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The iCare tonometer is an excellent tool for monitoring IOP (eye pressure) at home, however it requires careful instruction and supervision...
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article thumbnailGlaucoma and magnesium

There is now evidence that magnesium is deficient in patients with glaucoma. In one Russian study, magnesium levels were found to be...
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Glaucoma Specialist, Glaucoma Leeds, Glaucoma Hull
Glucosamine and glaucoma PDF Print E-mail
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Friday, 11 October 2013 08:53

Taking glucosamine supplements is linked to significant, but reversible increases in intraocular pressure (IOP) in a very small, retrospective study published in JAMA Ophthalmology online. The investigators were not able to exclude the potential for long lasting damage. To put into context the potential scale and possible implications of these issues, the US prevalence of osteoarthritis is around 27 million, and glaucoma exceeds 2 million.

In this small study, only 17 patients were studied (mean age 76 years) who had a history of glucosamine supplementation and ocular hypertension (IOP > 21 mm Hg) or diagnosed open-angle glaucoma, a desire to discontinue glucosamine, 3 or more IOP measurements within 2 years, and no associated changes in glaucoma medications or eye surgery. The study was limited with its small size and design, but small significant increases in eye pressure were noted with glusoamine use - the rise in eye pressure was about 3mmHg. Clearly further studies are required to establish this association more definitively. 

"Many questions are raised by glucosamine supplementation–associated IOP changes," the study authors write. "This study shows a reversible effect of those changes, which is reassuring. However, the possibility that permanent damage can result from prolonged use of glucosamine supplementation is not eliminated."

Glucosamine is a precursor to glycosaminoglycans, and deposits of glycosaminoglycans may be deposited in the trabecular meshwork (the area of the eye where fluid drains out); there are infact other hypotheses as to how glucosamine might affect eye pressure: possibly glycosaminoglycans might have an "osmotic effect", in effect increasing fluid production inside the eye.

Given the uncertainly that now surrounds glucosamine, it would wise for glaucoma patients to discuss the issue at their eye consultations, to evaluate forthcoming literature. The current study does by its small size carry serious limitations in generaliising its applicability to the population at large at present.

JAMA Ophthalmol. Published May 23, 2013.

glucosamine and glaucoma

chondroitin and glaucoma

Chondroitin (wiki commons) is often supplemented with glucosamine and the effect of these components is not known.

Last Updated on Friday, 11 October 2013 09:45
Home eye pressure measurement PDF Print E-mail
Written by Administrator   
Sunday, 21 October 2012 18:40

The iCare tonometer is an excellent tool for monitoring IOP (eye pressure) at home, however it requires careful instruction and supervision by an ophthalmologist for its use. The icare ONE tonometer is designed and recommended for home use by Glaucoma Patients who need regular IOP monitoring by their ophthalmologists recommendation. The tonometer works using a technique called rebound tonometry. No anaesthetic is required for its use.

icare tonometer

Last Updated on Sunday, 21 October 2012 18:49
Glaucoma and magnesium PDF Print E-mail
Written by Administrator   
Sunday, 21 October 2012 16:56

There is now evidence that magnesium is deficient in patients with glaucoma. In one Russian study, magnesium levels were found to be several fold lower. In normal subjects, levels were found to be about 180 mg/L whereas in glaucoma patients levels were around 18 mg/L. The role of magnesium supplementation is yet to be evaluated in detail; there is some concern about the toxicity of magnesium in patients with renal complaints. Magnesium deficiency may play a role in glaucoma by impairing mitochondrial function and activating NMDA receptors. One epidemiological study based on a dietary survey however has linked a higher intake of magnesium with an increased risk of glaucoma, so the data is quite hard to interpret really.

Magnesium is found naturally in green vegetables including spinach, nuts and whole grains. It helps the release of energy from food, and is important in the development of healthy bones, nerves and muscles. A typical adult male requires about 400mg of magnesium a day, and an adult female around 300mg daily.

Severe magnesium deficiencies are infact rare. They are more likely in those who have Crohn's disease and kidney disease, also in those who abuse alcohol.


Glaucoma and magnesium

Last Updated on Sunday, 21 October 2012 19:01
Research on SLT PDF Print E-mail
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Wednesday, 13 January 2010 11:18

Summary of selected papers on Selective Laser Trabeculoplasty

Selective laser trabeculoplasty study: SLT and ALT and retreatment options

Russo V et al. Eur J Ophthalmol. 2009 May-Jun;19(3):429-34. Selective laser trabeculoplasty versus argon laser trabeculoplasty in patients with uncontrolled open-angle glaucoma.

SLT is effective as treatment for patients with OAG and appears to be equivalent to ALT in IOP lowering at 12 months only in patients without a prior treatment. In case of retreatment SLT appears to be better than ALT in IOP lowering.

