To compare the visual and optical outcomes following femtosecond laser in situ keratomileusis (FS-LASIK) with asymmetric offset (AO) and pupil centered (PC) treatments
Design
Randomized clinical trial with concealed allocation, 2 parallel group and double blinded
Settings and conduct
In Noor Eye hospital, a total of 60 FS-LASIK candidates who meet the study criteria will be undergone hyperopic astigmatism (30 cases) and myopic astigmatism (30 cases) LASIK using the Schwind Amaris 1050 excimer laser platform, respectively. One eye of each individual will be randomly assigned to AO centration and the fellow eye will be undergone the PC-centered method.
Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), safety and efficacy indexes, subjective refraction and corneal aberrations will be measured at baseline and 6 months postoperatively. Neither the patients nor the examiners will be aware of the assigned eyes.
Participants/Inclusion and exclusion criteria
Inclusion criteria:
FS-LASIK candidates in following range:
Age: 18-60 years
Spherical Equivalent (SE): +400 to -6.00 Diopter
Corrected distance visual acuity (CDVA): 9/10 or better
HOA (higher order aberration) < 0.65 µm
Pupil to vertex offset values ≥ 0.2 mm
Exclusion criteria:
A history of any ocular surgery
Systematic diseases such as thyroid disease or diabetes
Presence of cataract
Glaucoma or intraocular pressure (IOP) > 21 mmHg
Any corneal irregularity or opacity
Any posterior segment disorders
Pregnancy or breastfeeding
Intervention groups
One eye of each individual will be randomly assigned to AO centration and the fellow eye will be undergone the PC-centered method
Comparison of asymmetric offset versus pupil centered ablation in refractive surgery
Public title
Centration in refractive surgery
Purpose
Treatment
Inclusion/Exclusion criteria
Inclusion criteria:
Femto-LASIK candidates in following criteria
Age: 18-60 years
Spherical Equivalent (SE): +400 to -6.00 Diopter
Corrected distance visual acuity (CDVA): 9/10 or better
HOA (higher order aberration) < 0.65 µm
Pupil offset ≥ 0.2 mm (200 µm)
Steady refractive errors (change < 0.5 diopter) during a year before Femto-LASIK
Discontinuing soft contact lens and hard contact lens 1 and 4 weeks before the first examination, respectively
Exclusion criteria:
A history of any ocular surgery
Systematic diseases such as thyroid disease or diabetes
Presence of cataract
Glaucoma or intraocular pressure (IOP) > 21 mmHg
Any corneal irregularity or opacity
Any posterior segment disorders
Pregnancy or breastfeeding
Age
From 18 years old to 60 years old
Gender
Both
Phase
N/A
Groups that have been masked
Participant
Care provider
Outcome assessor
Sample size
Target sample size:
60
More than 1 sample in each individual
Number of samples in each individual:
2
In this study, one eye of each individual will be randomly assigned to AO centration and the fellow eye will be undergone the PC-centered method
Randomization (investigator's opinion)
Randomized
Randomization description
In the present study, there will be two types of surgical methods, A and B, which represent Asymmetric offset and Pupil center, respectively. In each individual, the right eye will be randomly operated with one of these two methods and the opposite eye will be operated with another method. Balanced block randomization method will be used for random assignment of surgical procedure. This method will prevent any prediction of the order of intervention. The entire process of random assignment will be done by STATA software using the ralloc package. After determining the blocks with a size of 4, the type of treatment (A or B) specified by the software will determine the surgery method of the right eye, and the opposite eye will be operated by another method. For example, A, indicates that the right eye will be operated by the Asymmetric offset treatment and the left eye by the Pupil center method. It should be noted that, in order to the allocation concealment, the surgical method of each patient will be placed in a sealed envelope with a unique random code generated by the software. This ensures that the surgeon will be noticed the random sequence only when the envelope is opened.
