Influence of corneal astigmatism, corneal curvature and meridional differences on corneal hysteresis and corneal resistance factor

Corneal hysteresis and corneal resistance factor in pellucid marginal degeneration

Purpose To evaluate and compare corneal hysteresis (CH) and corneal resistance factor (CRF) in pellucid marginal degeneration (PMD), keratoconus (KCN), and normal eyes using the Ocular Response Analyzer (ORA). Methods In this retrospective study, corneal biomechanical parameters were measured in patients with PMD (n = 102) and KCN (n = 202) and normal subjects (n = 208) using the ORA. Data, i...

Total Corneal Astigmatism and Posterior Corneal Surface.

Contribution of posterior corneal astigmatism to total corneal astigmatism.

PURPOSE To determine the contribution of posterior corneal astigmatism to total corneal astigmatism and the error in estimating total corneal astigmatism from anterior corneal measurements only using a dual-Scheimpflug analyzer. SETTING Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA. DESIGN Case series. METHODS Total corneal astigmatism was calculated using ray trac...

Primary Corneal Keloid

Purpose: To report the clinical presentation, histopathologic findings, and surgical treatment in a series of cases with primary corneal keloid. Case Reports: Six Iranian patients (a father and two sons, a mother and her daughter, and one isolated male patient) without any history of corneal trauma or systemic diseases were clinically and histologically evaluated for a slowly-growing, white opa...

Corneal topographic astigmatism (CorT) to quantify total corneal astigmatism.

PURPOSE To evaluate the performance of corneal topographic astigmatism (CorT) based on total corneal power measurements. METHODS Anterior, posterior, and total corneal power measurements of 526 virgin eyes obtained using the CSO Sirius tomographer (Costuzione Strumenti Oftalmici, Scandicci, Florence, Italy) were analyzed. Individual CorTs were created from each set of data. These CorTs were a...