Optic Disc Appearance in Sleep Apnea Associated Optic Neuropathy

Abstract

Abstract: : Purpose: Sleep apnea is associated with both pseudotumor cerebri and anterior ischemic optic neuropathy. In acute pseudotumor cerebri, both optic discs are usually swollen. In contrast, in acute anterior ischemic optic neuropathy usually only one disc is affected. The ischemic disc is typically hyperemic with sectoral swelling and hemorrhages. This study’s purpose is to first determine if patients with sleep apnea have different disc appearances consistent with either anterior ischemic optic neuropathy or pseudotumor cerebri. Second, is bilateral involvement predictive of elevated intracranial pressure? Methods:The records of 50 consecutive patients with optic neuropathy with symptoms of sleep apnea were reviewed. All patients presented to a neuro–ophthalmology service at a university ophthalmology practice and had sleep studies. Their records were retrospectively studied for abnormal respiratory distress indexes (positive sleep studies), optic disc appearance and bilaterality. Patients with optic pallor in either eye were excluded as showing signs of chronicity. Results:37 of 50 (74%) patients had positive sleep studies. 21 of 37 (57%) patients with positive sleep studies had no evidence of optic atrophy in either eye and could be considered acute. 10 of 21 (48%) patients had generalized disc swelling while 11 of 21 (52%) had sectoral hemorrhages. 9 of 10 (90%) patients with generalized disc swelling were bilaterally affected while 4 of 11 (30%) of patients with sectoral hemorrhages were bilateral (p < 0.025). 100% of patients with bilateral disc swelling and positive sleep studies had elevated intracranial pressure. Similarly 100% of patients with positive sleep studies with bilateral sectoral hemorrhages had inflammatory optic neuropathy. Conclusions:Sleep apnea associated optic neuropathy has at least two separate manifestations: pseudotumor cerebri and anterior ischemic optic neuropathy. Bilateral disc swelling in sleep apnea should be treated like pseudotumor cerebri. Unilateral sectoral hemorrhages should be treated like anterior ischemic optic neuropathy. Bilateral sectoral hemorrhages should signal evaluation for inflammation. Unilateral disc swelling requires a lumbar puncture and rheologic evaluation.

Keywords: optic disc • neuro–ophthalmology: optic nerve • ischemia