Abstract
Purpose: :
The purpose of this study was to evaluate peripapillary retinal nerve fiber layer (RNFL) changes in patients with pseudotumor cerebri using OCT and to investigate the feasibility of this technique for monitoring the effectiveness of therapy in these patients.
Methods: :
This study included 10 patients with pseudotumor cerebri (6 children and 4 adults, mean age 26 years, range 10 to 48 years) and 10 age matched control subjects. All study subjects underwent a complete eye examination, and the OCT measurements were performed by an experienced operator (F.B.) using Stratus OCT. Peripapillary RNFL thickness was measured using the standard 3.4 mm diameter circular scan protocol and the values for four quadrants (superior, inferior, temporal and nasal) as well as overall values were analyzed. The eye with more severe swelling of the disc was included in the analysis. We performed optic nerve sheath decompression in 3 adult patients with more severe papilledema and visual loss. The other 7 patients were treated with acetazolamide. Repeated OCT measurements were performed in 7 patients according to the individual clinical course.
Results: :
Mean visual acuity in patients with pseudotumor cerebri was 20/32, range 20/400 to 20/20. A significant thickening of the RNFL was observed in all quadrants in the patient group compared to the control group (superior 191.3 ± 88.3 µm vs. 119.7 ± 12.4 µm, p=0.02; inferior 163.3 ± 53.0 µm vs. 124 ± 12.6 µm, p=0.03; temporal 101.1 ± 42 µm vs. 71.6 ± 9.7 µm, p=0.04 and nasal 112.4 ± 51.6 µm vs. 70.8 ± 9.5 µm, p=0.02). When comparing overall RNFL thickness between the groups, the difference was also statistically significant (144.5 ± 58.2 µm in pseudotumor cerebri patients vs. 96.5 ± 6.7 µm in controls, p=0.02). In patients who underwent surgery a significant reduction of papilledema and corresponding improvement in symptoms, visual acuity and visual field was observed 4 weeks postopearatively (p<0.05). Patients treated with acetazolamide showed improvement in symptoms, papilledema and visual function. However, the changes in RNFL-thickness over time were not statistically significant probably due to the mild papilledema in these patients.
Conclusions: :
Our data demonstrate that RNFL thickness measured using OCT can be clinically used as an accurate parameter for quantitative and objective evaluation of papilledema in patients with pseudotumor cerebri. This noninvasive technique may be particularly useful in clinical management of children with papilledema and pseudotumor cerebri.
Keywords: neuro-ophthalmology: optic nerve • nerve fiber layer • clinical research methodology