WHAT IS GLAUCOMA?
Glaucoma is a group of eye diseases that, if not treated in time, leads to progressive damage to the optic nerve and can eventually lead to loss of vision (optic neuropathy). It is usually caused by increased intraocular pressure, resulting in the gradual destruction of the optic nerve and consequently of the visual field. Glaucoma can result in irreversible blindness if not diagnosed and treated in time. For this reason, an annual eye examination is recommended, including measurement of eye pressure and optic nerve testing, and in cases where there is a family history of glaucoma, the examination should be done earlier, from the age of 35.
FREQUENCY OF OCCURRENCE
The rate of glaucoma in the general population is 2%. In particular , in people over the age of 40, the rate increases to 4% and also increases even more in older age.
WHERE IS IT DUE TO AND HOW IS IT CREATED?
Within the eye, and in particular from the Vitreous Body, a fluid is produced, the aqueous hum or, which circulates between the Posterior and Anterior Chambers and is ultimately drained by the venous circulation.The aqueous humor enters the posterior chamber between the iris and the lens, then passes through the pupil into the anterior chamber and is drained through the corner of the anterior chamber to the venous circulation. This is a continuous and uninterrupted lifelong process. If there is an obstruction to drainage, then volume of continuously produced aqueous humor is pathologically increased within the anterior and posterior chamber and presses on the walls of the eye, resulting in increased intraocular pressure. The pressure is exerted on the optic nerve fibres and gradually causes irreversible, progressive destruction.
TYPES OF GLAUCOMA
A : Chronic open-angle glaucoma
It is the most common form of glaucoma. The angle of the anterior chamber – where the drainage of the aqueous humor will take place – is open, but the drainage channels are insufficient and unable to maintain the balance between production and drainage of the aqueous humor. The result is a gradual increase in intraocular pressure.
B : CLOSED-angle glaucoma:
It is the rarest form of glaucoma. In this case the hydatid cannot access the angle of the anterior chamber because it is closed resulting in increased pressure. It usually occurs suddenly in acute form and the increase in intraocular pressure is abruptly high with severe symptoms, such as blurring of vision, pain and redness of the eye and requires immediate treatment.
C : SECONDARY GLOBULA:
Occasionally in the presence of other eye disease, High Intraocular Pressure occurs. Treatment of the primary disease leads to a drop in pressure.
D : Congenital glaucoma:
Extremely rare occurring in babies and young children , usually coexisting with other eye abnormalities . It is the reason why newborns and all children of all ages should be screened for glaucoma.
GLAUCOMA SYMPTOMS:
In the majority of cases, the initial appearance of the disease and for a long time does not give any subjective symptoms. Usually it is found accidentally during an ophthalmological examination. Unfortunately, in the last stage of the disease the patient comes in because he has a significant loss of visual field or visual acuity .
DIAGNOSIS :
The absolutely necessary eye examination includes:
- Personal and Family History.
- Determination of Optical Acidity.
- Tonometry.
- Corneal pachymetry for the accurate determination of Offth. Pressure.
- Check the angle of the anterior chamber.
- ‘ Optic nerve testing with Dethoscopy and GOLDMAN Biomicroscopy.
- Digital colour imaging of peripheral vision – Visual Fields.
- Optical Coherence Tomography – OCT
WHAT IS LOW-PRESSURE GLAUCOMA:
In a percentage of 15% of patients with existing Normal Intraocular Pressure, the presence of a special category – Low PressureGlaucoma – cannot be excluded . This percentage of patients does not show increased pressure and the simple measurement of intraocular pressure – although absolutely necessary – does not detect all possible cases, since about 15% do not show increased pressure ( low pressure glaucoma).
The above tests are absolutely necessary not only for the diagnosis of glaucoma but also for its monitoring.
In suspicious cases they are usually:
- Field of view control
- Optical coherence tomography of nerve fibre, macula and optic nerve.
- Cornealpachymetry
KEY TREATMENTS:
After the necessary first diagnosis of the presence of glaucoma and the determination of possible already existing lesions until the day of the start of treatment, are used:
1 : Antiglaucoma medicines – usually eye drops..
It is absolutely necessary to inform patients that glaucoma is a chronic disease and they should use the eye drops for the rest of their lives, sometimes even in cases where the surgery or the Laser was performed from the beginning or in the course of the surgery.
2 : Lasers – Trabeculoplasty – in selected cases.
The application of Laser : Argon or Yag – Trabeculoplasty in the majority of cases reduces the pressure and facilitates medication and is extremely useful but in 40-50% of patients its effect does not last more than 2-4 years.
3 : Microsurgical invasive.
When the intraocular pressure is not satisfactorily regulated and we have a progressive deterioration of the visual fields and other parameters – OCT concerning glaucoma, then we resort to surgery. The success rate of these operations is quite satisfactory. In cases where the usual interventions do not have the desired result, we resort to implantation of an artificial valve to drain the eye fluid . In addition, in extremely severe cases we can perform procedures with Diode – LASER or AND CRYOPICS of the ciliary body, resulting in the reduction of aqueous humor production.
WHAT TO REMEMBER
- Detection and early treatment, limit the progression of damage.
- It is a chronic condition, with UNCONTINUED treatment.
- Meticulous application of the Doctor ‘s recommendations for effective treatment.
By Dr. GEORGIOS N. VETTAS M.D. Ophthalmic Surgeon and Scientific Director of the Ophthalmology Department , Euromedica Egkefalos Chalandriou