Pseudoaccommodation May Lead to Higher Vertical Coma

October 26, 2011 (Orlando, Florida) — The association with higher values when vertical and horizontal comas aberrations are combined has been underscored in a study reported here at the American Academy of Ophthalmology 2011 Annual Meeting.

Investigators examined 55 eyes to assess how aspheric monofocal lenses affect corneal aberrations for pseudoaccommodation and presbyopia. Inclusion criteria included at least 20/30 vision. Exclusion criteria included corneal pathology and a history of keratorefractive surgery.

According to Rory Myer, MD, an ophthalmology resident at the University of Alabama at Birmingham, the findings show a vital mean difference for coma distance and vertical coma.

"We hypothesized vertical coma, but what I noticed at the wavefront outputs was that some of my pseudoaccommodaters had really small amounts of vertical coma. Looking at a large stack of wavefront outputs, I thought it should be about comparing terms instead of just focusing on one," Dr. Myer told Medscape Medical News.

He explained that it would be helpful if we could use preoperative topography to determine whether "patients will have good near vision with aspheric monofocal lenses, or if we should give them a multifocal lens.... We may find from this that we shouldn't sell them multifocus lenses because they could have an aberration pattern that would be good with a monofocal [lens]."

Standout statistics were low P values for vertical and spherical at .005 and .004, respectively, with a P value of no more than .05 considered significant for this study.

"This is an interesting study because a little aberration can increase depth of focus and functioning," says Herbert Kaufman, MD, professor emeritus of ophthalmology, pharmacology, and microbiology at Louisiana State University in Shreveport. "It's a good idea to consider this for a patient."

Dr. Myer added that a weakness of the study is its retrospective nature. He believes a better study design would be to measure the amount of pseudoaccommodation a patient has, then run correlations with wave terms.

The authors report relationships with Alcon Laboratories and Oculus. Dr. Kaufman has disclosed no relevant financial relationships.

American Academy of Ophthalmology (AAO) 2011 Annual Meeting: Abstract 188. Presented October 24, 2011.