Andrew A. Dahl, MD, is a board-certified ophthalmologist. Dr. Dahl's educational background includes a BA with Honors and Distinction from Wesleyan University, Middletown, CT, and an MD from Cornell University, where he was selected for Alpha Omega Alpha, the national medical honor society. He had an internal medical internship at the New York Hospital/Cornell Medical Center.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
During an examination for angle-closure glaucoma, an ophthalmologist performs the following tests: gonioscopy, tonometry, biomicroscopy, and ophthalmoscopy. Each test is described below.
Gonioscopy is performed to examine the drainage angle of the eye; to do so, a special contact lens is placed on the eye. This test is important to determine if the angles are open, narrowed, or closed and to rule out any other conditions that could cause elevated IOP. If the intraocular pressure is elevated and the angle is open, acute angle-closure glaucoma is not possible.
Tonometry is a method used to measure the pressure inside the eye. Eye pressure is measured in millimeters of mercury (mm Hg). Normal eye pressure ranges from 10 to 21 mm Hg. In a case of acute angle-closure glaucoma, IOP may be as high as 40 to 80 mm Hg.
Biomicroscopy is a technique to examine the front of the eyes and uses a special microscope called a slit lamp. This examination may reveal a poorly reactive pupil, a shallow anterior chamber, corneal swelling, redness around the iris, and inflammation.
Ophthalmoscopy is used to examine the optic nerves for any damage or abnormalities; this may require dilation of the pupils to ensure an adequate examination of the optic nerves. If episodes of angle-closure glaucoma have been chronic (long term), this test may reveal excavation of the optic disk, which is a depression in the front surface of the optic nerve.
If an attack persists or if several milder incidents of angle closure have occurred in the past, the ophthalmologist looks for signs of previous attacks.
Peripheral anterior synechiae (scarring) and adhesions may be visible between the cornea and the iris. Peripheral anterior synechiae may destroy the trabecular meshwork.
Prior attacks may cause a poorly reactive pupil because of damage to the muscle of the iris.
Glaucoma flecks (also known as glaukomflecken) are spots on the lens of the eye. Glaucoma flecks may be seen if an acute attack of angle closure has occurred in the past.
Atrophy of the iris provides further evidence of a prior attack if it occurred 3 or more weeks prior to the eye examination. The atrophied part of the iris appears gray, rather than blue, brown, or green.