Refractive Errors Clinical Trial
Official title:
Evaluation of Different Lenticule Diameters in Myopic Astigmatism Correction With SMILE Procedures
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.
Status | Recruiting |
Enrollment | 50 |
Est. completion date | April 30, 2024 |
Est. primary completion date | February 28, 2024 |
Accepts healthy volunteers | Accepts Healthy Volunteers |
Gender | All |
Age group | 18 Years to 50 Years |
Eligibility | Inclusion Criteria: - Age groups between 18 and 50 years - Myopic astigmatism with up to -10.00 D spherical equivalent (SE) and a minimum astigmatism of -1.0 D and a maximum of -5 D. The astigmatism will be divided into low astigmatism (<0.75 D), moderate astigmatism (1.5- 3 D) and high astigmatism (>3 D). - Corrected distance visual acuity (CDVA) of 0.7 or better (decimal) Exclusion Criteria: - Thin corneas (< 490 µm) - Proven or suspicious cases of corneal ectatic conditions by corneal tomography - Previous ocular surgeries - Patients taking systemic steroids, immunosuppressants, oral contraceptives, or antidepressants - Pregnant females - Corneal scars or any ocular pathology likely to affect visual outcomes |
Country | Name | City | State |
---|---|---|---|
Egypt | Al Watany Eye Hospital | Cairo |
Lead Sponsor | Collaborator |
---|---|
Al Watany Eye Hospital |
Egypt,
Ganesh S, Brar S, Pawar A. Results of Intraoperative Manual Cyclotorsion Compensation for Myopic Astigmatism in Patients Undergoing Small Incision Lenticule Extraction (SMILE). J Refract Surg. 2017 Aug 1;33(8):506-512. doi: 10.3928/1081597X-20170328-01. — View Citation
Ivarsen A, Hjortdal J. Correction of myopic astigmatism with small incision lenticule extraction. J Refract Surg. 2014 Apr;30(4):240-7. doi: 10.3928/1081597X-20140320-02. — View Citation
Pedersen IB, Ivarsen A, Hjortdal J. Changes in Astigmatism, Densitometry, and Aberrations After SMILE for Low to High Myopic Astigmatism: A 12-Month Prospective Study. J Refract Surg. 2017 Jan 1;33(1):11-17. doi: 10.3928/1081597X-20161006-04. — View Citation
Sekundo W, Kunert KS, Blum M. Small incision corneal refractive surgery using the small incision lenticule extraction (SMILE) procedure for the correction of myopia and myopic astigmatism: results of a 6 month prospective study. Br J Ophthalmol. 2011 Mar;95(3):335-9. doi: 10.1136/bjo.2009.174284. Epub 2010 Jul 3. — View Citation
Zhang J, Wang Y, Wu W, Xu L, Li X, Dou R. Vector analysis of low to moderate astigmatism with small incision lenticule extraction (SMILE): results of a 1-year follow-up. BMC Ophthalmol. 2015 Jan 24;15:8. doi: 10.1186/1471-2415-15-8. — View Citation
Type | Measure | Description | Time frame | Safety issue |
---|---|---|---|---|
Primary | The safety index of using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism | The safety index (unitless parameter) is calculated as postoperative CDVA/ preoperative CDVA (both in decimal units). | up to 6 months | |
Primary | The efficacy index of using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism | The efficacy index (unitless parameter) is calculated as postoperative UDVA/ preoperative CDVA (both in decimal units). | up to 6 months | |
Secondary | Refractive outcomes of using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism. | To compare subjective refractive outcomes including spherical equivalent and residual astigmatism (in diopters) of SMILE procedure using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism. | up to 6 months | |
Secondary | Visual acuity outcomes of using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism. | To compare postoperative UDVA and CDVA (in logMAR) of SMILE procedure using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism. | up to 6 months | |
Secondary | Contrast sensitivity outcomes of using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism. | To compare postoperative photopic and mesopic contrast sensitivity (in log unit) at 3, 6, 12, and 18 cycles per degree of SMILE procedure using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism. This will be done using the CSV1000E device (Good-Lite, Elgin, IL, USA) | up to 6 months | |
Secondary | Corneal curvature changes after SMILE procedure using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism. | To compare postoperative corneal curvature in flattest and steepest meridia (in keratometric diopters) after SMILE procedure using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism. This will be done using the Pentacam high resolution (HR) (Oculus Optikgeräte, Wetzlar, Germany). | up to 6 months | |
Secondary | Corneal structural changes after SMILE procedure using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism. | To compare postoperative and central corneal and epithelial thickness (in micrometers) and standard deviation of epithelial thickness in different locations (in micrometers) after SMILE procedure using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism. This will be done using the anterior segment OCT (Cirrus HD-OCT, Carl Zeiss Meditec, Jena, Germany) | up to 6 months |
Status | Clinical Trial | Phase | |
---|---|---|---|
Completed |
NCT04532099 -
Clinical Comparison of Two Daily Wear Frequent Replacement Silicone Hydrogel Soft Contact Lenses
|
N/A | |
Completed |
NCT05039112 -
Clinical Comparison of 2 Daily Disposable Toric Soft Contact Lenses
|
N/A | |
Completed |
NCT03670303 -
Trial of an Educational Intervention to Promote Spectacle Use Among Secondary School Children in Islamabad, Pakistan
|
N/A | |
Completed |
NCT02255474 -
Bifocal Lenses In Nearsighted Kids
|
N/A | |
Not yet recruiting |
NCT03222661 -
Direct Comparison of SVOne Obtained Refraction to Subjective Manifest Refraction
|
N/A | |
Completed |
NCT04055519 -
Clinical Performance Assessment of a Daily Wear Monthly Replacement Soft Silicone Hydrogel Contact Lens
|
N/A | |
Recruiting |
NCT05049070 -
Study to Evaluate the Reliability, Validity and Safety of Subjective Mobile Refraction
|
N/A | |
Completed |
NCT04527978 -
Clinical Comparison of 2 Daily Disposable Contact Lenses - Pilot Study 1
|
N/A | |
Completed |
NCT01430247 -
Vision Screening for the Detection of Amblyopia
|
N/A | |
Recruiting |
NCT06077682 -
Cycloplegic Refraction in Pediatric Patients With Esotropia
|
Phase 4 | |
Not yet recruiting |
NCT04077086 -
Correcting Myopia Among Secondary School Children to Increase Academic High School Attendance Rates in Rural Communities
|
N/A | |
Withdrawn |
NCT04352868 -
Customizing Myopia Control With Multifocal Toric Contact Lens
|
N/A | |
Completed |
NCT04528017 -
Clinical Comparison of 2 Daily Disposable Contact Lenses - Pilot Study 2
|
N/A | |
Recruiting |
NCT04338880 -
Academic Performance and Refractive Error
|
||
Recruiting |
NCT04545073 -
Outcomes of a Trifocal IOL in Post-refractive Patients
|
||
Enrolling by invitation |
NCT05992675 -
Air Optix® Night and Day® Aqua Continuous Wear
|
||
Enrolling by invitation |
NCT05976750 -
Air Optix® Night and Day® Aqua Daily Wear
|
||
Recruiting |
NCT04693247 -
Handheld Device Compared With a Standard Eye Care Diagnostic Device in Measuring Ophthalmic Refraction
|
N/A | |
Recruiting |
NCT06065631 -
Seeing to Learn in Sierra Leone
|
N/A | |
Not yet recruiting |
NCT05550740 -
Repeated Low-Level Red-Light Therapy for Shortening Axial Length
|
N/A |