Superior or inferior lenticule interface identification and dissection: impact on outcomes in SMILE

Session Details

Session Title: Femtosecond Small Lenticule Extraction II

Session Date/Time: Tuesday 08/09/2015 | 16:30-18:30

Paper Time: 17:00

Venue: Room 17

First Author: : D.Reinstein UK

Co Author(s): :    G. Carp   T. Archer   M. Gobbe              

Abstract Details

Purpose:

The established routine surgical protocol of small incision lenticule extraction (SMILE) has been to dissect the upper interface followed by the lower interface of the lenticule. If the lower interface is dissected first, it can be challenging to complete the dissection with SMILE aborted and switched to LASIK or PRK. We reviewed the incidence of unintended lower interface dissection, the rate of procedure abortion and the visual outcomes.

Setting:

London Vision Clinic, London, UK

Methods:

Retrospective analysis of 629 consecutive SMILE eyes using the VisuMax femtosecond laser. The routine surgical protocol was to open the 2-mm supero-temporal incision to delineate the upper and lower lenticule planes, then separate the upper followed by the lower interface. If the lower interface was dissected first, the sinskey tip was inserted sideways into the incision, then rotated tip upwards to engage the lenticule edge. The tip was moved in a nasal direction to release the lenticule edge, enabling the spatula to dissect the upper interface. A scale of 1-5 was used to assess the ease of dissecting each interface.

Results:

The routine surgical protocol (upper first) was followed in 555 (88%), and lower first in 74 (12%) of eyes. The lenticule was extracted successfully in all cases. In the upper interface group, mean ease of dissection was 1.25 (upper interface) and 1.29 (lower interface). In the lower interface group, this was 1.16 (upper interface) and 1.14 (lower interface). Safety index was 1.06 (upper interface group) and 1.11 (lower interface group). UDVA at day one was 20/25 or better in 81% for the upper group and 86% for the lower group (no statistically significant difference).

Conclusions:

Using a point up sweep technique enabled consistent identification of the superior lenticule interface in patients where the lower interface had inadvertently been dissected first with no cases of aborted procedure (95% C.I. 0-0.5%). Visual outcomes and safety were comparable between cases with an initial upper or lower interface dissection.

Financial Interest:

One of the authors receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented