Gonioscopy - examination of the glaucomatous angle as a key method of glaucoma diagnosis
Examination of the seepage angle, called gonioscopy, jest jednym z najważniejszych badań diagnostycznych w okulistyce, szczególnie w kontekście wykrywania i monitorowania jaskry. Gonioskopia, czyli examinations of the seepage angle, allows an accurate assessment the angle of the eye, The glaucoma is a glaucoma that is responsible for the outflow of aqueous humor from the inside of the eye. Its malfunction can lead to increased intraocular pressure and, consequently, to the development of glaucoma. Early recognition of these changes is key to preserving the patient's vision.
What is gonioscopy?
Gonioscopy is a specialised eye examination that allows the doctor to assess the corneal-iris seepage angle - The space between the cornea and the iris. What does gonioscopy involve? This examination assesses the corneal-iris seepage angle in the eye, which is crucial in the diagnosis of disorders such as glaucoma or ocular hypertension. This angle is responsible for the outflow of aqueous fluid from the eye, and its blockage can lead to increased intraocular pressure. This is why gonioscopy is an essential investigation in the diagnosis of glaucoma, especially Closing angle glaucoma, which can lead to rapid damage to the optic nerve.1
Gonioscopy findings - how do you interpret the width of the angle of seepage?
Results gonioscopy provide the doctor with important information about the state of the angle of the eye, which is crucial in assessing the risk of glaucoma. The doctor checks whether the angle is open, closed or partially closed, which affects the outflow of the aqueous fluid.
Open seepage angles allow free flow of fluid, which usually rules out closed-angle glaucoma, although there may still be a risk of open-angle glaucoma. Closing the angle signifies a high risk of angle-closure glaucoma and requires immediate intervention to avoid a sudden increase in pressure and loss of vision. The results of partial closure indicate the need for further monitoring. An important parameter is the width of the angle of the exits, which influences the normal circulation of the aqueous fluid in the eye and the intraocular pressure values.
The doctor may also analyse the presence of scarring or abnormal vessels, which may indicate previous trauma to the eye. Gonioscopy allows precise planning of further treatment.2
How does the gonioscopy examination work - is there anything to be afraid of?
Study gonioscopy is quick and painless, taking just a few minutes. Before it begins, the patient is given anaesthetic drops to eliminate the discomfort of applying a special gonioscopic lens to the surface of the eye. The patient must rest his or her forehead against the slit-lamp and look in a specific direction, which is key to obtaining correct results during diagnosis. This lens, in combination with the biomicroscope, allows the doctor to view the isthmic angle and assess its condition.
Once the gonioscopic lens has been placed on the eye, the doctor carefully observes the angles between the cornea and the iris, assessing whether the seethrough structure is working properly. The examination does not require any special preparations and the patient can return to normal activities immediately afterwards.3
What complications can occur after gonioscopy?
Complications after gonioscopy are very rare. Some patients may experience brief tearing, irritation or slight redness of the eye, which usually disappears within a few hours. In some cases, patients may feel a foreign body sensation due to the irritation caused by the examination. In very rare cases, temporary blurred vision may occur. Examination of the seepage angle However, it is a safe procedure that is performed routinely and any risk of complications is minimal.
Why is examination of the angle of descent important in the diagnosis of glaucoma?
Gonioscopy plays a key role in the diagnosis of glaucoma by assessing the anterior chamber of the eye and how the mechanism of outflow of the aqueous fluid in the eye works. Glaucoma is a disease that leads to gradual destruction of the optic nerve, often without previous pain symptoms. One of the main causes of this process is an increase in intraocular pressure, caused by abnormal functioning of the optic angle.4
With gonioscopy, the doctor can determine whether the angle is open, suggesting other causes of elevated pressure, or closed, indicating the possibility of a Closing angle glaucoma, one of the more dangerous forms of this disease. Early detection of angle problems allows treatment to be implemented quickly and reduces the risk of serious damage to vision.
How to prepare for a gonioscopy?
Preparation for gonioscopy is simple and does not require special measures. The patient does not need to be fasting, but should inform the doctor of any medications they are taking, especially those affecting intraocular pressure. Before the examination, the patient is given anaesthetic drops, which minimise discomfort during gonioscopic lens application. Wearers contact lenses should remove them before the examination. It is important that the patient avoids sudden movements of the head, as these may adversely affect the results of the examination and the patient's comfort.
The day before the examination, it is advisable to avoid eye cosmetics and contact with irritants such as smoke or dust. It is also important to inform the doctor of any previous eye health problems, such as surgery or trauma.
When is it worth having a gonioscopy?
Gonioscopy is primarily recommended for patients with suspected glaucoma. It can also be performed in patients with high intraocular pressure, ocular trauma, congenital anatomical abnormalities or other ocular conditions that may affect the normal function of the angle of descent, including the curvature of the peripheral part of the iris. Gonioscopy can also be performed at the time of surgical procedures, which is crucial for assessing the condition of the eyeball and allows the progress of treatment to be evaluated. Regular examinations of this type are important for patients at risk, such as the elderly or those with a genetic load.
In some cases, gonioscopy may be part of a broader diagnosis that includes other investigations such as tonography (measurement of intraocular pressure) or optyczna koherentna tomografia (OCT), which support the assessment of the condition of the eye.
