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37 EW GLAUCOMA November 2018 by Stefanie Petrou Binder, MD, EyeWorld Contributing Writer "Whatever the cause, the final common pathway is a vicious cycle of the transvitreal pressure increas- ing, poor conductivity of the vitre- ous that creates a ciliary blockage and trapping of aqueous humor, which leads to a shallowing of the anterior chamber and an increase in IOP, which will further aggravate the vicious cycle. The aim of any treat- ment is to break the vicious cycle and restore normal aqueous flow," Dr. Fekih explained. Second hurdle: Treatment Medical therapy, laser therapy, and surgical management are all options for the treatment of malignant glaucoma. The medical approach includes mydriatic and cycloplegic agents to relax the ciliary muscle and tighten the lens zonules, giving a posterior push to the iris and crys- talline lens diaphragms. Dr. Fekih combines this with acetazolamide, topical beta blockers, and osmotic agents to reduce the production of aqueous and the vitreous volume. This can help to deepen the anterior chamber and possibly increase vitre- ous permeability. She recommends this treatment be tried for 3–5 days before turning to other alternatives. Laser therapy is the second line of treatment. Nd:YAG laser is used to rupture the posterior capsule and the anterior hyaloid membrane, in both pseudophakic and phakic eyes. This releases the trapped aqueous from the vitreous and allows it to resume movement between the posterior and anterior segments. Dr. Fekih also lasers the ciliary processes with transpupillary argon laser pho- tocoagulation and cyclocryotherapy. Transscleral cyclodiode lasers help to eliminate vitreous blockage by al- lowing the posterior rotation of the ciliary process, however, by shrink- ing the ciliary process it can also induce aqueous humor production, she noted. The surgical approach involves an anterior vitrectomy, phacoemul- sification, and an iridectomy/hyaloi- do/zonulectomy, in both phakic and pseudophakic eyes with malignant glaucoma, which has been met with known to occur in eyes with axial hyperopia, nanophthalmos, plateau iris configuration, and is usually encountered after glaucoma surgery for primary angle closure glaucoma (PACG). Other associations have been post-laser treatment, cataract surgery or penetrating keratoplas- ty, trabeculectomy bleb needling, spontaneously by way of infection, retinal vein occlusion, or retinop- athy of prematurity. Many cases of malignant glaucoma are associated with the fellow eye. "Often there is a rise in IOP," Dr. Fekih explained. "The diagno- sis can include: flattening of the anterior chamber, iridocorneal touch, appositional angle closure, and apposition of the iris. The patient examination can be diffi- cult especially when doing UBM or anterior segment OCT, which is used for diagnosis and for treat- ment monitoring. These imaging techniques allow us to explore the structures surrounding the posterior chamber and visualize the anterior rotation of the ciliary body that is characteristic of this pathology, which is helpful for the differential diagnosis. There are three entities that should be ruled out: pupillary block, suprachoroidal hemorrhage, and choroid effusion. Once the diagnosis is made, it is important to understand the mechanism of malignant glaucoma because we are not talking about one disease but a multifactorial condition. The exact etiology, however, has not yet been understood," she said. Three mechanisms have been proposed in the etiology of malig- nant glaucoma. One theory propos- es that aqueous humor is directed posteriorly into the posterior seg- ment. The diversion of aqueous flow into the posterior segment comes from an abnormal relationship between the ciliary body process, lens, and anterior vitreous. 1 Another theory attributes the forward lens movement seen in this condition to laxity of the lens zonules. A final notion rejects the idea of aqueous misdirection and proposes that cho- roidal expansion is the trigger that increases vitreous pressure and leads to the shallowing of the anterior chamber. In a presentation given at the 2018 World Ophthalmology Con- gress, Oifa Fekih, MD, Glaucoma Center, Tunis, Tunisia, shared her expertise on this rare complica- tion, seen in 0.4–6% of glaucoma patients. "The European Glaucoma Society defines malignant glaucoma as secondary angle closure glaucoma with a posterior pushing mecha- nism caused by the forward rotation of the ciliary body and iris. It is a challenging problem when encoun- tered," she said. First hurdle: Diagnosis According to Dr. Fekih, the first step in the management of this pathol- ogy is making an empiric diagno- sis. Malignant glaucoma has been Thorough patient screening and timely intervention are critical to avoid malignant glaucoma M alignant glaucoma is described as a condi- tion characterized by elevated or normal IOP with a shallowing or flattening of the central and periph- eral parts of the anterior chamber (AC), usually occurring after ocular surgery, in eyes without pupillary block or posterior segment pathol- ogy. It has also been referred to as aqueous misdirection, ciliary block glaucoma, and lens block angle closure. Diagnostic and therapeutic challenge: malignant glaucoma Presentation spotlight continued on page 38 Like EyeWorld on Facebook facebook.com/EyeWorldMagazine Follow EyeWorld on Twitter twitter.com/EWNews Follow EyeWorld on Instagram eyeworldnews Find EyeWorld on social media

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