Clinical Case Of Laser Correction For Supermyopia (-20.0 D) And Astigmatism (-9.0 D) Using The Multi-Zone Ablation Method With Mel-90 And Visumax 500

To present a case description of a young patient undergoing laser vision correction due to high myopia.

Case Description: A 20-year-old, otherwise healthy male, a store employee, presented to our clinic for laser vision correction due to high myopia. Upon examination, ultrahigh myopia (SUPERMYOPIA) was diagnosed in both eyes: Right Eye (OD): UCDVA – 0.01; BCDVA – Sph -20.0 D, Cyl -6.0 D, ax 10° = 0.3; Left Eye (OS): UCDVA – 0.01; BCDVA – Sph -20.0 D, Cyl -7.0 D, ax 165° = 0.3.

These measurements are crucial for assessing the suitability of the patient for refractive surgeries.

In general, a central corneal thickness (CCT) of 540 ± 30 µm is considered normal.

The average keratometry (AvK) values of 47.25 D and 47.50 D are within the typical range for healthy eyes.

The spherical equivalent (SE) values of -25.12 D and -24.62 D indicate high myopia.

The density of endothelial cells of 2,669 cells/mm² and 2,730 cells/mm² is within the normal range.

Multi-zone ablation using FemtoLASIK technology involves creating a thin corneal flap, typically around 80 microns in thickness. The first stage of laser ablation is performed according to the Triple-A algorithm, which aims to eliminate the spherical component of refractive error. In this case, a -3.0 diopter spherical correction is applied over a wide optical zone of 6.3 mm in both eyes. Approximately 10–15 seconds after the first stage, the second stage of laser ablation is conducted, also following the Triple-A algorithm.

– 2 months later post-op multi-zone FemtoLASIK surgery:

    UCDVA OD = 0,4 (!)

    UCDVA OS = 0,5 (!)

FemtoLASIK multi-zone ablation can be one of the methods of lrefractive surgery correction in patients with ultra-high myopia

Multi-zone excimer laser ablation using FemtoLASIK technology is possible in the absence of general and ocular contraindications to laser vision correction in patients with thick corneas and normal density of corneal endothelial cells in such a way that the resudual stromal thickness (RCT) remains at least 250 - 300 mcm

Important technological features of the multi-zone FemtoLASIK are the сutting of a very thin corneal flap on the “VISUMAX” femtosecond laser and the use of two zones of excimer laser ablation on a modern high-speed “MEL-90” laser (“Carl Zeiss”)