Optical Coherence Tomography in the Diagnosis of Optic Pathway Gliomas

Abstract

PURPOSE. To compare visual function assessment, optic disc evaluation by indirect ophthalmoscopy, and retinal nerve fiber layer analysis by optical coherence tomography (OCT) for the screening of optic pathway gliomas in pediatric patients (2-15 years old) affected by neurofibromatosis type 1.METHODS. Fifty-seven consecutive patients with neurofibromatosis type 1 with recent (<6 months) orbital/brain magnetic resonance images (MRI) were included. Patients underwent visual function assessment (Hyvarinen symbols chart and/or Snellen charts) and optic disc evaluation by indirect ophthalmoscopy performed by experienced, masked pediatric ophthalmologists. Spectral domain OCT was performed to assess retinal nerve fiber layer. RESULTS.Fifteen of 57 enrolled patients (26%) were affected by MRI-proven optic pathway gliomas. Visual function assessment, optic disc evaluation, and retinal nerve fiber layer analysis by OCT were feasible in 84%, 95%, and 88% of patients, respectively. Visual function assessment, retinal nerve fiber layer analysis, and optic disc evaluation results correlated with the presence of optic pathway gliomas (P ¼ 0.007, P < 0.0001, and P ¼ 0.03, respectively). Specificity and negative predictive value of each test were statistically significant in detecting optic pathway glioma (P < 0.0001), whereas only retinal nerve fiber layers analysis reached statistically significant sensitivity and positive predictive value (P ¼ 0.0386). CONCLUSIONS.Retinal nerve fiber layer analysis assessment using spectral domain OCT is superior to visual function assessment and optic disc evaluation as a clinical screening tool for optic pathway gliomas.

Correlation of peripapillary retinal nerve fibre layer thickness with visual acuity in paediatric patients affected by optic pathway glioma

“…; Parrozzani et al. ). Optic pathway glioma is histologically defined as low‐grade tumour (WHO grade I pilocytic astrocytoma) and develops in 15–20% of NF1 patients (Listernick et al.…”

“…; Parrozzani et al. ). Decreased VA is considered the most clinically relevant indicator of OPG, whereas serial VA measurement the best method to follow‐up affected patients (Ferner et al.…”

“…Unfortunately, the use of VA as an objective diagnostic or treatment‐deciding factor in paediatric patients is problematic, due to the fact that subjects may not be able to complete age‐appropriate visual function tests, resulting in a large amount of non‐accurate and/or false‐positive results (Parrozzani et al. ). Moreover, a large proportion of NF1 children have moderate to severe impairment in one or more areas of cognitive function, further reducing the test compliance and the positive predictive value of VA assessment (Pride et al.…”

Spectral Domain Optical Coherence Tomography Evidence of Retinal Nerve Fiber Layer and Ganglion Cell Loss in Adult Patients With Neurofibromatosis Type 1

“…Chang et al 8 and Topcu-Yilmaz et al 9 showed decreased peripapillary retinal nerve fiber layer (pRNFL) in children with NF1 and optic nerve glioma and proposed evaluation of pRNFL thickness as a noninvasive testing method to detect early signs of OPG. Parrozzani et al 10 reported that retinal nerve fiber layer (RNFL) thickness has a significant sensitivity and positive predictive value in detecting OPG in children. The recent advent of segmentation measurements has led to retinal layer thickness evaluation in various pathologies affecting the RNFL.…”

OCT and Compressive Optic Neuropathy

“…Parrozzoni et al [ 26 ] compared visual function and SD-OCT measured RNFL thickness for the screening of OPG in 57 pediatric patients affected by NF-1. Visual function assessment, RNFL analysis, and optic disc evaluation results correlated with the presence of OPGs, but only RNFL analysis reached statistically signifi cant sensitivity and positive predictive value.…”