Narrow angle pupil dilation

Gonioscopy Because pupil dilation may precipitate an acute attack of narrow-angle glaucoma, evaluate anterior chamber angle by gonioscopy prior to beginning therapy. 

The goal of dilation should be a maximally dilated pupil. Minimally dilated or pupils that remain in a mid-dilated state pose a risk of pupillary-block glaucoma in eyes with narrow angles that is not present with maximally dilated pupils. 

The classic presentation of a patient with acute ACG includes complaints of eye pain, headache, blurred vision, photophobia, the perception of halos around lights, nausea, and vomiting. Clinical signs include an edematous cornea, a fixed mid-dilated pupil, ciliary injection, high lOP, convex iris (iris bombe), and cells and flare in the anterior chamber. There may also be evidence of previous episodes such as peripheral anterior synechiae, anterior subcapsular lens opacities (glaukomflecken), sector iris atrophy, an irregular pupil, and a narrow angle in the contralateral eye. 

During an eye examination at the hospital, it was found that Rob s IOP was above the normal range in the left eye (33 mmHg) and in the right eye was slightly increased (21.5 mmHg). In addition, it was found that the angle between his cornea and iris was very narrow this was worse in the left eye, where the pupil was dilated. Rob confirmed that eye problems are common in his mum s family. 

Figure 5-1 Example of informed consent document for dilation of the pupil when the patient has a narrow anterior chamber angle.

Dilation of the pupil in the preexisting narrow anterior chamber may cause the iris to block aqueous humor outflow via the anterior chamber. This leads to an abrupt increase in lOP, resulting in an acute attack of angle-closure glaucoma. Signs and symptoms include blurred vision (often with colored halos around the light), severe ocular pain, red conjunctiva, diaphoresis, and nausea/vomiting. The cornea may appear cloudy due to edema. Upon presentation, the lOP is frequently above 50 mm Hg. 

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