DALK may be option in eyes with severe infectious keratitis unresponsive to treatment
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Eyes with severe infectious keratitis unresponsive to topical, systemic and injection treatment can benefit from lamellar surgery rather than penetrating keratoplasty, according to one specialist.
“There is a window period where instead of doing PK, it is possible to do deep anterior lamellar keratoplasty, and this can offer some significant advantages,” Jodhbir S. Mehta, MD, PhD, said at the virtual EuCornea congress.
Conventionally, after everything else has failed, these eyes are treated with PK, but studies have shown poor results because a graft implanted in a highly inflamed, infected eye is at a high risk for rejection and endophthalmitis. DALK potentially offers significant advantages.
“It is an extraocular procedure, no postoperative steroids are needed, and the graft has a much better chance of surviving in the long term. The caveat is that surgery is more challenging in these hot eyes because you have to dissect away quite deep to remove all the affected stroma,” Mehta said.
In addition, there is only a small window within which DALK is an option: not too early, before medical therapy has proved ineffective, and not too late, when late-stage infection would leave no other choice than PK.
“We typically do DALK in patients that have been kept under close observation in our hospital, where we can rule out compliance issues, see the response to treatment, culture and identify the organism,” Mehta said.
A previous study compared the results of DALK vs. PK performed at the Singapore National Eye Centre in eyes with infectious keratitis. Success rates in terms of eradication of the infection were comparable. There was recurrence in four eyes (12%) in the DALK group, and surgery was repeated, leading to complete resolution in three eyes. In the PK group, there was recurrence in 14% to 15% of eyes, but of those, 80% eventually became blind.
“By avoiding PK, you give the eye a better chance to survive because you keep the infection out from inside the eye and can better control it. The idea is that you debulk the infected cornea, getting rid of all the bacteria, fungi or Acanthamoeba, giving medications a better chance to work,” Mehta said.