Off-Label Use Of Edge Cut Only Function On Schwind Atos To Convert Caps To Flaps For Enhancement After Klex

To explore options of enhancements after KLEx surgery on Schwind ATOS. 

So far officially after KLEx surgery on Schwinad ATOS the only options were - surface ablation or a LASIK with a thin flap above the cap or a LASIK below the originally lenticule. All there options had some potential issues, Zeiss has successfully deployed an addition - CIRCLE for the Visumax Femtosecond platform. Within ATOS software 1.6.1.1 an option for creating an edge cut only in the flap creation option was enabled. The goal was to see if this can be used off-label to enhance patients after SmartSight. 

Eye Clinic Svjetlost, Zagreb, Croatia 

I wish to report 24 cases of attempted use of the edge cut only option to convert a KLEx cap into a LASIK flap for enhancement. During the first year of KLEx surgery on ATOS at our centre we applied the rule of cap being 0.5 mm larger than intended total zone, but as time went on and as the Schwind KLEx geometry has 0 micron edges there was no penalty to make all caps 9mm (maximal allowed size) to enable easier intercept in the event of needed conversion from cap to flap. Also as the ATOS has semi-automated centration and rotation control it was very easy to know where the centre of mass and therefore the centre of the cap was placed during original surgery. With the software update package of 1.6.1.1 from December 2023 an option was enabled to use edge cut only for flaps. As I had a few patients who were scheduled for enhancement after KLEx i suggested to them we try this option, with PRK being a backup. As the first few cases were perfect we then proceeded to more liberally use the option. So far we have attempted 24 cap-to-flap conversions, our success rate was 95.3%. 23 caps were converted to flaps with no issues, minimal epithelial damage and next day UCVA of 20/20 or better, 1 cap was not intercepted correctly (the cap was originally just 7.5 mm) and after attempting to open it we proceeded with manual epithelium removal and PRK ablation, the patient recovered fully and was plano after 10 days.

Although still not approved by the company this new option can be applied with a high degree of success to enhance patients after lenticule extraction surgery. The semi-automated guidance from ATOS can increase the success rate of the interception of the cap edges to maximise the flap diameter for better enhancement options. Use of maximal cap size of 9 mm without regard for lenticule size enables good sized flaps of 8.5 mm with minimal risk of conversion to PRK.