Glaucoma surgery is required when treatments like drops fail to control the progression of glaucoma. Glaucoma management is evaluated continuously throughout the life of a glaucoma patient. Effective management can significantly delay the time from one method of management to another.
Trabeculectomy is the standard surgical procedure to lower the pressure in the eye and prevent further loss of vision in glaucoma, when drops, laser or MIGS are not sufficient. It was developed in the 1960s but since then it has been modified significantly, to achieve better results and reduce the risks. Other procedures are considered if a trabeculectomy has failed. These include implantation of a tube or shunt to drain fluid out of the eye or a Cylclodiode laser which reduced reduces the fluid production in the eye.
Trabeculectomy
The aim of a trabeculectomy is to create a permanent flow of fluid from inside the eye to the area under the skin that surrounds the eye, called the conjunctiva. As shown in the animation, a small opening is made in the outer wall of the eye (sclera). The opening is covered by a thin “trap‐door” in the sclera. As a result, there is a communication between the inside of the eye and the area under the conjunctiva where the fluid drains and forms a small blister-like reservoir (bleb) just under the eye surface. The bleb is not visible as it is hidden under the eyelid. The flow rate of the fluid determines the level of the eye pressure. This can be adjusted, as special sutures are placed on the “trab-door”, which can be removed in the clinic if the eye pressure is not low enough.
The natural reaction of the human body to any surgical procedure is healing. However, in trabeculectomy healing causes scarring, which would cause the operation to fail as it would block the new drainage channel. To prevent scarring, a special anti-scarring substance, called Mitomycin C is applied under the conjunctiva in almost all cases.
The operation is usually performed under local anaesthesia. However, general anaesthesia is available for anxious patients.
Experience & Expertise
Trabeculectomy is a very effective procedure but it carries risks, so it should be performed by glaucoma fellowship trained Ophthalmic surgeons. Risks include reduction in vision or even loss of sight due to an infection or a haemorrhage in the eye, cataract can form sooner and the upper lid can become droopy.
To overcome these complications, my technique is based on the Moorfields safe surgery system, which I was taught during my two years Glaucoma fellowship at Moorfields Eye Hospital in London. During my Consultant career, I have modified the technique, as a result, I can achieve excellent results with minimal risk. I pay particular attention on the planning of surgery and I make a specific plan for every patient. In addition, I also create a personalised postoperative plan, which requires intensive follow-up and adjustment of drops along with removal of sutures if required.