Glaucoma is a serious eye disease that can cause irreversible blindness. It is usually related to genes and damage to the eye nerve caused by elevated eye pressure. However, in a significant percentage of the glaucoma sufferers, eye pressure was not found to be high and yet damage to the eye nerve can still occur. It is therefore necessary to examine more than just the eye pressure for glaucoma.
Damage to the eye nerve manifests in a shrinking field of view. As the disease begins, the patient may not notice any problem whatsoever, until the limited visual filed in late stages cause falls or accidents. It can be such a silent disease that it is commonly called “the thief of sight”. This usually is the case in the subtype called open angle, which is a majority. In the smaller group called closed angle, the internal dimensions of the eye become crowded by an aging eye lens. This can cause the outflow of the internal fluid of the eye to become blocked, and give rise to an attack of high eye pressure. When the attack happens, the eye becomes very red, blurry and painful, often with associated headache and vomiting. It is one of the most common reasons for emergency admissions to the A&E department for the eye.
The main treatment option of either the open or closed angle type of the disease is to control and prevent an increase of the eye pressure. For open angle, eyedrops are usually prescribed to reduce eye pressure in the early phase. Often, the eye pressure continue to increase despite treatment, and additional eyedrops need to be prescribed. Some of these eyedrops can cause side effects such as red and irritated eyes. In the case when patients cannot tolerate eyedrops, alternative treatment such as lasers or glaucoma surgeries will be considered.
A recent innovation is the microinvasive stents for treatment of open angle glaucoma. These devices are tiny implants to create a more permanent outflow path for the eye fluid from internally. Some of these are made of inert and lasting material such as titanium. They can be implanted at the same time as a cataract surgery, or separately.
For angle closure patients, one of the most highly recommended management is actually prevention, since results of treatment during an attack is often much poorer. Prevention can be by performing a laser peripheral iridotomy, which effectively creates an internal passage to bypass the pupil which can become blocked. Another highly recommended method is a lens extraction surgery, which is basically a cataract surgery, but performed either with or without a cataract. The lens extraction method kills more birds with one stone, as it also allows for refractive correction by implanting an intraocular lens, which can be customized for the patient.
It is essential for those who have a family history of glaucoma to start screening for the disease from as early as in the 40s. Prevention is much better than cure in glaucoma, as cure is nigh difficult once the eye nerve is compromised!
by Dr Daphne Han – Senior Consultant Ophthalmology