26 EWAP DECEMBER 2023 FEATURE Malignant glaucoma is a rare but serious complication of anterior segment surgery, characterized by uniform shallowness of the anterior chamber with elevated intraocular pressure. This syndrome has been described under different names, including ciliary block glaucoma, aqueous misdirection syndrome, infusion misdirection syndrome, and fluid misdirection syndrome. 1 The exact pathophysiology of this syndrome has not been fully elucidated. According to the classical theory, the vitreous body becomes hydrated by the misdirection of aqueous humor, or infused balanced salt solution at the time of cataract surgery, which results in anterior displacement of the lens-iris diaphragm and subsequent collapse of the anterior chamber. 1 Another etiological hypothesis proposed by Quigley and associates is choroidal expansion, which leading to compression of the vitreous body and forward displacement of the lens-iris diaphragm without actual misdirection of fluid. 2 However, we believe that the misdirection of fluid is existing as the posterior chamber-anterior hyaloid membrane barrier impairment and distribution of fluid into the vitreous cavity during phacoemulsification has been described. 3, 4 Despite different theories on etiology for malignant glaucoma, it is now being widely accepted that the most important factor in the successful management of this syndrome is disrupting the anterior hyaloid face, debulking the vitreous body, and reestablishing the posteroanterior aqueous communication. 5 We appreciate the point raised by Dr. Aboobakar that surgical interventions are the main effective treatments for malignant glaucoma. Although medical and laser modalities can help partially or completely stabilize malignant glaucoma, their effects are mostly temporary and limited. Finally, as Dr. Schlenker stated, we agree that any manipulation in the eye, even phacoemulsification, in association with other risk factors, can led to malignant glaucoma. In our eye center, most cataract surgeons have occasionally experienced the condition of acute anterior chamber shallowing and marked increase of intraocular pressure in the absence of choroidal effusion or hemorrhage. It usually occurs toward the end of irrigation/aspiration during phacoemulsification. We suggested that it involves the movement of the balanced salt solution via the zonular fibers posteriorly into the vitreous cavity, a process described as acute aqueous misdirection syndrome. 6 Our strategy to manage these situations is as follows: (1) Make sure there is no evidence of choroidal effusion or hemorrhage, (2) OVD injection to the anterior chamber, (3) 20% mannitol rapid intravenous drip, (4) Cortex aspiration and IOL implantation after pars plana decompression of vitrectomy. However, my experience showed OVD or mannitol usually doesn’t work or limited role, and the anterior vitrectomy can solve the problem. References 1. Grzybowski A, Kanclerz P. Acute and chronic fluid misdirection syndrome: pathophysiology and treatment. Graefes Arch Clin Exp Ophthalmol. 2018;256(1):135-54. 2. Quigley HA. Angle-closure glaucoma-simpler answers to complex mechanisms: LXVI Edward Jackson Memorial Lecture. Am J Ophthalmol. 2009;148(5):657-69 e1. 3. Kawasaki S, et al. Influence of elevated intraocular pressure on the posterior chamber-anterior hyaloid membrane barrier during cataract operations. Arch Ophthalmol. 2011;129(6):751-7. 4. Kawasaki S, et al. Disruption of the posterior chamber-anterior hyaloid membrane barrier during phacoemulsification and aspiration as revealed by contrast-enhanced magnetic resonance imaging. Arch Ophthalmol. 2009;127(4):465-70. 5. Thompson AC, et al. Factors Impacting Outcomes and the Time to Recovery From Malignant Glaucoma. Am J Ophthalmol. 2020;209:141-50. 6. Grzybowski A, Prasad S. Acute aqueous misdirection syndrome: Pathophysiology and management. J Cataract Refract Surg. 2014;40(12):2167. Editors’ note: Prof. Yao disclosed no relevant financial interests. Yao Ke, MD Chief & Professor, Zhejiang University Eye Hospital Eye Center, Second Affiliated Hospital of Zhejiang University School of Medicine 1 Xihu Blvd., Hangzhou China xlren@zju.edu.cn ASIA-PACIFIC PERSPECTIVES
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