Assessment of compressive optic neuropathy in hipofizar tumors

Objective: Assessment of optic nerve head configuration in eyes with compressive optic neuropathy due to pituitary tumors--morphological aspects of "band atrophy" (documented by fundus biomicroscopy and digital stereo disc photography) and quantitative analysis of topographic changes (testing the abilities of HRT and OCT in detection and analysis the specific pattern of nerve fiber layer loss in chiasmal compression).

Methods: Optic disc morphological assessment of compressive optic neuropathy in 56 patients with pituitary macroadenomas (documented by direct ophthalmoscopy, fundus biomicroscopy using Volk lens of 90 degrees and digital stereo disc photography using Zeiss Visucam digital camera). Stereometric analysis of "band atrophy" using HRT in 9 cases and OCT in 5 cases.

Results: The optic disc morphology evaluation of the 54 patients showed bilateral "band atrophy" in 7 cases, different evolutive aspects (temporal pallor, global pallor, optic disc cupping) in 29 cases and normal configuration in 5 cases. HRT evaluation: overestimation of rim parameters and underestimation of cup parameters; reduction of the RNFL thickness and RNFL cross sectional area in 6 cases; reduction of HVC values in 6 eyes and positive values in 1 eye. OCT analysis of the Avg. thickness: outside normal limits values in 6 eyes and borderline values in 4 eyes.

Conclusions: HRT quantified RNFL thickness reduction for the long standing pituitary macroadenomas, its sensitivity increasing with the advanced stage of the compression, but lacking OCT's specificity. OCT is the election technique for documenting RNFL loss in compressive optic neuropathy due to pituitary tumors, more objective than conventional methods, especially in the process of postoperative management (subtle structural alterations being early detected before functional loss recordings.