Comparison of ray tracing-guided LASIK versus SMILE Pro for myopic and astigmatic correction
| ISRCTN | ISRCTN15458241 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN15458241 |
| Secondary identifying numbers | IIT #90760251 |
- Submission date
- 06/07/2025
- Registration date
- 11/07/2025
- Last edited
- 11/07/2025
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Eye Diseases
Plain English summary of protocol
Background and study aims
This study is designed as a contralateral eye comparison of two advanced refractive surgical techniques. Approximately ten years after the original comparison, the investigators repeat the evaluation using updated technologies. One eye undergoes ray tracing–optimised LASIK using the FS200 femtosecond laser and the EX500 excimer laser (Alcon/Wavelight), enhanced by the Sightmap diagnostic device and Wavelight Plus optimisation software. The contralateral eye is treated with SMILE Pro, the latest iteration of small incision lenticule extraction, performed using the Visumax 800 femtosecond laser. Both procedures are well-established, widely used in clinical practice, and supported by robust safety and efficacy data. The study aims to assess potential differences in visual acuity outcomes between these two enhanced surgical approaches.
Who can participate?
Otherwise healthy patients aged between 18 and 45 years with stable myopia or myopic astigmatism for at least 12 months before surgery.
What does the study involve?
This investigation was designed as a prospective, randomly allocated, within-person, contralateral eye clinical trial conducted at the Laservision Clinical and Research Institute in Athens, Greece. The contralateral eye design was deliberately chosen to eliminate inter-subject variability, allowing for a more precise comparison of the two refractive surgical techniques. By treating each patient with both procedures—SMILE Pro in one eye and wavelight plus customized femtosecond laser-assisted LASIK in the other—systemic, anatomical, and environmental factors were inherently controlled, enhancing the internal validity of the outcomes.
The study adhered to the tenets of the Declaration of Helsinki and received approval from the Laservision Ambulatory Surgical Center Institutional Ethics Board. Informed consent was obtained from all participants before enrollment.
What are the possible benefits and risks of participating?
No benefits and risks given at registration
Where is the study run from?
Alcon Greece
When is the study starting and how long is it expected to run for?
January 2025 to June 2025
Who is funding the study?
Alcon Greece
Who is the main contact?
A. John Kanellopoulos, MD, ajkmd@mac.com
Contact information
Public, Scientific, Principal Investigator
15-17 Tsocha Street
Athens
11521
Greece
 ORCID ID |
0000-0003-3595-3517 |
|---|---|
| Phone | +30210 7472777 |
| ajkmd@mac.com |
Study information
| Study design | Single-centre within-person randomized contralateral eye study |
|---|---|
| Primary study design | Interventional |
| Secondary study design | Randomised controlled trial |
| Study setting(s) | Medical and other records |
| Study type | Treatment, Safety, Efficacy |
| Scientific title | Contralateral eye comparison of femto-second laser-assisted, ray tracing-guided LASIK vs small incision lenticule extraction (SMILE Pro) for myopic and astigmatic correction calculated by ray tracing rather than conventional manifest refraction in all eyes |
| Study acronym | wpLASIKvsSMILEpro |
| Study objectives | Raytracing optimised LASIK will result in more lines of vision gained than Smile Pro in the correction of myopia in a contralateral eye study. |
| Ethics approval(s) |
Approved 01/01/2025, Ethics Committee for the Laservision Ambulatory Surgical Unit EC (15 Tsocha Street, Athens, 11521, Greece; +30 210 7472777; info@laservision.gr), ref: 2527 |
| Health condition(s) or problem(s) studied | Refractive error correction |
| Intervention | All participants are treated for correction of myopia with or without astigmatism. The intervention will be either raytracing optimised LASIK or Smile Pro, both laser-assisted lamellar procedures on the cornea. The contralateral eye design was deliberately chosen to eliminate inter-subject variability, allowing for a more precise comparison of the two refractive surgical techniques. By treating each patient with both procedures—SMILE Pro in one eye and Wavelight Plus customized femtosecond laser-assisted LASIK in the other—systemic, anatomical, and environmental factors were inherently controlled, enhancing the internal validity of the outcomes. Randomization of the procedure to either the right or left eye was computer-generated to avoid selection bias. |
