Abstract
Purpose: :
To evaluate the visual function and the peripapillary retinal nerve fiber layer (RNFL) thickness in patients with Idiopathic Intracranial Hypertension of long follow up.
Methods: :
36 eyes of 18 patients, were evaluated under complete ophthalmic examination, including best corrected visual acuity (BCVA), automated Humphrey visual fields (24-2) DM, Ishihara test and peripapillary RNFL analysis with OCT (Fast RNFL thickness 3.46; Carl Zeiss Meditec, Inc., Dublin, CA). Measurements were analyzed twice, at diagnosis and in the last visit, with an average follow up time of 5 years. Statistical analysis: Wilcoxon test, U Mann Whitney test, Kruskal Wallis test, SPSS 18.0 (software).
Results: :
At diagnosis, the RNFL thickness average was 116.6 ± 31.3 and in the last visit was 96.6 ± 29.22 microm. The RNFL average thickness measurements at each quadrant at the first visit were: Savg1= 122.2 ± 35.6, Tavg1= 81.63 ± 32.94, Iavg1 = 167.19 ± 43.71, Navgf1= 96.12 ± 52.15. The last visit showed the following results: Savg2=115.44 ± 37.88 , Tavg2= 71.04 ± 37.43, Iavg2= 137.48 ±37.46, Navgf2= 74.35 ±38.2. Respect to visual function at the first visit average BCVA was 0.93, Ishihara test was 15.14 plates of 17, and DM = -4,54 in visual field. At the last visit average BCVA was 0.91, Ishihara test was 15.06 plates of 17, and DM= -4.55 in visual field.
Conclusions: :
In patients with idiopathic intracranial hypertension, diagnosed and treated, we found mild loose of visual function which remains stable over long follow- up whereas average RNFL thickness, was progresively reduced over time in all quadrants. The most susceptible quadrants were, inferior and nasal. It is important to point out that at the moment of diagnosis, there was only edema in the inferior quadrant, while the other sectors were within normal limits. The reduction in average RNFL thickness, was probably not only caused by edema reduction, but also by continuous axonal damage in the RNFL.
Keywords: nerve fiber layer • neuro-ophthalmology: optic nerve • neuro-ophthalmology: diagnosis