Hot needle thermal keratoplasty to correct naturally occurring hyperopic astigmatism

To study the safety, effectiveness, predictability and stability of sectoral thermal keratoplasty in the treatment of naturally occurring hyperopic astigmatism.

Using Fyodorov's technique, sectoral controlled coagulations were applied on both sides of the flattest meridian in 12 eyes from eight patients with naturally occurring hyperopic astigmatism. Preoperative average refractive cylinder was +3.19 +/- 1.13 diopters (D), and the mean spherical component was +0.71 +/- 1.03 D. Mean follow-up time was 13.2 months.

Immediately after surgery, we observed a significant overcorrection in the treated meridian in all patients. Then, a gradual decrease of the refractive effect was noticed, since the average refractive astigmatism was +0.25 +/- 1.23 D at 6 months and +1.15 +/- 0.86 at 12 months after surgery. At 1 month after surgery, the mean shift in the cylinder axis was 83.75 degrees +/- 8.82 degrees and 12.08 degrees +/- 12.33 degrees at the 1-year examination. Uncorrected visual acuity was 20/40 or better in all patients 1 year after surgery. We did not observe severe corneal complications, such as irregular astigmatism or delayed epithelial wound healing.

Hot needle sectoral thermal keratoplasty appears to be safe and partially effective in reducing hyperopic astigmatism, but considerable postoperative regression may occur.