Preliminary results and complications of radial keratotomy

We preformed radial keratotomy for myopia on 126 eyes of 102 patients. We observed as much as 12 diopters of early postoperative refractive corneal flattening, but a mean of only 5.16 diopters of refractive change can be expected after one year. Among the many complications observed were corneal scarring, an endothelial cell loss of 220 cells/mm2 (6.9%), epithelial ingrowth in 18 eyes (14%), corneal vascularization in one of 126 patients (1%), pain, Cogan's corneal dystrophy, overcorrections in 18 patients (14%), anisometropia, perforations of the anterior chamber in 12 patients (10%), iatrogenic astigmatism, corticosteroid glaucoma, night glare in 99 patients (79%), and fluctuating vision in 95 (75%). We studied the following factors to determine if they had predictive value: the patient's age, diopters of myopia, corneal diameter, corneal thickness, anterior chamber depth, axial length, scleral rigidity, keratometric readings, and the size of the optical zone. We found that no preoperative factor can be used to estimate precisely the postoperative result. The only consistent variable was the size of the optical zone. The smaller the optical zone, the larger the refractive change. This lack of predictability is the most serious shortcoming of radial keratotomy.