Corneal elevation in a large number of myopic Chinese patients. Issue 3 (June 2016)

• Record Type: Journal Article
• Authors: Ying, Jinglu; Wang, Qinmei; Belin, Michael W.; Wan, Ting; Lin, Shishi; Feng, Yifan; Gao, Rongrong; Huang, Jinhai
• Is Part Of: Contact lens & anterior eye. Volume 39:Issue 3(2016)
• Page Start: 185
• Page End: 190
• Publication Date: 2016-06
• Subjects: Corneal elevation -- Normative database -- Myopia -- Scheimpflug imaging; Anterior segment (Eye) -- Periodicals; Contact lenses -- Periodicals; Segment antérieur (Œil) -- Périodiques; Lentilles de contact -- Périodiques; 617.752305
• DOI: 10.1016/j.clae.2016.01.005
• Languages: English
• ISSNs: 1367-0484

Abstract

Highlights: Corneal elevation measurements are highly important in refractive surgery. Previous normative databases for corneal elevation are based on limited geographic area and sample size. Our study establishes a Chinese normative database for corneal elevation based on a large sample. Thinner corneal pachymetry at the apex and greater anterior corneal astigmatism result in greater anterior corneal elevation values. Younger age, greater anterior corneal astigmatism, lower anterior and posterior keratometry, and shallower anterior chamber depth tend to yield greater posterior corneal elevation values. Abstract: Purpose: To establish a normative database for corneal elevation in Chinese myopic patients who underwent refractive surgery, and analyze the association of corneal elevation with sex, age, and ocular parameters. Methods: A total of 3000 eyes in 1500 patients were evaluated with the Pentacam. Anterior and posterior elevations were measured at the apex and thinnest point. Normative thresholds were defined according to the Tukey method. Univariate and multivariate analyses were performed to assess the association of corneal elevation with sex, age, and ocular parameters. Results: Normal upper limits for corneal elevation in adult Chinese were 4.95 μm, 5.25 μm, 6.2 μm, and 11.0 μm at the anterior apex, anterior thinnest point, posterior apex, and posterior thinnest point, respectively. Thinner corneal pachymetry at the apex and greater anterior corneal astigmatism tended to show greater anterior corneal elevation values. Younger age, greater anterior corneal astigmatism, lower anterior and posterior keratometry, and shallower anterior chamber depth resulted in greater posterior corneal elevation values. Conclusions: Locally derived thresholds may offer higher sensitivity and specificity when screening eyes for myopic refractive surgery, and keratoconic and post-orthokeratology eyes. Anterior and posterior corneal elevation at the apex and thinnest point were associated significantly with anterior corneal astigmatism, showing a positive correlation.