Keratoconus recurrence after PK deserves attention, further investigation

Recurrence might be from diseased cells migrating from host to donor tissue.

Issue: May 2012

Keratoconus recurrence after corneal transplantation is a rare and relatively unknown phenomenon, but it may occur in the short and long term, as shown by two cases reported by a specialist in Kuala Lumpur, Malaysia.

“The first case was a 19-year-old Indian patient with advanced keratoconus, initially presenting with acute hydrops in the right eye. There was also a descemetocele in the central cornea, threatening to burst. The left eye was less advanced, but the cornea was also very thin. Though scarring was present in both corneas, the patient could still see 20/80 in the left eye,” Jenny P. Deva, MD, said in an interview with Ocular Surgery News.

Initially, the right eye was treated conservatively. The hydrops regressed, and corneal edema was reduced. Corneal collagen cross-linking (CXL) was performed in both eyes.

Outcome of first case

Postoperatively, the patient still had count finger vision in the right eye because of the central corneal scarring but improved to 20/120 with a dilated pupil. The left eye achieved 20/40 with correction by rigid gas permeable lenses (RGPs). However, because of the poor vision in the right eye, penetrating keratoplasty was performed, and the eye regained 20/80 vision without any visual aid.

“Suddenly, 16 months later, the patient presented again with a dramatic loss of vision in the PK-operated eye. Clinically, he had corneal edema, and vision was reduced to count finger again,” Dr. Deva said.

“There was no increase in intraocular pressure, but the keratometry readings were high again because there was recurrence of keratoconus in that eye,” she said. “We treated it conservatively for 1 week, and then CXL was done. This resulted in good visual recovery of about 20/100. Hopefully, after corneal steepness has stabilized, we’ll be able to further improve his vision with RGPs.”

Second case

The second patient was a 42-year-old Malay man who had bilateral keratoconus. Fifteen years earlier, PK was performed in his right eye, which was the worst of his eyes. His left eye had moderate keratoconus, and he had maintained a stable best corrected vision of 20/60, despite having 6.5 D of astigmatism.

“He presented at our clinic 3 months ago, with his right eye gradually getting worse. He said he had been unable to see properly for the last 2 years and wished to have something done for both eyes if possible,” Dr. Deva said.

Cross-linking was performed in both eyes. With RGPs, the patient was able to see 20/80 with the right eye and 20/40 with the left eye. Although the patient is currently experiencing difficulty in retaining the contact lens in the right eye because of the very steep cornea, it is possible that in 6 to 12 months the cross-linking effect will allow a better fit with RGPs. If not, Dr. Deva said, a phakic IOL will be implanted.

“From these two cases, we know that recurrence of keratoconus can happen after penetrating keratoplasty, quite early but also after many years,” Dr. Deva said.

“The exact mechanism has not yet been established, but it is likely to involve some kind of host-graft interaction. Possibly, and most likely, ‘diseased’ keratoconus cells migrate from the host to the donor tissue,” she explained.

There are keratoconus patients who, after PK, develop progressive astigmatism. According to Dr. Deva, this might be a sign of keratoconus recurrence and should be monitored closely.

“Perhaps the number of keratoconus recurrences is underestimated and remains undiagnosed,” she said. “This also poses a dilemma for all ophthalmologists: Shouldn’t we be proactive and cross-link the keratoconus eye after PK?” – by Michela Cimberle

For more information:

Jenny P. Deva, MD, can be reached at Tun Hussein Onn National Eye Hospital, Kuala Lumpur, Malaysia; +60-12-3987601 or +60-3-71881488; email: jmpdeva16@gmail.com.

Disclosure: Dr. Deva has no relevant financial disclosures.