Optimizing the Treatment of Acute Angle Closure Glaucoma
Dr. Nathan M. Radcliffe
Primary acute angle closure glaucoma (AACG) is a challenging and serious glaucoma emergency. It is worth taking a moment to review a few tips for success. I have come up with five key strategies, compiled from cases referred to me by my residents and colleagues over the years.
1. Confirm the diagnosis. While a typical primary acute angle closure patient would be elderly and hyperopic, life is full of surprises. Ultrasound biomicroscopy can be helpful for imaging through an edematous cornea, but I also find standard ophthalmic biometry to be helpful. A thick lens, a short axial length, and a shallow anterior chamber are consistent with AACG, and a long eye or a deep anterior chamber should prompt consideration of alternative scenarios.
2. Don't rush to laser. While the placement of a peripheral laser iridotomy may ultimately be the treatment that resolves the attack, laser iridotomy in the presence of corneal edema is suboptimal for the iris, the cornea, and the glaucoma. Too much energy is often needed, too much inflammation may result, and the iridotomy is sometimes made too centrally (due to the mid-dilated pupil). Of course, in many cases medical therapy does not work and the laser is the only way to break the attack.
3. Maximize medical therapy. When faced with AACG, prompt and aggressive medical treatment is ideal. For me, this includes oral acetazolamide (standard tablets), a topical carbonic anhydrase inhibitor, an alpha agonist, a beta blocker and, of course, a prostaglandin analogue. I am surprised how often the latter class is omitted for fear of worsening inflammation or due to concerns that it will not work quickly enough. A single drop of pilocarpine, with careful assessment of its effects on IOP and anatomy, can be utilized. Intravenous mannitol may be used if the initial efforts are not efficacious.
4. Don't forget about the cornea. In AACG, the cornea is initially edematous because of an elevated IOP, but the cornea was likely weak prior to the attack from years of iridotrabecular contact injuring the endothelium. It may be worthwhile to assess the endothelial count in both eyes and to keep corneal health top of mind moving forward.
5. Don't forget about the other eye. In the cases where I do perform a laser iridotomy upon initially seeing a patient with acute angle closure glaucoma, I am usually treating the fellow eye, to prevent the next attack.
In summary, AACG may be challenging, but prompt, aggressive management may preserve vision in both eyes.
Dr. Nathan M. Radcliffe is the director of the glaucoma service and a clinical assistant professor at New York Univeristy Langone Ophthalmology Associates and is a cataract and glaucoma surgeon at the New York Eye Surgery Center.