Lisbon 2017 Delegate Registration Programme Exhibition Virtual Exhibition Satellites OneWorld Travel Discount
escrs app advert

Optimized asphericity after SmartSurf PRK

Search Title by author or title

Session Details

Session Title: Presented Poster Session: Keratorefractive Results I

Venue: Poster Village: Pod 2

First Author: : J.Hogden CANADA

Co Author(s): :    S. Holland   D. Lin   S. Mosquera   N. Davey     

Abstract Details


Asphericity optimized corneal treatments are a contemporary and welcome addition to the refinement of laser refractive surgery. The maintenance of natural asphericity is important when considering all parameters of laser refractive surgery. The purpose of our study is to assess the postoperative asphericity in low, moderate and high myopic eyes after SmartSurfACE PRK treatment and discuss the impact of this asphericity on visual function.


This retrospective study was based on a series of patients (106 eyes) treated by two surgeons, with the SmartSurfACE technique to correct myopic astigmatism, at the Pacific Laser Eye Centre, Vancouver, Canada.


A retrospective study was performed analyzing outcomes of myopic SmartSurfACE at 3-month follow-up in 106 eyes and divided into low (less than -4.125D), moderate (-4.125D to -6.25D) and high myopia (more than -6.25D) groups. All the treatments were prepared using the SCHWIND Custom Ablation Manager in Aberration-Free mode (SCHWIND eye-tech-solutions GmbH and Co. KG, Kleinostheim, Germany). SmartSurfACE treatment planning based on the total manifest refraction (sphere + cylinder correction in diopters). Corneal asphericity was extracted from the corneal topography both pre- and post-operatively.


At 3 months postoperatively the low myopia group (n = 33) improved average negative asphericity (Q = -0.04±0.17 Preop Vs. -0.19±0.20 post-op, p<0.05). The moderate myopia group (n = 35) maintained or slightly improved average negative asphericity (Q = -0.07±0.14 Preop Vs. -0.05±0.24 post-op, p=0.35). For the high myopia group (n = 38), the eyes became more oblate compared to the preoperative status (Q = -0.09±0.15 Preop Vs. 0.62±0.70 post-op, p<0.05). In terms of asphericity, the difference between the three groups was not statistically significant preoperatively (p>0.1), but showed significant differences postoperatively (p<0.007).


The preservation of low negative Q values with SmartSurfACE post-treatment likely benefit the emmetropic presbyopic group of patients, many of whom will also have or develop progressive spherification (Q value approaching 0) of their crystalline lens and therefore benefit from the negative asphericity of their corneas post treatment. In our study SmartSurfACE maintained or slightly improved preoperative corneal asphericity for low to moderate myopic corrections (up to -6D). This may provide advantages in the quality of vision and in the onset of presbyopic symptoms after laser refractive surgery in myopic patients.

Financial Disclosure:

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

Back to previous