Primary PterygiumNCT03406390
The Effects of Primary Pterygium on Contrast Sensitivity Preoperatively and Postoperatively
An observational study of Primary Pterygium, run by Zhongshan Ophthalmic Center, Sun Yat-sen University at 1 site in China.
Trial summary
Pterygium is the growth of conjunctival tissue onto the cornea, usually from the nasal quadrant of the cornea.Visual acuity may be reduced due to direct invasion of the visual axis or astigmatism induced by the pterygium. Read more about this study
- Who is it for?
- Ages 20 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Primary Pterygium
- What is being tested?
- Pterygium surgery
- Type of treatment
- Pill or oral medicine, Injection or infusion, Surgery or procedure
- How many people
- 60 participants
- Where
- 1 siteChina
- Study dates
- 1 Nov 2017to 31 Dec 2018
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: There would have two groups included in our study, which are 40 patients of primary pterygium group and 20 healthy volunteers.
Who may be able to join
- Clinical diagnosis of the primary pterygium;
- More than 18 and less than 60 years old;
- 0.0 or better logMAR BCVA;
- The absence of other ocular disorders and no history of eye surgery and other systemic diseases.
Who cannot join
- Clinical diagnosis of recurrent pterygium or accompanied with other ocular diseases;
- less than 18 or more than 60 years old;
- The logMAR BCVA is less than 0.0;
- With the history of eye surgery and other systemic diseases.
Trial locations and contacts
1 site in 1 country.
China1 site, 1 recruiting
- Recruiting
Zhongshan Opthalmic Center
Guangzhou, Guangdong, 510000
Jin Yuan, 8602087333391, yuanjincornea@126.com
Jin Yuan, Professor
About this study
Pterygium is the growth of conjunctival tissue onto the cornea, usually from the nasal quadrant of the cornea.Visual acuity may be reduced due to direct invasion of the visual axis or astigmatism induced by the pterygium. Contrast sensitivity measures two variables, size, and contrast which could comprehensively reflect the visual quality of the primary pterygium patients. In this study, we would investigate the the effects of primary pterygium on contrast sensitivity preoperatively and on the 1st, 3rd and 6th month postoperatively, moreover, the related parameters on the contrast sensitivity in the primary pterygium patients would be analyzed.
Read the detailed description
There would have two groups included in our study, which are primary pterygium group(40 patients) and the normal group (20 volunteers). The inclusion criteria for the primary pterygium group were: 1) more than 18 and less than 60 years old; 2)diagnosed as primary pterygium by the professional doctor; 3)0.0 or better logMAR BCVA; 4) absence of other ocular disorders and no history of eye surgery and other systemic diseases. The inclusion criteria for the normal group were: 1) between 18 and 60 years old; 2) 0.0 or better logMAR BCVA;3) no history of any ocular pathology, and normal physical and mental health.
All the subjects would receive the ophthalmic examination and contrast sensitivity test (quick contrast sensitivity function, quick CSF), in which the pterygium group would achieve the pterygium surgery by the same surgeon (Jin Yuan) and then be performed the contrast sensitivity test on the 1st, 3rd and 6th month postoperatively.
The quick CSF method, implemented in a 10 alternative forced-choice digit identification task, was used to assess the contrast sensitivity function34, 38. Stimuli were displayed on a gamma-corrected 46 inch LCD monitor (Model: NEC LCD P463) with a 1920×1080 pixel resolution, 50 cd/m2 mean luminance and 60 Hz vertical refresh rate. Observers viewed the display monocularly from a distance of 4 m in a dark room. For each trial, they were asked to verbally report the identities of three digits presented on the screen to the experimenter, who used the computer keyboard to enter their responses. The stimuli disappeared after all the responses were entered. Observers were given the option to report ''I don't know'' upon which the response was coded as incorrect. No feedback was provided. All three responses were used to update the posterior distribution of the CSF parameters, which in turn was used to adaptively choose the most informative combination of spatial frequency and contrast for the next trial. A new trial started 500 ms after the responses. There were 30 trials in approximately 5 min. The quick CSF data were scored to generate the cutoff spatial frequency, defined as the spatial frequency corresponding to a perceptual sensitivity of 1, and the area under the log CSF (AULCSF), a summary measure of the window to spatial vision
- Conditions
- Primary Pterygium
- Being tested
- Pterygium surgery
- Keywords
- contrast sensitivity, Pterygium
- Medical subject headings
- Pterygium
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Pterygium surgeryProcedure or surgery
The patients were anesthetized with subconjunctival injection.Symblepharon was released and fibrotic tissue was extensively dissected to expose the sclera and corneal stroma. The subconjunctival fibrovascular tissue, including Tenon's capsule, were thoroughly removed using scissors from the sclera and medial rectus muscle at the area of the superior and inferior fornices and the nasal caruncle. A cryopreserved human amniotic membrane (Zhongshan Ophthalmic Center, China) was then placed on the entire exposed bare sclera with the epithelial side facing upward, and secured with 10-0 nylon sutures.
