Retinal Nerve Fiber Layer Thickness Measurement for Predicting Visual Outcome after Transsphenoidal Surgery: Optic Disc Atrophy Is Not the Deciding Indicator

Abstract

Postoperative visual recovery is a major concern after transsphenoidal surgery. Optical coherence tomography (OCT) can visualize the anatomy of the retina, and retinal nerve fiber layer (RNFL) thinning reflects loss of optic nerve axons. Visual-evoked potential (VEP) is an electrophysiological response that confirms the nerve conductance. Therefore, these factors reflecting the optic nerve condition may be closely associated with the visual outcome after transsphenoidal surgery. A total of 124 eyes in 62 patients with sellar tumor who underwent transsphenoidal surgery were included. The following variables were retrospectively analyzed: age, sex, tumor diameter, histology, symptom duration, history of rapid deterioration, optic disc atrophy on fundoscopy, peripapillary RNFL thickness on OCT, and latency and reproducibility of the VEP waveform. Four eyes were excluded for no visual disturbance in 3 and glaucoma aggravation in 1. Eighty-three eyes manifested visual improvement, 37 revealed no change, and none showed postoperative deterioration. Univariate analysis demonstrated that thick RNFL of the inferior and temporal quadrants, reproducible VEP waveform, short symptom duration, histologic diagnosis of pituitary adenoma, and small tumor diameter were associated with good visual recovery. Multivariate analysis showed RNFL thickness of the temporal quadrant had significant association with visual recovery (P= 0.03). OCT is a useful diagnostic modality to assess optic nerve condition, and RNFL thickness of the temporal quadrant is correlated with visual outcome after transsphenoidal surgery. Patients with severe visual disturbance may still achieve visual recovery, so surgery should be considered even if optic disc atrophy is evident.