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.
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.
Study Type
OBSERVATIONAL
Enrollment
50,000
The Scheimpflug tomography system (Pentacam,Oculus GmbH, Wetzlar, Germany) is a rotating Scheimpflug camera that measures 138,000 true elevation points to compute corneal topography. Patients were asked to blink twice and then look at the fixation device. Image acquisition was a 2-second scan of 50 rotational Scheimpflug images through the corneal sighting point, the point where the ray of light from the fovea to the fixation device crossed the cornea. All measurements were performed just after a blink to minimize the effect of tear film alteration on the data. Acceptable maps had at least 10.0 mm of corneal coverage with no extrapolated data in the central 9.0 mm zone.
Tianjin Eye Hospital
Tianjin, China
RECRUITINGcorneal thickness
Time frame: preoperative
corneal curvature measured by the Pentacam system
Time frame: preoperative
coma aberration measured by the Pentacam system
Time frame: preoperative
aspherical index measured by the Pentacam system
Time frame: preoperative
spherical aberration measured by the Pentacam system
Time frame: preoperative
corrected distance visual acuity
Time frame: preoperative
uncorrected distance visual acuity
Time frame: preoperative
refractive diopter
Time frame: preoperative
corneal volume measured by the Pentacam system
Time frame: preoperative
kapple angle measured by the Pentacam system
Time frame: preoperative
introcular pressure
Time frame: preoperative
corneal diameter measured by the Pentacam system
Time frame: preoperative
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anterior chamber depth measured by the Pentacam system
Time frame: preoperative
anterior chamber angle measured by the Pentacam system
Time frame: preoperative