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

Primary Purpose

Refractive Errors, Myopic Astigmatism

Status
Recruiting
Phase
Not Applicable
Locations
Egypt
Study Type
Interventional
Intervention
Small Incision Lenticule Extraction (SMILE)
Sponsored by
Al Watany Eye Hospital
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional treatment trial for Refractive Errors focused on measuring SMILE, Myopia, Refractive Surgery, Astigmatism, Small Incision Lenticule Extraction

Eligibility Criteria

18 Years - 50 Years (Adult)All SexesAccepts Healthy Volunteers

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

Sites / Locations

  • Al Watany Eye HospitalRecruiting

Arms of the Study

Arm 1

Arm 2

Arm Type

Active Comparator

Active Comparator

Arm Label

Control

Study cases

Arm Description

group A, SMILE procedure with lenticule diameter of 6.5 mm

group B, SMILE procedure with lenticule diameter of 7.0 mm

Outcomes

Primary Outcome Measures

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).
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).

Secondary Outcome Measures

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.
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.
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)
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).
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)

Full Information

First Posted
July 12, 2023
Last Updated
September 25, 2023
Sponsor
Al Watany Eye Hospital
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1. Study Identification

Unique Protocol Identification Number
NCT06062004
Brief Title
Evaluation of Different Lenticule Diameters in Myopic Astigmatism Correction With SMILE Procedures
Official Title
Evaluation of Different Lenticule Diameters in Myopic Astigmatism Correction With SMILE Procedures
Study Type
Interventional

2. Study Status

Record Verification Date
September 2023
Overall Recruitment Status
Recruiting
Study Start Date
November 27, 2018 (Actual)
Primary Completion Date
February 28, 2024 (Anticipated)
Study Completion Date
April 30, 2024 (Anticipated)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor
Name of the Sponsor
Al Watany Eye Hospital

4. Oversight

Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Product Manufactured in and Exported from the U.S.
No
Data Monitoring Committee
Yes

5. Study Description

Brief 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.
Detailed Description
Study Title: Evaluation of different lenticule diameters in myopic astigmatic correction with SMILE procedures Primary Investigator: Dr. Ahmed Sedky (Eye Subspecialty Center, Cairo, Egypt, 18 Elkhalifa Elmamoun Street, Heliopolis, Cairo, Egypt) Co-Investigators: Sherine S Wahba, Maged M Roshdy, Nermeen A Refaat Study Objectives Primary Objective: To study the effect of changing the lenticule diameter on the safety and effectiveness of myopic astigmatism correction with the SMILE procedure. Secondary Objective: To compare other outcomes such as visual outcomes including immediate visual acuity, contrast sensitivity, and epithelial remodeling. Participants and Methods: Study Setting: Eye Subspecialty Center, Cairo, Egypt, 18 Elkhalifa Elmamoun Street, Heliopolis, Cairo, Egypt and Al Watany Eye Hospital, Althawra Street, Cairo, Egypt Study design: Hospital-based, comparative, prospective, interventional contralateral eye study Sample size and randomization: 50 participants fulfilling the inclusion criteria will be enrolled in the study. Their right eyes undergo SMILE procedure using the standard 6.5 mm lenticule diameter and their left eyes undergo SMILE procedure but using a larger lenticule diameter of 7.0 mm. Ethical issues: Institutional ethics committee approval will be obtained. Participants' informed consent will be taken and the procedure explained to them in their own language. Any intra-operative or post-operative complications occurring in either group will be documented and duly informed to the ethics committee Preoperative evaluation: Anterior and posterior segment clinical examination Uncorrected distance visual acuity (UDVA) in decimal and logMAR units Corrected distance visual acuity (CDVA) in decimal and logMAR units Corneal tomography using the Pentacam high resolution (HR) (Oculus Optikgeräte, Wetzlar, Germany) including the flattest and steepest meridians (in keratometric diopters (D), the axes (in degrees) Contrast sensitivity (CSV1000E test (Good-Lite, Elgin, Illinois, USA)) in 4 different special frequencies Anterior segment Optical Coherence Tomography (Cirrus, Carl Zeiss Meditec, Jena, Germany) measurement of total corneal and epithelial thickness in µm Study duration: 3 months for recruitment of the patients. Surgical technique: All surgeries will be performed under topical anesthesia using the VisuMax femtosecond laser with the following parameters: Cap thickness of 120 μm Cap diameter is either 7.5 mm for lenticule diameter 6.5 mm or 8.0 mm for lenticule diameter 7.0 mm. Cap side cut angle 70° 3 mm incision positioned at 100° and angled at 45° A 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 Directly preoperative, the limbus will be marked in the 0° to 180° axis with a marker pen in the upright head position on the slit lamp. Then, the patient will be positioned under the VisuMax femtosecond laser and instructed to look into the green flashing fixation light. Once proper centration is achieved, the eye will be docked to the patient interface and suction will be applied. Manual compensation will be done by gently rotating the contact glass to align the horizontal marks on the eye to the 0° to 180° axis. Once both are aligned, the laser process will be done to create the refractive lenticule followed by its dissection and washing of the interface by a balanced salt solution. Medication: will be the standard treatment; topical steroids and antibiotics 4 times per day for 10 days and tear substitutes 4 times daily for one to two months. Postoperative evaluation: Follow-up of the subjects will be done in 1 day, 1 week, 3 months, and 6 months. Data will be collected for analysis starting from 1 week, including: Uncorrected distance visual acuity (UDVA) in decimal and logMAR units Corrected distance visual acuity (CDVA) in decimal and logMAR units Corneal tomography using the Pentacam HR (Oculus Optikgeräte GmbH, Wetzlar, Germany) including the flattest and steepest meridians (in diopters (D), the axes (in degree) Contrast sensitivity (CSV1000E test (Good-Lite, Elgin, IL, USA)) in 4 different special frequencies Anterior segment Optical Coherence Tomography (Cirrus HD-OCT, Carl Zeiss Meditec, Jena, Germany) measurement of total corneal and epithelial thickness in µm.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Refractive Errors, Myopic Astigmatism
Keywords
SMILE, Myopia, Refractive Surgery, Astigmatism, Small Incision Lenticule Extraction

