Researchers in Brazil evaluated the impact of implantation of corneal ring segments on the quality of life of keratoconus patients using a survey developed by the U.S. National Eye Institute (NEI).

Sixty-nine eyes of 42 keratoconus patients received the implants. The average age of the participants in the study was 24.9 years.

All eyes in the study were implanted with Keraring intrastromal corneal rings segments (Mediphacos). Twenty-seven patients received the implants in both eyes and 15 had the procedure performed on one eye only.

All patients completed the NEI Refractive Error Quality of Life (NEI-RQL) questionnaire before surgery and 4.5 to 8 months after ICRS implantation.

The NEI-RQL survey contains 42 items that cover a range of issues such as clarity of vision, appearance, night vision and glare. Answers to each item are converted to a 100-point scale.

In addition to evaluating quality of life, the researchers took objective measurements of refractive error, best-corrected visual acuity (BCVA) and contrast sensitivity before surgery and 3 months after surgery.

After ICRS surgery, the researchers found significant improvements in all NEI-RQL scores and the overall survey score.

Survey items that showed the greatest improvement included:

• Clarity of vision
• Far vision
• Near vision
• Activity limitations
• Appearance

“Satisfaction with correction” had the greatest improvement, ranging from scores of 25 to 50 preoperatively to 80 to 90 after surgery.

At 3 months after surgery, best spectacle-corrected visual acuity and binocular BCVA improved significantly. There also was a significant decrease in corneal curvature values, from a mean of 50.22 diopters (D) pre-operatively to 46.27 D after the procedure. Contrast sensitivity also improved after ICRS implantation.

The study authors concluded that ICRS implantation not only improves objective measures of visual function such as visual acuity and refraction, but also has a positive impact on the subjective quality of life of patients with keratoconus.

[Ed. note: At present, Intacs corneal implants (Addition Technology, Inc.) are the only FDA-approved ICRS for use in the United States.]

SOURCE:  Evaluation of the impact of intracorneal ring segments implantation on the quality of life of patients with keratoconus using the NEI-RQL (National Eye Institute Refractive Error Quality of life) instrument. British Journal of Ophthalmology. January 2010.