Biomedical subjects

Kathryn A Diehl

Publications and source records attributed to Kathryn A Diehl.

4 recordsLinked to original sources

PubMed2005

Evaluation of intra- and interobserver reliability and image reproducibility to assess usefulness of high-resolution ultrasonography for measurement of anterior segment structures of canine eyes.

OBJECTIVE: To evaluate the usefulness of high-resolution ultrasonography (HRUS) for measurements of anterior segment structures in canine eyes. ANIMALS: 4 clinically normal Beagles. PROCEDURE: Images were obtained from 8 eyes with a handheld 20-MHz transducer. Eleven anterior segment structures on each image were measured 5 times by 2 independent observers. Coefficients of variation (CVs) for measurements were used to assess intraobserver reliability. Interobserver reliability was assessed by comparing measurements obtained by the 2 observers from the same images. Five images were sequentially obtained from 2 locations (ie, superior and temporal) to evaluate image reproducibility. Anterior segment structures were measured once on each image; image reproducibility was assessed by use of the CV for each parameter measured. Imaging location was assessed by comparison of CV for measurements from each location. RESULTS: CVs were < 10% for observer A for all measurements except the ciliary cleft area (11.63%). The CVs were > 10% for observer B for measurements of the angle recess area (18.51%) and ciliary cleft width (17.44%) and area (16.01%). Significant differences in measurements between observers were found for 5 of 11 anterior segment structures. Imaging the superior aspect of the globe provided the most reproducible images, although image reproducibility was still somewhat variable, with the highest and lowest CVs for measurements of 33.01% and 11.32%, respectively, in the superior position. CONCLUSIONS AND CLINICAL RELEVANCE: High-resolution ultrasound images can be used to reliably measure various anterior segment structures. Clinically relevant findings in the anterior segment of canine eyes may be detectable by use of HRUS.

Animals↗

PubMed2003

Use of high-resolution ultrasound as a diagnostic tool in veterinary ophthalmology.

The recent development of a 20-MHz, high-frequency ultrasound probe has allowed tissue to be visualized at resolutions of 20 to 80 microm, which is similar to a low-power histologic view. This high degree of resolution, however, limits tissue penetration to 5 to 10 mm, which is ideal for examination of the anterior segment of the eye. The detail provided by high-resolution ultrasound readily permits the clinician to distinguish between various anterior segment entities that may appear similar but are treated quite differently, such as anterior uveal tumors, iridociliary cysts, and iris bombé. High-frequency ultrasound is also a valuable aid in creating a surgical plan for treatment of ocular disorders in which the cornea is opaque, such as feline corneal sequestrum and tumor invasion into the cornea. Other applications of this technology include elucidation of the pathogenesis of glaucoma in veterinary patients and evaluation of regions of the lens that are difficult to examine directly.

Animals↗

PubMed2002

Advances in topical glaucoma therapy.

Significant advances have recently been achieved in the development of topical glaucoma medications. The primary advantage of a topical preparation is the reduced incidence of adverse systemic effects attributable to a given drug compared to its systemically administered counterpart. However, the strong protective barrier of the eye forces topical ophthalmic preparations to be highly concentrated and in some cases, they have the potential to produce unwanted systemic effects, particularly in smaller animals. Oral carbonic anhydrase inhibitors are commonly associated with adverse effects in both humans and animals. Two recently developed topical carbonic anhydrase inhibitors, dorzolamide and brinzolamide, have shown promise in reducing intraocular pressure in animals and systemic side effects are apparently limited with their use. The topical alpha2-agonist apraclonidine, on the other hand, effectively reduces intraocular pressure in cats and dogs, but in its currently available form is likely to induce unwanted systemic effects. Latanoprost is a topical prostaglandin F2alpha analog that has proven effective in reducing intraocular pressure in dogs and horses, but while systemic side effects have not yet been reported, this topical preparation may exacerbate pre-existing or concurrent ocular inflammatory disease.

Administration, Topical↗

PubMedDate not supplied

Effects of the application of neck pressure by a collar or harness on intraocular pressure in dogs.

The effect on intraocular pressure (IOP) from dogs pulling against a collar or a harness was evaluated in 51 eyes of 26 dogs. The force each dog generated while pulling against a collar or a harness was measured. Intraocular pressure measurements were obtained during application of corresponding pressures via collars or harnesses. Intraocular pressure increased significantly from baseline when pressure was applied via a collar but not via a harness. Based on the results of the study, dogs with weak or thin corneas, glaucoma, or conditions for which an increase in IOP could be harmful should wear a harness instead of a collar, especially during exercise or activity.

Animal Husbandry↗