Selective laser trabeculoplasty study: whether to have 180 degree or 360 degree treatments

Prasad N, Murthy S, Dagianis JJ, Latina MA. J Glaucoma. 2009 Feb;18(2):157-60. A comparison of the intervisit intraocular pressure fluctuation after 180 and 360 degrees of selective laser trabeculoplasty (SLT) as a primary therapy in primary open angle glaucoma and ocular hypertension.

This study suggests that 360-degree SLT is more efficacious in achieving smaller IOP fluctuations than treatment with 180-degree SLT.

Selective laser trabeculoplasty study: IOP fluctuation and SLT

Nagar M, Luhishi E, Shah N. J Glaucoma. Br J Ophthalmol. 2009 Apr;93(4):497-501. Intraocular pressure control and fluctuation: the effect of treatment with selective laser trabeculoplasty.

Both SLT and latanoprost had a significant impact on IOP control and fluctuation / ... / SLT has the benefit of being a one-time intervention not requiring ongoing patient compliance..

SLT laser SLT laser machine

Images of the SLT laser machine

Last Updated on Monday, 07 October 2013 10:13
What is glaucoma? PDF Print E-mail
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Wednesday, 13 January 2010 11:23

All about glaucoma; symptoms, types and diagnosis of glaucoma

Glaucoma is a condition that leads to slow, but progressive loss of nerve fibres in the optic nerve. Many factors may increase the risk of this condition. If left untreated, this can lead to loss of peripheral vision (i.e. what can be seen at the sides of the visual field, rather than in the centre). In older people, glaucoma is one of the commonest causes of preventable blindness. If glaucoma progresses, it can affect all peripheral vision, then impair central vision, and -- very rarely -- may lead to very significant visual impairment. Treatments for glaucoma are aimed at bringing down the pressure in the eye to a level that is low enough to prevent harm to the optic nerve. Once the optic nerve is affected by glaucoma, lowering the pressure in the eye prevents further damage to the nerve. Damage already done to the optic nerve cannot be reversed. Screening for glaucoma is important from around age 40, every two years at least, unless you are in a higher risk group (eg Afro-caribbean race, or very strong family history of glaucoma).

Signs and symptoms of glaucoma

Symptoms of glaucoma are often absent in the early stages of the disease. Unfortunately, impaired vision is sometimes the first sign of glaucoma. Classically in angle closure glaucoma, symptoms and signs of glaucoma may include eye pain, cloudy vision, red eyes, headaches, and nausea.

How Is Glaucoma Diagnosed?

Frequent eye examinations are the best way to detect glaucoma. Your ophthalmologist will test the eye’s drainage angle, evaluate the optic nerve (ophthalmoscopy), measure eye pressure, and test the visual field of each eye (perimetry). The information from these examinations is compared at regular intervals to determine if glaucoma damage has progressed over time. Regular examinations play a critical role in the early detection of glaucoma.

Glaucoma Progression

Glaucoma typically initially affects side (peripheral) vision first. If left untreated, vision loss will continue, eventually resulting in total blindness. If glaucoma is identified early and treated appropriately, good eyesight can most likely be maintained.

Types of glaucoma.

There are several types of glaucoma, all of which affect the optic nerve. Open-angle glaucoma, the commonest form of the disease, develops when the angle between the cornea and the iris where fluid is supposed to drain from the eye is open, but the fluid drains out too slowly. Closed or narrow angle glaucoma occurs when the drainage angle is blocked by part of the iris and fluid cannot drain from the eye. Normal-tension glaucoma occurs in patients with normal intraocular pressure and is treated in the same way as open-angle glaucoma. Congenital glaucoma occurs when a child is born with a poor drainage outflow facility.

Treatment for glaucoma.

There are two main types of treatment for glaucoma: medication and surgery. Both of these treatments for glaucoma manage the disease by lowering the intraocular pressure. Medications and eye drops are common treatments, but there is the possibility of side effects, and they may eventually become ineffective over time. If the IOP cannot be managed by medications or eye drops alone, surgery or laser may be recommended. Your ophthalmologist will decide on your "target IOP" to help plan your treatment.

Recovery after Glaucoma Treatment

Glaucoma surgery is usually painless, although some patients may experience a slight stinging sensation following the procedure. Local anaesthetics are used to minimise any patient discomfort. After surgical treatments for glaucoma, it is possible to experience blurred vision or irritation. Typically, however, these effects are short-lived and normal activities, such as going to work or running errands, can be resumed after 2-3 days. This time period can be variable, it depends on the exact procedure performed.

optic disc

Last Updated on Thursday, 21 January 2010 23:27

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