Retinal NFL thinning on OCT correlates with visual field loss in pediatric craniopharyngioma

Abstract

ObjectiveTo investigate the use of peripapillary optical coherence tomography for monitoring optic neuropathy in pediatric craniopharyngioma. DesignRetrospective, consecutive-cohort, single-centre chart analysis. ParticipantsTwenty children with craniopharyngioma treated at a pediatric medical centre from 1999 to 2011. MethodsThe medical files were reviewed for demographics and optic nerve function. Findings for visual acuity and visual fields were analyzed against repeated optical coherence tomography (OCT) measurements of peripapillary nerve fibre layer thickness (using either time-domain Stratus OCT or spectral-domain Cirrus OCT). ResultsAverage age at diagnosis was 6.5 ± 3.88 years. The most common presenting symptom was headache; only 1 child complained of visual loss. Mean best corrected visual acuity (logMAR) was 0.036 ± 0.06 in the 17 healthy eyes and 1.05 ± 1.45 in the 23 eyes with optic neuropathy. Positive signs included relative afferent pupillary defect (8/20), visual acuity loss (7/20), temporal visual field loss (bilateral 4/15, unilateral 4/15), papilledema (3/20), and unilateral/bilateral optic disc pallor (14/20). RNFL thickness was significantly lower in eyes with optic neuropathy than in healthy eyes (65 ± 22 µm vs 86.2 ± 29 µm; p = 0.000) and correlated with visual acuity (r = –0.43 to –0.17, p = 0.0001) and presence or absence of a visual field defect (mean difference, 26.1 ± 5.8 µm, p = 0.003). Ten children showed no change in RNFL thickness over time (mean 18 ± 14.2 months). ConclusionsA thinner RNFL on ocular coherence tomography is correlated with poorer visual acuity and visual field loss. Ocular coherence tomography may serve as an objective method to quantify axonal loss caused by craniopharyngioma. Further investigation is needed to determine its use for evaluating progressive axonal loss over time.