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Trial registered on ANZCTR


Registration number
ACTRN12612001200875
Ethics application status
Approved
Date submitted
13/11/2012
Date registered
14/11/2012
Date last updated
20/11/2012
Type of registration
Retrospectively registered

Titles & IDs
Public title
Changes in anterior chamber characteristics measured with a dual Scheimpflug analyzer and an anterior segment optical coherence tomography after laser in situ keratomileusis for myopia
Scientific title
Does laser in situ keratomileusis (LASIK) surgery affect anterior chamber characteristics measured with a dual Scheimpflug analyzer and an anterior segment optical coherence tomography in myopic patients?
Secondary ID [1] 281530 0
Nil
Universal Trial Number (UTN)
Nil
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Myopia 287794 0
Condition category
Condition code
Eye 288146 288146 0 0
Diseases / disorders of the eye

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
In this study, all participants undergo standard laser in situ keratomileusis (LASIK) surgery in both eyes only once. The LASIK procedures are performed in each eye by first creating a superiorly hinged corneal flap using the Hansatome microkeratome with a 160 micron m head and 8.5 mm ring. The laser ablation is performed using excimer Laser with a goal of emmetropia. The surgery procedures usually takes about 20 minutes for each patient. The central anterior chamber depth (ACD), anterior chamber volume (ACV), average radius of posterior axial curvature (ARPAC) are measured using the Galilei Scheimpflug analyser. Measurements with the dual Scheimpflug analyzer are performed according to the manufacturer’s guidelines. The
device is brought into focus and the subject’s eye is
aligned along the visual axis by a central fixation light. The
subjects are asked to sit back after each measurement,
and the device is realigned before each measurement.The superior, inferior, nasal, temporal anterior chamber angles (ACAs) are respectively measured using Visante anterior segment optical coherence tomography (AS-OCT). Scans of the ACAs of each eye are obtained at the 3 and 9 o’clock positions (horizontal), and at the 6 and 12 o’clock positions (vertical). Subjects are instructed to blink prior to all measurements and open their eyes wide during scan acquisition. As the eyelids may interfere with AS-OCT image acquisition of the ACA at 6 and 12 o’clock positions, the upper and lower lids are gently moved out of the way to image the superior and inferior angle- taking care to avoid inadvertent pressure on the globe. Measurements using the Galilei and Visante AS-OCT are taken before and 2 weeks and 2 months after LASIK. Each measurement needs about 5 minutes.
Intervention code [1] 286045 0
Treatment: Surgery
Intervention code [2] 286057 0
Treatment: Devices
Comparator / control treatment
To compare the postoperative anterior chamber parameters with preoperative values, including central ACD, ACV, ACAs, ARPAC.
Control group
Uncontrolled

Outcomes
Primary outcome [1] 288349 0
change in anterior chamber volume after surgery measured by the Galilei Scheimpflug analyer
Timepoint [1] 288349 0
2 weeks and 2 months after LASIK
Primary outcome [2] 288350 0
changes in anterior chamber angles after surgery measured by Visante AS-OCT
Timepoint [2] 288350 0
2 weeks and 2 months after LASIK
Primary outcome [3] 288351 0
change in central anterior chamber depth after surgery measured by the Galilei Scheimpflug analyzer
Timepoint [3] 288351 0
2 weeks and 2 months after LASIK
Secondary outcome [1] 299931 0
change in average radius of posterior axial curvature after surgery measured by the Galilei Scheimpflug analyzer
Timepoint [1] 299931 0
2 weeks and 2 months after LASIK

Eligibility
Key inclusion criteria
Myopic patients with stable refraction for at least 2 years, no contact lens wear for 2 weeks prior to the baseline examination
Minimum age
18 Years
Maximum age
50 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
history of following diseases: keratoconus or keratoconus suspect, corneal dystrophy, ocular trauma, diabetes, retinal disease, glaucoma and severe dry eye disease

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Single group
Other design features
Phase
Type of endpoint/s
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
10/11/2011
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
80
Accrual to date
Final
Recruitment outside Australia
Country [1] 4677 0
China
State/province [1] 4677 0
Guangdong Province

Funding & Sponsors
Funding source category [1] 286312 0
Charities/Societies/Foundations
Name [1] 286312 0
Guangdong Natural Science Foundation (S2012010008821)
Country [1] 286312 0
China
Primary sponsor type
Individual
Name
Zhong Xingwu
Address
54 South Xianlie Road, Yuexiu District, Guangzhou
Postcode: 510060
Country
China
Secondary sponsor category [1] 285099 0
Individual
Name [1] 285099 0
Wu Junshu
Address [1] 285099 0
54 South Xianlie Road, Yuexiu District, Guangzhou
Postcode: 510060
Country [1] 285099 0
China
Other collaborator category [1] 277168 0
Hospital
Name [1] 277168 0
Zhongshan Ophthalmic Center
Address [1] 277168 0
54 South Xianlie Road, Yuexiu District, Guangzhou
Postcode: 510060
Country [1] 277168 0
China

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 288384 0
Medical Ethics Committee of Zhongshan Ophthalmic Center of Sun Yat-sen University
Ethics committee address [1] 288384 0
54 South Xianlie Road, Yuexiu District, Guangzhou
Postcode: 510060
Ethics committee country [1] 288384 0
China
Date submitted for ethics approval [1] 288384 0
Approval date [1] 288384 0
06/11/2011
Ethics approval number [1] 288384 0
2011KYNL037

Summary
Brief summary
Laser in situ keratomileusis (LASIK) has been proven to be safe and effective for correction of myopia and myopic astigmatism. However, postoperative complications such as iatrogenic corneal protrusion occasionally occurred. Given that the position of the lens is unchangeable after refractive surgery, the corneal protrusion should be associated with structural changes of the anterior segment such as deepening of the anterior chamber depth. Most of the previous studies mainly focused on the central or midperipheral anterior chamber structure, but ignored the changes of peripheral anterior chamber parameters post-LASIK. In the present study, we plan to investigate the anterior chamber characteristics changes after LASIK not only in terms of central anterior chamber structure, but also in terms of peripheral anterior chamber angles. The purpose is to evaluate the effects of LASIK surgery on anterior ocular structures.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 34943 0
Address 34943 0
Country 34943 0
Phone 34943 0
Fax 34943 0
Email 34943 0
Contact person for public queries
Name 18190 0
Wu Junshu
Address 18190 0
54 South Xianlie Road, Yuexiu District, Guangzhou
Postcode: 510060
Country 18190 0
China
Phone 18190 0
+86 020 87330381
Fax 18190 0
Email 18190 0
[email protected]
Contact person for scientific queries
Name 9118 0
Zhong Xingwu
Address 9118 0
54 South Xianlie Road, Yuexiu District, Guangzhou
Postcode: 510060
Country 9118 0
China
Phone 9118 0
+86 13609649279
Fax 9118 0
Email 9118 0
[email protected]

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Results publications and other study-related documents

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