Abstract
Purpose:
Currently, OCT is used to image macular disease and for measurement of the retinal nerve fiber layer (RNFL) thickness in optic nerve disease. OCT is an objective method to measure RNFL thickness in patients with papilledema. Diagnosing shunt malfunction currently relies on using many diagnostic tools, including the clinical history, change in ventricular size on CT, shunt tap findings, shuntograms, MRI, and CSF pressure studies. We hypothesize that OCT may have greater sensitivity and specificity in detecting papilledema caused by hydrocephalus and shunt malfunction.
Methods:
All patients ages four and over with hydrocephalus are being evaluated before and/or after shunt placement or revision. These patients are prospectively followed with OCT, fundus photographs, and examination.
Results:
Fifteen patients have been enrolled to date (eight females, seven males). Diagnoses include hydrocephalus, brain tumors, Chiari malformation, and pseudotumor. One pediatric patient had a new diagnosis of hydrocephalus with papilledema and two pediatric patients had questionable shunt malfunction. One adult patient had papilledema with a diagnosis of a brain tumor and one adult patient had questionable shunt malfunction. Baseline average RNFL thickness measurements for pediatric patients without optic atrophy: 85.0 μm (SD 4.06). Baseline average RNFL thickness measurements for pediatric patients with optic atrophy: 66.75 μm (SD 8.12). Baseline average RNFL thickness measurements for adult patients without optic atrophy: 99.1 μm (SD 22.77). Baseline average RNFL thickness measurements for adult patients with optic atrophy: 53.5 μm (SD 5.94). A fourteen-year-old patient with a new diagnosis of hydrocephalus had elevated RNFL measurements OU, which returned to normal after endoscopic third ventriculostomy surgery. A nine-year-old girl with communicating hydrocephalus and optic atrophy showed microcystic changes in the inner nuclear layer on OCT.
Conclusions:
OCT may be a valuable tool to quantitatively assess the development and resolution of papilledema and to detect shunt malfunction in patients with hydrocephalus. Microcystic changes have been previously described in patients with optic neuropathy secondary to hydrocephalus. The significance of this finding is not clearly understood, but may have an impact on the measurement of true retinal thinning in these patients.
Keywords: 610 nerve fiber layer