Service Information

Heidelberg Retinal Tomography III

Glaucoma is a progressive disease of the optic nerve that leads to irreversible visual loss. However, clinical studies have confirmed that early detection and treatment of glaucoma can slow the progression of permanent optic nerve damage and blindness.

Common conventional methods of evaluating the optic nerve are very subjective: Doctors try to assess the nerve by way of observations and diagrams to identify glaucomatous cupping and damage. These methods do not provide exact quantitative measurements, and comparisons for subtle changes over time are very difficult. Regardless of their limitations, these methods are considered the current standard of care, and are covered by OHIP.

Now patients have a newer, more advanced option: The Heidelberg Retinal Tomograph III (HRT III) has been proven to be superior to all other available optic nerve imaging techniques, and uses the latest in scanning laser technology for early detection and follow-up of glaucoma. This machine is a laser ophthalmoscope, which can precicely measure and analyze the shape of the optic nerve. The HRT III is not a treatment laser, and is not harmful to the eye (it operates similar to a CAT scan, minus the x-rays).

Data from successive HRT III exams is superimposed on the original data (or baseline exam) for a point-by-point comparison to identify changes over time. Therefore, repeated measurements of the optic nerve using the HRT III can pick up glaucoma damage up to four years earlier than visual field testing. These subtle changes will help to determine:

  • When treatment is necessary (for glaucoma suspects)
  • When treatment should be increased or surgery considered (for patients with existing glaucoma damage)

The test is safe and takes moments to complete: Patients look at a target light and must not blink or move the eye for several seconds while the photograph of their optic nerve is being taken. (Dilating drops may be necessary if a patient has cataracts or corneal scarring). The HRT III exam takes place in this office, and the test is used to monitor the progression of your glaucoma. The frequency of follow-up exams is determined by your doctor, and based on whether the progression of your glaucoma is stable or aggressive.

The cost of this examination is not covered by OHIP. The examination fee is billed directly to the patient, and a receipt for your health insurance or tax purposes will be issued. Methods of acceptable payment include Interac, Visa, Mastercard, cash, or cheque.