EyeWorld Asia-Pacific March 2018 Issue

March 2018 EWAP FEATURE 13 Ultra-thin option Dr. Shamie said the surgical technique is easier with ultra-thin DSAEK but that the vision qual- ity and optimal vision may still be better with DMEK in certain patients. “I would suggest having all of these techniques in one’s arma- mentarium to be able to custom- ize the treatment to the patient's condition and visual needs,” Dr. Shamie said. The current data suggest that ultra-thin DSAEK is better than DSAEK, Dr. Deng said, but there is not enough data to compare the procedures directly. Both procedures deliver excel- lent BCVA, Dr. Shah said. For his ultra-thin DSAEK cases, Dr. Shah requests tissue of 40–70 microns. “My DMEK patients have a higher chance of achieving 20/20 BCVA compared to ultra-thin DSAEK,” Dr. Shah said. “Also, because of thinner tissue in DMEK, I am seeing a slightly lower rejec- tion rate with DMEK. But again, we need larger studies that evaluate the role of ultra-thin graft thick- ness with rejection and BCVA.” The ideal candidates for DMEK over ultra-thin DSAEK are patients who have a premium IOL. “DMEK works great with toric IOLs and results in a smaller hyper- opic shift compared to ultra-thin DSAEK,” Dr. Shah said. Patient communication Patient discussions about the dif- ferent forms of EK should include the surgeon’s experience with DSAEK and DMEK, Dr. Deng said. “The surgeon should inform the patient that DMEK appears to have better visual outcomes but the air injection rate is higher in the early learning curve,” Dr. Deng said. “My experience is that as long as patients understand the risks and benefit of each procedure, they often are willing to go with DMEK.” Dr. Busin tells patients that DSAEK has a somewhat slower re- covery of vision, but less complica- tions. One exception is for the risk of immunologic rejection, which is minimal in DMEK. However, Dr. Shah has found that unless a patient directly asks about the nuances among DMEK, ultra-thin DSAEK, and DSAEK, going into the details about the procedures is often overwhelming and confusing for patients. “Having said that, I typically let my patients know about the dif- ferent types of EK, but focus on the surgery I think is most appropriate for them,” Dr. Shah said. He provides them with hand- outs explaining the different forms of EKs and has them come back for an additional visit, typically with a family member, prior to surgery to address any questions or concerns. Although more data and long- term studies with ultra-thin DSAEK are needed, Dr. Shah said, a con- sensus is that the 3-year rejection rate is 1–2.5% for DMEK, 3–6% for ultra-thin DSAEK, and 5–10% for standard DSAEK. There is general evidence that EK has less rejection than PK, Dr. Busin said. He noted that pro- longed steroidal treatment can lower DMEK rejection rates below 1% annually at 2 years. However, the higher DSAEK rejection rate re- mains much lower than PK. In his statistics review, Dr. Busin found a 6.9% rejection rate at 5 years for ultra-thin DSAEK, compared to a 17% rate for DSAEK and 2.4% for DMEK. Patient selection Dr. Deng said selecting which pro- cedure to use is based on surgeons’ experience. “I do DMEK in every patient except the aphakic and those with ACIOLs,” Dr. Deng said. All eyes with anatomical ab- normalities that may cause graft luxation into the vitreous cavity are suitable only for DSAEK or ultra-thin DSAEK, Dr. Busin said. “It is useless to choose DMEK in eyes with poor visual potential, as 20/20 vision does not come in question,” Dr. Busin said. “In gen- eral each surgeon should choose the method he is comfortable with, as long-term results show identical visual outcomes for DSAEK, ultra- thin DSAEK, and DMEK.” Among patients with glau- coma or post-glaucoma surgery, Dr. Shamie said the selection of proce- dures depends on the condition of the anterior segment. “If the iris structures are nor- mal and there are no large iridoto- mies, if the tube is not too disrup- tive in the AC, and if the patient's corneal view allows for DMEK sur- gery, I would proceed with DMEK,” Dr. Shamie said. However, the difficulty of air tamponade in post-surgical glau- comatous eyes may make DSAEK preferable, unless other issues are more relevant, Dr. Busin said. For instance, surgeons may limit pos- sible immunologic rejection in eyes at higher risk by preferring DMEK. Dr. Deng has found in her experience that DMEK is better for glaucoma patients “We have published our outcomes of DMEK in eyes with previous glaucoma surgery,” Dr. Deng said. 1 “However, the majority of surgeons still feel more comfort- able with DSAEK in these patients.” EWAP Reference 1. Aravena C, Yu F, Deng SX. Outcomes of Descemet membrane endothelial keratoplasty in patients with previous glaucoma surgery. Cornea. 2017;36(3):284–89. Editors’ note: Dr. Shamie has financial interests with SightLife (Seattle) and KeraLink (Baltimore). Dr. Busin has financial interests with Moria (Antony, France). Drs. Shah and Deng have no financial interests related to their comments. Contact information Busin: massimo.busin@unife.it Shah: k e v i n . j . s h a h @ g ma i l . c Shamie: nshamie@doheny.org Deng: deng@jsei.ucla.edu