The hallmark signs of angle closure include significantly elevated intraocular pressure, a closed angle upon gonioscopic evaluation, deep conjunctival and episcleral injection in a circumlimbal fashion, and a fixed, mid-dilated pupil. Applanation tonometry may reveal IOP in the range of 30 to 60mm Hg, or even higher in some cases. Gonioscopy, which may prove difficult because of microcystic corneal edema, reveals no visible angle structures without indentation.
Several mechanisms are possible.
The most common etiology of angle closure is pupillary block, whereby the flow of aqueous from the posterior to anterior chamber is inhibited, causing iris bomb . The paramount concern in managing an angle closure attack is to lower IOP quickly. Your choice of primary medication depends upon the pressure at presentation. Next, perform corneal compression with a gonioprism to aid in lowering the IOP by forcing aqueous into the trabeculum and temporarily opening the angle. It may be necessary to use topical glycerin to clear the cornea if there is significant edema.