Glaucoma

CONDITION

Glaucoma is often referred to as the ‘silent thief of sight’, as in early stage it causes a gradual loss of peripheral vision which may go unnoticed. Glaucoma causes irreversible damage to the optic nerve that connects the eye to the brain, and it is most caused by raised eye pressure. Glaucoma can be detected and monitored on a routine eye examination by looking at the optic nerve, checking the eye pressure and conducting a visual field test.  

 

TREATMENTS 

Although there is no cure for glaucoma, there are treatments which can slow or halt its progression. These treatments aim to lower the eye pressure by either reducing the aqueous (fluid) production in the eye, or increasing the fluid outflow from the eye. 

Antiglaucoma eye drops are most used to reduce the eye pressure. These have the benefit of being non-invasive, however they need to be continually taken to be effective. Similarly, oral medications can also be prescribed for a short period of time. 

 Selective Laser Trabeculoplasty (SLT) can be used to increase the drainage pathway in the eye and therefore achieving eye pressure reduction. This treatment modality complements and sometimes minimises the need for eye drops and can be repeated if necessary. 

 If neither eyedrops nor SLT laser are sufficient in reducing eye pressure to a level where there is minimal progression of glaucoma, surgeries may be indicated. Depending on the target eye pressure, minimally invasive glaucoma surugery (MIGS) may be the first line surgical intervention, sometimes combined with cataract surgeries. However, in advanced glaucoma, traditional incisional surgeries (trabeculectomy or glaucoma tube surgery) are required to achieve a greater eye pressure reduction in order to slow down progression of glaucoma.  

 

FAQs 

Will glaucoma affect my ability to drive? 

This depends on the severity of your glaucoma. In advanced cases, there may be significantly reduced peripheral vision, even encroaching on central vision. You can have a visual field test to assess your fitness to drive, as a certain amount of peripheral vision is required to hold a driver’s license. 

 

I don’t have any symptoms, how can I have glaucoma? 

Unfortunately, early glaucoma does not cause any symptoms, as a result, some patient only presents to an eye care professional once their glaucoma is already advanced which causes symptoms. Glaucoma Australia recommends everyone aged 50 or older to visit an optometrist every 2 years in order to detect any signs of glaucoma. Those with additional risk factors, such as having a family history, short-sightedness (myopia), history of eye trauma, are recommended to be checked every 2 years from the age of 40. 

 

Is glaucoma inherited? 

If you have a family member affected by glaucoma, you are at a much higher risk of developing glaucoma yourself. It is very important for those with a family history of glaucoma to have regular eye examinations in order to detect the condition as early as possible. 

 

Which is better? SLT Laser or drops? 

Both SLT laser and glaucoma drops are effective in reducing intraocular pressure and are appropriate first line treatments in open angle glaucoma. The decision to start with SLT laser or drops will depend on your discussion with your ophthalmologist and will be based on your preferences, lifestyle and tolerance of topical eye drop medication. If the intraocular pressure is not satisfactorily controlled with laser or drops alone, the two treatments can also be used in combination. 

 

Does SLT laser last forever? 

The intraocular pressure lowering effects of SLT laser unfortunately wear off with time. Therefore it is necessary to have follow up following SLT, even if the initial response is positive. The treatment can be repeated if the eye pressure begins to rise some times after the procedure.  

 

What is trabeculectomy surgery? 

 In cases of progressive glaucoma despite maximally tolerable medical treatment, surgical intervention is recommended. This special procedure is called trabeculectomy. During trabeculectomy, an alternative drainage pathway for the aqueous is created. The aqueous drains out of the eye through a guarded fistula into a special pocket on the surface of the eye (bleb), where it is then resorbed by the body. Trabeculectomy therefore lowers the eye pressure and prevents further day-night variation or spike in the eye pressure to limit further damage to the optic nerve. After the surgery patient will need to start frequent and regular topical steroid eye drops and have regular follow up visits to ensure the drainage continues to work. Additional office-based injection of anti-scarring medication, and return to theatre may be required to ensure survival of the bleb.  

 

 What is tube surgery?  

In cases where previous trabeculectomy surgeries have failed, the alternative therapy for advanced glaucoma would be a glaucoma drainage implant procedure, also known as tube surgery. Instead of a fistula formation in a trabeculectomy surgery, the drainage tube redirects the aqueous from the eye into a reservoir that is surgically attached to the external surface of the eyeball. The aqueous then is resorbed by the body. To ensure effective reservoir formation, the tube may be initially blocked with a stent and suture ties, and by 3 months the reservoir has matured and the drainage can become fully functional. Tube surgery therefore lowers the eye pressure and prevents further day-night variation or spike in the eye pressure to limit further damage to the optic nerve. After the surgery patient will need to start frequent and regular topical steroid eye drops and have regular follow up visits. In the initial 3 months, regular antiglaucoma drops may need to be continued for optimal eye pressure control.  

 

What happens to my vision after glaucoma surgery?  

Unlike cataract surgery, glaucoma surgeries do not improve your vision. In fact, you should expect reduction in your vision in the early post-op period and fluctuation of your vision as the operated eye begins to heal. This is due to variation in the eye pressure and minute change in the shape and size of the eyeball, which changes the focus of the eye. Eventually this would settle down and by 3 to 6 months the vision should stabilize. You should expect your vision to return to your baseline with or without new prescription glasses.