Awareness of post-LASIK corneal infiltrates guides accurate diagnosis treatment

March 1, 2010

The differential diagnosis for corneal infiltrate after refractive surgery includes several infectious and non-infectious etiologies.

Key Points

Chicago-The differential diagnosis for corneal infiltrate after refractive surgery includes several infectious and non-infectious etiologies.

Awareness of the variety of infiltrate causes and their associated features can help to guide accurate diagnosis and timely intervention with appropriate treatment to minimize the risk of visual complications, said Dimitri Azar, MD.

Dr. Azar reviewed the features and management of the spectrum of causes with a focus on microbial keratitis. He is holder of the B. Alexander Field Endowed Chair of Ophthalmic Research, and professor and chairman, Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago.

A single pathogen is identified in the majority of cases of microbial keratitis after refractive surgery, but polymicrobial infections are emerging, he said.

Early onset infection, defined as occurring within 1 week after surgery, accounts for about half of the reported cases of infections following LASIK and is frequently caused by gram-positive bacteria, whereas atypical mycobacteria or fungi are the most common isolates in cases of late-onset infections, developing 2 to 3 weeks after the procedure, he said.

Many of the symptoms of corneal infection, including pain, photophobia, decreased vision, and irritation, are nonspecific.

Adding to the diagnostic challenge is the fact that about 10% of postLASIK infections may be asymptomatic, especially if the infection is originating within the flap and the surface is not yet affected. The presence of redness and tearing, pain, discharge, flap separation, epithelial defects, and anterior chamber reaction should raise suspicion of an infection.