PubMed HealthSearch

PubMed · 8867683

Optic nerve head stereoscopic digital imaging using bichromatic techniques.

Abstract

The variability of optic nerve parameters obtained with versions 3.4 and 3.5 of the Topcon IMAGEnet computer stereo analysis system was studied. The consistency of horizontal cup-to-disc ratio, vertical cup-to-disc ratio, cup volume, neuroretinal rim area, neuroretinal rim-to-disc area, and the percentage of poorly correlated conjugate points (bad points) on the stereo pair was compared. The updated computer program for stereo analysis provides a significantly more accurate means to assess both the cup volume and the neuroretinal rim area as evidenced by the smaller number of bad points.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

B Rector, B J Ludwig, J E Terry. 1996. Optic nerve head stereoscopic digital imaging using bichromatic techniques.. https://doi.org/10.1097/00006324-199601000-00009

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Simultaneous three wavelength imaging with a scanning laser ophthalmoscope.

BACKGROUND: Various imaging properties of scanning laser ophthalmoscopes (SLO) such as contrast or depth discrimination, are superior to those of the traditional photographic fundus camera. However, most SLO are monochromatic whereas photographic systems produce colour images, which inherently contain information over a broad wavelength range. METHODS: An SLO system has been modified to allow simultaneous three channel imaging. Laser light sources in the visible and infrared spectrum were concurrently launched into the system. Using different wavelength triads, digital fundus images were acquired at high frame rates. RESULTS: Favourable wavelengths combinations were established and high contrast, true (red, green, blue) or false (red, green, infrared) colour images of the retina were recorded. The monochromatic frames which form the colour image exhibit improved distinctness of different retinal structures such as the nerve fibre layer, the blood vessels, and the choroid. CONCLUSIONS: A multi-channel SLO combines the advantageous imaging properties of a tunable, monochrome SLO with the benefits and convenience of colour ophthalmoscopy. The options to modify parameters such as wavelength, intensity, gain, beam profile, aperture sizes, independently for every channel assign a high degree of versatility to the system.

Color

A confocal microscopic study relating the autofluorescence of carious dentine to its microhardness.

OBJECTIVE: An in-vitro study to examine the correlation between the distribution of the autofluorescent signal emitted from carious dentine (detected using confocal laser scanning microscopy) and its microhardness, within the depths of human dentine lesions. MATERIALS AND METHODS: Twelve carious teeth were sectioned longitudinally, the cut faces marked with a grid reference line system and colour photomicrographs taken. The same samples were imaged using confocal laser-scanning microscopy for autofluorescence and then subjected to microhardness testing using a Knoop microhardness indenter. Adjacent sound dentine was used as a control reference. Digital image superimposition allowed direct comparisons to be made between the colour, autofluorescence and microhardness of each lesion. RESULTS: Sound enamel and dentine did not autofluorescence. Autofluorescence distribution from carious dentine correlated with the highly softened tissue (detected using the Knoop indenter) and terminated at a level superficial to the translucent zone. This zone was still pigmented. Normal, sound dentine hardness levels were found deep to the translucent zone. CONCLUSIONS: A correlation existed between the zone of autofluorescence and carious dentine that was markedly softened by the carious process. These findings highlighted a possibility that the autofluorescence might be used as an in-vitro, objective histological marker for the softened, carious dentine requiring clinical excavation.

Color