Hydrogel keratophakia: a microkeratome dissection in the monkey model.
High water content intracorneal implants were fabricated from Vistamarc hydrogel (Vistakon, Inc.) at 58%, 68%, and 72% water content and a range of powers from +7.25 to +17.00 dioptres. The Barraquer microkeratome technique was used to implant the lens at 59.0 +/- 9% (+/- SD) depth in the corneas of 14 rhesus monkey eyes. The contralateral eye served as a control. Three eyes were lost to the study because of complications. The remaining 11 animals were followed up for 51 +/- 2 weeks with the refractive yield being 118 +/- 34% and the keratometric yield being 92 +/- 30%. The measured and theoretically expected refractive changes have a linear regression line correlation coefficient of 0.74, whereas the respective keratometric data had a correlation coefficient of 0.04. The measured refraction became stable within 2 to 3 dioptres after 20 postoperative weeks. The hydrogels were well tolerated within the corneal tissue. There was a minimum of interface problems except along the edge of the implant. Implants with abruptly cut edges versus a fine wedge tended to have more light scattering collagen at the implant margin.
D000818:Animals; D001672:Biocompatible Materials; D003315:Cornea / Q000033:anatomy & histology / Q000601:surgery*; D005260:Female; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D007910:Lenses, Intraocular; D008253:Macaca mulatta; D008297:Male; D008722:Methods; D011092:Polyethylene Glycols; D012029:Refraction, Ocular; D013997:Time Factors
D001672:Biocompatible Materials; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011092:Polyethylene Glycols