research digest

Study Compares Amadeus with IntraLase FS Laser

A study by Atlanta surgeon Trevor Woodhams, M.D., comparing LASIK keratectomies with the AMO Amadeus microkeratome and the IntraLase femtosecond laser found that patients treated with the mechanical method enjoyed better visual outcomes even as the laser created more accurate and predictable flap thicknesses.

The study was a prospective case series of 100 distance eyes in 100 patients in each of the two groups. The Amadeus group's flaps were made according to a customary protocol. The IntraLase group had planned flaps of 140 microns and 9.5-mm diameter.

Researchers measured the visual acuities using a 100% contrast ETDRS chart postoperatively at 1 day, 1 month and 3 months. The flap thicknesses were determined by subtracting the surgical corneal bed from the presurgical corneal thickness. Investigators polled or measured various subjective and objective factors among the patients.

At 3 months, 95% of the Amadeus eyes enjoyed uncorrected visual acuity of 20/20 or better vs. 82% of the IntraLase eyes whose vision matched that level. A greater number of Amadeus eyes (74%) vs. IntraLase eyes (52.3%) achieved UCVA of 20/16.

IntraLase flap thicknesses averaged 114 microns (standard deviation: 19 microns) vs. 126 microns (standard deviation: 29) for the Amadeus flaps. Patients undergoing IntraLase keratectomies had a significantly higher rate of photophobia, DLK and perisurgical discomfort.

Generally, patients undergoing LASIK with Amadeus microkeratome flaps enjoyed quicker visual recovery with sharper and more comfortable visual performance vs. eyes that underwent IntraLase keratectomies. However, the femtosecond laser created a more accurate and precise corneal thickness.

IntraLase technology may provide a safer and more predictable surgical flap. But in this study, the visual outcomes did not match those of the Amadeus mechanical microkeratome.

Study Compares Hansatome with IntraLase FS Laser

A study by Daniel S. Durrie, M.D., of Overland Park, Kan., involving 51 LASIK patients (102 eyes) undergoing flap creation with the Bausch & Lomb Hansatome microkeratome in one eye and the IntraLase femtosecond laser in the other found that eyes treated with the IntraLase laser achieved better visual outcomes and superior predictability.

The patients selected for the study satisfied the standard inclusion and exclusions criteria, and had myopia up to 7.49D and cylinder up to 1.49D. The average MRSE was ­3.94D (range: ­7.25D to ­0.75D), the average cylinder 0.50D (range: 0 to 1.25D).

Among the Hansatome eyes, at 1 day 27% of eyes had UCVA of 20/15 or better, 63% 20/20 or better, 84% 20/25 or better and 98% 20/40 or better. Among the IntraLase eyes, at 1 day 47% had UCVA of 20/15 or better, 75% 20/20 or better, 92% 20/25 or better and 98% 20/40 or better.

At 30 days, among the Hansatome eyes, 51% had UCVA of 20/15 or better, 88% 20/20 or better, 96% 20/25 or better and 100% 20/40 or better. Among the IntraLase eyes at 30 days, 67% had UCVA of 20/15 or better, 96% 20/20 or better and 100% 20/25 or better.

The Intralase eyes had better predictability as well. At 1 month, 80% of the IntraLase eyes were within +/- 0.25D and 94% within +/- 0.50D. Of the Hansatome eyes, 59% were within +/- 0.25D and 80% within +/- 0.50D. Dry eye tests and subjective evaluations favored the IntraLase eyes as well. Neither group had any significant complications.

The study author speculates that the flap architecture and dry bed may account for the IntraLase eyes' superior results.