Abstract
Purpose: :
To define objectively the extent of functional and structural loss in pituitary compressive optic neuropathy by standard automated perimetry (SAP) and retinal nerve fiber layer thickness (RNFLT) measured by optical coherence tomography (StratusOCT) and to evaluate the correlation between structural damage and visual recovery after surgical intervention.
Methods: :
Prospective cohort study including 50 eyes of 25 pituitary adenoma patients. Thirteen had compressive macroadenoma and surgical intervention, 6 with macroadenoma followed for visual field changes, 6 had microadenoma, defined as negative controls for the disease, all compared with 50 eyes of 25 healthy persons. Any other optic neuropathy and retinal disease were excluded. RNFLT measurements and SAP were done every 4 to 6 months. In cases of surgical intervention these tests were performed one week before and one week, one month and three months after the surgery. One-way ANOVA with Tukey or Games-Howell post hoc tests, Pearson correlation and ROC curve defining the best discriminating parameters were employed using SPSS 16.0 statistical software, accepting p<0.05 significant.
Results: :
Based on post-surgical VF recovery of 26 eyes of 13 patients the baseline average (AVG0) RNFLT were 94.8 ±13.3 µm in those with total VF recovery (n=8), but 79.3±8.5 µm when permanent visual loss was present (n=5) and 96.5 ±8.2 µm in healthy controls. AVG0 and the follow up (AVG3) RNFL were in good correlation with the final visual field parameters in the visually impaired (AVG0 vs MD = 0.947 and PSD = -0.969 ; AVG3 vs MD = 0.800 and PSD = -0.690). AVG0 and AVG3 of 69.3-73.8 µm could differenciate the two groups either at baseline or follow-up (92% specificity, 83% sensitivity, AROC 0.905 and 0.798, respectively). VF mean sensitivity in the temporal hemifield, in contrast to mean deviation (MD) provided a more accurate measure of the visual impairment during follow-up of surgically treated patients.
Conclusions: :
Objective data aquisition with SAP and RNFLT imaging by means of OCT at baseline and follow-up of patients with pituitary adenoma provides valuable information about the extent of the optic nerve damage. Impaired visual field and a possible nerve fiber loss detectable at the level of the retina can be a helpful tool when surgical intervention is designed.
Keywords: neuro-ophthalmology: optic nerve • visual impairment: neuro-ophthalmological disease • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)