What is Glaucoma?
Glaucoma is an important disease because it is common and potentially serious. Approximately 1.5% to 2% of the population over 40 years of age suffers from it and its incidence increases with increasing age. It is the second leading cause of blindness in our population. Nevertheless, this blindness could be avoided by diagnosing and treating the disease properly.
Glaucoma is a chronic, progressive and irreversible disease of the optic nerve. It is characterized by a loss of the field of vision, usually asymptomatic until advanced stages of the disease and, in most cases, it is associated with elevated ocular pressure.
There are some acute forms of glaucoma, with rapid clinical manifestation and usually accompanied by pain and loss of vision, which are less frequent. In these, ocular pressure rises rapidly due to the anatomical configuration of the eye (primary angle-closure glaucoma) or secondary to inflammation, trauma or other ocular disease.
There are many risk factors that can contribute to glaucoma. Among them, elevated eye pressure is the most important. In most cases, elevated eye pressure is secondary to a difficulty in the elimination of aqueous humor (intraocular fluid). Eye pressure is considered normal below 22 mmHg, but some eyes with glaucoma need to maintain lower pressures to prevent progression of the disease.
Other important factors, such as genetic predisposition or vascular factors, also influence each patient to varying degrees.
Types of Glaucoma
There are many types of glaucoma, although we highlight the following:
- Primary open-angle glaucoma. It is the most common, usually appears after the age of 40, it is of slow evolution and does not present symptoms until the final stages in which vision loss occurs. It is usually diagnosed during routine check-ups at the ophthalmologist’s office.
- Angle-closure glaucoma. It may present acutely or chronically. The acute form usually presents with severe eye pain, eye redness and blurred vision, so most patients go to an emergency department, where the diagnosis is made. It is a serious disease, with a high risk of vision loss. Therefore, early diagnosis and preventive laser treatment (iridotomies/iridoplasty) can prevent it.
- Secondary glaucomas. Heterogeneous group of glaucomas. In them there is a specific cause, often another ocular disease, which generates the pressure elevation. These include pigmentary glaucoma, pseudoexfoliative glaucoma, glaucoma associated with inflammation, glaucoma secondary to corticosteroid treatment, neovascular glaucoma, etc.
- Congenital glaucoma. It occurs in the first days or months of the patient’s life and is secondary to abnormalities in the development of the eye during gestation. Specifically, it occurs at the level of the trabecular meshwork (where the aqueous humor drains).
Who is most at risk?
- People over 40 years of age are at higher risk for the disease. The risk increases with age.
- People with high eye pressure. It is the main risk factor for the development of glaucoma, so following a treatment to reduce this pressure is the most important thing to achieve an improvement in the prognosis of the disease.
- People with a family history of glaucoma. There is between 4% and 16% risk of developing glaucoma if a first-degree relative (father, mother and/or siblings) suffers from it.
- Myopia. Myopic people have approximately twice the risk of developing glaucoma than the rest of the population.
- People belonging to certain ethnic groups. African-Americans have a higher incidence of glaucoma than whites, and glaucoma tends to present earlier and more aggressively.
People who are at higher risk for glaucoma should undergo an ophthalmologic evaluation to rule out or facilitate early diagnosis of the disease. Also, if you have already been diagnosed with glaucoma, it is important to comply with the check-ups and treatment prescribed by the ophthalmologist and to recommend that your immediate family members undergo an ophthalmologic examination (aqueous).
How is glaucoma diagnosed?
In acute glaucoma, the patient usually suffers pain and loss of vision, so he or she usually goes to the ophthalmologic emergency room, which makes it easier to diagnose from the clinical evaluation and the examinations mentioned below.
However, chronic glaucoma (the most frequent) is a silent, slow disease that does not cause discomfort to patients until very advanced stages. Patients are not aware of their disease until it is at a very advanced stage. For this reason, people who are at greater risk of suffering from it should undergo evaluations to rule it out or facilitate its early diagnosis.
The diagnosis of glaucoma is made by a complete ophthalmologic examination, aimed at evaluating intraocular pressure, optic nerve status and optic nerve function.
In addition to the general ophthalmological examination, the following tests are performed:
- Tonometry: intraocular pressure analysis.
- Campimetry: visual field examination
- Detailed examination of the papilla and the nerve fiber layer by slit lamp. Currently, several imaging tools contribute to the early diagnosis and follow-up of glaucoma: GDX, OCT, or HRT.
- Gonioscopy: examination of the aqueous humor drainage angle.
Once the first visit has been made and according to our doctor’s opinion, the pertinent controls will be carried out for the appropriate follow-up depending on the type and degree of glaucoma. Chronic glaucomas require periodic check-ups throughout the patient’s life.
What is the treatment?
The main objective of treatment is to preserve the patient’s vision and quality of life. Currently, treatment is aimed at treating the cause in secondary glaucoma and, in all types of glaucoma, at reducing ocular pressure.
The main treatment is medical and consists of the instillation of eye drops into the eyeball by means of eye drops. These eye drops contain different drugs that help lower intraocular pressure. There are many types of eye drops that are effective but may cause mild eye discomfort after application (eye redness, foreign body sensation, etc.). However, it is very important to carry out the treatment according to the guidelines indicated by the ophthalmologist. If the treatment is not strictly followed, the evolution of the disease is worse. Likewise, not applying the drops correctly poses a risk to vision.
Laser treatment is also useful in glaucoma. There are different types:
- Trabeculoplasty, suitable for open-angle glaucoma.
- Iridotomy (small hole in the iris) and iridoplasty (large impacts that stretch the peripheral iris and open the angle). It is used in angle-closure glaucoma.
- Cyclophotocoagulation. It is used in few cases, only in those that do not respond to other medical or surgical treatments.
It should be noted that all laser treatments are performed on an outpatient basis.
Surgical treatment is necessary in a considerable number of cases. Generally, it must be performed when medical or laser treatment is not sufficient to control the pressure and/or stop the progression of the disease.
The most commonly used surgical techniques for the treatment of glaucoma are:
- Deep non-perforating sclerotomy with or without implant.
- Drainage devices to the sub-conjunctival space (Ahmed, Baerdvelt, Molteno…)
- Trabecular implants
All these surgeries are performed on an outpatient basis but require strict postoperative control and treatment that the patient must perform at home. The success of the surgery depends to a great extent on the patient’s compliance with the treatment prescribed by the ophthalmologist.
Frequently Asked Questions
- Can glaucoma cause blindness?
Yes, some glaucomas lead to blindness. In fact, this disease is the second leading cause of blindness in our population. However, with the available treatments, in most cases it is possible to control the disease.
- Can I swim at the beach if I have glaucoma?
In general, a person with glaucoma can swim in the sea. However, it is very important to avoid swimming with glasses on and, if possible, the eyes should be protected with diving goggles. At any sign of redness or irritation, glaucoma drops should never be discontinued. It is also very important to protect the eyes from the sun by wearing sunglasses and a hat when going to the beach.