Simple measures improve cataract surgery outcomes for postLASIK eyes

November 10, 2008

The difficulty of accurate IOL power calculation in postLASIK eyes is an issue being faced increasingly by cataract surgeons. Jack T. Holladay, MD, clinical professor of ophthalmology, Baylor College of Medicine, Houston, offered several tips for achieving better refractive outcomes in this growing population of eyes.

The difficulty of accurate IOL power calculation in postLASIK eyes is an issue being faced increasingly by cataract surgeons. Jack T. Holladay, MD, clinical professor of ophthalmology, Baylor College of Medicine, Houston, offered several tips for achieving better refractive outcomes in this growing population of eyes.

With accurate biometry being a critical factor to achieving precise IOL power calculations, Dr. Holladay said that a proprietary diagnostic system (IOLMaster, Carl Zeiss Meditec) should be considered the gold standard for axial length measurement. He also advocated selecting an IOL power calculation formula that includes horizontal corneal diameter for predicting the effective lens position.

Accurate keratometry is the most important problem faced in postLASIK eyes, and it may be best achieved using a tomographer that, in contrast to conventional keratometry and topography, measures the central power (rather than paracentral) and both the front and back surfaces of the cornea (versus front only). Dr. Holladay also recommended that all surgeons use a personalized lens constant that will reflect their surgical technique and to target mild myopia as the refractive outcome, since aiming for emmetropia leaves a 50:50 chance of a hyperopic result.

"However, even with careful attention to all of these issues, cataract surgeons still need to prepare postLASIK patients for the possibility that they may need a secondary procedure to fine tune the refractive results," Dr. Holladay said.