glaucoma 

Glaucoma is a potentially blinding eye condition when not detected and treated appropriately. According to a 2019 study, the prevalence of glaucoma in Australia is 3.4% among non-Indigenous and 1.6% in Indigenous Australians (1). Glaucoma is often underdiagnosed so there are many Australians that may have glaucoma but do not yet know. Regular eye examinations for patients over 40 are needed to ensure glaucoma is diagnosed. Earlier diagnosis is better for long term outcomes.

What is glaucoma?  

Glaucoma is the name for a group of eye diseases that affects the optic nerve. Usually, but not always, the pressure within the eye is raised and this causes damage to the optic nerve which results in the loss of peripheral vision and in the late stages, loss of central vision as well.  

There are 2 different types of primary glaucoma – open angle and closed angle. There are also secondary glaucomas where the pressure in the eye builds up due to conditions such as pseudoexfoliation, pigment dispersion, trauma or neovascularization (new blood vessels).

How is glaucoma diagnosed?

Often patient’s can think of the pressure test as the “glaucoma test”. This is only partially accurate. To diagnose glaucoma a number of tests have to be performed. This includes assessing the intraocular pressure, the angle of the eye, the optic nerve, and the peripheral vision using a visual field test. Scanning the optic nerve with OCT (optical coherence tomography) and visual field testing are necessary to diagnose and monitor glaucoma accurately. Specialist Eye has invested in the latest technology OCT scan (Zeiss brand) and visual field machine (Humphrey) to be able to diagnose and monitor glaucoma accurately.

How is glaucoma treated?

This depends on which type of glaucoma.

Open angle glaucoma is the most common form of glaucoma in Australia. This is usually treated with medication in the form of eye drops. The most commonly used eye drop is a type of drug called a prostaglandin analogue. Most patients tolerate this drop very well and it is very safe and effective at lowering pressure within the eye. There are other drops which can be prescribed when required such as beta blockers or carbonic anhydrase inhibitors. Dr Adam Rudkin, Dr Jaz Aujla or optometrists, John Wysling and Russell Todd, can provide information on which eye drop is best for your glaucoma.

Another safe and effective option for open angle glaucoma is selective laser trabeculoplasty (SLT). This treatment also is able to lower the intraocular pressure (in most patients) and often means patients do not have to instill drops nightly. Dr Adam and Dr Jaz are able to perform this painless procedure in office. This treatment usually lasts several years but patients will still have to be monitored closely to watch for any rise in pressure or change to the optic nerve.

Patients with closed angle or narrow angle glaucoma will require a procedure called a laser peripheral iridotomy. This will prevent that patient from developing acute angle closure glaucoma where the intraocular pressure rises very high and very rapidly. This is a medical emergency. Patients who have had laser peripheral iridotomy will still have to be watched to ensure they do not progress to chronic angle closed glaucoma.

In very advanced and severe cases of glaucoma patients will require filtering surgery to surgically lower the pressure within the eye.

Are there any new treatments for glaucoma?

In recent years “MIGS” or minimally invasive glaucoma surgery has become a safe and successful treatment for glaucoma. This type of surgery is most often done at the same time as cataract surgery. A tiny microscopic device or stent is placed within the eye (in the trabecular meshwork) to lower the intraocular pressure. If successful, patients may no longer need eye drops to treat their glaucoma, although patients will require ongoing monitoring. A recent study (2) of a device called the “iStent” found that after 12 months the mean reduction in intraocular pressure from prior to surgery was 39% (26.3 (SD 3.5) mmHg to 15.7 (SD 3.7) mmHg). Promisingly, 86% of patients who had the istent implanted had less eye drop medications for their glaucoma after 12 months of follow up.

Is vitamin b3 (nicotinamide) an effective treatment for glaucoma?

A 2020 study (3) indicates that there is hope that vitamin b3 (nicotinamide) will help protect the retinal ganglion cells which play an important role in glaucoma. The study showed that patients taking up to 3g a day of vitamin b3 had better inner retinal function than patients taking placebo. The treated patients were taking vitamin b3 for a period of 12 weeks. It is important to note the patients were continuing with their regular glaucoma treatment. More studies are needed to determine long term effects of vitamin b3.

Other questions?

Dr Adam Rudkin, Dr Jaz Aujla, John and Russell will be very happy to answer any concerns you have about glaucoma at your next consultation.

Further information can be obtained from Glaucoma Australia. https://glaucoma.org.au/ 

• Keel S, Xie J, Foreman J, et alPrevalence of glaucoma in the Australian National Eye Health SurveyBritish Journal of Ophthalmology 2019;103:191-195.
• Voskanyan, L., García-Feijoó, J., Belda, J.I. et al. Prospective, Unmasked Evaluation of the iStent® Inject System for Open-Angle Glaucoma: Synergy Trial. Adv Ther 31, 189–201 (2014). https://doi.org/10.1007/s12325-014-0095-y
• Hui, F, Tang, J, Williams, PA, et al. Improvement in inner retinal function in glaucoma with nicotinamide (vitamin B3) supplementation: A crossover randomized clinical trial. Clin Experiment Ophthalmol. 2020; 48: 903– 914. https://doi.org/10.1111/ceo.13818