Impact of chamber pressure and material properties on the deformation response of corneal models measured by dynamic ultra-high-speed Scheimpflug imaging.

Purpose: To study the deformation response of three distinct contact lenses with known structures, which served as corneal models, under different chamber pressures using ultra-high-speed (UHS) Scheimpflug imaging.

Methods: Three hydrophilic contact lenses were mounted on a sealed water chamber with precisely adjustable pressure: TAN-G5X (41% hydroxyethylmethacrylate/glycolmethacrylate, 550 µm thick), TAN-40 (62% hydroxyethylmethacrylate, 525 µm thick) and TAN-58 (42% methylmethacrylate, 258 µm thick). Each model was tested five times under different pressures (5, 15, 25, 35 and 45 mmHg), using ultra-high-speed Scheimpflug imaging during non-contact tonometry.

International Values of Central Pachymetry in Normal Subjects by Rotating Scheimpflug Camera.

Purpose: In corneal refractive surgery, postoperative ectasia risk assessment routinely includes pachymetric analysis at the apex and thinnest point. We examined whether these data differ worldwide and constructed preliminary country-specific normative thresholds.

Design: This was a multicenter, cross-sectional study.

International values of corneal elevation in normal subjects by rotating Scheimpflug camera.

Purpose: To examine whether clinically significant differences exist in corneal elevation data from a sampling of countries worldwide.

Setting: International multicenter.

Design: Evaluation of diagnostic test or technology.

Anterior chamber depth in normal subjects by rotating scheimpflug imaging.

Purpose: Anterior chamber depth (ACD) is an important preoperative parameter in anterior segment surgery. Several factors are known to influence ACD, including race and geography. Our purpose was to sample data from various countries to characterize differences in ACD worldwide and, if any, assess their level of clinical significance.

Corneal power measurements using scheimpflug imaging in eyes with prior corneal refractive surgery.

Purpose: To evaluate the accuracy of central corneal power measurements by Scheimpflug imaging (Pentacam) for eyes that had corneal refractive surgery.

Methods: This study comprised two groups: a pilot group of 100 eyes with prior hyperopic or myopic LASIK that did not have cataract surgery, and a test group of 41 eyes with prior radial keratotomy (RK) and cataract surgery. In the pilot group, Pentacam images and refraction were taken preoperatively and 3 months after LASIK.

Distribution of corneal spherical aberration in a comprehensive ophthalmology practice and whether keratometry can predict aberration values.

Purpose: To determine the spherical aberration of the cornea in the general population and whether keratometry readings are predictive of corneal spherical aberration values.

Setting: Private comprehensive ophthalmology practice.

Methods: Corneal spherical aberration and keratometry readings were measured in 696 normal eyes of patients presenting for ocular examination to a comprehensive ophthalmologist.