Eyeworld

EW FEATURE 56 Complicated glaucoma surgery management • November 2016 "There's a high incidence of com- plications with nanophthalmos because the sclera is thick and you can have choroidal effusion," she said, adding that the presence of complications decreases with scleral cut-downs. Another way to decrease such choroidal effusions after cat- aract surgery is to avoid hypotony during and after surgery. "In most cataract surgery patients, I do not put a stitch in, but in nanophthal- mic eyes, I always put in a suture," Dr. Al-Aswad said. Likewise, Dr. Crandall changes his cataract plan depending upon the issue causing the shallow cham- ber. If it's related to pseudoexfolia- tion, he emphasized the importance of performing zonular-friendly cataract surgery. With natural hyperopes, Dr. Crandall stressed the need to take a protective approach. "I'll frequently refill with a dispersive viscoelastic to protect the cornea. Also, I do as much of the nuclear disassembly inside the bag as possible," he said. "One of the approaches that I like is pre-chopping because I can break the lens into four quadrants so that there's room to disassemble the rest of the pieces while it's still in the bag." He cited an approach by Jim Davidson, MD, Des Moines, Iowa. This involves shaving down the cor- ners of the quadrant so that there's room to disassemble the rest of the pieces while it's still inside the bag. Dr. Crandall avoids any techniques like phaco-flip that involve bringing the lens up into the anterior cham- ber. "I try to do as much as I can far away from the cornea," he said. In these small eyes, it is import- ant to be cognizant of malignant glaucoma. Dr. Crandall has seen this occur both intraoperatively and postoperatively. "These patients are also more at risk for having spon- taneous misdirection without any surgery," Dr. Crandall said. With a case of malignant glau- coma, Dr. Crandall checks to see how severe it is to determine how to best handle this. "If it's mild, usually you can refill the viscoelastic and finish the procedure," he said, adding that if it's more severe, the easiest thing is to suture the wound and send the patient to recovery for 20 or 30 minutes. When you resume the surgery, the issues tend to be resolved. "I've never seen a good explanation for why that's the case, but I've done it a few times," Dr. Crandall said. "By closing the wound, there is no more fluid going through the eye, and it seems when you get back in to clear up." It's as though you're giving the eye a break to reset itself and then it seems to behave fine, he observed. There can also be issues in selecting the right lenses in these patients. Very high powers can be required especially in the nanoph- thalmic eyes, Dr. Crandall finds. "I usually prefer to special order a lens in a high power rather than doing a piggyback because these eyes are already a bit small," he said. "If you piggyback lenses in the sulcus long term, a lot of them tend to run into angle closures later or iris transillu- mination defects and other prob- lems." Dr. Al-Aswad said that if sur- geons do piggyback lenses, they might want to use two different types. "You never want to piggyback the same type of lens," she said, adding that it isn't favored, and with two acrylic IOLs in the capsular bag, there is more interlenticular opaci- fication. In general, use of a silicone sulcus piggyback IOL is recommend- ed to prevent the development of interlenticular opacification. Dr. Al-Aswad emphasized the need for accurate measurements here. "Even minor errors in measure- ments can lead to major refractive errors afterward," she said. "Most of us will use the Hoffer Q and the Holladay IOL Consultant [Holladay Consulting, Bellaire, Texas] for deter- mining IOL power." Overall, when handling these shallow eyes, Dr. Al-Aswad stressed the importance of identifying the situation and dealing with it appro- priately. "I usually prepare for the worst and hope for the best. That's my motto," she concluded. EW Editors' note: Drs. Al-Aswad and Crandall have no financial interests related to their comments. Contact information Al-Aswad: laa2003@cumc.columbia.edu Crandall: dackakarot@hotmail.com more," Dr. Al-Aswad said. "Then I can do the cataract the way I usually do it." She finds the chop technique has the most effect in these situa- tions, but acknowledges that some surgeons might prefer divide and conquer. Another approach may be to give an osmotic agent to dehydrate the vitreous and deepen the anterior chamber. "That can help deepen the anterior chamber, decrease the posterior pressure, and protect against corneal decompensation," Dr. Al-Aswad said. In cases where the chamber is extremely shallow, a dry pars plana vitrectomy may be warranted. This, however, can be tricky for an ante- rior surgeon, Dr. Al-Aswad said. "I wouldn't do it in a nanophthalmic eye because it's hard to estimate where the pars plana is and may cause a retinal detachment," she said, adding that she would have a retinal specialist help with that. Altering cataract plans When the chamber is shallow, it is necessary to alter the cataract removal plans, Dr. Al-Aswad finds. "I might want to protect the eye with viscoelastic to protect the cornea," she said. "I might also make my wound a bit longer, and some- times that can deepen the anterior chamber." In very small eyes, Dr. Al-Aswad may do a scleral cut-down to decrease the complications of choroidal effusions or hemorrhages. In a tight continued from page 55 A shallow angle in a patient with high hyperopia A hyperopic patient with a large, mature lens Source (all): David Crandall, MD

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