White Ring Sign and Sequential Segmental Terminal Lenticular Side Cut Dissection for Uneventful and Complete Lenticular Extraction in SMILE.

We wanted to congratulate Ng et al.1 for describing an effective lenticular hydration technique for identification and extraction of a lenticular remnant after small incision lenticule extraction (SMILE). We also agree with their observation that prevention is the best solution for this condition and we would like to add here two techniques described by one of us (SJ) to facilitate easy extraction and to prevent lenticular tears. The first is the white ring sign, which prevents unintentional initial posterior dissection and thereby a lenticule adherent to the cap.2 This sign uses the anteroposterior relationship between the dissecting instrument and the circular light reflex (the white ring) thrown by the lenticular side cut. Anterior dissection should be performed first and this can be confirmed by seeing the instrument in front of the white ring (Figure 1A). This is followed by dissecting the refractive cut or the posterior plane and is confirmed when the white ring is seen over the dissecting instrument (Figure 1B). This technique helps identify unintentional initial dissection posterior to the lenticule. The second technique is the sequential segmental terminal lenticular side cut dissection.3 This facilitates complete dissection and prevents lenticular tears by breaking down dissection of the lenticular side cut into small segments while keeping undissected anchored segments on either side to prevent lenticular movement. This is especially useful in thin lenticules where the risk of tearing the lenticule during dissection is higher (Figures 1C and 1D).