Visual acuity, other tasks appear unaffected by inlay decentration

August 1, 2017

Decentration of less than 0.75 mm from a light-constricted pupil with a novel corneal inlay for the surgical correction of presbyopia does not affect visual acuity, task performance, or severity of halos and glare.

Reviewed by Robert J. Cionni, MD

Decentration of a novel corneal inlay for the surgical correction of presbyopia (Raindrop Near Vision Inlay, ReVision Optics) by less than 0.75 mm from a light-constricted pupil did not affect visual acuity, tasks, or halos and glare, according to a study presented by Robert J. Cionni, MD.

The study focused on the clinically acceptable range of inlay decentration with a light-constricted pupil, explained Dr. Cionni, MD, medical director, The Eye Institute of Utah, Salt Lake City.
 

About the study

All 115 patients in the study were emmetropic or low hyperopic presbyopes with the inlay implanted in the non-dominant eye. Preoperatively, patients had a mean uncorrected near visual acuity (UNVA) of 20/80 and a mean uncorrected distance acuity (UDVA) of 20/20. No patient had LASIK in the non-dominant eye.

Ray-tracing aberrometry/topography (iTrace, Tracey Technologies) was used to take wavefront measurements as they related to the light-constricted pupil center and the coaxially sighted corneal light reflex.

Dr. Cionni used a multivariate regression model to assess the influence of inlay position on visual outcomes preoperatively and at 3 months postoperatively.

Visual acuity, task performance, reports of halos and glare, and patient satisfaction were analyzed, he explained.

The study found that the mean monocular UNVA improved 4.9 lines in the inlay eye, with no change in binocular distance vision.

Eighty-three percent of the implants were centered radially within 0.5 mm of the pupil center, according to Dr. Cionni.
 

Decentration range

 

 

Decentration range

There were no significant reductions in distance vision related to inlay decentration monocularly or binocularly within the decentration range found in this study, Dr. Cionni noted.

Decentration of the inlay also showed no significant reduction of the improvement in near vision provided by the inlay except for decentrations greater than 0.75 mm, he added.

“A decentration greater than 0.75 mm had a mean monocular uncorrected near visual acuity loss of 1 line,” he said.

This difference was statistically significant. However, only 4 of the 115 eyes had decentration of more than 0.75 mm.

Visual parallax

 

Visual parallax

One caution that Dr. Cionni shared is that when the center of the pupil is marked using an excimer system and then placed under the slit lamp, the central mark may be shifted. Dr. Cionni highlighted a method (see box, above) to account for this parallax.

 

Robert J. Cionni, MD

E: rcionni@theyeinstitute.com

This article was adapted from Dr. Cionni’s presentation at the 2017 meeting of the American Society of Cataract and Refractive Surgery. Dr. Cionni is a clinical investigator for ReVision Optics.