The effect of scleral cautery on corneal astigmatism in cadaver eyes.

We studied the effect of scleral cautery on corneal astigmatism in 20 cadaver eyes using the Zeiss wetfield bipolar cautery either at or 2 mm posterior to the corneoscleral limbus. The chord of cauterized area was set at either 5.5 or 11 mm. Cautery induced net corneal steepening along the meridian of the cauterized area, and induced the greatest astigmatism when applied at the limbus. At each location the 11-mm cautery application induced less astigmatism. The majority of the astigmatic change occurred within the first 5 to 10 seconds of application. We found that scleral cautery at or 2 mm posterior to the limbus can induce extensive corneal astigmatism.