Optical coherence tomography in preoperative workup and visual outcome of pituitary macroadenomas

Pituitary macroadenomas often cause progressive visual loss secondary to chiasmatic or optic nerve compression. At present, there are no precise preoperative evaluation methods capable of predicting postoperative visual outcome. The evaluation of the peripapillary retinal nerve fiber layer (RNFL) and macular thicknesses by optical coherence tomography (OCT) can provide parameters for the severity of optic neuropathy, with possible prognostic value.

30 patients were enrolled in this prospective study. Adult patients with sellar preoperative magnetic resonance imaging suggestive of pituitary macroadenomas with suprasellar extensions were included in the study. Patients were evaluated with computerized visual perimetry (VP) and OCT before and after pituitary surgery. Postoperatively, OCTs and VPs were repeated at 30 and 120 days. Surgical procedure consisted of endoscopic endonasal transsphenoidal resection (EETR) of the macroadenoma.

There was a significant improvement in VPs after surgery. Except for two, the thicknesses of the eight sectors of the peripapillary RNFL and the 27 sectors of the three layers of ganglion cell complex of the macula showed no changes postoperatively. All patients with altered preoperative RNFL scans already demonstrated PV abnormalities.

Despite most patients show important perimetric improvements after EETR of pituitary macroadenomas, OCT parameters tend to remain stable, suggesting that postoperative visual recovery is independent of the increase in retinal neuronal layers. Furthermore, OCT is capable of adequately detecting signs of compressive optic neuropathy, but peripapillary RNFL appears to demonstrate no advantage over VP for the early detection of visual compromise in the scenario of pituitary macroadenomas.