Risk for endophthalmitis after keratoprosthesis implantation may persist despite treatment

A study found cases of the sight-threatening complication despite prophylactic antibiotics and a therapeutic contact lens.

Issue: July 10, 2012

Even when prescribed prophylactic antibiotics and a therapeutic contact lens, patients are still at risk for developing infectious endophthalmitis after keratoprosthesis implantation, according to a study.

The retrospective, consecutive case series included 126 eyes of 105 patients implanted with the Boston type 1 keratoprosthesis (KPro) between November 2004 and November 2010. All patients had been prescribed vancomycin, a fourth-generation fluoroquinolone and a bandage contact lens. After at least 1 month of follow-up (mean: 25 months), the incidence of infectious endophthalmitis was 2.4%.

“This incidence rate is within the range of what has previously been reported,” study co-author Edward J. Holland, MD, OSN Cornea/External Disease Board member, said.

Dr. Holland performed all the implantations in the study, which was published in Cornea. He said he has treated approximately 250 eyes with the KPro to date.

Despite the incidence of infectious endophthalmitis found in the study, Dr. Holland believes the KPro serves a beneficial purpose.

“The KPro, for the right indications, has been a tremendous breakthrough and is a very useful technology to help a very challenged groups of patients,” Dr. Holland told Ocular Surgery News.

Role of ocular surface disease

The two groups that most benefit are the immunologically challenged — eg, those who have had multiple corneal transplant rejections — and those with severe ocular surface disease.

“It is among these surface disease patients that we are certainly seeing more infections,” Dr. Holland said.

For these patients, ocular surface stem cell transplantation is typically a first-line treatment.

“However, if unsuccessful, we move on to the KPro,” he said.

Similarly, if a patient has a good surface transplant but keeps rejecting a corneal transplant, Dr. Holland said he then uses the KPro after an ocular surface transplant.

Dr. Holland said that the inventor of the device, Claes Dohlman, MD, PhD, advocates long-term dual coverage of an antibiotic to reduce the incidence of infectious endophthalmitis. Vancomycin and fourth-generation fluoroquinolones are the antibiotics of choice.

“We definitely adhere to Dr. Dohlman’s recommendations, and that has been important for treatment,” Dr. Holland said.

Patients at risk for fungal keratitis and endophthalmitis tend to have ocular surface disease.

“Patients with severe surface disease have abnormal conjunctiva, besides having an abnormal cornea, and are more prone to fungal infections, especially if they are immunosuppressed,” Dr. Holland said. “Hence, we follow these patients very closely and sometimes we have them on topical antifungal prophylaxis.”

Although many of these corneas are opaque and sometimes difficult to examine, Dr. Holland said he pays particular attention to the area of the cornea adjacent to the KPro stem.

“This is usually the site of the infection,” he said. “If we see kind of an indolent opacity and have a high index of suspicion that it is not a scarred cornea, that may be the first sign of a fungal keratitis, which potentially can lead to endophthalmitis.”

Endophthalmitis cases

All three cases of endophthalmitis reported in the study occurred in women (mean age: 52 years). Two patients had KPro implantation for a failed penetrating keratoplasty and the third had necrosis from a previous KPro cornea. All three patients wore a bandage contacts lens, changed every 3 months, and were taking vancomycin and moxifloxacin.

Vitreous fluid cultures detected Ochrobactrum anthropi, Candida parapsilosis and Candida albicans in all three patients.

Two of the three patients presented with vision decreased to light perception, for which no visual recovery was achieved. The third patient presented with visual acuity of 20/400 and eventually achieved 20/60.

“Infectious keratitis and endophthalmitis are two of the gravest complications of keratoplasty devices,” Dr. Holland said. “Clinicians need to have a high index of suspicion when they see infiltrates of the cornea or an intraocular inflammatory reaction. They need to be aggressive about the diagnosis and treatment.”

Patients should also be counseled about the importance of compliance with infection prophylaxis and of seeking immediate medical attention if they notice progressive decreased vision, increased floaters or pain. – by Bob Kronemyer

Reference:

Chan CC, Holland EJ. Infectious endophthalmitis after Boston type 1 keratoprosthesis im-plantation. Cornea. 2012;31(4):346-349.

For more information:

Edward J. Holland, MD, can be reached at Cincinnati Eye Institute, 580 S. Loop Road, Suite 200, Edgewood, KY 41017; 859-331-9000; email: eholland@holprovision.com.
Disclosure: Dr. Holland has no relevant financial disclosures.