“Cliff Sign” To Identify Anterior And Posterior Lenticular Plane In Small-Incision Lenticule Extraction.

To elucidate the “Cliff Sign” that helps to identify anterior and posterior lenticular plane in small-incision lenticule extraction to prevent inadvertent cap lenticular adhesion, cap or lenticule tears, partial lenticular dissection.

Dr Om Parkash Eye Institute

In this technique, hooked end of the lamellar dissector was used to open the cap side cut. Same instrument was used to delineate the anterior dissection plane on one side of the side cut(left hand side for the right handed) to facilitate small anterior pocket creation and was also used to delineate the posterior dissection plane on the other side of the side cut to create posterior pocket.Prior to final dissection of anterior plane,lifting of cap by arm of blunt dissector at the junction of dissected anterior and  posterior planes reveals a sloping lenticule tissue ridge rising from the bed as the lenticule is attached to the cap on one side and to the stromal bed on the other side.This confirmatory sign guides entry into the correct plane.

This technique was successfully undertaken in 50 eyes of 25 patients. Cliff sign was observed in all cases, and no case had cap lenticular adhesions.Visualisation of Cliff sign validates whether or not we are in the correct plane and this reconfirmation gives surgeon confidence to proceed with the correct dissection. i.e. anterior plane prior to the posterior plane.Absence of the sign exhibits the inadvertent entry into the posterior plane because the lenticule unintentionally gets attached to the cap as the instrument is moved.This helps the surgeon to terminate entry into the posterior plane at the initial step itself .With that the surgeon is given another chance at trying to find the anterior plane in non dissected half of the lenticule

Cliff sign offers a new confirmatory sign for correct dissection of anterior and posterior lamellas.The confirmatory sign gives a go ahead for proceeding with the final separation of the cap and the Lenticule. The absence of cliff sign cautions the surgeon and indicates the need to find the anterior plane in the non dissected half of the lenticule