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Results for “Anterior Eye Segment”

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At least 19 recordsLinked to original sources
PubMed1982

Ophthalmic changes from age of 10 to 18 years. A longitudinal study of sequels to low birth weight. III. Ultrasound oculometry and keratometry of anterior eye segment.

Anterior eye segment features were investigated longitudinally by ultrasound and keratometry in 70 low-birth-weight subjects (LBW less than 2000 g) and 67 full-term controls, at the ages of 10 and 18 years. Concerning the changes during adolescence, a slight significant deepening of anterior chamber and lens position is found (about 0.1 mm), while lens thickness, corneal curvature radius and corneal astigmatism have remained stable. Differences between BW-groups indicate a permanent influence of LBW on ocular development, as evident from a presumed early environmental (LBW) arrest of corneal growth, given by a significantly lower value of corneal curvature radius, just as zonular slackness due to a smaller suspension ring may explain a thicker lens. Further a LBW disturbance of correlation between refraction and anterior eye segment parameters is suggested. Besides the documented occasional posterior eye segment damage of LBW (retinopathy of prematurity), the present study indicates a more general restraining influence also on anterior eye segment development.

Adolescent↗
PubMedDate not supplied

[A study of total IgE in inflammatory pathologies of the eye anterior segment].

The paper contains data on comparative research of the IgE content in blood serum and lachrymal fluid in patients with ophthalmoherpes and with other inflammatory diseases of the eye. A higher IgE level was found in blood serum and lachrymal fluid in cases of ophthalmoherpes as well as in lachrymal fluid in cases of allergic, Chlamydia and fungus diseases of the eye. The data obtained can be used in the diagnostics of allergic eye diseases as well as in elaborating complex treatment methods for herpetic, Chlamydia and fungus lesions of the anterior eye segment. A detection of the local allergenic effect of acaricide drugs exerted on the conjunctiva and eyelids makes it obligatory to consider the above fact while treating patients with demodectic blepharoconjunctivitis.

Anterior Eye Segment↗
PubMed2002

Intra-observer and inter-observer repeatability of anterior eye segment analysis system (EAS-1000) in anterior chamber configuration.

BACKGROUND: Anterior chamber configuration can be assessed via optical or ultrasonic techniques. Scheimpflug photography is a non-invasive method measuring the anterior segment. The Anterior Eye Segment analysis system, EAS-1000, utilises the Scheimpflug principle and was found to have good repeatability. Previous repeatability studies, however, have had limitations in their design. The current study investigated the intra-observer and interobserver repeatability of the EAS-1000. METHODS: Twenty-five healthy young subjects were recruited. The anterior chamber angles in different quadrants were measured by two examiners for interobserver analysis. The first examiner repeated the measurement at another session for intra-observer analysis. The 95% limits of agreement and intra-class correlation coefficient (ICC) were calculated. The anterior chamber depth was also measured and compared with ultrasound biometry. RESULTS: The anterior chamber angle assessment demonstrated good intra-observer (ICC ranging from 0.77 to 0.90 for different quadrants) and interobserver (ICC ranging from 0.68 to 0.81 for different quadrants) repeatability. The 95% intra-observer limits of agreement were within +/-5 degrees. The 95% interobserver limits of agreement were within +/-6 degrees. There was no significant difference between male and female subjects or among angles at different quadrants. The anterior chamber depth was found to be repeatable (ICC > 0.90) with 95% limits of agreement +/-0.1 mm. The anterior chamber depth was shallower than that obtained from ultrasound biometry. CONCLUSIONS: The EAS-100 is a non-invasive instrument which is repeatable for measuring the anterior chamber angle and depth. It provides quick results and is good for screening purposes. There is an under-estimation of anterior chamber depth, as previously reported.

Adolescent↗
PubMedDate not supplied

[Methods of the analysis of images in the diagnosis of diseases of the anterior eye segment].

Methods of mathematical computerized analysis of images obtained through the microscopy of the eye by the slit lamp were used in examining patients with different pathologies of the eye anterior segment. Densitometric and planimetric analysis of images of the cornea, lens as well as of the posterior and anterior capsules of the lens was made for patients with aphakia and artiphakia. The optic corneal density (which depends on a type and degree of refraction and an administered medication therapy) was found to change after excimerlaser procedures. The corneal transparency, which also depends on an administered medication therapy, was examined in cases of its opacities and photokeratitis. Examinations of the lens led to elaborating a clinical classification of cataract maturity degrees, which can be used during the preoperative period for planning a type and tactics of the therapeutic and surgical treatment. Main complications occurring after cataract extraction, i.e. opacities in the anterior and posterior capsules, were evaluated densitometrically. A classification of opacities in the lens capsule was worked out; it was used to determine the optimal time and types of the therapeutic and surgical treatment at secondary cataracts.

Anterior Eye Segment↗
PubMed1998

[Effect of pilocarpine in tissue structures of the anterior eye segment from the aspect of its interaction with free amino acids].

On the basis of the proofs of pilocarpine interaction with free amino acids, the mechanism of this alkaloid effect in the tissue structures of the eye anterior segment is explained. Differences of colour reactions of amino acids mixtures with pilocarpine, decrease of radioactivity of Na[I125]tyrosine mixture with pilocarpine, unsteadiness of radioactivity of Na[I125]protein A mixture with pilocarpine and rise of 16 radioactivity fractions after adding pilocarpine to Na[I125]proteins A a) show the specificity of interaction of each amino acid with pilocarpine; b) give evidence of a strong covalent bond between pilocarpine and free amino acid and give rise to new biologically active metabolite; c) show non-cholinergic pathway of pilocarpine effect; d) for ophthalmo-physiological practice it is said that with respect to the rate between pilocarpine quantity and concentration and free amino acid quantity and concentration requested therapeutical effect by lower pilocarpine dose in glaucoma disease treatment might be achieved. Thus free amino acids being reactants can be identified as mechanism by which pilocarpine becomes biologically active.

Anterior Eye Segment↗
PubMed1997

Superior cervical ganglionectomy in monkeys: light and electron microscopy of the anterior eye segment.

Morphological changes in the anterior eye segment of eight cynomolgus monkeys were investigated 2 days to 2.2 years after unilateral surgical superior cervical ganglionectomy (SCGx). SCGx was confirmed by histologic examination of the excised surgical specimen and persistent ipsilateral miosis. In four short-term monkeys (2, 4, 7 and 11 days), iris, ciliary muscle and trabecular meshwork were studied by electron microscopy. In the other four longer-term monkeys (3 week, 4 week, 5 week, 2.2 year) the anterior eye segment was investigated with tyrosine hydroxylase immunohistochemistry (TH-IR) and catecholamine fluorescence (CF). Electron microscopy of experimental eyes showed characteristic signs of Wallerian degeneration in numerous nerve fibers and terminals in the iris, but to a lesser extent in the ciliary muscle and the trabecular meshwork. TH-IR and CF showed marked interindividual differences. In all experimental eyes, there was a marked reduction, but never a complete absence of adrenergic nerves in the iris. In two animals (4 week and 2.2 years), the adrenergic innervation of the ciliary body and the chamber angle was similarly reduced. In contrast, in the experimental eyes of the other two animals (3 and 5 weeks), changes in adrenergic innervation to the ciliary body and chamber angle were minimal or absent. The results indicate that following apparently complete SCGx in the cynomolgus monkey, reduction of adrenergic innervation to the iris as evidenced by pupillary physiology, electron microscopy, TH-IR and CF does not guarantee reduction in adrenergic innervation to the ciliary body and trabecular meshwork. SCGx may not extirpate all third order sympathetic neurons in the distal stump, or there may be a significant contribution of accessory ganglion cells to the adrenergic innervation of the anterior eye segment.

Adrenergic Fibers↗
PubMed1997

[Ultrasound biomicroscopic observation of the anterior eye segment in a sclerocornea and a microcornea].

We observed the anterior segment of eyes in one case of sclerocornea and one case of microcornea using an ultrasound biomicroscope. The sclerocornea was the peripheral type. The contrast in the image of ultrasound biomicroscopy changes from low to high density in proportion to the optical opacity at the peripheral portion of the cornea. There was no abnormality in the anatomical figures of the anterior chamber angle in ultrasound biomicroscopic findings, which gave significant information in the cataract surgery. The patient with microcornea had horizontal nystagmus, partial coloboma of the iris, choroidal coloboma, and cataract in both eyes. We observed the iris tissue in all the meridians in the ultrasound biomicroscopic pictures. Ultrasound biomicroscopy is a promising procedure for examining the anterior segment of eyes with corneal opacity.

Adult↗
PubMed1991

Liability for the treatment of anterior segment eye disease.

About 25% of large professional liability claims against optometrists involve misdiagnosis of anterior segment anomalies, most notably corneal abrasions (especially secondary to contact lens wear), tumors of the lid (principally basal cell carcinoma), pigmentary and angle-closure glaucoma, and, less commonly, anterior uveitis. Treatment of anterior segment eye disease is an infrequent cause of litigation involving optometrists. Potential causes of litigation include mismanagement of corneal abrasions and ocular foreign bodies, side effects of topical and systemic steroids, and adverse effects of glaucoma medications. In determining an optometrist's liability for care, a medical standard of care will be applied.

