Biomedical subjects

Scott Piette

Publications and source records attributed to Scott Piette.

3 recordsLinked to original sources

PubMed2002

Detecting the inner and outer borders of the retinal nerve fiber layer using optical coherence tomography.

BACKGROUND: The purpose of this study was to develop a new algorithm to detect the inner and outer borders of the retinal nerve fiber layer (RNFL) using optical coherence tomography (OCT). METHODS: A program featuring a new algorithm was developed using a commercially available software development environment. The algorithm searches for peaks on each sampling line instead of applying conventional thresholding techniques. All circular peripapillary OCT images obtained at the New York Eye and Ear Infirmary from October 1996 to December 2000 were analyzed using the new and the commercially available algorithms. RESULTS: Four hundred one images of 98 patients were analyzed. The detection error rate (defined as number of scans with five consecutive sampling lines with disrupted RNFL borders) was significantly lower with the new algorithm (25/401 images, 6.2%) than with the commercially available algorithm (70/401 images, 17.5%) (P=0.018, chi-square). CONCLUSION: The new algorithm improved the ability of OCT to detect the borders of the RNFL.

Adult↗

PubMed2002

Ultrasound biomicroscopy in uveitis-glaucoma-hyphema syndrome.

PURPOSE: To assess anterior segment anatomy in uveitis-glaucoma- hyphema syndrome. DESIGN: Retrospective case series. METHODS: Nine pseudophakic eyes (nine patients) with complete or incomplete uveitis-glaucoma-hyphema syndrome underwent ultrasound biomicroscopy. RESULTS: Ultrasound biomicroscopy revealed intraocular lens malposition in each case. Of the eight eyes with posterior chamber intraocular lenses, haptics were in contact with the iris pigment epithelium (four eyes) or the pars plicata (three eyes) or prolapsed into the angle recess near a filtration bleb internal ostium (one eye). All other posterior chamber intraocular lens haptics were located in the ciliary sulcus with the exception of two in the capsular bag. Both haptics in the eye with the anterior chamber intraocular lens had eroded into the ciliary body. CONCLUSION: By its ability to detect haptic position, ultrasound biomicroscopy can assist in elucidating the cause of uveitis-glaucoma-hyphema syndrome and in deciding on the course of treatment.

Aged↗

PubMedDate not supplied

Acute conformational changes in the optic nerve head with rapid intraocular pressure elevation: implications for LASIK surgery.

BACKGROUND AND OBJECTIVE: To investigate the effects of acute intraocular pressure (IOP) elevation on optic disc morphology. PATIENTS AND METHODS: Ophthalmodynamometry was used to increase the IOP of normal, healthy eyes. Confocal scanning laser ophthalmoscopy of the optic nerve head using the Heidelberg Retinal Tomograph II (Heidelberg GmbH, Heidelberg, Germany) and IOP measurements were obtained before, during, and after IOP elevation. RESULTS: Sixteen eyes of 16 normal volunteers (mean age, 32.8 +/- 11.9 years) were enrolled. Rim area, rim volume, cup area, cup volume, cup-to-disc ratio, mean cup depth, maximum cup depth, mean retinal nerve fiber layer (RNFL) thickness, and RNFL cross-sectional area showed significant changes during IOP elevation (all P < .05, paired t test). All measured parameters returned to their original values after pressure resolution (all P > .2) except mean RNFL thickness (P = .03). CONCLUSION: Transient elevation of IOP results in measurable alterations in optic nerve head topography.

Adult↗