SMILE for hyperopia: optical zone centration, diameter and aberration induction

Session Details

Session Title: Smile: Small Intrastromal Lenticule Extraction II

Session Date/Time: Tuesday 13/09/2016 | 16:00-17:30

Paper Time: 17:06

Venue: Hall C3

First Author: : K.Pradhan NEPAL

Co Author(s): :    D. Reinstein   P. Dhungana   G. Carp   T. Archer   R. Khan        

Abstract Details

Purpose:

To evaluate optical zone centration, optical zone diameter, and aberration induction of small incision lenticule extraction (SMILE) for hyperopia.

Setting:

Tilganga Institute of Ophthalmology, Kathmandu, Nepal

Methods:

Prospective study of vertex-centered hyperopic SMILE using the VisuMax femtosecond laser. Inclusion criteria were intended sphere ≤+7.00D, astigmatism ≤6.00D, and age ≥21 years. Lenticule parameters were 6.3-6.5mm diameter optical zone, 2mm transition zone, 30μm minimum thickness, and 120μm cap. The study was phased by CDVA, from dense amblyopia to sighted eyes. Atlas topography was obtained before and 3 months after surgery for 58 eyes. Optical zone centration, diameter (from tangential curvature difference maps), and corneal spherical aberration were analyzed for all eyes and compared to MEL80 LASIK matched control groups for 6.5mm and 7mm optical zones.

Results:

Mean attempted SEQ was +5.58±0.95 D (+3.20 to +6.50 D). Mean astigmatism was 1.22±1.00 D (0.00 to 2.75 D). Mean optical zone offset was not different between SMILE and LASIK (p>0.15); 0.29±0.21 mm in SMILE, 0.34±0.14 mm in 6.5 mm LASIK, and 0.32±0.20 mm in 7 mm LASIK. Mean achieved optical zone diameter was 4.99±0.34 mm for 6.3 mm SMILE; equivalent to 7 mm LASIK (4.95±0.23 mm, p>0.05), but greater than 6.5 mm LASIK (4.51±0.21 mm, p<0.01). Mean spherical aberration change was -0.52 μm in 6.3 mm SMILE, equivalent to 7 mm LASIK (-0.49 μm, p=0.916), but less than 6.5 mm LASIK (-0.69 μm, p<0.01).

Conclusions:

Optical zone centration was equivalent between vertex-centered hyperopic SMILE and LASIK. Achieved topographic optical zone diameter for 6.3 mm SMILE was equivalent to 7 mm LASIK and larger than 6.5 mm LASIK. Consequently, less spherical aberration was induced by 6.3 mm SMILE than 6.5 mm LASIK and was equivalent to 7 mm LASIK.

Financial Disclosure:

... receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented, ... travel has been funded, fully or partially, by a company producing, developing or supplying the product or procedure presented