The role of optical coherence tomography in patients with sellar masses: Are the 2016 guidelines on the neuro-ophthalmic evaluation of pituitary adenomas already obsolete?
Author Disclosure Block: J.A. Micieli: None. R.J. Blanch: None. E. Hawy: None. J.H. Peragallo: None. K. Narayana: None. N.J. Newman: None. V. Biousse: None.
Abstract Body:
Purpose: The 2016 Congress of Neurological Surgeons guidelines on pre-treatment ophthalmology evaluation in patients with pituitary adenomas recommend pre-operative, “Optical Coherence Tomography (OCT) to measure both retinal nerve fiber layer (RNFL) thickness and the presence of damage to the ganglion cell layer (GCL) on algorithms that segment the macular cube,” to assess prognosis for visual recovery. Although RNFL and GCL thickness are routinely used to predict recovery of visual function after treatment, the importance of OCT for compressive optic neuropathy or chiasmopathy diagnosis is less well recognized. We report a patient series with sellar masses causing mass effect on the anterior visual pathways who had normal visual fields but binasal decreased GCL thickness, suggesting preclinical evidence of compression.
Study Design: Retrospective case series
Methods: 12 patients seen for assessment and monitoring of sellar lesions without a definite visual field defect, but abnormal macular GCL were included. Visual fields were classified as suspicious or not for chiasmal compression. GCL/RNFL analyses using Cirrus-OCT were classified into percentiles based on the manufacturer’s reference range. Chiasmal compression was determined by review of coronal images from MRIs with dedicated views of the pituitary and sellar region.
Results: Visual fields were completely normal in 6 of 12 (50%) cases, but GCL analysis showed a macular nasal sextant with a thickness less than 1% of that seen in the normal population in all cases. RNFL thickness was within the reference range in 2 of 6 of these cases, less than 5% in 2 of 6 of these cases and less than 1% in 2 of 6 of these cases.
Visual fields were suspicious for chiasmal compression in that there was a subtle bitemporal visual field defect not easily recognized in 6 of 12 (50%) cases. All of these cases had a macular GCL thickness less than 1% of the normal population in a nasal sextant or clear binasal loss of the macular GCL. RNFL analysis was in the reference range in 2 of 6 of these cases, less than 5% in 2 of 6 of these cases and less than 1% in 2 of 6 of these cases.
Conclusions: In our patients, macular GCL analysis was more sensitive than visual fields in detecting chronic chiasmal compression, suggesting that GCL analysis is an essential test in the diagnosis of compressive optic neuropathy, even before visual fields become abnormal. Macular GCL analysis should be obtained in all patients with radiologic evidence of anterior visual pathway compression even when visual fields appear normal.
