Glaucoma is a group of eye diseases damaging the optic nerve, the health of which is vital for good eyesight. This damage in the majority of times is caused by unusually high pressure in the eyes (intraocular pressure-IOP). Glaucoma is one of the leading causes of blindness in people over the age of 60 but can occur at any age, with greater prevalence in older adults.
Many forms of glaucoma have no warning signs and the result is so gradual that the patient will not notice any change in vision until the condition is advanced.
For this reason, glaucoma is also called a "silent killer of sight".
As it is well known glaucoma vision loss is irreversible, so it is important to have regular eye check-ups to measure your intraocular pressure, so the diagnosis can be made at an earlier stage of the condition when can be treated appropriately. If glaucoma is diagnosed early, vision loss can be slowed down or prevented. By principle, if patients diagnosed with glaucoma, they will need treatment for the rest of their lives.
The symptoms of glaucoma vary depending on the type and stage of the condition. The following are indicative:
Open angle glaucoma
Blind areas on the peripheral or central vision (called scotomas), often in both eyes
In advanced stages of the disease, the peripheral vision is lost, so patient can see only with his central vision (like tunnel vision)
Closed angle glaucoma
Strong headache, usually one-sided
Nausea and vomiting
"Halos" around the lights
Redness of the eyes
If left untreated, glaucoma can eventually lead to blindness.
Glaucoma is the result of damage to the optic nerve. As the damage to the optic nerve gradually worsen, opaque areas (black spots) appear in the patient's visual field (scotomas).
The main cause of this pathogenesis remains unknown, but it is believed that it is largely an inherited disease, and in some people, researchers have identified genes associated with high intraocular pressure and optic nerve damage.
The increased pressure in the eyes is due to the accumulation of fluid that is normally produced (aqueous humor) and flows inside the eye. This fluid is usually drained through the drainage channel off the eye which is the angle formed between the iris and the cornea. When there is excessive production of this liquid or the drainage system does not work properly, the outflow at a normal rate and the intraocular pressure increases.
The main types of glaucoma are:
Open-angle glaucoma: It is the most common type of glaucoma and in this case the drainage angle formed by the cornea and iris remains open but is partially blocked. This causes a gradual increase in eye pressure which damages the optic nerve. It happens so slowly that the patient may lose his sight before he even realizes the problem
Closed-angle glaucoma: This type of glaucoma occurs when the iris is blocking the angle formed by the cornea and iris drainage channel. The result is that the aqueous humor cannot circulate in the eye and the pressure increases. Some people have narrow drainage angles, putting them at increased risk of angle-closure glaucoma and are more common in hyperopia and in elderly patients. Closed-angle glaucoma can occur suddenly (acute closed-angle glaucoma) or gradually (chronic closed-angle glaucoma)
Normal pressure glaucoma: In this type of glaucoma, the optic nerve can be damaged even if the intraocular pressure is within the normal range (below 20 mmHg). We do not know the exact reasons for this, but there may be increased sensitivity to the optic nerve or limited blood flow. This limited blood flow can be caused by atherosclerosis - the accumulation of fat deposits in the arteries - or other conditions that affect blood circulation.
Congenital glaucoma: It is rare but still possible for infants and children to have glaucoma. In these cases, glaucoma can be present at birth or in the first years of life. Optic nerve damage can be caused by blockage of the eye's drainage system or by an underlying medical condition. Usually children with congenital glaucoma are anxious, rub their eyes, cry a lot and show photosensitivity.
As far as chronic forms of glaucoma can cause permanent vision loss before the patient notices anything, it is good to know the following risk factors:
High intraocular pressure
Age over 60 years
Family history of glaucoma
Underlying conditions such as diabetes, heart disease, high blood pressure and sickle cell disease
High myopia or hyperopia
Injury and previous eye surgery
Taking steroid drugs (cortisone) for a long time (especially in the form of eye drops)
To diagnose glaucoma, the ophthalmologist will examine the patient's medical history and perform a complete ophthalmological examination. Usually glaucoma tests, among others, include:
Intraocular pressure measurement (tonometry)
Examination under mydriasis (with dilated pupils) to assess possible optic nerve damage
Visual field test (control for areas with vision loss- scotomas)
The damage caused by glaucoma is irreversible. However, early diagnosis and treatment of the disease can help slow down or prevent vision loss.
Glaucoma is treated by reducing intraocular pressure. Depending on the case, the options that the ophthalmologist will choose may include eye drops, oral therapy (pills), laser treatment, surgery or a combination of the above.
Eye drops: The treatment of glaucoma most often begins with the use of eye drops. These can help reduce intraocular pressure by improving the drainage of watery fluid from the eyes or reducing the amount produced by the eye. Depending on how low the eye pressure should be, more than one drug may need to be prescribed.
Oral therapy (pills): If the eye drops alone do not lower down the intraocular pressure to the desired level, an ophthalmologist may also prescribe oral therapy (pills). Possible side effects in this case include frequent urination, tingling in the fingers and toes, depression, stomach upsets and kidney stones.
Selective Laser Trabeculoplasty (SLT) can be used to regenerate and open the infiltrative path. This method has the advantage that it can be repeated as it does not cause tissue damage.
Nowadays we use also the new Cyclo-Diode laser technology which is applied to the eye and reduces the rate of production of aqueous humor.
YAG Laser technology: can be used to make small incisions(iridotomies) in the periphery of the iris in order to create communication between the anterior and posterior chamber of the eye to eliminate the flow blockage (iridotomies are used in cases of closed-angle glaucoma or when the angle is narrow as safety valves).
Surgery: The most common method of glaucoma surgery includes trabeculectomy (the creation of an artificial drainage pathway) and the implantation of valves that drain the aqueous humor from it.
At Emmetropia Eye Clinic, we are investing in new technology to ensure that all measurements, examinations, and finally treatments are performed accurately.
Our medical staff will inform you and advise you in detail on the best possible solution. Emmetropia is the only ophthalmology clinic in Crete with two ophthalmologists, with subspecialty in glaucoma (fellowship in Glaucoma), Dr. Aslanides and Dr. Sykakis.
In our Clinic we have a dedicated glaucoma department with state-of-the-art technology available to diagnose and monitor any type of glaucoma. All modern methods of laser treatment (such as Ellex's only state-of-the-art SLT laser technology in Crete) as well as surgical treatments such as trabeculectomy and valve implants for more complicated cases of glaucoma, are available for emergency treatments.