OCT 18, 2012
This article in the July issue of Cornea describes the use of phototherapeutic keratectomy (PTK) and transepithelial photorefractive keratectomy (PRK) for the treatment of subepithelial fibrosis and anterior corneal scarring after Descemet stripping automated endothelial keratoplasty (DSAEK). The authors conclude that excimer laser ablation is an effective option for treating these residual conditions after DSAEK. It can expand the number of patients with corneal edema who can benefit from DSAEK, and when appropriate, PTK or PRK can eliminate residual refractive error.
This study describes the cases of two patients with mild to moderate preoperative subepithelial fibrosis secondary to Fuchs’ endothelial dystrophy. Both patients underwent DSAEK combined with cataract surgery and IOL implantation. Each demonstrated improvement in corneal edema after DSAEK but was left with visually significant residual anterior corneal opacities.
Subsequently, they underwent elimination of anterior corneal opacity using PTK or transepithelial PRK and demonstrated improvement in BCVA.
The authors report no recurrences of the subepithelial fibrosis with this treatment, although longer-term follow-up was still underway. In the current study, one-month results were reported for one patient, and the other was followed and stable for more than a year before being lost to follow-up.
The authors say that when preoperatively evaluating patients with Fuchs’ dystrophy who present with subepithelial scarring, surgeons must anticipate the effect of this fibrosis on the ultimate BCVA. They suggest consideration of a myopic target for the endothelial keratoplasty/cataract extraction procedure if an eventual PTK for removal of central anterior pathology is anticipated, since PTK induces a hyperopic shift. If cataract extraction is not performed at the same time, PTK will induce hyperopia, but this should still provide a more predictable refractive outcome than penetrating keratoplasty.