Glaucoma quietly damages your optic nerve and can lead to irreversible vision loss. Early diagnosis, ongoing care, and advanced treatment are vital to preserve your sight.
Glaucoma isn’t a single disease but a group of conditions that harm the optic nerve – usually due to elevated eye pressure. It’s the second-leading cause of irreversible blindness worldwide.
The most common form, open-angle glaucoma, often has no early symptoms and gradually impairs peripheral vision. Angle-closure glaucoma is less common but can cause sudden, severe vision impairment and requires immediate care. Regular comprehensive eye exams are critical for early detection and management.
Types of Glaucoma
Open-Angle Glaucoma
Angle-Closure Glaucoma
Congenital Glaucoma
Treatment
The goal of glaucoma treatment is to maintain a patient’s quality of life by limiting the effect glaucoma has on vision and vision-related tasks. The main strategy is for achieving this reduction of intraocular pressure as this has been shown to slow or halt glaucoma progression. This can be achieved by using special eye-drops or medications or by treating the eye with a laser. Surgery is recommended if medications and/or laser don’t yield the desired result, or with an aim to prevent further vision loss or blindness. Depending on your particular situation, options include:
Laser Treatment
Laser treatment is usually recommended if the use of eye drops does not control your glaucoma adequately. However, there is an increasing trend towards offering some laser treatments as first line therapy because of its good efficacy and safety profile.
Depending on the type of laser surgery, your eye will be numbed with anaesthetic eye drops. Then, your doctor will place a special lens in front of your eye. Afterwards, a laser beam is aimed into your eye and you can see flashes of coloured light.
Types of laser surgery for glaucoma include:
Laser trabeculoplasty
Selective laser trabeculoplasty (SLT)
Laser iridotomy
Cyclophotocoagulation or laser cyclo-ablation
Risks and complications
Surgical Interventions
Penetrating Filtration Surgery
Trabeculectomy
Trabeculectomy is the most commonly performed surgical procedure to reduce intraocular pressure in the eyes with glaucoma. It involves the creation of a new drainage channel that allows the fluid to drain from the inside of the eye to a space under the conjunctiva leading to the formation of a fluid filled space termed the “bleb”. The drainage site may scar over time leading to its closure and subsequent elevation in eye pressure. This scar formation can be prevented or minimised by using antimetabolites during and after surgery. These act by inhibiting the multiplication of cells that form scar tissue.
Non-Penetrating Filtration Surgery
A number of surgical techniques are classified under this heading including deep sclerectomy, viscocanalostomy and canaloplasty. The common feature of all these types of surgery is the lack of full-thickness incision in the inside of the eye. Instead, they aim to open and expose a structure called Schlemm’s canal, a circular passage that travels for 360 degrees around the front of the eye near the junction between the cornea (clear front part of the eye) and sclera (the white part of the eye). They lower intra-ocular pressure by increasing the flow of aqueous through the natural pathways of the eye as well as via a mechanism very similar to trabeculectomy (described above). These surgeries are only likely to work if the angle between the iris and cornea is open. Therefore, glaucoma in which this angle is closed should not be treated with this type of surgery.
Deep Sclerectomy
This technique is similar to a trabeculectomy, except no full thickness drainage channel is created. Instead the dissection opens into Schlemm’s canal, but leaves the trabecular meshwork intact. Fluid from within the eye then flows across the trabecular meshwork and is then dispersed along Schlemm’s canal, under the sclera and into the “bleb”. The intraocular pressure reduction achieved is slightly less than a trabeculectomy, however, the speed of recovery after surgery is often quicker and it has a different complication profile. For example, cataract and chronically low intraocular pressure (hypotony) are less frequent following deep sclerectomy.
Viscocanalostomy
A clear jelly-like material called viscoelastic is injected into Schlemms canal in an attempt to dilate it and increase the rate of fluid flow along it. This can be performed as stand alone procedure or in combination with other techniques such as deep sclerectomy.
Canaloplasty
A fine suture is threaded along the entire circumference of the Schlemm’s canal and pulled taught. This opens the Schlemm’s canal and aids in the flow of fluid along it.
Minimally – Invasive Glaucoma Surgery
Known as MIGS, minimally-invasive glaucoma surgery is a new and evolving area of glaucoma surgical treatment. It aims to lower intraocular pressure with a procedure or device that is minimally invasive and has little or no effect on the surface layers of the eye. All MIGS procedures have the following characteristics:
1) performed within the eye in the junction between iris and cornea (iridocorneal angle).
2) minimal tissue handling or destruction.
3) relatively quick.
4) very good safety profile.
5) multiple treatments are possible.
6) can be combined with cataract surgery.
MIGS is best suited for eyes with mild to moderate glaucoma or ocular hypertension with an open angle in whom an intraocular pressure in the mid to high teens is desirable. MIGS can also be helpful in reducing the need for topical glaucoma medication.