| Study group | Role | What they receive |
|---|---|---|
| primary pterygium | Observe the contrast sensitivity of primary pterygium patients and healthy control by quick CSF methods, and the pterygium group would achieve the pterygium surgery by the same surgeon (Jin Yuan) and then be performed the contrast sensitivity test on the 1st, 3rd and 6th month postoperatively. Receives: Procedure: Pterygium surgery |
What is being measured
The primary outcome is the main question the study is designed to answer.
The contrast sensitivity function tested by quick CSF of the Primary Pterygium patients preoperatively
The contrast sensitivity function of the Primary Pterygium patients is lower than the normal people by qucik CSF method
Measured: Preoperatively
Secondary outcomes (1)
The contrast sensitivity function tested by quick CSF of the Primary Pterygium patients postoperatively
The contrast sensitivity function of the Primary Pterygium patients is improved compared with the normal people by quick CSF method
Measured: 1st, 3rd and 6th month postoperatively
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Jan 2018
- Study start1 Nov 2017
- Primary completion1 Nov 2018 (estimated)
- Study completion31 Dec 2018 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Primary PterygiumStudies of the same condition, open and under way.
- More trials run by Zhongshan Ophthalmic Center, Sun Yat-sen UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jin Yuan, Zhongshan Ophthalmic Center, Sun Yat-sen University
- Investigators
- Jin Yuan, Professor, Study director, Zhongshan Ophthalmic Center, Sun Yat-sen University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03406390
- Sponsor's protocol ID
- 2017011
- Status last verified
- Jan 2018
- First submitted
- 3 Nov 2017
- Last updated
- 23 Jan 2018
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 Jan 2018. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effects of Primary Pterygium on Contrast Sensitivity Preoperatively and Postoperatively
- ClinicalTrials.gov ID
- NCT03406390
- Acronym / sponsor ID
- 2017011
- Conditions
- Primary Pterygium
- Keywords
- contrast sensitivity, Pterygium
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Zhongshan Ophthalmic Center, Sun Yat-sen UniversityUniversity, hospital or other
- Study start
- 1 Nov 2017 (actual)
- Primary completion
- 1 Nov 2018 (estimated)
- Study completion
- 31 Dec 2018 (estimated)
- First posted
- 23 Jan 2018 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Pterygium is the growth of conjunctival tissue onto the cornea, usually from the nasal quadrant of the cornea.Visual acuity may be reduced due to direct invasion of the visual axis or astigmatism induced by the pterygium. Contrast sensitivity measures two variables, size, and contrast which could comprehensively reflect the visual quality of the primary pterygium patients. In this study, we would investigate the the effects of primary pterygium on contrast sensitivity preoperatively and on the 1st, 3rd and 6th month postoperatively, moreover, the related parameters on the contrast sensitivity in the primary pterygium patients would be analyzed.
Detailed description
There would have two groups included in our study, which are primary pterygium group(40 patients) and the normal group (20 volunteers). The inclusion criteria for the primary pterygium group were: 1) more than 18 and less than 60 years old; 2)diagnosed as primary pterygium by the professional doctor; 3)0.0 or better logMAR BCVA; 4) absence of other ocular disorders and no history of eye surgery and other systemic diseases. The inclusion criteria for the normal group were: 1) between 18 and 60 years old; 2) 0.0 or better logMAR BCVA;3) no history of any ocular pathology, and normal physical and mental health.
