Spire Hull and East Riding Hospital now offers SLT for patients suffering from Glaucoma. This procedure is offered by Mr Craig Burnett, consultant ophthalmologist
What is Glaucoma?
Glaucoma is the leading cause of irreversible blindness in the world. It happens when there is damage to the optic nerve which connects the eye to the brain. High pressure inside the eye (raised intra-ocular pressure) is the biggest risk factor for developing Glaucoma. Another risk factor is having a family member with Glaucoma. Thankfully, we can treat this condition and prevent most people from going blind – if caught early. It is possible to screen for Glaucoma by checking your intra-ocular pressure, field of vision, and optic nerve appearance.
How do you treat Glaucoma?
There are eyedrops (drugs), laser treatments, and operations for the various different types and stages of Glaucoma. Most patients are traditionally treated with eyedrops to lower the intraocular pressure. Some patients have what’s called a tight drainage angle and need a laser iridotomy or even cataract surgery to open up this drainage angle. Others have furring up of the structures (trabecular meshwork) within the drainage angle and could have a by-pass operation (trabeculectomy) or a laser trabeculoplasty (SLT).
What is SLT?
SLT stands for ‘Selective Laser Trabeculoplasty’. This is a laser procedure used to reduce the pressure in the eye.
SLT can be an effective addition to eyedrop treatment or it can be used as a primary treatment to reduce or eliminate the need for glaucoma eyedrops, along with their common side effects.
It may be used as a ‘lifestyle choice’ – rather than using eyedrops.
Furthermore, SLT may be an alternative for those who have been treated unsuccessfully with other glaucoma treatments or in order to avoid risky glaucoma surgery.
What are the advantages of SLT?
There are a few key reasons why SLT may be deemed beneficial for you:
Safe: SLT is not associated with systemic side effects or the compliance issues of medications.
Selective: SLT selectively targets only specific cells, leaving the surrounding tissue intact.
Smart: SLT stimulates the body’s natural mechanisms to enhance outflow of the fluid in your eye.
Sensible: SLT therapy is covered by insurance providers, but it is also available for those who self-pay.
SLT does not rely on medicines. Instead, it uses an advanced laser system to target only specific cells of the eye – those containing melanin, a natural pigment. This allows for only these cells to be affected, leaving surrounding tissue intact. As a result, your body’s own healing response helps lower the pressure in your eye.
How does it work?
The eye pressure rises when there is a blockage of fluid leaving the eye through the fine, sieve-like structure called the 'trabecular meshwork', which is located in the 'drainage angle' of the eye, at the boundary of the iris. This elevated pressure results in damage to the optic nerve and vision loss occurs.
A goal in glaucoma therapy is to improve the flow of fluid out of the eye through the trabecular meshwork
SLT selectively targets the pigment-containing cells of the trabecular meshwork, while preserving the surrounding tissue. Each laser application is only three nanoseconds (an incredibly short period of time) and uses very low energy levels (1000 times less energy than older treatments). This makes the laser gentle and safe with no damage to other cells. Therefore, the tissue is protected and there is no scarring.
This selective targeting is believed to stimulate the body's own repair mechanisms in the trabecular meshwork, which increases the fluid drainage out of the eye and reduces the eye pressure. SLT is an established treatment that can safely and effectively reduce eye pressure. Typically, the eye pressure is lowered by 25-30% (approximately 6-8mmHg) in about 80-90% of patients. However, it is important to understand that individual results can vary (the drop in eye pressure can be more or less than this).
How is SLT performed?
SLT is an outpatient procedure. Many aspects of the treatment are similar to a slitlamp examination at a clinic visit and, therefore, it will be very familiar to you. You will sit in a conventional exam chair, where the doctor will use a slit lamp to examine your eye. The same slit lamp contains the SLT laser. During the procedure, the doctor will put anesthetic drops in your eye to numb it, and then place a contact lens (‘gonioscopy lens’) on your eye for better viewing (most patients will have had this same examination previously in the clinic). The laser is shone into one of the mirrors of the gonioscopy contact lens and then reflected into the drainage angle of the eye. SLT is a procedure that usually causes no discomfort, and it only takes a few minutes to perform.
A lens is placed over the eye to direct the laser light into the trabecular meshwork.
The SLT laser is applied to trabecular meshwork, at the boundary of the iris.
Will I feel anything with the laser treatment?
Generally, the laser treatment does not cause pain. However, studies show some patients experience a slight sensation during treatment. You may see a green flash of light. The lens used on your eye may cause some redness or irritation.
What are the side effects of SLT?
Unlike glaucoma medications, there are no incidences of allergy or systemic side-effects with SLT.
Unlike risky glaucoma surgery, SLT is extremely safe – for instance, there is no risk of infection inside the eye with SLT.
Complications from SLT are minimal but may include: inflammation (it is normal to have a little light sensitivity & a slightly red eye for a day or so); temporary increase in eye pressure (however, eyedrops are used prior to the laser treatment in order to minimise this risk); blurred vision, headache, and eye pain have also been reported.
SLT cannot guarantee elimination/reduction of eyedrops.
In the long-term, the effect of the laser can wear off, but SLT can be effectively repeated.
After the laser procedure
It may be sensible to have someone with you to drive you home.
You will need to have your eye pressures checked.
Follow up is usually a few weeks after the procedure.