Visual function analyzer objectively measures accommodation in scleral implant-treated presbyopes

BARCELONA — The iTrace visual function analyzer from Tracey is an effective tool for assessing the efficacy of procedures intended to restore accommodation, according to a surgeon speaking here.

Investigators used the device to measure accommodation in phakic and pseudophakic eyes that had undergone the scleral spacing procedure for presbyopia with Refocus Group's PresView scleral implants.

"With this method, we can measure accommodation objectively by mapping the refractive power across the pupil during fixation at any distance through an open field of view," Barrie Soloway, MD, said at the European Society of Cataract and Refractive Surgeons Winter Refractive Surgery Meeting.

A preliminary study of 15 eyes of eight patients who underwent the spacing procedure was performed using the iTrace visual function analyzer. The power refraction wavefront map was obtained by viewing Snellen letters at a fixation distance of 20 feet and Sloan letters at 50 cm for near fixation.

Investigators then created a difference plot between these two measurements to assess the depth of field in near vision during fixation. This depth of field was then compared to near acuity in each eye, Dr. Soloway said.

"The eyes were found to have a depth of field in near vision of 1.2 D with a total range of 0.5 D to 2.5 D. There was a trend correlating depth of field in near vision with the ability to read smaller print," he said.

Further studies with larger numbers of patients undergoing the scleral spacing procedure will be conducted to confirm the method's reliability, he noted.