Comparison of Local Made and Imported Porous Polyethylene Orbital Implant for Enucleation in Thailand
This study wants to compare between two types of implants in enucleation. Both of them are made from porous polyethylene but have different fabricating techniques. The investigators chose an exposure rate as a main outcome because the investigators think it is the most important outcome for the surgeons. The study hypothesis is: Is the exposure rate of a local-made polyethylene orbital implant the same as an imported one?
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Outcomes Assessor)
Primary Purpose: Treatment
|Official Title:||Comparison of Exposure Rate Between Local Made and Imported Porous Polyethylene Orbital Implant for Enucleation in Thailand: A Randomized, Equivalence Controlled Trial and Multicenter Study|
- Exposure rate [ Time Frame: From date of surgery until the date of first exposure, assessed up to 12 months ] [ Designated as safety issue: No ]Exposure was defined as the separation of tissue over the anterior surface of an implant.
- Infection rate [ Time Frame: From date of surgery until the date of first infection, assessed up to 12 months ] [ Designated as safety issue: No ]Infection was defined as the presence of pus or abscess at or around an implant. It can be diagnosed clinically or confirmed by the histopathology report after explantation.
- Motility [ Time Frame: 2,3,6,9,12 months post surgery ] [ Designated as safety issue: No ]Motility was defined as the distance in millimeters the patients can move their eyes in abduction, adduction, supraduction and infraduction. The rulers will be attached to the slit lamp in horizontal and vertical axis.The observer then take a photo of patients in 4 directions, with and without prosthesis. Two independent observers will measure motilities from the photographs. If the difference from two independent observers is more than 2 standard deviation, the measurement process will be started again.
- Gadolinium enhancement [ Time Frame: 6, 12 months post surgery ] [ Designated as safety issue: No ]Gadolinium uptake from MRI orbit represents implant vascularization. They will be taken in axial, coronal and sagittal plane with standard protocol MRI study. In T1-weighted post contrast image, an equatorial image will be identified. The equatorial image was defined as the image at the level of implant size divided by two, measured from the anterior surface. Two independent observer will mark between contrast and non-contrast area. Then area of enhancement was calculated by subtracting non-enhancement area from total equatorial surface area.
|Study Start Date:||March 2011|
|Estimated Study Completion Date:||December 2015|
|Estimated Primary Completion Date:||December 2015 (Final data collection date for primary outcome measure)|
Experimental: local made implant (3DP)
Enucleation and local made implant (3DP) insertion
intervention involving local made implant with different fabricating technique-3-dimensional printing (3DP) technique.
Experimental: imported implant (Medpor)
Enucleation and imported implant (Medpor) insertion
commercial porous polyethylene
Sample size assessment
- The sample size was calculated by using an equivalence formula. From a literature and our own experiences, the success rate for Medpor and 3DP were 92% and 94% respectively, the difference (D) of the success rate between two groups was 10% and assuming a 15% of drop out rate.
- Then allocation sequence was generated by a computerized program, using block of six with varying block size.
- All definition of data, recruiting techniques, data collection techniques and data management flow were mentioned in the SOP.
- After double entry technique, each case record form from each site will be sent via DataFax system to the data center at Center of Excellence for Biomedical and Public Health Informatics (BIOPHICS), Thailand.
- Then data will be validated, analyzed and reported by staff at BIOPHICS.
Plan for missing data
- by adding a drop out rate to the sample size calculation.
- by choosing the right patients. Actually, Thai patients have good co-operation especially in surgical research.
- Intention to treat and per protocol model would be used to see the difference between two types of implants in this project.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01312545
|Contact: Sunisa Sintuwong, MD||66 34 225818 ext email@example.com|
|Mettapracharak Eye Center, Mettapracharak (Wat Raikhing) Hospital||Recruiting|
|Amphoe Sam Phran, Nakhon Pathom, Thailand, 73210|
|Contact: Sunisa Sintuwong, M.D. 66 34 225 818 ext 7168 firstname.lastname@example.org|
|Contact: Kanjana Leelapatranurak, MD 66 34 225 818 email@example.com|
|Principal Investigator: Sunisa Sintuwong, MD|
|Principal Investigator:||Sunisa Sintuwong, MD||Mettapracharak (Wat Raikhing) Hospital|