All the subjects would receive the ophthalmic examination and contrast sensitivity test (quick contrast sensitivity function, quick CSF), in which the pterygium group would achieve the pterygium surgery by the same surgeon (Jin Yuan) and then be performed the contrast sensitivity test on the 1st, 3rd and 6th month postoperatively.
The quick CSF method, implemented in a 10 alternative forced-choice digit identification task, was used to assess the contrast sensitivity function34, 38. Stimuli were displayed on a gamma-corrected 46 inch LCD monitor (Model: NEC LCD P463) with a 1920×1080 pixel resolution, 50 cd/m2 mean luminance and 60 Hz vertical refresh rate. Observers viewed the display monocularly from a distance of 4 m in a dark room. For each trial, they were asked to verbally report the identities of three digits presented on the screen to the experimenter, who used the computer keyboard to enter their responses. The stimuli disappeared after all the responses were entered. Observers were given the option to report ''I don't know'' upon which the response was coded as incorrect. No feedback was provided. All three responses were used to update the posterior distribution of the CSF parameters, which in turn was used to adaptively choose the most informative combination of spatial frequency and contrast for the next trial. A new trial started 500 ms after the responses. There were 30 trials in approximately 5 min. The quick CSF data were scored to generate the cutoff spatial frequency, defined as the spatial frequency corresponding to a perceptual sensitivity of 1, and the area under the log CSF (AULCSF), a summary measure of the window to spatial vision
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| primary pterygium | – | Procedure: Pterygium surgeryObserve the contrast sensitivity of primary pterygium patients and healthy control by quick CSF methods, and the pterygium group would achieve the pterygium surgery by the same surgeon (Jin Yuan) and then be performed the contrast sensitivity test on the 1st, 3rd and 6th month postoperatively. |
Who may qualify
- Ages
- 20 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- There would have two groups included in our study, which are 40 patients of primary pterygium group and 20 healthy volunteers.
Key inclusion criteria (4 listed)
- Clinical diagnosis of the primary pterygium;
- More than 18 and less than 60 years old;
- 0.0 or better logMAR BCVA;
- The absence of other ocular disorders and no history of eye surgery and other systemic diseases.
Key exclusion criteria (4 listed)
- Clinical diagnosis of recurrent pterygium or accompanied with other ocular diseases;
- less than 18 or more than 60 years old;
- The logMAR BCVA is less than 0.0;
- With the history of eye surgery and other systemic diseases.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Pterygium surgeryThe patients were anesthetized with subconjunctival injection.Symblepharon was released and fibrotic tissue was extensively dissected to expose the sclera and corneal stroma. The subconjunctival fibrovascular tissue, including Tenon's capsule, were thoroughly removed using scissors from the sclera and medial rectus muscle at the area of the superior and inferior fornices and the nasal caruncle. A cryopreserved human amniotic membrane (Zhongshan Ophthalmic Center, China) was then placed on the entire exposed bare sclera with the epithelial side facing upward, and secured with 10-0 nylon sutures. | Procedure or surgery | primary pterygium |
Primary outcome
The contrast sensitivity function tested by quick CSF of the Primary Pterygium patients preoperatively
Time frame: Preoperatively
The contrast sensitivity function of the Primary Pterygium patients is lower than the normal people by qucik CSF method
1 secondary outcome
The contrast sensitivity function tested by quick CSF of the Primary Pterygium patients postoperatively
Time frame: 1st, 3rd and 6th month postoperatively
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Jan 2018.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Jin Yuan, Professor study director
Zhongshan Ophthalmic Center, Sun Yat-sen University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Primary Pterygium, run by Zhongshan Ophthalmic Center, Sun Yat-sen University at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 23 Jan 2018. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Jing Zhong, Doctor (13527841235, zhongjing_90@163.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The contrast sensitivity function tested by quick CSF of the Primary Pterygium patients preoperatively (time frame: Preoperatively). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Jan 2018.