Complications with SMILE
Most SMILE intraoperative complications related to learning curve
Most of the intraoperative complications encountered in small incision lenticule extraction (SMILE®) procedures seem to be related to initial surgical inexperience with the technique, according to a study presented at the 37th Congress of the ESCRS in Paris.
“We think that the inexperience of the surgeon at the beginning of the learning curve, and in particular the inability to detect the edge of the lenticule with numerous attempts of dissection above or below the lenticule, is the major cause of most intraoperative complications,” said Ahmed El Shahed MD.
Dr El Shahed presented the results of a retrospective study by Abdelmonem M Hamed MD of 282 eyes of 141 patients who underwent SMILE surgery for myopia and/or myopic astigmatism at Ebsar Eye Center, Benha, Egypt.
Suction loss was found to be the biggest complication, occurring in 18 eyes (6.4%), followed by treatment decentration in six eyes (2.1%), wound bleeding in 21 eyes (7.4%), incomplete bubble separation in three eyes and epithelial defects in 15 eyes (5.3%).
To avoid problems of suction loss, Dr El Shahed said it was important to select the appropriate cone size according to corneal diameter and to use a globe fixator if necessary to ensure successful engagement of suction.
In cases where suction was lost before the total creation of the lenticule, the procedure could be aborted and rescheduled after the reabsorption of the cavitation bubbles, said Dr El Shahed. If the lost suction occurred after the total creation of the lenticule or during the creation of the cap, the eye could be re-docked and the surgeon could restart the cap, side cut and wound creation and dissect it normally, he said.
Decentration can have a significant effect on vision outcomes in SMILE procedures. In the absence of an eye tracker it is important to ensure that the patient is correctly self-fixating on the green microscope light in order to correctly align the treatment on the pupil centre, said Dr El Shahed.
Intraoperative wound bleeding is more likely to occur in patients with vascular pannus, noted Dr El Shahed, while the risk of black islands appearing from incomplete bubble separation happens due to meibomian secretions or debris at the interface of the cone and the cornea during docking.
“We can overcome this type of issue by washing the eye with BSS before docking and ensure optimal hydration of the cornea before proceeding with the surgery,” he said.
Further studies with larger patient numbers were required to evaluate intraoperative complications during SMILE and standardise management strategies, he said.
Ahmed El Shahed: email@example.com