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Evaluation of Different Lenticule Diameters in Myopic Astigmatism Correction With SMILE Procedures

NCT06062004 · Status: UNKNOWN · Phase: NA · Type: INTERVENTIONAL · Enrollment: 50

Last updated 2023-10-02

No results posted yet for this study

Summary

Small incision lenticule extraction (SMILE) is a refractive intrastromal procedure for myopia and myopic astigmatism correction. Most of the studies evaluating astigmatic correction by SMILE reported astigmatic under-correction, especially in high degrees of astigmatism.

This under-correction could be due to: first, the active eye tracker or the iris registration is not yet available to overcome the cyclotorsion that occurred during the treatment with the VisuMax femtosecond laser system (Carl Zeiss Meditec, Jena, Germany) which could be overcome by manual compensation technique, especially in higher degrees of cylinders (\> 1.5 diopters (D)). Second, in patients with small lenticule diameters, the more abrupt change in thickness at the edge of the treated area could induce more stromal and epithelial healing in this area. Thus, the astigmatic correction would be less effective with small than large lenticule diameters for similar high preoperative astigmatism.

This study assessed the outcome of using a 0.5 millimeter (mm) larger lenticule diameter in the fellow eyes of myopic astigmatic correction SMILE participants. This assessment included the safety and effectiveness indices, the refractive and visual outcomes, the contrast sensitivity, and some morphological outcomes such as corneal curvature and epithelial and corneal thickness.

Conditions

  • Refractive Errors
  • Myopic Astigmatism

Interventions

PROCEDURE

Small Incision Lenticule Extraction (SMILE)

All surgeries will be performed under topical anesthesia using the VisuMax femtosecond laser with the following parameters: * Cap thickness of 120 μm * Cap diameter of 1 mm larger than the lenticule diameter * Cap side cut angle 70° * 3 mm incision positioned at 100° and angled at 45° * Transition zone of 0.1 mm and clearance of 0.5 mm * Lenticule side cut angle of 90° and edge lenticule thickness of 15 μm

Sponsors & Collaborators

  • Al Watany Eye Hospital

    lead OTHER

Study Design

Allocation
NON_RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Model
PARALLEL

Eligibility

Min Age
18 Years
Max Age
50 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2018-11-27
Primary Completion
2024-02-28
Completion
2024-04-30

Countries

  • Egypt

Study Locations

More Related Trials

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT06062004 on ClinicalTrials.gov