Gonioscopy
Gonioscopy is a specialized ophthalmic procedure used to examine the drainage angle of the eye, focusing on the area between the cornea and the iris. It is primarily performed to identify any growths or obstructions that may affect fluid drainage, which is crucial for maintaining eye health and preventing vision loss. During the procedure, the ophthalmologist applies numbing eye drops and uses a specialized lens and lamp to visualize the angle, usually completing the examination within five to ten minutes. Patients may need to remove contact lenses beforehand and are advised to avoid rubbing their eyes afterward, as they may experience temporary vision changes.
Advancements in gonioscopy techniques have led to the development of automated and digitalized systems, including devices that capture detailed images of the anterior chamber angles and optical coherence tomography for less invasive assessments. While generally considered safe, gonioscopy carries minor risks, such as allergic reactions to eye drops or slight chances of infection. The results of the procedure can indicate whether drainage is normal, with a wide and open angle, or if abnormalities such as blockages are present, guiding further diagnostic and treatment decisions.
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Gonioscopy
DEFINITION: Gonioscopy is a procedure used by eye health professionals to examine the interior of the eye to check the drainage angle for growths, problems, and obstructions.
Cancers diagnosed:Eye cancers
Why performed: A gonioscopy allows the doctor to see into the patient’s eye to examine the area in which fluid drains and check for problems.
Patient preparation: A patient wearing contact lenses must remove them.
Steps of the procedure: Gonioscopy is usually performed in a doctor’s office, although it can also be performed in other settings. It is usually performed by an ophthalmologist. The doctor begins by applying eye drops to the patient’s eye to numb it, allowing the doctor and instruments to touch the eye without the patient feeling it. The patient may be asked to lie down or rest their head on a headrest if the procedure is performed while the patient is sitting up. The patient is asked to try to refrain from blinking during the procedure.
The doctor uses a special lamp and a special lens to examine the area between the cornea and the iris inside the patient's eye. Problems with this area can cause the eye not to drain fluid correctly, leading to many eye and vision problems, including eventual loss of vision. In total, gonioscopy usually takes between five and ten minutes for the doctor to perform.
After the procedure: The patient should refrain from rubbing the eye for a period after the procedure. The patient’s eye may need to be dilated during the procedure, so they may experience loss of vision quality for a few hours afterward.
In the twenty-first century, several advances have been made in gonioscopy procedures, which have become increasingly automated and digitalized. Devices using multi-mirror prismatic lenses can capture 360-degree color images of the eye’s anterior chamber angles (ACA). Devices using a six-mirror lens allow a more comprehensive view of the ACA. Optical coherence tomography is an imaging technique that can offer a view of the ACA externally, allowing for a less-invasive procedure to aid diagnostics and treatment planning. Improved photography systems and endoscopic techniques are additional innovations in gonioscopy and are aided by the use of artificial intelligence to classify ACA findings.
Risks: In general, no significant risks are associated with gonioscopy. There is a small risk of an allergic reaction to the eye drops used by the ophthalmologist to numb the eye, and there is also a very small chance of eye infection.
Results: Gonioscopy allows the doctor to see into the area of the eye where fluid drainage occurs. This can help the doctor determine whether normal drainage is occurring or if a growth or other blockage is preventing it. Normal results for this procedure will show a drainage angle that is wide and open. Abnormal results will show a drainage angle that is blocked or closed.
Bibliography
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