Anterior Eye Segment↗
PubMedDate not supplied

Ultrasound biomicroscopic morphometry of the anterior eye segment before and after one drop of pilocarpine.

PURPOSE: To measure anterior eye-segment morphometric data using ultrasound biomicroscopy. This is a new high-frequency, high-resolution ultrasound method enabling the visualisation of the anterior segment of the living eye with magnification similar to a light microscope. METHODS: Thirteen morphometric parameters of the anterior eye segment were measured before and after the application of one drop of pilocarpine in 10 eyes of 5 persons, using a Zeiss-Humphrey Ultrasound Biomicroscope at a frequency of 50 MHz. In each session, 3 morphometric parameters in the central images (corneal thickness, anterior chamber depth, pupillary diameter) were measured 4 times, and 10 parameters in the radial images (scleral thickness, angle-opening distance, trabecular-iris angle, trabecular-ciliary process distance [TCPD], iris thickness, 1, 2 and 3, iris-ciliary process distance, iris-lens contact distance [ILCD], iris elevation) were measured on the 3, 6 and 9 o'clock meridians three times each. RESULTS: Statistically significant changes were noted in the following parameters: pupillary diameter, iris thickness 1 and 2, and TCPD were decreased, while ILCD was increased after pilocarpine. Wide chamber angles showed a tendency to become narrower and narrow ones to become wider after pilocarpine. CONCLUSION: One drop of pilocarpine caused significant changes in the anterior eye segment morphology. Not only the pupillary diameter decreased but iris thickness and trabecular-ciliary process distance were also decreased simultaneously. At the same time the contact surface between the lens and iris increased significantly. Ultrasound biomicroscopy gives new morphometric image information about the anterior eye segment which is not available using conventional gonioscopy or ophthalmic echography.

Administration, Topical↗
PubMed1997

[Optical coherence tomography of the cornea and the anterior eye segment].

TARGET: The method of optical coherence tomography (OCT) was investigated regarding its suitability and limits for measuring the cornea and the anterior segment of the eye. Furthermore, the stromal expansion of thermally induced lesions in the cornea directly after irradiation was determined within the scope of the laser thermokeratoplasty (LTK). MATERIAL AND METHODS: With the experimental scanning OCT system, x-z sections of the anterior eye segment were made with an optical resolution of about 20 microns axially and 25 microns laterally. Freshly enucleated, tonicized porcine eyes were used as model eyes. Thermal lesions were applied with a continuously emitting laser diode (lambda = 1.86 microns) and various radiation parameters. Before and after coagulation, the cornea was viewed from limbus to limbus in a central OCT scan and the individual coagulation source was measured. RESULTS: Global and local changes of the thickness of the cornea as well as the distance between cornea and lens were measured with high precision. Thermal lesions in their expansion can be dearly presented and matching well with the histologically stained sections, but are not as exactly defined at the edges due to the limited optical resolution, as known from histological preparations. CONCLUSION: With the OCT method quantitative measuring of the anterior eye segment can be performed in vitro and with reduced resolutions also in vivo. Due to the qualitatively good correspondence regarding the dimensions of thermal damage of the cornea with histologically obtained morphometric results, this method can be used for supervision of coagulation directly after LTK as well as for examination of the individual healing process.

Animals↗
PubMed1993

Investigation of enzyme activities in severe burns of the anterior eye segment.

In severe burns of the anterior eye segment, including the cornea, limbus and adjacent conjunctiva, ischemia resulted from the necroses. While necrotic conjunctival and subconjunctival tissues may be removed to eliminate the toxic influence, the opaque cornea and ischemic sclera could not be removed. In the surrounding healthy tissues an inflammatory reaction developed, which brought about an infiltration of the damaged tissues by leukocytes and the release of lysosomal marker enzymes. N-Acetylglucosaminidase and cathepsin-D represent a number of other destructive enzymes involved with corneal and corneoscleral ulceration. Initially, their activities were low in the turbid, acellular cornea and increased 3 weeks after the burn. In the surrounding conjunctiva, these enzyme activities were normally higher than in the cornea and increased significantly after the burn. The elevated activities of N-acetylglucosaminidase and cathepsin-D in the conjunctiva and cornea were related clinically to corneal and corneoscleral ulceration.

Acetylglucosaminidase↗
PubMed1990

Application of an anterior eye segment analysis system in clinical cataract research.

Clinical application of a newly developed ANTERIOR EYE SEGMENT ANALYSIS SYSTEM was introduced. By this system, a Scheimpflug and a retroillumination image of the anterior eye segment are obtained through a CCD camera, separately. To overcome difficult problems experienced with previous types of lens documentation systems, several kinds of new mechanisms were built into this system. Slit and retroillumination images of some cases with cataracts and some examples of anterior eye segment analysis were described.

Aged↗