EyeWorld Asia-Pacific December 2015 Issue

December 2015 8 EWAP FEATURE The Event Horizon - Complex cataract surgery by Chiles Aedam R. Samaniego EyeWorld Asia-Pacific Senior Staff Writer The Combined Symposium of Cataract and Refractive Societies (CSCRS) tackles complex cataract surgery at the 28th APACRS annual meeting in Kuala Lumpur I mmediate past president of APACRS Graham Barrett, MD , Perth, Australia, has called the Combined Symposium of Cataract and Refractive Societies (CSCRS) the society’s “landmark symposium.” Beginning 10 years ago in Beijing, the symposium has been held at the respective annual meetings of the APACRS’s sister societies—the American Society of Cataract and Refractive Surgery (ASCRS), the European Society of Cataract and Refractive Surgeons (ESCRS) and the Latin American Society of Cataract and Refractive Surgery (ALACCSA). At the 28th APACRS annual meeting held in Kuala Lumpur last August, experts representing the participating societies APACRS, ASCRS, and ESCRS took on the management of dreaded complications that are “event horizons” in cataract surgery. In general relativity, an event horizon is a boundary in spacetime popularly associated with black holes, beyond which the gravitational pull is so great that escape is impossible. Similarly, the complications discussed at the symposium represent potential points of no return for cataract surgeons beyond which visual outcomes, even the eye itself, may be unsalvageable—unless they are identified and dealt with appropriately. Fluid misdirection syndrome “I thought I knew something about fluid misdirection when I was asked to speak on this topic,” Chee Soon Phaik, MD , Singapore, said at the symposium. “When I searched the literature there’s a paucity of information that has been published.” Dr. Chee said the syndrome is best described as “the sudden, dramatic, and persistent shallowing of the anterior chamber in the absence of choroidal hemorrhage or external pressure on the eye and usually occurs during the irrigation/aspiration [I/A] step of phacoemulsification or irrigation of the posterior capsule during cataract surgery.” “It is not that different from misdirection of the aqueous except that that does not occur during the time of surgery,” Dr. Chee added. “This does.” The pathophysiology “really is not clear,” she said. Richard Mackool, MD, postulated that fluid could accumulate in the potential space between the posterior capsule and anterior vitreous. 1 He suggested that the fluid could travel through a peripheral posterior capsular rupture or weak zonules, accumulating in Berger’s space to push the posterior capsule forward. Dr. Mackool also coined the term “infusion misdirection syndrome.” More recently, Oliver Lau, MD, and colleagues published a report in the Journal of Cataract and Refractive Surgery describing a similar phenomenon they called “acute intraoperative rock-hard eye syndrome.” 2 The authors, Dr. Chee said, “saw acute anterior chamber shallowing and a rock-hard eye in the absence of choroidal hemorrhage or effusion.” “This happened very quickly over a few seconds that made them think that this was slightly different from infusion misdirection syndrome,” she said. The authors further reported that the anterior chamber shallowing occurred during irrigation, when fluid was introduced at very high speed with a 27-gauge cannula. Dr. Chee believes this fluid could have travelled through minor zonular defects to collect in the potential space behind the posterior capsule. One thing she found interesting in the literature was a 2009 Archives of Ophthalmology study investigating the effect of phaco and aspiration at different settings on the posterior chamber–anterior hyaloid membrane barrier of enucleated porcine eyes. 3 In this study, Shiro Kawasaki, MD, and colleagues found that prolonged irrigation and inflation and deflation of the anterior chamber were risk factors for anterior hyaloid membrane detachment, while the use of 27-gauge hydrodissection was a risk factor for anterior hyaloid membrane tear, causing separation and allowing fluid into Berger’s space. Going further back, Tomohiro Ikeda, MD, and colleagues published a paper in 1999 in which they attempted to surgically separate the posterior capsule from the anterior hyaloid membrane without risking rupture or damage. 4 They were able to do so by injecting