7. Study Design

Primary Purpose
Treatment
Study Phase
Not Applicable
Interventional Study Model
Parallel Assignment
Model Description
Hospital-based, comparative, prospective, interventional contralateral eye study
Masking
None (Open Label)
Allocation
Non-Randomized
Enrollment
50 (Anticipated)

8. Arms, Groups, and Interventions

Arm Title
Control
Arm Type
Active Comparator
Arm Description
group A, SMILE procedure with lenticule diameter of 6.5 mm
Arm Title
Study cases
Arm Type
Active Comparator
Arm Description
group B, SMILE procedure with lenticule diameter of 7.0 mm
Intervention Type
Procedure
Intervention Name(s)
Small Incision Lenticule Extraction (SMILE)
Intervention Description
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
Primary Outcome Measure Information:
Title
The safety index of using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism
Description
The safety index (unitless parameter) is calculated as postoperative CDVA/ preoperative CDVA (both in decimal units).
Time Frame
up to 6 months
Title
The efficacy index of using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism
Description
The efficacy index (unitless parameter) is calculated as postoperative UDVA/ preoperative CDVA (both in decimal units).
Time Frame
up to 6 months
Secondary Outcome Measure Information:
Title
Refractive outcomes of using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism.
Description
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.
Time Frame
up to 6 months
Title
Visual acuity outcomes of using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism.
Description
To compare postoperative UDVA and CDVA (in logMAR) of SMILE procedure using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism.
Time Frame
up to 6 months
Title
Contrast sensitivity outcomes of using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism.
Description
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)
Time Frame
up to 6 months
Title
Corneal curvature changes after SMILE procedure using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism.
Description
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).
Time Frame
up to 6 months
Title
Corneal structural changes after SMILE procedure using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism.
Description
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)
Time Frame
up to 6 months

10. Eligibility

Sex
All
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
50 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
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
Central Contact Person:
First Name & Middle Initial & Last Name or Official Title & Degree
Sherine Shafik, PhD
Phone
00201222421896
Email
s_shafik@hotmail.com
Facility Information:
Facility Name
Al Watany Eye Hospital
City
Cairo
ZIP/Postal Code
11775
Country
Egypt
Individual Site Status
Recruiting
Facility Contact:
First Name & Middle Initial & Last Name & Degree
Mohamed El Bahrawy, PhD
Phone
00201144777100
Email
bahrawy.mohamed@gmail.com

12. IPD Sharing Statement

Plan to Share IPD
No
Citations:
PubMed Identifier
20601657
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.
Results Reference
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PubMed Identifier
25618419
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.
Results Reference
background
PubMed Identifier
24702575
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.
Results Reference
background
PubMed Identifier
28787514
Citation
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.
Results Reference
background
PubMed Identifier
28068441
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.
Results Reference
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Evaluation of Different Lenticule Diameters in Myopic Astigmatism Correction With SMILE Procedures

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