Jerusalem-Findings from a retrospective study of patients undergoing corneal collagen crosslinking (CXL) for keratoconus provide new insight on the risk of early ocular surface related complications.

The study included 206 eyes of 180 patients with keratoconus and found 23 eyes (11.2%) of 22 patients presented with 28 marked ocular surface complications. The research was conducted by Denise Wajnsztajn, MD, Joseph Frucht-Pery, MD, and colleagues from the Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, who extracted data on clinical features and early adverse events/complications of patients who underwent CXL between August 2007 and March 2012.

Compared with the 183 eyes that did not develop an early complication, the complication group was similar with respect to age and gender. However, they presented with more advanced keratoconus as evidenced by a significantly steeper mean K_max and significantly thinner mean pachymetry.

In addition, features leading to ocular surface compromise were prominent in the complication group prior to CXL. Ocular surface and external disorders were common, half of the patients were contact lens-dependent, and 17% had limited tolerance to contact lenses.

Best-corrected visual acuity (BCVA) loss of 1 to 3 lines compared with the pre-CXL level occurred in 6 eyes.

“Long-term complications of CXL, including scarring and loss of BCVA, have been well described,” said Dr. Wajnsztajn, second-year corneal fellow. “However, there is insufficient information on the early complications that can occur

“Our data show that compromised ocular surface healing after CXL may be more common than recognized and that it can compromise final visual acuity,” Dr. Wajnsztajn added. “This information indicates that eyes should be in the best ocular surface condition before undergoing CXL in order to achieve the best outcomes.”

The patients in the study had been treated over a period of about 4.5 years beginning in August 2007. All of the CXL procedures were performed using the Dresden protocol.

Findings prior to CXL in the eyes that developed early ocular surface complications included floppy eyelids in more than half, mild superficial punctate keratitis in almost half, and allergic conjunctivitis in 13%

The most common complications represented epithelial healing failure (19 eyes) followed by corneal infiltrates (8 eyes), of which two were associated with a positive microbial culture. In addition, one eye developed severe stromal edema that lasted for more than 1 month and led to subsequent scarring.

“The findings in this eye led us to question the development of corneal hydrops as a result of CXL,” Dr. Wajnsztajn said.

No eye went on to develop corneal melt or perforation.

Dr. Wajnsztajn proposed a model to explain the risk of early ocular surface complications after CXL treatment for keratoconus

“These patients may suffer from chronic inflammation associated with prolonged contact lens wear and exposure to cleaning solutions, chronic allergies, blepharitis, eye rubbing, and floppy eyelids that can lead to dry eye, corneal hyposensitivity, and compromised ocular surface healing after CXL,” Dr. Wajnsztajn said.

Dr. Wajnsztajn has no financial interest in the subject matter.

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