The use of Nd:YAG laser in pituitary surgery and evaluation of visual function by visual evoked potential (VEP).

Abstract

Surgery of pituitary tumors has been improved by microneurosurgical methods. However, despite improvements in surgical results, pituitary tumors still continue to represent a problem and, therefore, prompt a search for new surgical techniques. Since Nd:YAG laser energy penetrates the target tissue more deeply than other instruments, its use in the para- and suprasellar region should be considered. It is well known that Visual Evoked Potential (VEP) is a sensitive and objective method for the valuation of compressive or destructive lesions in or around the optic nerve. Visual function correlates with the latency and amplitude of P100 wave in VEP. We used the Nd:YAG laser in 50 transsphenoidal operations of pituitary adenomas. Postoperative effects of the laser on visual function was evaluated by conventional neurophthalmological tests as well as VEP and was compared with preoperative values. Following surgery using Nd:YAG laser, both conventional neurophthalmological tests and VEP values improved due to decompression of optic nerves by tumor removal. In this study, we also examined anterior lobe functions and found that Nd:YAG laser does not affect these functions. Our study shows that Nd:YAG laser has no harmful effects and seems to be very helpful especially for surgery for invading hormone-active adenomas.