gms | German Medical Science

The primary goal of corneal laser refractive surgery is the correction of ametropia. Excimer laser treatments evolved from simple myopic ablations using the subjective refraction to the most sophisticated topography- or wavefront-guided treatments.

Which procedure shall we use today?

There are aspheric (wavefront-optimized) profiles and customized treatments (wavefront based or topography based profiles).

Laser treatments should be performed using at least an aspheric (wavefront-optimized) ablation pattern to preserve the preoperative level of higher-order aberrations and to prevent or minimize the induction of spherical aberration.

Patients with gross irregularities of the cornea e.g. due to scars, decentration after laser treatment or irregular astigmatism after keratoplasty will benefit from a topography-guided treatment. The first step will then be to regularize the cornea; a second treatment might be necessary to also correct the residual refractive error.

Some laser systems have shown to provide better results using wavefront-guided (WG-) profiles compared to wavefront-optimized profiles. WG-treatments in general should be taken into account for all retreatments, if the preoperative higher order aberration RMS value is high (>0.3 µm), the visual acuity is <20/20 in eyes with clear media, the mesopic pupil diameter is >6 mm or if the patient complains about bad visual quality.

For a successful customized treatment the delivery of the ablation to the exact corneal location is necessary. Therefore eye tracking and iris registration are mandatory to compensate for cyclotorsion and pupil centroid shift.

The most appropriate ablation pattern has to be chosen based on the eye’s anamnesis, diagnosis and visual demands.

Specific patients with specific demands require specific treatment solutions.