Near, intermediate vision with inlay maintained over the long-term

Take-Home

A corneal inlay improves near and intermediate vision with minimal compromise in distance acuity. Results are maintained over the long-term.

By Lynda Charters; Reviewed by John A. Vukich, MD

Madison, WI-Use of a small-aperture corneal inlay (Kamra, AcuFocus) for treatment of presbyopia in emmetropic patients is an effective procedure, said by John A. Vukich, MD

The device improves near and intermediate vision with minimal compromise in distance acuity, and results are maintained over the long-term, he added.

“The [inlay] takes advantage of small-aperture optics to provide clear vision with a natural transition from distance to near,” said John A. Vukich, MD, in private practice, Madison, WI.

The device-which is 3.8 mm in diameter with a center aperture of 1.6 mm-is smaller than a contact lens, weighs about the same as a salt crystal, and is one-tenth the thickness of a sheet of paper. Its cup shape matches the average corneal curvature, and it is sufficiently flexible to bend to different curvatures without buckling, Dr. Vukich explained.

Three-year results

The inlay was evaluated in a 24-center prospective, non-randomized IDE clinical study that included 507 patients with the device implanted in their non-dominant eyes into either a pocket or under a flap. All patients ranged in age from 45 to 60 years with a spherical equivalent from +0.50 to –0.75 D with an uncorrected near visual acuity (UCNVA) level of worse than 20/40 and better than 20/100. The best-corrected visual acuity was 20/20 or better bilaterally.

The UCNVA increased by an average of 3.4 lines in the eye from J8 to J2 with the inlay from preoperatively to the 36-month follow-up visit. Fifty-three percent of patients had more than a three-line improvement and 78% had more than a two-line improvement in the near visual acuity.

The mean uncorrected intermediate visual acuity also improved to 20/25 postoperatively in the eye with the inlay at the time of the 36-month visit.

The uncorrected monocular distance visual acuity in the eye with the inlay remained 20/20, and the best-corrected distance visual acuity in the eye with the inlay was 20/20 at 36 months.

When investigators compared the laser settings used among the patients, those 6 × 6 or less achieved better results compared with 7 × 7 and 8 × 8. More patients in the 6 × 6 group achieved 20/40 or better visual acuity compared with the other groups and more patients expressed satisfaction with the ability to read without glasses.

Patient assessment

Investigators asked patients to rate near-vision tasks with the question: “How easy is it to perform a series of near vision tasks with both eyes without glasses?”

Patients’ responses indicated that at 24 months postoperatively, there was a statistically significant (p < 0.001) improvement seen in the mean scores for performing near tasks in both dim and bright light conditions. The tasks included assessment of the ability to perform activities in dim light-such as seeing small print, seeing numbers on a PDA, viewing a computer and reading a book or newspaper, performing small-item tasks, and the same tasks performed in daylight.

On a scale of 1 to 7-with 1 indicating not easy at all and 7 indicating easy-most tasks were rated as a 5 at 24 months postoperatively. Performing small item tasks and seeing small print in dim light were rated a 2 at that time point.

Using the same scale, patients also rated their ability to perform distance vision tasks. In response to the question: “How easy is it to perform a series of distance vision tasks with both eyes without glasses?” they reported that the ease-of-distance task performance remained stable at 24 months postoperatively, with little to no change in ranking (p = 0.016), Dr. Vukich explained.

The tasks that were rated included watching a movie or TV, judging distances, participating in sports, and driving at night and during the day. Most activities were scored high at a 6 or 7; driving at night was scored a bit lower at about 5.

The incidence of visual symptoms, including halos and glare and night vision problems, was very low.

John A. Vukich, MD

E: javukich@gmail.com

Dr. Vukich is a consultant to AcuFocus. The inlay is not approved for use in the United States and is considered an investigational device.