Patients with concurrent corneal disease may be candidates for premium IOLs to correct presbyopia and/or astigmatism, but often these individuals need corneal surgery before or after the cataract procedure, said William B. Trattler, MD.
The first step in planning the cataract surgery and choosing an appropriate IOL is to identify the presence of corneal disease, and making the diagnosis will require the use of topography.
“When examined at the slit-lamp, eyes with keratoconus or pellucid marginal degeneration (PMD) may show no signs of their corneal disorder, and even epithelial basement membrane dystrophy (EBMD) can be subtle," said Dr. Trattler, director of Cornea Center for Excellence in Eye Care, Miami. "These conditions all affect corneal shape, and so topography is key.”
Once the diagnosis is made, the question becomes whether it is possible to normalize the cornea so that the patient becomes a candidate for a premium IOL. The answer may be "yes."
Superficial keratectomy can be performed to regularize the cornea in an eye with EBMD, Descemet stripping endothelial keratoplasty or Descemet membrane endothelial keratoplasty can be performed for eyes with Fuchs disease. Surgery can also be performed to remove the pathology and make eyes with pterygia or Salzmann nodular degeneration a candidate for premium IOLs, while eyes with corneal irregularity associated with dry eye disease should also be managed prior to cataract surgery.
Dr. Trattler presented several case examples to illustrate the outcomes of corneal surgery prior to a cataract procedure in eyes with corneal disease. One example involved a patient whose astigmatism was reduced from +3.5 to +1.3 D after surgery to remove a nasal pterygium.
“This patient was now eligible to be implanted with a toric presbyopia-correcting IOL,” Dr. Trattler said.