Early approach to DALK for refractory corneal infection yields good results

SAN DIEGO — A precocious, or early, approach to deep anterior lamellar keratoplasty prevented recurrence in cases of corneal infection that responded poorly to medical treatment, according to a study presented here.

Perspective from Christopher J. Rapuano, md

Because DALK is a safe procedure with good long-term graft survival, has a low rate of rejection and has a very low risk of secondary complication in Acanthamoeba or fungal infection, precocious DALK should be considered in cases that are poorly responsive to medical treatment, Enrica Sarnicola, MD, said at the World Cornea Congress.

Enrica Sarnicola

“Of course, you need a DALK surgeon with a low [PK] conversion rate,” Sarnicola said.

The study included 21 cases of Descemetic DALK and six cases of pre-Descemetic DALK. There were no recurrences of infection and significant improvement in visual acuity. Average postoperative visual acuity was 7/10, Sarnicola said.

No secondary complications such as cataract or glaucoma were reported.

“We believe that didn’t happen thanks to the surgical timing and the lamellar nature of the keratoplasty,” Sarnicola said.

The deep margin was free of infection in 25 cases; however, two cases of Descemetic DALK were not, Sarnicola said. – by Matt Hasson

Disclosure: Sarnicola reports no relevant financial disclosures.

Perspective

Christopher J. Rapuano, md

In general, infections should be treated with antimicrobial medications in an attempt to eradicate them. Once the infection has resolved and the cornea has healed, visual rehabilitation with glasses or contact lenses should be attempted. If unsuccessful, a corneal transplant (either DALK or PK) is a great option, with a high success rate. Dr. Sarnicola presented data on 27 eyes with a variety of corneal infections that were not responding medically and underwent DALK. Most of these were big bubble DALK, while others left some posterior stroma. Overall, she reported good results. Full thickness corneal transplantations have been the standard treatment for impending or completed perforations. And while they often save the eye, they have a high rate of graft failure. The advantage to DALK is that it retains the host Descemet’s and endothelium, significantly decreasing the chance of rejection. However, some infections are known to invade into the deep cornea, which would be expected to be removed by a PK, but not necessarily by a DALK. And fungal infections can invade though Descemet’s and into the anterior chamber without a frank perforation. While none of the eyes in the study developed a recurrent infection, surgeons considering a DALK in such eyes should be wary of that possibility.

Christopher J. Rapuano, md

Cornea Service, Wills Eye Hospital, Philadelphia

Disclosures: Rapuano reports no relevant financial disclosures.