EyeWorld India September 2016 Issue

EWAP CO RNEA 61 September 2016 the experienced surgeon and trainees. A separate, multicenter study published this year in the British Journal of Ophthalmology reached similar conclusions. 3 Eight centers in three countries—India, the United States, and Mexico— performed SLET on 68 patients with clinical success in 57 cases with a median follow-up of 1 year. “I think we have enough evidence to show that [SLET] works and can offer very good long-term results in patients with unilateral chemical injury,” Guillermo Amescua, MD , Bascom Palmer Eye Institute, Miami, said, adding later that the data from these studies show that the technique is at least safe and “as good as CLET,” and data suggest SLET may be superior to CLET in the pediatric population. Dr. Amescua said that in his 5 years using SLET, he noticed that it seems to work best in patients with LSCD induced by chemical burns or trauma. In patients with autoimmune conditions such as Stevens–Johnson syndrome and mucous membrane pemphigoid with asymmetric presentation that are clinically quiet or under control with systemic immunosuppression, SLET was not effective, Dr. Amescua observed. “In an eye that’s quiet with a wet ocular surface and good eyelid function, [SLET] works very well,” he said. Dr. Amescua recommended that those performing SLET use a cryopreserved human amniotic membrane (the membrane placed on the ocular surface of the recipient eye and used as a substrate for the donor tissue), rather than a dry preserved amniotic membrane. “For this procedure, you need a really smooth surface, and you don’t get that with dry preserved,” he said. Like Dr. Basu, Dr. Amescua said SLET is far less expensive and more accessible than CLET, but he said he doesn’t think it will replace CLET completely. “There has been resistance toward SLET from some surgeons who would rather wait for CLET to be available in the U.S., but with the current evidence I think more surgeons will be willing to start doing SLET. We should continue to improve our stem cell expansion labs and research this fascinating area of ocular surface reconstruction so we can improve patient outcomes.” In an audience poll conducted at the “Pardon the Ophthalmology: Hot Topics in Cornea and External Disease” symposium at the 2016 ASCRS•ASOA Symposium & Congress, SLET was voted the best technique for limbal stem cell transplantation, receiving 53% of the votes as compared to conjunctival limbal grafting (35%) and CLET (13%). Future research, Dr. Amescua said, will include creating an animal model that allows them to track the cells to answer questions such as where the new cells are being made: Are the transplants repopulating the stem cell niche at the limbus or are they becoming “satellites, little areas of production for cells”? Dr. Basu said he and his colleagues are conducting research using in vivo imaging to understand how the corneal surface is healing after the continued on page 65