One-year results of the intrastromal corneal ring in nonfunctional human eyes. Intrastromal Corneal Ring Study Group.
OBJECTIVE
The intrastromal corneal ring (ICR), a new keratorefractive device designed to correct myopia, was evaluated for safety and efficacy as part of a phase I Food and Drug Administration clinical trial.


METHODS
Ten patients, each with one nonfunctional eye, underwent surgical implantation of the ICR, which is a split ring composed of polymethyl methacrylate. The eyes were followed up during a 1-year period and were evaluated for wound healing, implant-related inflammation, intraocular pressure, corneal thickness, endothelial cell count, and refractive effects.


RESULTS
Wound healing was uncomplicated in all of the patients. No patient experienced implant-associated inflammation or extrusion. Intraocular pressure, corneal thickness, and endothelial cell counts were unaffected by the ICR. Non-sight-threatening intraoperative events included ring decentration and inadequate attachment of a vacuum-centering guide. The ICR reduced keratometrically determined spherical equivalence by an average of -2.5 +/- 1.1 diopters (mean +/- SD). Spherical equivalence, as determined by retinoscopy, was reduced by an average of -2.4 +/- 1.0 D. Results of corneoscopy and computerized videokeratography further confirmed this reduction of myopia.


CONCLUSIONS
The ICR may be a safe and efficacious device that offers predictable results with few side effects, and it may be a feasible alternative to current keratore-fractive procedures.
Assil
K K
KK
Anheuser-Busch Eye Institute, St Louis University, MO.
Barrett
A M
AM
Fouraker
B D
BD
Schanzlin
D J
DJ
D000328:Adult; D001766:Blindness / Q000601:surgery; D002452:Cell Count; D003315:Cornea / Q000502:physiology; D003319:Corneal Stroma / Q000601:surgery*; D004728:Endothelium, Corneal / Q000166:cytology / Q000502:physiology; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D020366:Methylmethacrylate; D008768:Methylmethacrylates; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D011379:Prognosis; D019736:Prostheses and Implants; D012030:Refractive Errors / Q000503:physiopathology; D014945:Wound Healing / Q000502:physiology
D008768:Methylmethacrylates; D020366:Methylmethacrylate