EyeWorld Asia-Pacific September 2011 Issue

49 EW CORNEA September 2011 Surgeons are able to perform surgery earlier in the progression of the disease, and newer techniques may offer visual outcomes comparable to full-thickness transplants P atients with Fuchs’ dystrophy present some additional challenges for corneal surgeons—the disease is more slowly progressive than other corneal diseases (such as edema from trauma or herpes simplex virus), Descemet’s membrane is typically thicker than in patients without Fuchs’, patients have significant guttata, and, in general, the location of the portion of the cornea most affected and needing replacement is different from those without Fuchs’. “These are patients who are slowly losing their vision, and the timing of when to perform a transplant is variable from patient to patient,” said Mark A. Terry, MD, director of corneal services, Devers Eye Institute, and professor of clinical ophthalmology, Oregon Health & Science University, Portland, Ore., USA. Some patients want to undergo surgery as soon as vision begins deteriorating, while others prefer to wait until their vision has been severely impacted, he said. “Treating Fuchs’ was no different than treating other corneal disorders until endothelial keratoplasty (EK) came along, which made it much easier,” said David T. Vroman, MD, medical director, Lifepoint Ocular Division, Charleston, SC, USA, and founder, Carolina Cataract & Laser Center, Ladson, SC, USA. The first of the EK procedures, deep lamellar EK (DLEK), evolved to the currently Endothelial keratoplasty preferred choice for Fuchs’ dystrophy by Michelle Dalton EyeWorld Contributing Editor Slit lamp photo with side illumination showing the mid-peripheral cornea in a patient with Fuchs’ dystrophy after treatment with DMEK. The central cornea (area 1) is clear and the donor Descemet’s membrane and endothelium have replaced those of the recipient. At the graft periphery, donor and recipient Descemet’s membranes overlap (area 2). The edge of the stripped recipient Descemet’s membrane is scalloped while the edge of the DMEK graft just to the right is smooth and circular. Area 3 is the recipient Descemet’s membrane beyond the edge of the graft DSAEK air bubble Source: Marianne Price, PhD used Descemet’s stripping automated EK (DSAEK), which is a partial-thickness technique that replaces only the inner endothelial cell layer. A newer technique, Descemet’s membrane EK (DMEK), is based on the idea that stromal dissection is an extraneous step and leaves the patient’s cornea closer to its original condition than other techniques. “I used to give patients the option between penetrating keratoplasty (PK) and the newer techniques,” said Francis W. Price Jr., MD, founder, PriceVision Group, Indianapolis, Ind., USA. “But after performing DSEK for a month, I realized it was so much better than PK, and I stopped giving patients the option. I’d still tell them about PK, but I’d explain why they probably wouldn’t want it.” One disadvantage is that PK wounds do not heal well. Even 10 to 15 years after the initial surgery, if someone falls or bumps the eye, “the wound can break open, creating a superchoroidal hemorrhage,” Dr. Price said. “With the EK procedure, we finally had a selective transplant for patients who specifically have endothelial dysfunction,” Dr. Vroman said. “The bulk of endothelial dysfunction in this country is Fuchs’ dystrophy.” Patients with Fuchs’ have a better prognosis post-surgery when compared to most graft patients, said Woodford Van Meter, MD, professor of ophthalmology, Kentucky School of Medicine, Lexington, Ky., USA. “Outcomes are not as good for those with Fuchs’ as for those with keratoconus, but they are much better than those with corneal scarring,” he said. In his experience, patients with Fuchs’ dystrophy “liked the EK results better than the PK results with one or two exceptions”. Benefits of EK include the ability to avoid a considerable amount of astigmatism and a much faster rehabilitation time; the downside is vision may not be as sharp as AT A GLANCE • Endothelial keratoplasty has become the procedure of choice for Fuchs’ dystrophy • Cell loss hovers around 30% at year 1, but seems to stabilize over 3 to 5 years • DMEK may result in better visual outcomes, but has numerous obstacles to overcome before it’s easily reproducible • Eye banks will play a large role in how readily DMEK procedures are accepted continued on page 50