Should patients with severe glaucoma allow their eyes to be dilated during exam?

For patients with severe peripheral vision loss due to open angle glaucoma, there is usually little risk from being dilated for an exam. Some patients with open angle glaucoma will have a pressure spike (high intraocular pressure) after dilation, so your ophthalmologist should occasionally check your eye pressure after you have been dilated to see if your eye pressure rises. Patients who are found to “spike” with dilation can be given pressure lowering drops before dilation to prevent the spike. This is particularly important for patients who require frequent dilation, such as those seeing a retina specialist for macular degeneration or diabetic retinopathy.

Dilation is more risky in patients who have a narrow angle, where the iris (colored part of the eye) is very close to the cornea (clear window at the front of the eye). Dilating drops can raise pressure in these patients by closing off the drainage angle of the eye. If your narrow angle poses such a risk, your ophthalmologist will usually perform a laser peripheral iridotomy, which makes a microscopic hole in the iris so the pressure will not go up when the eye is dilated. Cataract surgery also “cures” this condition. In summary, your ophthalmologist will know whether your eye is safe to be dilated after the initial exam.