Sector dilation

The clinical use of pledgets is usually reserved for administration of mydriatic solutions such as phenylephrine. This method of drug delivery allows maximum mydriasis in attempts to break posterior synechiae or dilate sluggish pupils. Mydriasis of the inferior pupillary quadrant for intentional sector dilation of the pupil can also be achieved (see Chapter 20). 

Figure 20-8 Vertically oval pupil produced by sector dilation.

Figure 20-9 Sector dilation technique using cotton-tipped applicator held at inferior limbus. Phenylephrine-moistened swab is applied for approximately 20 seconds.

Locke LC, Meetz R. Sector pupillary dilation an alternative technique. Optom Vis Sci 1990 67 291-296. 

If, however, the patient exhibits only a unilateral fixed and dilated pupil without evidence of ptosis or extraocular muscle involvement, the clinician should perform the pilocarpine test, first using a 0.125% solution to reveal any cholinergic hypersensitivity as evidence for Adie s pupil. If there is no local iris damage by slit-lamp examination, no sector palsy of the iris sphincter, and no cholinergic hypersensitivity demonstrated by the 0.125% pilocarpine test, then the condition might be associated with interruption of the preganglionic innervation to the iris sphincter (i.e., third-nerve palsy). If the patient has third-nerve palsy, topically instilled pilocarpine in moderate concentrations activates the muscarinic receptor sites on the iris sphincter. Therefore if 0.125% pilocarpine reveals no cholinergic hypersensitivity, the practitioner... 

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. 

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