Eyeworld

EW CORNEA 42 November 2016 by Rich Daly EyeWorld Contributing Writer Proper patient selection may bolster success rates of a newer and less invasive procedure to treat a common corneal condition E arly research has shown the promise of a relatively low-intensity procedure to provide significant visual benefits among patients with Fuchs' endothelial dystrophy (FED). Stripping the central 3 mm to 4 mm of Descemet's membrane of Fuchs' endothelial dystrophy patients and allowing the cornea to spontaneously heal benefited both endothelial function and morphol- ogy among patients in two small studies. A report in the Canadian Journal of Ophthalmology examined two Fuchs' dystrophy cases in which descemetorhexis resulted in full corneal clarity at approximately 1 month postop. 1 Central endothelial cell counts at the last follow-up were 753 cells/mm and 731cells/mm, respectively. Best spectacle corrected visual acuity was 6/6 in both cases at 6 weeks postop and was retained at 9 months. "The benefit to the patient is visual improvement via removal of the central guttata, without the use of organ donor tissue," said Greg Moloney, MD, corneal staff special- ist, Sydney Eye Hospital, clinical lecturer, Sydney University, princi- pal ophthalmologist, Mosman Eye Centre, Sydney, and a co-author of the research. The benefits for successfully treated patients include avoiding an invasive transplant procedure and the need for long-term topical steroid medications, Dr. Moloney said. Additionally, the procedure could reduce the drain on the limit- ed resource of donor tissue from eye banks. Those findings echoed a ret- rospective case series in Cornea, in which 13 eyes of 11 patients with FED had 4 mm of the central Descemet's membrane stripped, resulting in 10 eyes responding positively. 2 That included resolution of corneal edema with visible central endothelial cell mosaic occurring in four eyes by 1 month postop, while visual acuity ranged from 20/25 to 20/40. Four additional eyes demon- strated a similar response by 3 months postop. Two additional eyes had resolution of corneal edema with an intact central endothelial mosaic at postop 6 months or later. Cell counts that ranged from 428 cells/mm to 864 cells/mm were maintained in all 10 responding eyes, and their final vision ranged from 20/15 to 20/20, except for two eyes with retinal pathology. Three non-responsive eyes re- quired endothelial keratoplasty. "If you told someone 15 years ago—in the days when we were doing penetrating keratoplasty and it took a year or more for visual re- habilitation—that all we would have to do is strip the central Descemet's membrane off to treat Fuchs' dys- trophy, people would have said you were crazy," said Kathryn Colby, MD, PhD, Louis Block professor, chair of the Department of Ophthal- mology and Visual Science, Univer- sity of Chicago, and senior author of the research. "Our results have led us to reevaluate this very common corneal disease and how we think about its basic biology." Positive early results in Fuchs' with Descemet's stripping I n the 2015 Eye Banking Statistical Report from the Eye Bank Association of America, it was reported that endothelial keratoplasty (EK) was the most common domestic keratoplasty procedure performed. Close to 40% of U.S.-donated tissue was used for surgery to treat endothelial disease. Descemet's membrane endothelial keratoplasty (DMEK) saw an increase of 63.8% with 4,694 cases in total, and De- scemet's stripping endothelial keratoplasty (DSEK) decreased by 2.5% with 22,514 cases in total being performed. The most common indications for EK were Fuchs' dystrophy (14,472 cases) and post-cataract surgery corneal edema (5,385 cases). Over the last decade, we have seen instrumen- tation and surgical techniques advance corneal surgeons toward more targeted approaches to managing corneal disease. Recently, there have been a few case reports and case series describing success using an even simpler approach to manag- ing Fuchs' dystrophy. Primary descemeto- rhexis involves stripping the central 3 to 4 mm of Descemet's membrane and allowing the cornea to spontaneously heal. Without the need for any allograft donor corneal tissue, there is no risk of rejection. Greg Moloney, MD, and Kathryn Colby, MD, discuss patient selection for this procedure and the outcomes of their studies on this surgical technique in this month's "Cornea editor's corner of the world." Clara Chan, MD, FRCSC, FACS, cornea editor This is a 58-year-old male patient 1.5 years after undergoing Descemet's stripping to treat Fuchs' endothelial dystrophy who has 20/20 VA with a clear cornea. The arrows indicate the edge of the descemetorhexis. Source: Kathryn Colby, MD, PhD Cornea editor's corner of the world continued on page 44

• Blank Page
• Blank Page (1)