Corneal sensitivity after percutaneous radiofrequency trigeminal rhizotomy: a quantitative study.

Using the Cochet-Bonnet esthesiometer, we evaluated the corneal sensation in 13 patients with trigeminal neuralgia. We compared the preoperative and postoperative results after the trigeminal rhizotomy in a quantitative study. Of 13 patients who underwent operation, a decrease in corneal sensation developed compared with the eye that was not operated on in five patients. This decrease in sensitivity was not suggested by clinical symptoms or signs, and up to 23 months of follow-up failed to reveal any clinical symptoms. The failure to manifested clinical corneal symptoms in the follow-up period may result from the selective fiber destruction technique employed in radiofrequency rhizotomy with preservation of other myelinated nerves maintaining corneal nutrition.