Normal pressure glaucoma Print
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Wednesday, 13 January 2010 11:28

Normal pressure glaucoma (or normal tension glaucoma) is an optic neuropathy associated with low intraocular pressure (ie less than 22 mmHg).

The following are known associations of normal pressure glaucoma:
steroid use (eg nasal sprays, inhaled or oral steroids, or steroid creams) - in this case steroids may infact elevate IOP but this may not be detected and be falsely diagnosed as normal pressure glaucoma
vasospasm migraine / Raynauds
coagulopathies previous blood loss or shock like epsiode
systemic nocturnal hypotension
autoimmune disease
thyroid disease (increased risk)
sleep apnoea (especially in overweight men)
Alzheimer's disease

Other problems to be considered
intermittent IOP elevation - can be excluded with diurnal IOP measurements
burnt out glaucoma
congenital anomaly
myopia with peri-papillary atrophy
optic nerve coloboma
vascular etiology
carotid occlusion
previous blood loss
hereditary optic neuropathy
Lebers optic neuropathy
tonometric error (thin cornea)

Investigations
FBC rule out anaemia
CRP / ESR rule out a condition called "anterior ischaemic optic neuropathy"
VDRL/FTA syphilis is a very rare association
ANA autoimmune diseases, also Ro, La, Sm
paraproteinaemia rule out lymphoproliferative disease
Lebers mitochondrial testing where indicated

Imaging
HRT / OCT / GDx
MRI if asymmetry, unusual VF, progressive fields, dyschromatopsia, APD with mild cupping
carotid dopplers
CXR to rule out sarcoidosis

Other tests
24 hour ambulatory blood pressure monitoring

Treatment
ALT not recommended
Trabeculectomy with Mitomycin C, if IOP in single digits is required
In some cases, your physician might recommend Ginkgo Biloba (40mg three times a day). There is some evidence that points to a benefit here, but this medication is not suitable for everyone and it's use is advised on a case-by-case basis, after discussion with your glaucoma specialist.
Future medication, for selected subgroups of patients with glaucoma, may include memantine, a tablet medication that may have beneficial protective effects on the optic nerve (randomised controlled trials are awaited).

alternative treatment for NPG

Ginkgo Biloba - not recommended for most patients with glaucoma - little evidence for benefit.

Last Updated on Sunday, 21 October 2012 18:53