No abstract

PURPOSE.To compare intraocular pressure (IOP) measurements obtained using the Topocon noncontact tonometer (NCT), the Goldmann applanation tonometer (GAT), and the Corvis ST (CST), a newly developed tonometer with features of visualization and measurement of the corneal deformation response to an air impulse. A secondary objective was to assess the agreement among the devices.METHODS. Fifty-nine participants, including glaucoma patients (36 cases) and control volunteers (23 cases), were enrolled. One eye was selected randomly for further study. IOP measurements were obtained with the CST, NCT, and GAT by two experienced clinicians. IOP values were compared. Intraobserver variability and interobserver variability were assessed by the coefficient of variation and intraclass correlation coefficient. Device agreement was calculated by BlandAltman analysis. RESULTS.Mean IOP for all examined eyes was 18.9 6 5.8 mm Hg for CST, 21.3 6 6.8 mm Hg for NCT, and 20.3 6 5.7 mm Hg for GAT. There was no statistically significant difference in IOP measurements among the tonometers except between the CST and NCT. Correlation analysis showed a high correlation between each pair of devices (all P < 0.001). The CST displayed the best intraobserver variability and interobserver variability. Bland-Altman analysis revealed a bias between CST and GAT, CST and NCT, and GAT and NCT of À1.3, À2.4, and À1.1 mm Hg, with 95% limits of agreement of À6.2 to 3.5 mm Hg, À10.1 to 5.2 mm Hg, and À8.3 to 6.2 mm Hg, respectively.CONCLUSIONS. The CST offers an alternative method for measuring IOP. IOP measurements taken with these devices may not be interchangeable. (Invest Ophthalmol Vis Sci. 2013; 54:659-665)

Measurements of NI-BUT obtained with the newly developed corneal topographer may provide a simple, noninvasive screening test for dry eyes with acceptable sensitivity, specificity, and repeatability.

The paracentral corneal epithelium, as well as the nasal and temporal limbal epithelium, became thinner with aging, while the central CET seemed to remain constant. Measurement with AS-OCT of the corneal and limbal ET could aid in clinical assessment and planning treatments of the cornea.

Limbal stem cells (LSCs) maintain the normal homeostasis and wound healing of corneal epithelium. Limbal stem cell deficiency (LSCD) is a pathologic condition that results from the dysfunction and/or an insufficient quantity of LSCs. The diagnosis of LSCD has been made mainly based on medical history and clinical signs, which often are not specific to LSCD. Methods to stage the severity of LSCD have been lacking. With the application of newly developed ocular imaging modalities and molecular methods as diagnostic tools, standardized quantitative criteria for the staging of LSCD can be established. Because of these recent advancements, effective patient-specific therapy for different stages of LSCD may be feasible.