What is Glaucoma?
Glaucoma is a disease of the optic nerve, which is the conduit carrying the information packets about the world we see, from our eyes to the brain. It causes a progressive loss of peripheral vision. Glaucoma is in the top four conditions causing blindness in Australia.
Glaucoma can be a very difficult condition to diagnose early, and relatively easy to diagnose late. However, because it is an irreversible cause of loss of vision, early diagnosis is important in giving patients the best chance of retaining vision. There is no single test which is ideal for the diagnosis of glaucoma. It requires clinical assessment and often multiple tests, and sometimes these tests need to be repeated to confirm the findings.
Patients with glaucoma have an intraocular pressure that is too high for that eye. We define a range of normal intraocular pressure being 10 to 21 mmHg, and having a higher pressure increases the risk of developing glaucoma. However, some patients with high pressure will not develop glaucoma, and about half of all patients with glaucoma have intraocular pressures within the normal range (but too high for that particular eye). Therefore, having a normal range intraocular pressure does not exclude glaucoma, and having a high pressure does not equate to having glaucoma.
The aim of treatment for glaucoma is to reduce the rate of progression of the disease, and to maintain good vision throughout the patient’s life. Treatment may be in the form of eye drops to lower the intraocular pressure, laser treatment, surgery, or a combination of these options. Our eye surgeons Dr Daya Sharma and Dr Shanel Sharma use a Humphrey Visual field and a spectral domain OCT as part of the assessment of patients for glaucoma, in addition to measuring intraocular pressure, and measuring corneal thickness. A specialised glaucoma laser (selective laser trabeculoplasty; SLT) is on site at both our Bondi Junction and Miranda offices.
Laser treatment for glaucoma can help reduce high internal eye (intraocular) pressure. Selective laser trabeculoplasty (SLT) may be offered as a first-line treatment to lower intraocular pressure by increasing drainage of aqueous fluid from the front of the eye. SLT is performed in the office, and is relatively quick with minimal discomfort. SLT may also be performed as an adjunct ongoing eye drop therapy.
Glaucoma stents are a relatively recent innovation in glaucoma care. The stents are microscopic titanium devices which are designed to help drain fluid from the front of the eye effectively in order to keep the intraocular pressure down. Although the stents are typically used in combination with cataract surgery, they can be used in a standalone procedure. The main advantage of stents are that they can potentially get patients off the need for glaucoma drops. This is particularly useful in patients who have difficulty putting eye drops in, remembering to use the drops, or have side effects from the drops.