January - March 2008, Volume 4, Issue 1

Predoi D, Badiu C, Alexandrescu D, Agarbiceanu C, Stangu C, Ogrezeanu I, Ciubotaru V, Dumitrascu A, Constantinescu AI

Assessment of compressive optic neuropathy in long standing pituitary adenomas

Acta Endo (Buc) 2008, 4 (1): 11-22
doi: 10.4183/aeb.2008.11

In this study we aimed to evaluate and quantify optic nerve damage caused by long standing compressive pituitary macroadenomas with conventional (ophthalmoscopy) and modern techniques such as fundus camera, confocal scanning laser tomography for quantitative measurements of the thickness of retinal layers as well as visual evoked potentials (VEP) for electrophysiological quantification. Seven patients with large, long standing pituitary macroadenomas were submitted to ophthalmologic evaluation, including a visual field (VF), visual acuity (VA) and eye fundus (F). Heidelberg retinal tomography (HRT) was used for retinal thickness and evaluation of nerve fibers loss, and VEP were measured by pattern reversal and flash stimulus. In addition, all patients underwent tumor imaging (MRI/CT) and specific endocrine evaluation. All cases presented with macroadenomas with suprasellar extension and residual or progressive optic chiasma syndrome; all but one (prolactinoma) were nonfunctioning adenomas, after radical treatment (surgery ? radiotherapy). Adrenal and thyroid substitutive treatment was instituted in all cases due to associated pituitary failure. Evaluation of VF showed 9 eyes with temporal hemianopia, 2 with nasal islands of vision and 1 with nasal hemianopia in a homonymous hemianopia case; another case presented for left 3rd nerve palsy due to a cavernous sinus syndrome, therefore the visual field was not measurable in 2 eyes. Visual acuity was very low (counting fingers) in 4 eyes, while in the rest the VA was between 0.5-0.9. The fundus revealed total atrophy in 2 eyes, band atrophy in 4, temporal pallor in 5 and global pallor in 1. Cup/disk ratio in the case with 3rd nerve palsy was 0.5 (RE) and 0.3 (LE). HRT II stereometric analysis of the optic nerve head showed abnormal values, documenting retinal nerve fiber layer (RNFL) loss that correlated with fundus appearance and visual field defects. Mean RNFL thickness had abnormal values in 8 eyes (from 0.074 to 0.173 μm), correlated with RNFL cross sectional area in 7 eyes (from 0.362 to 0.846 μm2) and 1 eye with low limit values (1000 μm2). In agreement with these data, VEP–P100 presented increased latency over 120 ms in 8 eyes, borderline (100-120 ms) in 5 and 97.5 ms in only 1 eye. In conclusion, HRT can document the papilla and nerve fiber layer more objective, permitting quantification of the disc’s alterations due to compressive pituitary macroadenomas. HRT is useful in quantifying RNFL loss in other conditions than glaucoma, when other optic disc imaging tools are not available.

Keywords: pituitary macroadenomas, compressive optic neuropathy, band atrophy, visual evoked potentials, retinal nerve fiber layer, Heidelberg Retina Tomograph II (HRT II)

Correspondence: Daniela Predoi, MD, ophthalmologist CMDTA "Dr. N. Kretzulescu", 24 Stefan cel Mare Str., Bucharest, Romania, tel +40 722348266, mail: dana.eye2@yahoo.com