery.
Keywords: refractive surgery: other technologies • cornea: stroma and keratocytes • clinical (human) or epidemiologic studies: systems/equipment/techniques