Sli-Cat: Streamlight Assisted Customized Ablation Treatment

To discuss the use of the refractive neutral StreamLight trans-epithelial PTK function, in combination with a topography guided treatment in aberrated corneas. The dicsussion indicates approach to this treatment modality helping understand the influence of both the epithelium and anterior stroma on topography.

All cases were completed by a single surgeon, Dr DA Joseph in Knysna, South Africa in private practice. Patients were selected based on abnormal topography, their data collected by the Vario topolyxer and transferred to the WaveLight EX500 laser.

Epithelial mapping was interpretted using the MS39 device and refractive change for the trans-epithelial component taken into account when calculating the nett treatment. 

The surgery was done on the same day under two programmed laser profiles, one being the refractive neutral or targeted refractive outcome on the StreamLight program, the second being a topography guided laser treatment, with or withour refractive data input.

Cases were worked up with assistance from Phoricdes software to interpret vector analysis and influence of corneal higher orders on refractive outcomes.

The paper discusses the approach to the procedure using a few cases to highlight how topography can be improved on using both a trans-epithelial PTK approach and a topography guided laser apporach simulateneously.

The benefit of understanding and utilizing the Phrocides software helps us achieve a refractive target too, which is traditionally difficult when applying a topography guided apporach alone.

The laser ablations can be done either with the topgraphy guided portion first followed by the epithelial component which is my preference on the WaveLight, or it can be done the other way around. 

SLi-CAT is a novel tool that can help the surgeon treat the full topographic error, that being both the influence of the epithelium and anterior stroma on the refractive and topographic abnormalities. Using the Phorcides software in our approach helps understand vector analysis of all the components repsonsible for the irregular topographic data, and helps us refine refractive outcomes at the same time.