Purpose: To examine the cognitive and neuropsychiatric characteristics of patients with Normal Tension Glaucoma (NTG).
Methods:A cross-sectional observational study of 99 patients with glaucoma and untreated intraocular pressure consistently <22 mmHg on phasing. All subjects underwent cognitive assessment and psychiatric symptom screening using the mini mental state examination (MMSE), adult verbal learning test (AVLT) and general health questionnaire (GHQ). All subjects had comprehensive ophthalmic examination and documentation of past medical and psychiatric history.Results: Subjects had a mean age of 70.5 years and 59 (59%) were female. 57 (57%) had an advanced visual field defect in the worse eye, 19 (19%) a moderate defect and 23 (23%) a mild defect. There were a high proportion of patients with impaired MMSE, AVLT or GHQ scores. 28 (28%) had significant short-term memory impairment on AVLT, and 28 (28%) scored 5 or more on the GHQ suggesting psychiatric caseness. 12 (12%) scored 24 or less on the MMSE. 43 subjects underwent CT or MRI neuroimaging, with 13 (30%) showing age excessive generalised cerebral atrophy and 9 (20%) showing excessive small vessel disease. 41 patients had systemic hypertension, 28 is chaemic heart disease, 21 diabetes, 18 migraine, 13 transient ischaemic attack and 3 Raynaud's disease.
Conclusion:Patients with NTG had a high prevalence of cognitive impairment and psychiatric symptoms identified using common screening tools, suggesting a possible shared intraocular pressure independent mechanism of disease. Ophthalmologists should be aware of the possibility of undiagnosed cognitive impairment and psychiatric morbidity in some patients with NTG.