PERIPAPILLARY ALTERATIONS IN IDIOPATHIC NORMAL PRESSURE HYDROCEPHALUS

Purpose:To evaluate the peripapillary area in eyes of patients with idiopathic normal pressure hydrocephalus (iNPH) before and after shunt surgery.Methods:Twenty patients with iNPH were prospectively recruited. Enhance depth imaging-optical coherence tomography (EDI-OCT) was performed to image the peripapillary region. Using a 360° 3.4 mm diameter peripapillary circle scan, the peripapillary choroidal thickness was manually measured and compared with 20 healthy age-matched controls. Peripapillary choroidal thickness was assessed before and after at least 6 months from ventriculoperitoneal shunt surgery in 12 patients.Results:Mean age of patients with iNPH was 75 ±7.4 years, and 45% were females. Mean peripapillary choroidal thickness was increased in patients with nonshunted iNPH compared with healthy individuals (113 ± 39 vs. 82 ± 43 m, P = 0.026). Also, OCT scans in the peripapillary region showed a set of recurrent alterations, such as subclinical optic disc edema (30%), choroidal folds (40%) peripapillary intraretinal cysts (30%), peripapillary atrophy (85%), peripapillary pigment epithelium alterations (45%), and pachyvessels (70%). After 79 ± 29 weeks from ventriculoperitoneal shunt surgery, 84% (10 out of 12) of patients with iNPH presented a reduction in peripapillary choroidal thickness (111 ± 47 vs. 95 ± 49, P = 0.011). This reduction was associated with a subjective improvement of the neurologic symptoms in 9 out of 10 of patients, and resolution of optic disc edema (75%), intraretinal cysts (66%), and choroidal folds (20%).Conclusion:The ophthalmologic findings observed in patients with iNPH may be attributed to a framework of venous overload choroidopathy. Shunt surgery relieved peripapillary choroidal congestion, leading to improvements in OCT parameters.