An observational study in Primary Pterygium, sponsored by Zhongshan Ophthalmic Center, Sun Yat-sen University. Status unknown at 1 site in China. Open to participants aged 20 Years to 60 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2018-01-23.
Sponsored by Zhongshan Ophthalmic Center, Sun Yat-sen University · Observational
Among 23 studies in Pterygium with a site in China — 2 open to participants now, 4 under way, 1 of them phase 3. Pterygium · China.
Among the 23 studies in Pterygium with a site in China, this one is one of 2 that started in 2017, is one of 3 observational ones, and was the 13th registered.
109 studies on the registry are indexed under Pterygium; 9 are open to participants now.
Browse Pterygium studies →2 of the 23 studies in Pterygium with a site in China are open now. Recruiting first, the newest first:
Tianjin Eye Hospital · Sites in China
Zhongshan Ophthalmic Center, Sun Yat-sen University · Sites in China
A study can be open while its sites in China have not opened yet or have stopped. Only those recruiting at a site in China →
Of the 3 Pterygium studies recruiting now, 2 (67%) set no upper age limit and 1 (33%) stop at 75 or younger; 0 take children under 18; 2 take healthy volunteers.
This study: 20 Years to 60 Years · all sexes · healthy volunteers too.
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23 studies; the count open now beside each. This study's row is marked.
First in 2003; this study’s year is marked. 2 started in 2017.
This study's planned enrollment of 60 is close to the median of 58 across 14 observational studies indexed under Pterygium.
Median enrollment 60 across the 20 interventional studies, 615 across the 3 observational. Of the 8 that completed or were terminated, 1 (13%) have results posted.
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5 of 23 have an industry lead sponsor. The 10 most frequent:
Zhongshan Ophthalmic Center, Sun Yat-sen University is the lead sponsor of 164 studies on the registry; 80 are open to participants now.
Zhongshan Ophthalmic Center, Sun Yat-sen University has 4 studies filed under Pterygium — fewer than ten, so there is no comparison to draw.
1 of the studies in Pterygium with a site in China that are under way reach primary completion within a year, 1 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT05456425Phase 3Cloudbreak Therapeutics, LLCA Clinical Trial on Safety and Efficacy of CBT-001 in Patients With Pterygium | 2026-12-31 |
Among the 23 studies in Pterygium with a site in China, from their registry updates:
Nothing recorded among them since 2026-09-25.
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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.
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
There would have two groups included in our study, which are 40 patients of primary pterygium group and 20 healthy volunteers.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
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.
Procedure: Pterygium 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.
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
Time frame: Preoperatively
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
Time frame: 1st, 3rd and 6th month postoperatively
Started Nov 2017 (actual). Primary completion is estimated for Nov 2018, 12 months after the start.
How these figures are worked out, and which studies are left out of them.
This study is status unknown, as verified in Jan 2018. You cannot join it, but the record below documents what was studied.
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Zhongshan Ophthalmic Center, Sun Yat-sen University →