The circle procedure
There is just one official touch-up technique for SMILE, known as the circle procedure. A series of four circle patterns that are programmed into the femtosecond laser (VisuMax, Carl Zeiss Meditec) can be used to create a corneal flap after a previous SMILE procedure.
The surgeon will convert the original SMILE incision pocket into a LASIK-like flap that is easily lifted for stromal ablation of the residual refractive error with an excimer laser. With the circle procedure, the patient loses the flap-free approach, which comes along with all the possible complications of creating the flap.
In a prospective, single-centre case study series, researchers followed 27 patients 3 months after the circle procedure to assess its efficacy and safety. Efficacy was determined by the surgeon’s ability to lift the created corneal flap.
In 100% of cases, the flap lift was possible, as planned. No eyes lost two or more Snellen lines of corrected distance visual acuity and no procedure or flap-related complications or serious adverse events occurred. Researchers concluded that the circle technique is a suitable method for correction following SMILE.6