EyeWorld Asia-Pacific December 2015 Issue

December 2015 9 EWAP FEATURE BSS through a 27-gauge cannula. “I’ve done cataract surgery for many years now and my personal observations are that I’ve had similar cases whenever I had an incomplete or ineffective hydrodissection,” Dr. Chee said. “If I’ve tried many times but was not able to achieve a beautiful fluid wave and subsequently had some difficulty rotating the nucleus, I’ve seen some fluid go into just that space…just behind the posterior capsule.” In one such case, Dr. Chee decided to manage the fluid misdirection by aspirating the collection of fluid by going through the pars plana. However, she cautioned, “you don’t want to aspirate too much either…sometimes I put my finger to the eye to take note of how much I’ve removed, so the eye is not too soft.” Straightaway, she said, the anterior chamber deepened. Fluid misdirection might be prevented by performing gentle hydrodissection—perhaps avoiding a 27-gauge cannula—but in any case must be recognized early. In severe cases, a choroidal hemorrhage must be ruled out, but once the diagnosis is certain, the surgeon can proceed with a pars plana needle aspiration or even use a vitrector to remove the fluid. “Be on the alert in high-risk eyes, especially those with weak zonules,” she added. “You probably don’t experience it so much because you’re so quick,” Dr. Barrett said, referring to Dr. Chee’s vast experience as a cataract surgeon at SNEC. “I think time really is a factor as well.” Although Dr. Chee focused on the syndrome as seen intraoperatively, Clara Chan, MD , Toronto, who chaired the symposium together with Dr. Barrett and Roberto Bellucci, MD , president, ESCRS, said they sometimes saw “pressurized” eyes 2 hours postoperatively. “There was really no true explanation, and aqueous misdirection was one thought,” Dr. Chan said. “Would you tap right there, at the slitlamp? … We just manage medically, and send the patient to a glaucoma specialist.” “If you can just tide over with glaucoma medication, I think that would be safer than reducing the aqueous because the anterior chamber may already be a little shallow,” Dr. Chee said. “You don’t really want to have that lens popping out of the rhexis as well.” Dr. Bellucci believes that the syndrome occurs much more frequently than surgeons might think. Injecting triamcinolone with BSS in uncomplicated cataract surgeries, Dr. Bellucci said he found triamcinolone behind the posterior capsule in 7 out of 10 eyes. “I think this is something that happens almost in every surgery and is probably one explanation why vitreous floaters increase with cataract surgery in many of our patients,” he said. Descemet’s detachment “When we do cataract surgery…we basically go through the whole cornea,” said Thomas Kohnen, MD, PhD, FEBO , Frankfurt. “We’re coming through this procedure to Descemet’s membrane.” Prof. Kohnen discussed Descemet’s membrane detachment, an event horizon in cataract surgery that Dr. Barrett said creates a “terrible feeling of impending doom” in surgeons when it happens. “Descemet’s membrane detachment can be a major complication in cataract surgery,” Prof. Kohnen said. “It causes persistent corneal edema…and this causes a decrease in visual acuity.” Prof. Kohnen believes that one of the most important steps in the prevention of Descemet’s membrane detachment is the careful observation of the inner lip at every step of the procedure. He also recommended enlarging incisions using a sharp metal or diamond knife. He presented scanning electron microscopy pictures illustrating the effect of IOL implantation on the incision. Older, larger incisions about 3.0–3.5 mm, he said, presented no problem, but as we reduce incision size to minimize surgically induced astigmatism, creating 2.0-, 2.5-mm incisions, tears may begin to appear in the Descemet’s membrane during IOL insertion. Descemet’s membrane detachment can also be caused by the injection of viscoelastic material into the cornea, causing dissection of the cornea at the membrane. If this occurs, the agent needs to be removed with a blunt cannula. Should detachment occur, the Descemet’s membrane can be repositioned intraoperatively by injecting different agents such as air, BSS, gas, or even viscoelastic material. Usually, with visually significant Descemet’s detachment seen postoperatively, Prof. Kohnen intervenes 2 to 3 weeks later because literature describes the possibility of late, spontaneous reattachment. At this time, he said, reattachment can be performed at the slitlamp. After several drops of anesthesia and prophylactic antibiotics, a paracentesis is inserted infratemporally and a 27- to 30-gauge cannula attached to a syringe can be used to fill the anterior chamber with air or gas. Treatment also occasionally requires sutures. This, Prof. Kohnen said, is a rare indication, particularly as surgeons’ experience grows with newer endothelial keratoplasty techniques. Today, while Descemet’s detachment can still be a major postoperative complication, and even as Prof. Kohnen provided immunohistochemistry images demonstrating Descemet’s detachment, he said that various topography and tomography devices such as Scheimpflug systems and OCTs provide an opportunity to look at the condition immediately in the postoperative period—perhaps even checking the state of the Descemet’s membrane intraoperatively. One pearl that Dr. Chan said she shares with her residents for preventing Descemet’s membrane detachment is to ensure that the anterior chamber is fully inflated before hydrating the wounds. “One of the risks of it happening is at the time of hydrating,” she said. “If you have a shallow AC, then the flow actually shears through the Descemet’s as continued on page 10