THE CUPPED DISC - WHO NEEDS NEUROIMAGING

Objective: To determine the incidence of positive neuroradiologic stud ies in consecutive patients with glaucoma associated with normal intra ocular pressure and to compare the psychophysical and clinical charact eristics of these eyes with eyes with disc cupping associated with int racranial masses. Design: Retrospective case-controlled study. Partici pants: Fifty-two eyes of 29 patients with glaucoma associated with nor mal intraocular pressure and 44 eyes of 28 control patients with compr essive lesions were reviewed. Intervention: The medical records of con secutive glaucoma patients with normal intraocular pressure who underw ent brain magnetic resonance imaging or computed tomography scanning a s part of a diagnostic evaluation between January 1, 1995, and July 1, 1995, were reviewed. A masked reading of optic nerve photographs and visual fields was performed by one observer. A similar analysis was pe rformed on a control group of consecutive patients with nonglaucomatou s optic nerve cupping with known intracranial mass lesions. Main Outco me Measures: The neuroradiologic findings, clinical characteristics, o ptic nerve head appearance, and patterns of visual field loss were com pared between groups. Results: None of the patients diagnosed with gla ucoma had neuroradiologic evidence of a mass lesion involving the ante rior visual pathway. Compared to control subjects, patients with glauc oma were older (P = 0.0001), had better visual acuity (P = 0.002), gre ater vertical loss of neuroretinal rim tissue (P = 0.0001), more frequ ent optic disc hemorrhages (P = 0.01), less neuroretinal rim pallor (P = 0.0001), and more nerve fiber bundle visual field defects aligned a t the horizontal midline (P = 0.0001). Visual acuity less than 20/40, vertically aligned visual field defects, optic nerve parlor in excess of cupping, and age younger than 50 years were 77%, 81%, 90%, and 93% specific for nonglaucomatous cupping associated with compressive lesio ns, respectively. Conclusions: Anterior visual pathway compression is an uncommon finding in the neuroradiologic evaluation of patients with a presumptive diagnosis of normal-tension glaucoma. Younger age, lowe r levels of visual acuity, vertically aligned visual field defects, an d neuroretinal rim pallor may increase the likelihood of identifying a n intracranial mass lesion.