| Intervention type | Procedure/Surgery |
| Primary outcome measure | Lines of vision gained, comparing preoperative best corrected distance acuity, measured using data collected from patient records, measured at baseline and 3 months following each procedure |
| Secondary outcome measures | 1. % of eyes with defocus equivalent within ±0.25D, ±0.50D, ±0.75 and ±1.0D measured using subjective manifest refraction at baseline and 3 months 2. % of eyes with absolute MRSE (manifest refraction spherical equivalent) within ±0.25D, ±0.5D, ±0.75 and ±1.0D measured using subjective manifest refraction again at baseline and 3 months 3. % of eyes with UCDVA and BCDVA of 20/10, 20/12.5, 20/16, 20/20, 20/25, 20/32, or better measured using subjective manifest refraction at baseline and 3 months 4. Lines of vision gained in LogMAR (defined as the change in pre-CDVA to post-op CDVA (1 week and 1 month) and pre-CDVA to post UDVA at all time points), measured using subjective manifest refraction at baseline and 3 months |
| Overall study start date | 01/01/2025 |
| Completion date | 01/06/2025 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Upper age limit | 45 Years |
| Sex | Both |
| Target number of participants | 60 |
| Total final enrolment | 68 |
| Key inclusion criteria | 1. Age between 18 and 45 years 2. Stable myopia or myopic astigmatism for at least 12 months before surgery, within the following limits: Preoperative myopia from -1 to -8 D (minimum spherical equivalent -2D) and up to -3 D of astigmatism. Stable refraction (within ± 0.50 D) as determined by manifest refraction spherical equivalent for a minimum of 12 months before surgery, verified by consecutive subjective refractions or medical records or prescription history. 3. Preoperative corrected distance visual acuity (CDVA) of 20/20 or better in both eyes 4. Minimum central corneal thickness of 500µm 5. Absence of ocular surface disease or significant dry eye 6. Willingness to comply with the postoperative follow-up schedule |
| Key exclusion criteria | 1. Anisometropia >1D in sphere and >0.5D cylinder between the eyes 2. History of ocular surgery or trauma 3. History or clinical evidence of dry eye. 4. Evidence of corneal ectatic disorders such as keratoconus or pellucid marginal degeneration 5. Presence of corneal scars, opacity, or other structural abnormalities 6. Active ocular inflammation or infection 7. Systemic conditions affecting wound healing (e.g., uncontrolled diabetes, autoimmune disorders) |
| Date of first enrolment | 01/01/2025 |
| Date of final enrolment | 01/03/2025 |
Locations
Countries of recruitment
- Greece
Study participating centre
athens
11521
Greece
Sponsor information
Industry
Agiou Thoma 27
Marousi
15124
Greece
| Phone | +30 21 0687 8300 |
|---|---|
| argiris.apiranthitis@alconlabs.com | |
| Website | https://www.alcon.com/ |
Funders
Funder type
Industry
No information available
Results and Publications
| Intention to publish date | 01/01/2026 |
|---|---|
| Individual participant data (IPD) Intention to share | Yes |
| IPD sharing plan summary | Available on request |
| Publication and dissemination plan | Planned publication in the Journal of Refractive Surgery or similar journal |
| IPD sharing plan | The datasets generated during and/or analysed during the current study will be available upon request. • The name and email address of the investigator/body who should be contacted for access to the datasets: Anastasios John Kanellopoulos, MD, ajkmd@mac.com • The type of data that will be shared: all informed consent, preoperative data and postoperative evaluations, along with analysed statistical comparison data on all outcomes measured, along with any adverse effects noted • Timing for availability: up to 10 years • Whether consent from participants was required and obtained: it is required and will be obtained from all participants • Comments on data anonymization: All data will be anonymised and used only identified by number from 1 to 60 allocated at the time of enrolment |
Editorial Notes
11/07/2025: Study's existence confirmed by the Ethics Committee for the Laservision Ambulatory Surgical Unit EC.