Blinding (investigator's opinion)
Double blinded
Blinding description
Patients are unaware of which eye is in the control or intervention group. Also, those who perform the tests (optometrist and the clinical ophthalmologist responsible for ocular examination) will also be unaware of which eye (intervention or placebo) is evaluating
Placebo
Not used
Assignment
Parallel
Other design features
Secondary Ids
empty
Ethics committees
1
Ethics committee
Name of ethics committee
Ethics committee of Tehran University of Medical Sciences
Street address
University Central Building,Ghods St, Keshavarz Blvd
City
Tehran
Province
Tehran
Postal code
1417733161
Approval date
2022-12-19, 1401/09/28
Ethics committee reference number
IR.TUMS.MEDICINE.REC.1401.613
Health conditions studied
1
Description of health condition studied
Centration of ablation profile in refractive surgery
ICD-10 code
ICD-10 code description
Primary outcomes
1
Description
Uncorrected distance visual acuity (UDVA)
Timepoint
Before and 6 months after surgery
Method of measurement
Snellen Chart
2
Description
Corrected distance visual acuity (CDVA)
Timepoint
Before and 6 months after surgery
Method of measurement
Trial frame, Snellen Chart
3
Description
Safety index
Timepoint
6 months after surgery
Method of measurement
Calculation based on UDVA
4
Description
Efficacy index
Timepoint
6 months after surgery
Method of measurement
Calculation based on UDVA and CDVA
Secondary outcomes
1
Description
Refraction
Timepoint
Before and 6 months after surgery
Method of measurement
Auto-refractometer, trial frame, Snellen chart
2
Description
Corneal Aberrations
Timepoint
Before and 6 months after surgery
Method of measurement
Pentacam
Intervention groups
1
Description
Intervention group: After local anesthesia, a flap (110 μm thick) is created using a Femto LDV (Ziemer Ophthalmic Systems AG, Port, Switzerland). After flap removal, ablation is performed using AMARIS 1050RS (SCHWIND, Munich, Germany) with asymmetric offset centering. After the operation, chloramphenicol 0.5% Sina Daro drops will be prescribed 4 times a day for 3 days and betamethasone 0.1% Sina Daro 4 times a day for one week.
Category
Treatment - Surgery
2
Description
Control group: After local anesthesia, a flap (110 μm thick) is created using a Femto LDV (Ziemer Ophthalmic Systems AG, Port, Switzerland). After flap removal, ablation is performed using AMARIS 1050RS (SCHWIND, Munich, Germany) with pupil center treatment. After the operation, chloramphenicol 0.5% Sina Daro drops will be prescribed 4 times a day for 3 days and betamethasone 0.1% Sina Daro 4 times a day for one week.
Category
Treatment - Surgery
Recruitment centers
1
Recruitment center
Name of recruitment center
Noor Eye Hospital
Full name of responsible person
Mojgan Pakbin
Street address
96, Esfandiar Blvd, Valiasr St
City
Tehran
Province
Tehran
Postal code
1968653111
Phone
+98 21 8240 1675
Fax
+98 21 8865 1514
Email
m_pakbin@alumnus.tums.ac.ir
Sponsors / Funding sources
1
Sponsor
Name of organization / entity
NOOR Eye Hospital
Full name of responsible person
Dr. Hassan Hashemi
Street address
96, Esfandiar Blvd, Valiasr St.
City
Tehran
Province
Tehran
Postal code
1968653111
Phone
+98 21 8865 1515
Fax
+98 21 8865 1514
Email
research@norc.ac.ir
Grant name
Grant code / Reference number
Is the source of funding the same sponsor organization/entity?
Yes
Title of funding source
NOOR Eye Hospital
Proportion provided by this source
100
Public or private sector
Private
Domestic or foreign origin
Domestic
Category of foreign source of funding
empty
Country of origin
Type of organization providing the funding
Persons
Person responsible for general inquiries
Contact
Name of organization / entity
NOOR EYE Hospital
Full name of responsible person
Mojgan Pakbin
Position
Researcher
Latest degree
Ph.D.
Other areas of specialty/work
Optometry
Street address
96, Esfandiar Blvd, Valiasr St.
City
Tehran
Province
Tehran
Postal code
1968653131
Phone
+98 21 8240 1675
Email
m_pakbin@razi.tums.ac.ir
Person responsible for scientific inquiries
Contact
Name of organization / entity
Tehran University of Medical Sciences
Full name of responsible person
Dr. Hassan Hashemi
Position
Professor, Ophthalmology Department, Tehran University of Medical Sciences, Tehran, Iran
Latest degree
Subspecialist
Other areas of specialty/work
Ophthalmology
Street address
96, Esfandiar Blvd, Valiasr St.
City
Tehran
Province
Tehran
Postal code
1968653131
Phone
+98 21 8240 1675
Email
research@norc.ac.ir
Person responsible for updating data
Contact
Name of organization / entity
NOOR EYE Hospital
Full name of responsible person
Mojgan Pakbin
Position
Researcher
Latest degree
Ph.D.
Other areas of specialty/work
Optometry
Street address
96, Esfandiar Blvd, Valiasr St.
City
Tehran
Province
Tehran
Postal code
1968653131
Phone
+98 21 8240 1675
Email
m_pakbin@alumnus.tums.ac.ir
Sharing plan
Deidentified Individual Participant Data Set (IPD)
No - There is not a plan to make this available
Justification/reason for indecision/not sharing IPD
Per request, we will decide about the dissemination of the data
Study Protocol
No - There is not a plan to make this available
Statistical Analysis Plan
Not applicable
Informed Consent Form
Undecided - It is not yet known if there will be a plan to make this available