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Biomedical subjects

E Fariza

Publications and source records attributed to E Fariza.

10 recordsLinked to original sources
PubMed1995

Dynamics of external ocular blood flow studied by scanning angiographic microscopy.

The scanning angiographic microscope (SAM) provides a solution to the considerable technical difficulties associated with conventional episcleral fluorescein angiography. Standardised anterior segment fluorescein videoangiograms were performed using the SAM in each episcleral quadrant of the right eye in 6 normal subjects; frame-by-frame analysis proved important. Centripetal flow was seen in all 37 scleral perforating arteries investigated. Other features were the marked individual variability, much larger vertical anterior ciliary arteries, the high frequency of arteriovenous anastomoses, the complex flow patterns, the absence of a 'watershed' zone between anterior ciliary and posterior episcleral circulations, a characteristic and discontinuous distribution of 'leaky' episcleral veins, and the primacy of venous drainage into the plexus of muscular veins. Reports of retrograde blood flow in the anterior ciliary arteries in most fluorescein angiographic studies are probably incorrect, the result of unappreciated methodological problems. The SAM is an important advance on previous anterior segment fluorescein angiography techniques.

Adult↗
PubMed1993

Emmetropization as a first-order feedback system.

The existence of a regulatory mechanism that controls the growth of the eye toward emmetropia is generally agreed upon, but such an emmetropization mechanism has never been verified experimentally. This report supports the hypothesis that emmetropization can be described as a feedback process with a first-order equation and establishes a theoretical framework for future study, experimentation, and manipulation of this elusive mechanism. The feedback hypothesis has been tested by comparing two models. The first is a first-order feedback system, the second a non-feedback model with an almost identical equation. The feedback model fits data from human subjects significantly better.

Adolescent↗
PubMed1991

Enhancement of tumor-associated glycoprotein-72 antigen expression in hormone-related ovarian serous borderline tumors.

The immunoreactivity of monoclonal antibody (MoAb) B72.3 with ovarian serous tumors of borderline malignancy from 44 women who were pregnant, were on hormone medication containing a progestin, or were known to be in the secretory phase of the menstrual cycle, was compared with that of similar tumors of 32 patients who were not known to be in any of these three categories. All 76 borderline tumors expressed the tumor-associated glycoprotein (TAG-72) recognized by MoAb B72.3. Striking staining differences (P less than 0.0001) were observed between the hormone-related and the nonhormone-related tumors. Differences were also noticed between the staining of tumors from pregnant patients and that of previous, persistent, or recurrent tumors of the ipsilateral or contralateral ovaries when the same patients were not pregnant. Tumor MoAb B72.3 reactivity increased with progressive gestational age and fell to lower levels at term and during the postpartum period. Although it has been suggested by cell culture studies, enhanced TAG-72 expression in human tumors under hormonal stimulation has not been described before.

Antibodies, Monoclonal↗
PubMed1991

Practical anterior segment fluorescein angiography.

Anterior segment fluorescein angiography is a useful investigative technique for diagnosing and assessing anterior segment disease. However, a number of technical problems are inherent in current methodology, such as confounding reflexes, off-axis illumination, and shallow depth of field. We developed a simple technique using readily available equipment, polarized light, and an easy-to-construct auxiliary bracket to provide an inexpensive and optimal photographic system for anterior segment fluorescein angiography.

Anterior Eye Segment↗
PubMed1990

Anterior segment fluorescein videoangiography with a scanning angiographic microscope.

The scanning laser ophthalmoscope can be modified to operate as a scanning laser biomicroscope for use in anterior segment fluorescein angiography. The substantial depth of focus, large field of view, co-axial illumination, low light levels, real-time television operation, and videorecording with immediate recall provide advantages not available with conventional photographic methods. Video techniques give a resolution slightly inferior to photography, but this is unlikely to be significant in clinical practice. A technique of traversing the entire anterior episcleral vasculature has been developed to give a comprehensive and reproducible angiographic record. Previous fluorescein studies suggesting the primary importance of retrograde (centrifugal) flow in the perforating anterior ciliary arteries were not supported; methodologic explanations are advanced. Several principles are proposed to improve techniques of anterior segment angiography.

Adult↗
PubMed1990

Testing visual acuity of children using vanishing optotypes.

To test visual acuity in children, we developed a chart constructed so that the mean Fourier transform of the luminance of the figures on the chart at zero spatial frequency is the same as the background luminance. When the eye reaches its limit of resolution, the figures vanish into the gray background of the chart rather than becoming "blurred" as in conventional visual acuity charts. We compared the number of errors in determining the visual acuity of children aged 3-4.5 years using this high-frequency chart and a standard black-and-white high-contrast chart. Significantly fewer errors were found with the high-frequency chart, suggesting that this type of testing may improve the accuracy of visual acuity measurements in children.

Child, Preschool↗
PubMed1989

Use of cross-polarized light in anterior segment photography.

A photographic technique improved the quality of anterior segment photography by using one polarizer in the illumination path and another polarizer that was perpendicularly oriented to the first in front of the camera film back. A significant improvement was noted by impartial masked observers who assessed standard photographs of the iris, conjunctiva, and sclera. A crosslike artifact, observed in photographs using cross-polarizers, was present and originated from corneal birefringence. The significance of the artifact and its possible diagnostic applications were determined.

Anterior Eye Segment↗
PubMed1988

Use of circularly polarized light in fundus and optic disc photography.

Circularly polarized light was used in fundus and optic disc photography to reduce reflected glare and photographic artifacts originating from the ocular media and the lenses of the fundus camera. A standard fundus camera was used, with circular polarizers placed in the illumination and observation paths. The quality of fundus photography was improved significantly in eyes with intraocular lenses, cataract, vitreous haze, or high myopia as well as in normal eyes, in fundus photography of the retinal periphery, and in optic disc photography.

Fundus Oculi↗