Abstract
Purpose: :
To compare the ability of optical coherence tomography (Stratus–OCT) macular and retinal nerve fiber layer (RNFL) thickness parameters to differentiate between eyes with band atrophy of the optic nerve and eyes from normal controls.
Methods: :
Forty eyes from 40 consecutive patients with band atrophy (BA) of the optic nerve and permanent temporal hemianopia due to chiasmal compression, and 31 eyes from an age– and sex–matched control group of 31 healthy individuals were studied prospectively. All patients were submitted to an ophthalmic examination including perimetry and evaluation of macular and RNFL thickness using optical coherence tomography. A temporal mean deviation (TMD) was calculated in each patient from 22 points in the temporal field using standard automated perimetry. Mean macular and RNFL thickness around the optic disc was compared between the two groups. Receiver operating characteristic (ROC) curves were calculated for each parameter. The influence of disease severity was evaluated by calculating a regression curve, using the TMD as a covariate on the ROC curves.
Results: :
Average macular thickness and thickness from the temporal, superior, nasal and inferior inner segments as well as from the superior, nasal and inferior outer segments and the temporo–nasal relationship were also significantly smaller in eyes with band atrophy when compared to normal controls. There was no difference in measurements of the temporal outer segment in both groups. The peripapillary RNFL thickness (mean ± SD) of eyes with band atrophy was significantly smaller in eyes with band atrophy when compared with normal controls in the superior, temporal, inferior and nasal quadrants as well as in the total RNFL average measurement. Area under the ROC curves (AUC’s) indicated that both macular and RNFL thickness parameters showed good capacity of differentiation of eyes with BA and normal eyes. No statistically significant difference (p=0.073) was found between the AUC’s for the best macular parameter (nasal outer, AUC=0.93) and the best RNFL parameter (total average, AUC= 0.99).
Conclusions: :
Both RNFL and macular thickness parameters are able to differentiate normal eyes from BA and the combined use of both would probably increase the diagnostic performance of OCT.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • nerve fiber layer • neuro-ophthalmology: diagnosis