A donor cornea with metastatic cells from a cutaneous malignant melanoma.

Purpose: To describe the case of a donor cornea that showed hematogenous metastatic spread of cutaneous melanoma to the sclerocorneal limbus.

Methods: Corneal tissue obtained from a donor with cutaneous malignant melanoma was evaluated for endothelial cell density, corneal transparency, and epithelial morphology. Subsequently, hematoxylin and eosin staining and immunohistochemical characterization using S100, HMB45, Melan-A, and CD34 antibodies were performed on the corneal sections.

Protective effects of deswelling on stromal collagen denaturation after a corneal femtosecond laser cut.

Purpose: To evaluate the effect of corneal deswelling prior to a microkeratome and femtosecond (fs) laser cut and the impact of the fs laser energy settings on the tissue surface and collagen quality.

Methods: Porcine and human corneas were incubated in THIN-C (deswelled) or EUSOL-C (control) at 4°C for 4 hours. Porcine corneas were cut using a microkeratome or an Intralase fs laser 150 Hz and 0.

Characterization of age-related variation in corneal biomechanical properties.

An experimental study has been conducted to determine the stress-strain behaviour of human corneal tissue and how the behaviour varies with age. Fifty-seven well-preserved ex vivo donor corneas aged between 30 and 99 years were subjected to cycles of posterior pressure up to 60 mm Hg while monitoring their behaviour. The corneas were mechanically clamped along their ring of scleral tissue and kept in physiological conditions of temperature and hydration.

Regional variation in the biomechanical properties of the human sclera.

The study aimed to determine the variation in thickness and biomechanical properties between the different regions of the human sclera. Thickness measurements were carried out along eight meridian lines extending from the posterior pole to limbus in 36 human donor scleras aged 52-96 years. Strip specimens were extracted from areas close to the limbus, equator and posterior pole, and tested under cycles of uniaxial tension.

Experimental assessment of human corneal hysteresis.

Purpose: Hysteresis is a viscoelastic property characterized by the difference in behavior under loading and unloading. The aim of the study was to determine corneal hysteresis using experimental means.

Methods: Twenty-nine human corneas with 50-95 year age were subjected to cycles of pressure loading and unloading.

Experimental assessment of corneal anisotropy.

Purpose: To determine the variation of corneal biomechanical properties with anatomical orientation.

Methods: Strip specimens extracted from fresh porcine corneas were tested under uniaxial tension with strain rates representing static and dynamic loading conditions. The specimens were extracted from the vertical, horizontal, and 45 degrees diagonal directions.

Assessment of corneal biomechanical properties and their variation with age.

Purpose: The aim of this study was to determine the stress-strain behavior of corneal tissue and how the behavior was affected by age.

Methods: Human corneal specimens ranging in age between 50 and 95 years were tested under inflation conditions to determine their stress-strain behavior. The corneas were subjected to two load rates that represent dynamic and static loading conditions.