What Is Glaucoma?
Glaucoma is the group of diseases that damages the optic nerve of the eye causing a gradual loss of vision. The loss of vision is very gradual and is often not noticed until the disease process is more advanced. Early detection and treatment are therefore essential to protect against serious loss of vision.
The front of the eye is filled with a clear fluid called Aqueous. The aqueous flow from behind the iris. It drains at the front through an area in the angle of the eye known as the Trabecular Meshwork.
‘Normal’ eye pressure ranges from 12 to 22 mmHg (millimetres of mercury). Eyes with pressure above 22 mmHg, but with no signs of glaucoma, are defined as having Ocular Hypertension. It is not unusual for eyes within the ‘normal’ pressure range to develop glaucoma.
How Does Glaucoma Affect Sight?
Glaucoma usually begins to affect the peripheral or side vision.
Early peripheral vision is not usually symptomatic. The brain tends to fill in the missing areas in the field of vision. It is only symptomatic when these areas begin to enlarge that patches of blurry vision or dark areas become noticeable.
We offer a comprehensive Glaucoma package that offers superb value for your Glaucoma initial assessment continued monitoring. It includes:
- A visual field test
- High-resolution scanning (OCT) of your optic nerves and corneas at every visit
- A complete clinical assessment by a Glaucoma specialist
Our annual fee of £400 includes two visits per year. The initial assessment fee is £100. This represents a saving of nearly 40%.
How Is Glaucoma Detected?
There is no specific single test for glaucoma.
The diagnosis relies on accurate investigative tests and the clinical expertise of the professional assessing your eyes. This should include a detailed examination of the front part of your eye (anterior chamber), as well as your Optic Nerve.
A special lens is used to examine the drainage angle of the eye (gonioscope).
A check of your intraocular pressure using a device that gently touches the cornea.
Visual Field Testing
This test helps detect and monitor glaucoma. A visual field test maps out what your world looks like to you. It measures the area of vision, or how wide of an area your eye can see. It is important when taking this test that you concentrate on the fixation light in the centre. You must press the button when the blinking test light is seen with your side vision.
If you move your eyes to follow or look for the blinking lights, it decreases the reliability of the test. It also decreases the ability of your doctor to monitor your disease. Visual field shows changes that are not noticed by the patient until the damage is severe.
It is important when taking this test that you concentrate on the fixation light in the centre. You must press the button when the blinking test light is seen with your side vision. If you move your eyes to follow or look for the blinking lights, it decreases the reliability of the test. It also decreases the ability of your doctor to monitor your disease.
Areas that appear grey or black on the test results reflect areas in your vision that are blurred or missing. If your glaucoma remains uncontrolled, these areas will get darker and larger.
Corneal Thickness Measurement (Pachymetry)
This simple test measures the thickness of the central cornea and is used to help adjust for intraocular pressure measurements. Generally speaking, the thicker the cornea, the lower the true intraocular pressure.
Optic Nerve Scanning (OCT)
This is a highly sensitive objective optical scan of the optic nerve and surrounding neural structures. The OCT is capable of detecting objects of 10 microns or sometimes less in size. Good quality scans can sometimes pick up disease before they are clinically detectable by the doctor. The measurements can be compared over time to detect if the nerve has changed.
Selective Laser Trabeculoplasty (SLT) uses a laser that works at very low levels. It treats specific cells “selectively,” leaving untreated portions of the trabecular meshwork intact. For this reason, SLT may be safely repeated. SLT can be an alternative for those who have been treated unsuccessfully with pressure-lowering drops.
A number of medications are recommended by our glaucoma doctor in Yorkshire to treat glaucoma.
Your doctor may prescribe a combination of medications or change prescription over time to reduce side-effects or provide more effective treatment.
Typically medications are intended to reduce elevated intraocular pressure and prevent damage to the optic nerve.
Minimally invasive surgery (deep sclerectomy)
Deep sclerectomy has a safety advantage compared with standard filtration surgery.
This is primarily because the drainage area is created without entering into the eye.
A meticulous surgical technique is required. However, its efficacy and low rates of complications, particularly in surgically-induced cataracts, are very appealing. It makes this a procedure of choice in suitable eyes.
In Trabeculectomy, a full-thickness cuts into the eye. It allows the fluid inside the eye to drain through a flap created from the white of the eye (Sclera).
Trabeculectomy is considered the standard operation for glaucoma. It works well for the majority of patients. The risk profile is higher than that for Deep Sclerectomy.
There are a number of different tube implants to help lower intraocular pressure.
These are usually reserved for complex cases; such as glaucoma associated with uveitis all in eyes where previous surgery has failed.