Mel 90 excimer laser for myopic LASIK yields predictable outcomes

An updated excimer laser with a faster pulse rate and new ablation profile delivered predictable refractive outcomes in myopic LASIK, according to a study.

Perspective from Richard J. Duffey, MD

The retrospective study included 286 eyes of 147 patients who underwent myopic LASIK with the Mel 90 excimer laser and VisuMax femtosecond laser (both Carl Zeiss Meditec). The Mel 90 laser, an upgrade of the Mel 80 platform, can be operated with a pulse rate of 250 Hz or 500 Hz. It features the Triple-A ablation profile for low and high myopic corrections.

Patients with preoperative spherical equivalent refraction up to –10.38 D, cylinder up to 5 D and corrected distance visual acuity of 20/25 or better were included. There were no nomogram adjustments. Patients were followed for 3 months.

Mean preoperative spherical equivalent refraction was –3.83 D, and mean preoperative cylinder was –0.94 D. Preoperative corrected distance visual acuity was 20/20 or better in 97% of eyes.

Mean predictability of spherical equivalent refraction was –0.13 D. Postoperative spherical equivalent refraction was 0.5 D in 88% of eyes and 1 D in 100% of eyes.

Postoperative uncorrected distance visual acuity was 20/20 or better in 92% of eyes and 20/25 or better in 99% of eyes.

One line of corrected distance visual acuity was lost in 6% of eyes; no eyes lost two or more lines.

Mesopic contrast sensitivity improved significantly at 3 and 18 cycles per degree (P = .021 and P ≤ .001, respectively). – by Matt Hasson

Disclosure: Reinstein reports he is a consultant for Carl Zeiss Meditec and has a proprietary interest in Artemis technology (ArcScan). The other authors report no relevant financial disclosures.

Perspective

Richard J. Duffey, MD

The authors have shown that they can double the speed of the Mel 90 laser compared with the earlier Mel 80 and not compromise the precision of outcomes for low, moderate and high myopia patients undergoing LASIK. With manipulation of software to minimize thermal damage to the corneal stromal bed in the face of 500-Hz repetition rate ablation, the laser is capable of correcting 1 D of myopia per 1.2 seconds of treatment. This rapid treatment showed excellent refractive outcomes with a slight reduction in contrast sensitivity loss for patients. All in all, this is a positive step forward for patient comfort and visual outcomes.

Richard J. Duffey, MD

OSN Refractive Surgery Board Member

Disclosures: Duffey reports no relevant financial disclosures.

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Source:

Reinstein DZ, et al. J Refract Surg. 2015;doi:10.3928/1081597X-20150423-05.