Therapeutic Excimer Laser-Based Surgery for SMILE Complications

In this chapter, we describe the diagnostic approach in cases of irregular astigmatism using front surface corneal topography and epithelial thickness mapping. Topography-guided custom ablation is an appropriate, safe and effective method for the treatment of global irregularities such as a zone enlargement or decentration. In cases of irregularly irregular astigmatism with localised irregularities, the natural compensatory mechanism of epithelial remodelling acts to mask a proportion of the stromal surface irregularity from front surface corneal topography. In these cases, the more appropriate and effective treatment is a trans-epithelial phototherapeutic keratectomy (PTK), which uses the epithelium as a natural masking agent to target the ablation onto the raised areas of stroma where the epithelium is thinnest.