Clinical trial NCT03010748: Multi-center Clinical Trial on Corneal Morphology Analysis in Chinese Population
Official title: Multi-center Clinical Trial on Corneal Morphology Analysis in Chinese Population
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Cornea
Keywords: corneal morphology
Chinese population
corneal curvature
corneal thickness
higher order aberrations
Lead sponsor: Tianjin Eye Hospital
Sponsor class: OTHER
Collaborators: name: Jilin University
name: Xi'an Jiaotong University
name: Second People's Hospital of Yunnan Province
name: Wuhan General Hospital of Guangzhou Military Command
name: Xinjiang Medical University
name: Gansu Provincial Hospital
First posted: 2017-01-05
Enrollment: 50000
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CROSSOVER
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Chinese population of different nation from several provinces,including Jilin, Xi'an, Yunnan, Wuhan,etc.

Brief summary: Based on the corneal morphometry instrumentation Oculus Pentacam, which is commonly used before and after clinical refractive surgery, we will collect the corneal morphological and biologic parameters of the population under refractive surgery screening in refractive surgery centers around the country, and construct corneal morphology database in different living areas of Chinese people. Based on this, compared with the suspected keratoconus and keratoconus population, the screening criteria and reference standards accord with the characteristics of keratoconus of Chinese ethnic will be achieved.

Detailed description: The safety of refractive surgery has always been the focus of attention, keratoconus screening is the most important part for the preoperative examination of refractive surgery. Favorable tools and appropriate indicators are the premise of fast and accurate screening, and the corneal morphology from various regions of China have various characteristics, the use of uniform standards developed by foreign screening will always induce a lot of problems, for example, the differences of cornea morphological features between European and American ethnic and Chinese race, as well as the corneal morphometric indicators between various regions of China, will cause varying degrees of false-positive or false-negative screening results. Based on this, in order to further improve the safety of refractive surgery effectively and to obtain the effective and accurate screening of suspected keratoconus population, this study will be conducted to collect the corneal morphological characteristics database of Chinese people from all over the country, and to develop a database of Chinese ethnographic characteristics for screening keratoconus indicators and reference valuable to guide clinical screening and surgical design.

Eligibility criteria: Inclusion Criteria:

* No less than 18 years old, in good health, have no active disease in the body and eye, have permanent resident status and have lived in the local area for at least 5 years (please mark the nation).

Exclusion Criteria:

* Eye diseases, glaucoma, ocular hypertension, glaucoma patients with normal pressure, fundus lesions, ptosis and other eyelid abnormalities.

Primary outcomes:
measure: corneal thickness
timeFrame: preoperative
Secondary outcomes:
measure: corneal curvature measured by the Pentacam system
timeFrame: preoperative
measure: coma aberration measured by the Pentacam system
timeFrame: preoperative
measure: aspherical index measured by the Pentacam system
timeFrame: preoperative
measure: spherical aberration measured by the Pentacam system
timeFrame: preoperative
measure: corrected distance visual acuity
timeFrame: preoperative
measure: uncorrected distance visual acuity
timeFrame: preoperative
measure: refractive diopter
timeFrame: preoperative
measure: corneal volume measured by the Pentacam system
timeFrame: preoperative
measure: kapple angle measured by the Pentacam system
timeFrame: preoperative
measure: introcular pressure
timeFrame: preoperative
measure: corneal diameter measured by the Pentacam system
timeFrame: preoperative
measure: anterior chamber depth measured by the Pentacam system
timeFrame: preoperative
measure: anterior chamber angle measured by the Pentacam system
timeFrame: preoperative
Other outcomes:
Locations:
city: Tianjin
country: China
facility: Tianjin Eye Hospital
Study officials:
affiliation: Tianjin Eye Hospital
name: Yan Wang, director
role: STUDY_DIRECTOR
affiliation: Second People's Hospital of Yunnan Province
name: Xiaoyu li
role: PRINCIPAL_INVESTIGATOR
affiliation: Jilin University
name: Yan Zhang
role: PRINCIPAL_INVESTIGATOR
affiliation: Gansu Provincial Hospital
name: Jun Yang
role: PRINCIPAL_INVESTIGATOR
affiliation: Xi'an Jiaotong University
name: Jing Li
role: PRINCIPAL_INVESTIGATOR
affiliation: Xinjiang Medical University
name: Xianglong Yi
role: PRINCIPAL_INVESTIGATOR
affiliation: Wuhan General Hospital of Guangzhou Military Command
name: Zhengwei Shen
role: PRINCIPAL_INVESTIGATOR
References:
citation: Silverman RH, Urs R, RoyChoudhury A, Archer TJ, Gobbe M, Reinstein DZ. Combined tomography and epithelial thickness mapping for diagnosis of keratoconus. Eur J Ophthalmol. 2017 Mar 10;27(2):129-134. doi: 10.5301/ejo.5000850. Epub 2016 Aug 8.
citation: Chan TCY, Biswas S, Yu M, Jhanji V. Comparison of corneal measurements in keratoconus using swept-source optical coherence tomography and combined Placido-Scheimpflug imaging. Acta Ophthalmol. 2017 Sep;95(6):e486-e494. doi: 10.1111/aos.13298. Epub 2016 Nov 2.
citation: Patrao LF, Canedo AL, Azevedo JL, Correa R, Ambrosio R Jr. Differentiation of mild keratoconus from corneal warpage according to topographic inferior steepening based on corneal tomography data. Arq Bras Oftalmol. 2016 Jul-Aug;79(4):264-7. doi: 10.5935/0004-2749.20160075.
citation: Naderan M, Rajabi MT, Zarrinbakhsh P, Farjadnia M. Is keratoconus more severe in pediatric population? Int Ophthalmol. 2017 Oct;37(5):1169-1173. doi: 10.1007/s10792-016-0382-5. Epub 2016 Oct 25.
citation: Ma J, Zhao L, Yang Y, Yun D, Yu-Wai-Man P, Zhu Y, Chen C, Li JO, Li M, Zhang Y, Cui T, Meng X, Zhang L, Zhang J, Song Y, Lei Y, Liu J, Huangfu X, Jiang L, Cai J, Wu H, Shang L, Wen D, Yi X, Zhang Y, Li X, Xiao J, He R, Yang Y, Yang J, Cheng GPM, Bai J, Zhong X, Guo H, Yan P, Wang Y, Lin H. Associations Between Regional Environment and Cornea-Related Morphology of the Eye in Young Adults: A Large-Scale Multicenter Cross-Sectional Study. Invest Ophthalmol Vis Sci. 2021 Feb 1;62(2):35. doi: 10.1167/iovs.62.2.35.