CK improved presbyopia at 1 year postop in trial

Eighty-four percent of patients reported being satisfied with their quality of vision 1 year postop.

Issue: March 1, 2004

ByNicole Nader

	The keratoplasty tip delivers radiofrequency energy into the corneal stroma at the treatment points. (Images courtesy of Daniel S. Durrie, MD.)
	Steepening of the cornea is produced by applying eight to 24 treatment spots within the corneal periphery.

ANAHEIM, Calif. — Conductive keratoplasty can be effective for improving near vision in patients with presbyopia, according to results of a study presented here.

Daniel S. Durrie, MD, and colleagues reported 12-month outcomes in presbyopic patients treated with CK using the ViewPoint CK System (Refractec Inc.) in a poster presentation at the American Academy of Ophthalmology annual meeting.

“CK can be used to produce functional vision in presbyopes safely and effectively,” the study authors reported. According to the study, 84% of patients achieved near vision of J3 or better postoperatively.

In February, CK for correction of presbyopia was recommended for approval by an advisory panel to the Food and Drug Administration. The procedure increases corneal asphericity by shrinking the stroma with radiofrequency pulses. Steepening of the cornea is produced by applying eight to 24 treatment spots within the corneal periphery.

Presbyopia treatment with the ViewPoint CK System requires surgeons to induce slight to moderate myopia (–1 D to –1.5 D) in the nondominant eye. Distance vision is preserved in the other eye. This approach to presbyopia correction is a mild version of monovision or blended vision.

The current trial evaluated CK blended vision for correcting presbyopic patients with refractive errors ranging from 0 D to +2 D with up to 0.75 D of cylinder.

Study methods, outcomes

The data on Dr. Durrie’s poster included 150 eyes of 150 patients age 44 to 71 years. All together, 188 eyes of 150 patients were treated; 112 were treated unilaterally to improve near vision, and 38 were treated bilaterally to improve near vision in one eye and distance vision in the other eye.

Patients were treated at multiple centers throughout the United States. Follow-up evaluation was carried out at 1, 6 and 12 months postoperatively.

At 12 months follow-up, 98% of patients reported a subjective improvement in vision, and 84% reported being able to read fine newspaper print. Overall, 83% of patients achieved uncorrected distance vision of 20/20 with concurrent J3 near vision.

Patient satisfaction

According to the study, at 12 months, no patients lost more than two lines of best-corrected visual acuity, experienced a significant increase in residual cylinder or maintained a visual acuity of 20/40 or worse.

“Ninety-eight percent of patients saw improvement in visual quality,” the study authors reported in the poster presentation. Researchers noted that 96% of patients were very satisfied, satisfied or neutral about their quality of vision at 1 year.

Regarding night vision, contrast sensitivity (with or without glare) remained unchanged from preoperative measurements to after CK surgery. Quality of depth perception also remained stable, and 94% of patients reported good to excellent depth perception at 12 months postop.

For Your Information:

Daniel S. Durrie, MD, can be reached at Durrie Vision, 5520 College Blvd., Suite 200, Overland Park, KS 66211; 913-491-3737; fax: 913-491-9650. Dr. Durrie has no financial interest in the products mentioned in this article. He is a paid consultant for Refractec.

Refractec Inc., manufacturer of the ViewPoint CK system, can be reached at 5 Jenner, Suite 150, Irvine, CA 92618; 949-784-2600; fax: 949-784-2601.