Penetrating Keratoplasty Effective for Corneal Complications of Shingles

By Marilynn Larkin

February 25, 2019

NEW YORK (Reuters Health) - Even in eyes with preoperative risks, penetrating keratoplasty (PKP) can achieve favorable results for the corneal complications of herpes zoster ophthalmicus (HZO), researchers say.

"What we learned is corneal transplants can make a significant difference in visual acuity, but it's important to control inflammation before transplant," Dr. Christopher Hood of the University of Michigan in Ann Arbor, said in an email to Reuters Health. "We emphasize the importance of operating on a quiet eye."

Dr. Hood and colleagues studied 53 eyes of 53 patients who underwent PKP due to corneal complications of HZO. The mean age at the time of PKP was 68; 68% were women and almost all were white. The mean quiescent period was 6.5 years from HZO to PKP.

All surgeries involved use of an oversized donor cornea. Interrupted nylon sutures were used alone or in combination with continuous nylon sutures. After surgery, all patients received subconjunctival injections of an antibiotic and a corticosteroid.

Postoperatively, corticosteroid drops were used every two to six hours and tapered at the surgeon's discretion, typically over the first year. Some patients were also prescribed oral acyclovir. The mean follow-up was four years.

As reported online February 7 in the British Journal of Ophthalmology, preoperatively, 25 (47.2%) eyes had no corneal sensation, while 16 (30.2%) had deep corneal neovascularization in four quadrants. Twenty-five (47.2%) eyes also had comorbid ocular disease, including cataract, glaucoma and macular disease.

Twenty patients (37.8%) were given acyclovir for the entire postoperative period.

Zoster keratitis did not recur in any eye. The most common complications were difficulty healing the ocular surface (22.6%) and glaucoma (26.4%). Thirty percent of eyes required additional postoperative procedures, most commonly tarsorrhaphy (18.9%) and amniotic membrane graft (11.3%).

Grafts remained clear at one (94%), two to four (82%) and five or more years (70%) of followup.

"Although most grafts remained clear," the authors note, "long-term visual potential may be limited by comorbid ocular diseases."

Visual acuity improved at one year postoperatively; however, the improvement was not sustained.

Further, long-term acyclovir conferred no significant benefit of on visual acuity or graft survival.

The authors stress "the importance of choosing surgical candidates conservatively, operating on quiet eyes whenever possible, monitoring the patient closely after surgery, and assiduously treating postoperative inflammation and ocular surface problems."

Dr. Uyen Tran, Chief, Cornea and External Diseases at Vanderbilt Eye Institute in Nashville, told Reuters Health, "I agree that corneal transplantation is a very effective treatment in patients with HZO, as often the level of corneal scarring will reduce their vision to legal blindness."

"Corneal neovascularization is a significant risk for graft rejection," he said by email. "At Vanderbilt, we will consider pretreatment of the neovascularization with an argon laser or (bevacizumab) injections to close the blood vessels."

"Corneal anesthesia is common after herpes zoster infections and can lead to prolonged epithelial defects, ulcers, and ultimately to graft failure," he noted. "We also aggressively treat these complications with ambiodiscs, prokeras, and amniotic membrane grafts."

"Tarsorrhaphy is also an option," he added. "A new treatment that we are looking into is corneal neurotization to restore the function of the corneal nerves prior to surgery."

SOURCE: http://bit.ly/2SglRCy

Br J Ophthalmol 2019.

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