Eyeworld

EW NEWS & OPINION 25 clear elements. There is no question in my mind that careful attention to detail in proceeding with nucleus re- moval can minimize any endothelial damage. Corneal rejection It is controversial whether cataract surgery increases the risk of corneal rejection. Those of us who have been involved with corneal trans- plantation for a long period of time have seen enough cases of rejection soon after cataract surgery to be sus- picious that something about the cataract surgery increases the risk of this type of immune response. In cases of penetrating keratoplasty, I start steroids, like prednisolone ac- etate 1%, four times a day, 48 hours before surgery, and I normally taper these patients off steroids at about 4 weeks. I maintain steroids twice a day up to 2 months after surgery be- fore taking them off the regimen. Clearly, this means that intraocular pressure needs to be watched a little more carefully. I tend not to use non-steroidal anti-inflammatories because they can be very hard on the corneal epithelium after surgery in penetrating keratoplasty and deep lamellar keratoplasty patients. How- ever, in cases where there is concern or there is higher risk for cystoid macular edema, the careful use of non-steroidals topically makes sense, but watch very carefully for any ep- itheliopathy. Patients with only en- dothelial replacement are routinely put on non-steroidal anti-inflamma- tory drops without any unusual con- cern. Dealing with pre-op astigmatism Many of these patients have signifi- cant amounts of regular and irregu- lar astigmatism as well as significant other refractive error. Doing cataract surgery in cases with a previous pen- etrating keratoplasty is a chance for the surgeon to be a real hero. Not only can refractive error itself be cor- rected, we also have excellent means of working on the astigmatism. I consider this as important as the cataract surgery itself. Toric intraocular lenses certainly are helpful, but often the amount of astigmatism, particularly on topog- raphy, is quite high. I have found, with a system put together by Doug Mastel (Mastel Precision, Rapid City, S.D.), for all cases of topographic cylinder greater than 4.00 D that I make partial thickness incisions, usually at 90 degrees of the corneal depth just inside of the original graft incisions, centered on the axis of steepest astigmatism with a 60-de- gree long incision. I then look at the result with a handheld surgical ker- atometer designed by Mastel (Figure 1). This is repeated, centered on the opposite steep incision (look at the topography carefully and note the opposite hemimeridian is often not orthogonal, so follow the true axis and do not just go 180 degrees away from the first incision). The hand- held surgical keratometer findings are followed to increase either inci- sion length, always leaving at least 90 degrees between opposing inci- sions. If I still have not been able to create a spherical cornea, I add lim- bal relaxing incisions, which are much more effective than they are in regular cataract surgery. In fact they are very effective alone for ker- atoplasty-induced astigmatism up to 4.00 D, and I titrate these incisions as well by doing just 30 degrees at a time and looking at the effect with the surgical keratometer until at the end of all incision placements the corneal astigmatism looks slightly overcorrected. This combination of procedures can often decrease 7, 8, and even more diopters of astigmatism down to less than one, and with a good re- fractive correction can make the sur- geon a hero. Taking someone from –9.50 + 8.50 x at 140 degrees to 20/20 uncorrected is a real kick. This approach also seems to be able to decrease irregular cylinder at the same time (this approach must be relieving some irregular incisional contraction forces). Wound closure Where clear corneal surgery is my usual approach in essentially all cases, I have found that after corneal transplantation, and specifically in cases of keratoconus, these clear corneal incisions do frequently open, and this is one of the few times I have seen an open fish mouth incision the day after surgery. For this reason I generally will place a suture in all of these incisions and carefully check even the side port in- cision for leakage, which often will not seal as well and can require an additional suture. This is where the peripheral cornea is very thin with pellucid type changes, which are quite common after long-standing grafts for keratoconus. Furthermore, with an endothe- lium that is often marginal, a flat anterior chamber is not well toler- ated and the risk of endophthalmitis goes up 44 times. 2 Make sure when you finish these cases you know the incisions are tight and sealed. I take the suture out with a well-closed in- cision in a week, and where inci- sions might cause concern (i.e., very thin tissue), I wait 6 weeks before these sutures are removed. Even at 6 weeks I have had one incision leak after suture removal where the cornea was quite thin and I had to promptly replace a suture. If in doubt, wait longer. In summary, careful attention to detail can make cataract surgery in cases of penetrating keratoplasty un- complicated and extremely satisfy- ing for the surgeon and the patient. A few details are important to con- sider with these patients to see that the graft survives, and there is an optimal overall visual recovery as well. EW References 1. Craig M, Olson R, Mamalis N, Olson R. Air bubble endothelial damage during pha- coemulsification in human eye bank eyes: the protective effects of Healon and Viscoat. J Cataract Refract Surg 1990;16:597-602. 2. Wallin T, Parker J, Jin Y, Kefalopoulis G, Olson R. Cohort study of 27 cases of endoph- thalmitis at a single institution. J Cataract Refract Surg 2005;31:735-741. Editors' note: Dr. Olson has no finan- cial interests related to his comments. Contact information Olson: 801-581-2352, randall.olson@hsc.utah.edu September 2011 Research center turns cornea donations into cutting-edge science T his month, as part of its efforts to ed- ucate the commu- nity about the positive impact of organ dona- tion and to help give the gift of sight, the Tampa Lions Eye Insti- tute for Transplant and Research Inc. (LEITR) will host its annual Eye Ball Gala. The evening will include speeches by the mother of for- mer Cincinnati Ben- gals football player and organ donor Chris Henry and by this year's Light of Sight award recipient Florida State Senator Steve Oelrich. The nonprofit LEITR collaborates with researchers in academia, gov- ernment, and industry to explore the causes of ocular diseases, spur inno- vation, and speed therapeutic advances. With the world's largest eye bank and a first-of-its-kind, 12,000-square-foot research facility, LEITR is uniquely positioned to provide access to high-volume, high-quality human ocular tissue for research. The facility includes labs and sleeping quarters for round-the-clock studies. Researchers may obtain whole globes, corneas, lenses, sclera, reti- nas/RPE, trabecular meshwork, optic nerves, endothelial cells, and other tissues from healthy or diseased eyes. "Conducting research at LEITR greatly reduces the post-mortem time interval, contributing to better sci- ence," says Jason Woody, president and CEO. To learn more about the In- stitute and its research opportunities, visit www.lionseyeinstitute.org.

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