Exams and Tests

During an examination for angle-closure glaucoma, your ophthalmologist performs the following tests: gonioscopy, tonometry, biomicroscopy, and ophthalmoscopy. Each test is described below.

• Gonioscopy is performed to check the drainage angle of your 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.
• 
  
• 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 10-21 mm Hg. In a case of acute angle-closure glaucoma, IOP may be as high as 40-80 mm Hg.
• 
  
• Biomicroscopy is a technique to examine the front of your 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. This test may reveal a swollen optic nerve in an acute attack of angle-closure glaucoma. 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, your ophthalmologist looks for additional 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, and adhesions may cause permanent dilation 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.