PURPOSE: To develop a universal standard for comparison of the results from different studies using Scheimpflug photography. MATERIAL AND METHOD: A suspension including polystyrene spheres was selected as the universal standard. The polystyrene suspension was diluted into 10 concentrations by adding spectroscopic quality water. An artificial eye chamber was designed to hold the diluted suspension for photography. Each concentration was photographed by both a Topcon SL-45 slit-lamp camera and a Nidek EAS-1000 system. The intensity of back-scattered light was analyzed statistically. RESULTS: The relationship between the concentration of the polystyrene suspension and the internal gray scale step within the Topcon SL-45 camera can be described by a second-order polynomial. The relationship between the concentration of the polystyrene suspension and the measurement of the Nidek EAS-1000 system can also be expressed by a second-order polynomial. The relationship between the Topcon SL-45 camera and the Nidek EAS-1000 system is linear. CONCLUSIONS: The results of lens nuclear opacity measured with different Scheimpflug cameras can be compared using the method established in the study. The linear relationship between the Topcon SL-45 and Nidek EAS-1000 systems can be used to convert measurements from one system to the other.

Anterior Chamber↗

PubMedDate not supplied

Calcification in the human lens.

A calcified cataractous lens from a 12 year old boy suffering from chronic uveitis was analysed using a microradiographic technique, X-ray crystallography and transmission electron microscopy. A 0.2 mm thick shell of calcified tissue was found in the subcapsular cortex. The mineral consisted of well-crystallized hydroxyapatite with a random orientation of the crystals. The underlying cortex consisted of a fibrous matrix containing collagen fibers. In the matrix, single or groups of epitheloid cells and fibroblast-like cells were found. Membrane-enclosed vesicles were found scattered in the matrix. The content of these vesicles had a wide range of electron density. A cell-induced mechanism for calcification is suggested.

Calcinosis↗

PubMedDate not supplied

Microspectrophotometric study of the compound rhabdom in the moth (Manduca sexta) eye.

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Animals↗