Sarcoidosis of the anterior visual pathway: 24 new cases.

Objectives: To describe the clinical spectrum and a rational approach to the diagnosis of anterior visual pathway sarcoidosis.
Methods: Retrospective chart review of all patients examined in neuro-ophthalmic consultation by 1 author from 1989 to 1998 with a diagnosis of sarcoidosis.
Results: There were 24 patients (17 female, 7 male, mean age 40 years) with anterior visual pathway sarcoidosis, 17 (71%) of whom were not previously known to have sarcoidosis. Visual acuity ranged from 20/20 to NLP. Normal fundi were observed in 15%. Among the 85% who had fundus abnormalities, pallor was present in 55%, disc edema in 26%, periphlebitis/sheathing in 14%, and optic disc granuloma in 10%. Ten patients (42%) had uveitis, active in only 3 (13%). An elevated angiotensin-converting enzyme (ACE) was present in 16 (76%) of 21 patients tested; evidence of sarcoidosis on chest radiograph was present in 13 (72%) of 18; gallium scanning was abnormal in 13 (93%) of 14; neuroimaging abnormalities of the optic nerves, chiasm, or tract were present in 16 (70%) of 23; lymphocytic pleocytosis or elevated cerebrospinal fluid protein was identified in 14 (88%) of 16 patients, with both values elevated in 7 (44%) patients. Histologic confirmation was obtained in 13 (81%) of 16 who underwent biopsy; in the remaining patients, diagnosis was based entirely on clinical and laboratory evidence.
Conclusions: Anterior visual pathway disease may be underrecognized as a presentation of sarcoidosis. Classic fundus findings of periphlebitis and optic granuloma are typically absent. An aggressive diagnostic evaluation may help establish the diagnosis early in its course.