Final answer:
To identify a narrow anterior chamber angle during a slit lamp exam, a healthcare provider examines the angle between the iris and cornea using the slit lamp's light to assess the depth of the anterior chamber. A narrow anterior chamber angle may indicate angle-closure glaucoma and requires careful inspection and possibly further diagnostic procedures such as gonioscopy.
Step-by-step explanation:
To identify a patient with a narrow anterior chamber angle on slit lamp exam, an eye care professional will examine the anterior chamber of the eye using a slit lamp microscope. Through this examination, the angle between the iris and the cornea where the trabecular meshwork resides, known as the anterior chamber angle, can be assessed. A narrow anterior chamber angle is suggestive of angle-closure glaucoma and is characterized by an angle that is too small, potentially impeding aqueous humor outflow and leading to increased intraocular pressure.
During the exam, the patient is seated with their chin resting on the slit lamp's chin rest while the examiner uses a narrow beam of light to visually inspect the depth of the anterior chamber. This light beam is adjusted to a very thin slit, which is directed into the eye perpendicular to the plane of the angle in question. If the depth appears shallow and the angle appears closed or nearly closed upon inspection, the patient might be diagnosed with a narrow angle. If the angle is narrow, additional diagnostic procedures like gonioscopy, which involves the use of a special lens to directly visualize the anterior chamber angle, could be performed for a definitive diagnosis.