Normal tension glaucoma following the treatment of normal pressure hydrocephalus.

A man in his 70s developed progressive normal tension glaucoma following treatment for normal pressure hydrocephalus. This treatment included cerebrospinal fluid drainage and ventriculo-peritoneal shunt insertion to lower the intracranial pressure (ICP). Subsequent retinal nerve fibre layer thinning was visible on optical coherence tomography scans and was accompanied by corresponding glaucomatous visual field defects on perimetry. These changes occurred with normal intraocular pressure, indicating the patient had progressive normal tension glaucoma. The patient's ICP-lowering treatment for normal pressure hydrocephalus may, therefore, have contributed to his normal tension glaucoma, for which there is an emerging association.