Cornea Program

DMEK

Descemet membrane endothelial keratoplasty (DMEK) is our treatment of choice for conditions impacting the corneal endothelium and patients who need an endothelial keratoplasty. This partial-thickness transplant is often performed as a treatment for Fuch’s corneal dystrophy and bullous keratopathy, however, very complicated surgical cases may require treatment via DSEK instead. Some major advantages of DMEK over DSEK include decreased risk of tissue rejection and superior visual acuity after healing has occurred. Post-operatively, patients undergoing DMEK can often achieve 20/20 vision, and may even be considered a candidate for a multifocal IOL.

DSEK

Descemet stripping endothelial keratoplasty (DSEK) is another method of endothelial transplantation. While a DMEK transfers the endothelial layer alone, a DSEK will strip a small layer of the stroma in addition to the endothelial layer. As a result, the transplanted tissue will also include a small layer of stroma. The new interface of host stromal tissue and donor stroma can cause a small hyperopic shift, as well as a slight reduction in visual acuity after the cornea is healed. This procedure is often reserved for patients with complicated anterior chambers such as tube shunts, anterior chamber IOLs, and other complex anterior chamber findings. While some patients can achieve 20/20 vision post-DSEK, the majority experience visual acuity of 20/25 or 20/30 post-operatively.

Corneal Cross-Linking

Vance Thompson Vision has been involved with corneal cross-linking since 2011 through our participation in the clinical trials leading up to the procedure’s FDA approval. Corneal cross-linking is a procedure indicated for patients with progressing ectatic conditions like keratoconus and post-LASIK ectasia. We commonly perform epithelium-off corneal cross-linking, as it is currently the approved method by the FDA. During the procedure, the corneal epithelium is loosened and removed, followed by instillation of a riboflavin solution called Photrexa in combination with exposure to UV light. The combination of riboflavin and UV light enhances the strength of the stroma by inducing covalent bonds between the corneal collagen fibers. Ongoing FDA studies are researching the stability and efficacy of epithelium-on corneal cross-linking, and the results appear promising thus far.

PTK

Phototherapeutic keratectomy (PTK) is indicated for irregular corneal surfaces, impacted by conditions such as anterior basement membrane dystrophy (ABMD) or anterior stromal scars. Prior to PTK, the only way to remove anterior corneal scarring was via a full-thickness corneal transplant. During PTK, the surface epithelium is first loosened and removed. Then a laser is utilized to remove anterior stromal scars. The laser also improves the ability of the new epithelial cells to grow back in a smoother and more regular fashion. Due to the removal of the epithelium, a bandage contact lens is applied to the ocular surface to promote patient comfort and protect the new cells. The bandage lens is removed around 4-5 days after the procedure, and vision will continue to improve over the following 1-2 weeks. Our very own Dr. Vance Thompson was a national medical monitor in the FDA-controlled clinical trials during the development of PTK in the United States in 1995.