Abstract
Purpose: :
Patients with optic nerve swelling are often monitored with perimetry exams looking at visual field changes. In this study, we demonstrate the value of optical coherence tomography (OCT) in evaluating the progression and resolution of papilledema in pseudotumor cerebri.
Methods: :
A retrospective review of patients who were diagnosed and followed at Montefiore Medical Center (Bronx, New York) from 2005 to 2010. In addition to conventional studies of visual field using perimetry exams, the retinal nerve fiber layer (RNFL) thickness was also evaluated using OCT. Average RNFL thickness was examined in relation to visual field changes measured by mean deviation (MD) and pattern standard deviation (PSD). Data was divided into three month follow-up intervals in the first year, then yearly thereafter.
Results: :
The study included 24 patients (47 eyes). Ages ranged from 11 to 50 with an average age of 25.5. Intracranial pressure was measured by lumbar puncture with an average opening pressure of 39 ± 10.3 cm H20. Average RNFL thickness was 253.1 ± 122.7 µm in the right eye (OD) and 241.9 ± 128 µm in the left eye (OS) at the time of diagnosis and trended downward with treatment (oral medication and/or weight loss) over the follow-up period. At the three month mark, OD RNFL was averaged to be 223 µm with OS RNFL 201.1 µm. After six months, it was calculated to be significantly thinner at 166.5 µm OD and 147.5 µm OS, at nine months, 127.8 µm OD and 129.5 µm OS, and at 12 months, 138.18 µm OD and 123.4 µm OS. Visual field losses were reported at the time of diagnosis with MD -4.08 ± 3.49 OD, PSD 3.65 ± 2.56 OD and MD -4.42 ± 3.95 OS, PSD 3.61 ± 2.51 OS. Similar to RNFL thickness, visual field losses were noted to improve with resolution of papilledema: at 12 months, OD MD -1.0, OD PSD 1.22, OS MD -1.8, OS PSD 2.23.
Conclusions: :
OCT is a useful, noninvasive modality in quantitatively measuring the course of papilledema in pseudotumor cerebri. We postulate the value of OCT as an adjuvant diagnostic tool in assessing optic disc edema in idiopathic intracranial hypertension. It may also be useful in acute and recurrent cases of papilledema and allow for prompt diagnosis and treatment.
Keywords: optic nerve • optic disc • neuro-ophthalmology: optic nerve