Swelling of Atrophic Optic Discs in Idiopathic Intracranial Hypertension

BACKGROUND: Monitoring patients with idiopathic intracranial hypertension (IIH) and optic atrophy may be difficult as papilledema may not be appreciable on ophthalmoscopy. This retrospective chart review evaluated whether papilledema recurrence can be detected in this population using optical coherence tomography (OCT). METHODS: Serial clinical assessments, ophthalmoscopy, and peripapillary OCT were reviewed in a cohort of patients with IIH and optic atrophy. Atrophy was defined as moderate if average peripapillary retinal nerve fiber layer (pRNFL) thickness was ≤80 μm and severe if average pRNFL thickness was ≤60 μm on at least 2 consecutive high-quality OCT scans. Based on the upper tolerance limit of test-retest variability, mean pRNFL elevation of ≥6 μm with subsequent decrease to baseline thickness was considered papilledema. RESULTS: In a cohort of 165 patients with IIH, 32 eyes of 20 patients and 22 eyes of 12 patients demonstrated moderate and severe optic atrophy, respectively. Over a median follow-up of 198.5 weeks (range, 14.0-428.9), 63.3% (19 of 30) of patients had at least 1 episode of relapse, and 50.0% (15 of 30) had at least 1 episode of papilledema. There was a total of 36 relapse episodes, of which 7 occurred in patients with clinical signs and symptoms but no OCT evidence of relapse, 12 occurred in patients with OCT changes but no clinical signs and symptoms of relapse, and 17 occurred in patients with both clinical and OCT evidence to support relapse. The median percent pRNFL increase in the latter 2 groups was 13.7% (range, 7.5-111.8), and 7 eyes (13.0%) of 5 patients (16.7%) showed thickening greater than 20.0% from baseline. The rate, magnitude, and concordance of pRNFL swelling were similar between moderately vs severely atrophic eyes. CONCLUSIONS: Papilledema recurrence can be detected in atrophic optic discs using OCT. All patients with atrophic IIH should be longitudinally monitored with pRNFL measurement. Concurrence of other relapse-suggestive features should prompt further evaluation.