Biomedical subjects

Christina Leydolt

Publications and source records attributed to Christina Leydolt.

3 recordsLinked to original sources

PubMed2006

Effect of anterior capsule polishing on the posterior capsule opacification-inhibiting properties of a sharp-edged, 3-piece, silicone intraocular lens: three- and 5-year results of a randomized trial.

PURPOSE: To evaluate the long-term effects of anterior capsule polishing on regeneratory posterior capsule opacification (PCO), anterior capsule opacification (ACO), and fibrotic PCO with a silicone intraocular lens (IOL) with sharp optic edges. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: This prospective bilateral randomized patient- and examiner-masked clinical trial comprised 130 eyes of 65 patients with bilateral age-related cataract. All eyes had implantation of a 3-piece silicone IOL with a truncated, sharp-edged optic (CeeOn Edge 911A, Advanced Medical Optics). In 1 eye, the anterior capsule was extensively polished using an aspiration curette after phacoemulsification and cortex aspiration. Regenerative PCO was quantified objectively, while ACO and fibrotic PCO were graded subjectively 1, 2, 3, and 5 years postoperatively. RESULTS: The mean ACO score was significantly lower in the eyes in which the anterior capsule had been polished (1 year, P<.02; 2 years, P<.03; 3 years, P<.01; 5 years, P<.01). The mean difference in regeneratory PCO and fibrotic PCO scores between the 2 groups was not statistically significant. CONCLUSIONS: Three years after cataract surgery, eyes in which the anterior capsule had been polished had significantly less ACO. However, polishing did not lower PCO intensity when a sharp-edged CeeOn 911A IOL was implanted in the bag. Although results indicate that anterior capsule polishing may enhance the development of regeneratory PCO, this trend did not reach statistical significance.

Cataract↗

PubMed2006

Human macula investigated in vivo with polarization-sensitive optical coherence tomography.

PURPOSE: To investigate a depolarizing layer that is visible in polarization-sensitive optical coherence tomography (PS-OCT) images of the retina. To identify this layer and characterize its depolarizing effect quantitatively. METHODS: Ten healthy human subjects (mean age, 31 +/- 8 years) and two patients with RPE diseases participated in the study. The macular region of one eye of each subject was investigated with a phase-resolved PS-OCT system. The instrument measured backscattered intensity (standard OCT), phase retardation, and (cumulative) birefringent axis orientation, simultaneously. For a quantification of the depolarizing layer, plots of the distributions of retardation and axis orientation within and above this layer were analyzed. RESULTS: A polarization-scrambling layer (PSL) was observed at the posterior boundary of the retina in PS-OCT images of all volunteers. It was identified in PS-OCT images by determining random retardation and axis orientation in a transverse direction. Measurements in patients with neurosensory retinal detachment, retinal pigment epithelium (RPE) detachment, and RPE atrophy suggest that the PSL is the RPE. The statistical analysis provided objective discrimination of the RPE from the other retinal structures. CONCLUSIONS: PS-OCT represents a powerful tool for increasing image contrast in ocular tissues. The observed polarization-scrambling nature of the RPE may be used in diseased eyes to locate the RPE or remains of the RPE definitively in OCT images.

Adult↗

PubMed2006

Comparison of partial coherence interferometers: Acmaster versus laboratory prototype.

PURPOSE: To evaluate anterior segment biometry using the ACMaster (Carl Zeiss Meditec AG, Jena, Germany) in regard to precision of measurement and clinical performance compared to the original laboratory prototype of the partial coherence interferometry technique. METHODS: Ten phakic (20 eyes) and 27 pseudophakic (44 eyes) patients were included in this study. Anterior segment biometry of phakic and pseudophakic study eyes was performed using the ACMaster and the laboratory prototype of the partial coherence interferometry technique. The ACMaster is a commercially available device based on the partial coherence interferometry technique, which provides high precision anterior segment measurements in a quick and user-friendly fashion. Examination included measurement of central corneal thickness, anterior chamber depth, and lens thickness, the latter only in the phakic eyes. RESULTS: The consistency of anterior segment measurements performed with both units was excellent in phakic as well as in pseudophakic eyes. In pseudophakic eyes, the measurement of anterior chamber thickness and lens thickness with the ACMaster produced several (typical) measurement artifacts in some cases, which partially aggravated the identification of the A-scan peak representing the anterior intraocular lens surface. CONCLUSIONS: The ACMaster is a user-friendly device that enables axial anterior segment biometry using the partial coherence interferometry technique with a reproducibility similar to that of the original laboratory prototype.

Anterior Eye Segment↗