Peripapillary alterations in Idiopathic Normal Pressure Hydrocephalus

Area of Science:

• Ophthalmology
• Neurology
• Neurosurgery

Background:

• Idiopathic Normal Pressure Hydrocephalus (iNPH) is a neurological condition characterized by gait disturbance, urinary incontinence, and cognitive impairment.
• Ophthalmological manifestations in iNPH are not fully understood, but may involve venous congestion.

Purpose of the Study:

• To evaluate peripapillary choroidal thickness (PPCT) and associated ocular findings in iNPH patients before and after shunt surgery.
• To investigate the impact of ventriculoperitoneal (VP) shunt surgery on peripapillary changes in iNPH.

Main Methods:

• Prospective study of 20 iNPH patients and 20 age-matched healthy controls.
• Enhanced depth imaging-optical coherence tomography (EDI-OCT) used to measure PPCT.
• PPCT assessed before and after VP shunt surgery (at least 6 months post-op) in 12 iNPH patients.

Main Results:

• Non-shunted iNPH patients showed significantly increased PPCT compared to controls (113 ± 39 vs 82 ± 43 μm, p=0.026).
• Common OCT findings in iNPH included peripapillary atrophy (85%), pachyvessels (70%), and choroidal folds (40%).
• Following VP shunt surgery, 84% of patients showed reduced PPCT (111 ± 47 vs 95 ± 49 μm, p=0.011), with resolution of optic disc edema and intraretinal cysts.

Conclusions:

• Ophthalmological findings in iNPH suggest a venous overload choroidopathy.
• VP shunt surgery effectively reduces peripapillary choroidal congestion and improves OCT parameters in iNPH patients.
• Surgical intervention may alleviate ocular manifestations associated with iNPH.