Biomedical subjects

Heike Häberle

Publications and source records attributed to Heike Häberle.

5 recordsLinked to original sources

PubMed2005

Noncontact goniometry with optical coherence tomography.

OBJECTIVE: To assess the value of noncontact goniometry with optical coherence tomography (OCT) compared with current clinical parameters in the evaluation of the anterior chamber angle (ACA). DESIGN: Prospective observational study of 138 eyes of 109 patients. METHODS: The ACA parameters and angle-opening distance (AOD) were measured with slitlamp-adapted OCT goniometry. The iris and scleral thickness and the iris convexity were assessed with OCT. Both ACA and AOD were compared with the clinical parameters of gonioscopy grade, limbal anterior chamber depth (ACD), ultrasonographic central ACD, and lens-axial length (LAL) ratio. RESULTS: Noncontact goniometry with OCT revealed mean +/- SD values of 28 degrees +/- 16 degrees for the ACA and 381 +/- 234 mum for the AOD. The mean +/- SD iris thickness was 369 +/- 84 mum, and the scleral thickness at the scleral spur was 943 +/- 148 mum. There was a significant correlation (P<.001) with the clinical parameters of gonioscopic grading, limbal ACD, ultrasonographic central ACD, and LAL ratio. The sensitivity and specificity of OCT goniometry to detect an occludable angle were 86% and 95% for ACA and 85% and 90% for AOD, respectively. CONCLUSIONS: Noncontact goniometry with OCT was helpful in evaluating the anterior chamber structures and as a screening modality. Goniometry with OCT could improve the noninvasive clinical assessment and treatment of patients with glaucoma.

Adult↗

PubMed2004

Lamellar keratotomy to correct astigmatism in cataract surgery.

BACKGROUND: For the correction of astigmatism in cataract surgery, several incisional procedures have been developed. In this study, a modification of lamellar keratotomy was evaluated to correct astigmatism in cataract surgery. METHODS: Prospectively 32 eyes of 25 patients with a preoperative astigmatism greater than 1.5 D were studied. All patients were treated with lamellar keratotomy with an incision width of 6 mm and a radial length of 1.5 mm placed at the limbus in the steep meridian. Phacoemulsification and IOL implantation were then performed through a 3.2-mm corneal tunnel incision. After 4 weeks, mean astigmatism, mean corneal power changes, and mean surgically-induced astigmatism derived from vector analysis in the central 3-mm optical zone were determined. RESULTS: The mean astigmatism decreased from 2.75 +/- 0.80 D preoperatively to 1.58 +/- 0.91 D after 4 weeks (P < 0.001). There were no significant changes (P=0.614) of the mean corneal power. The mean surgically-induced astigmatism was 2.59 +/- 1.50 D. The induced changes were more accentuated in superior incisions. In corneal topography, 78% of the treated eyes revealed a characteristic threefold pattern of the mid-peripheral cornea postoperatively, which impaired the corneal optical performance in ray-tracing analysis. CONCLUSIONS: Lamellar keratotomy effectively reduced high preoperative astigmatism in cataract surgery. This surgical approach was combined with a superior, temporal, or oblique corneal incision.

Adult↗

PubMed2002

Histopathological correlation of corneal diseases with optical coherence tomography.

PURPOSE: To correlate the cross-sectional images of corneal diseases obtained by optical coherence tomography (OCT) with light microscopy (LM) to determine the corneal components represented in OCT images. METHODS: In a prospective comparative tissue study clinicopathological correlations of six patients with pseudophakic bullous keratopathy ( n=3), advanced keratoconus ( n=1), persistent epithelial defect with corneal thinning ( n=1), and retrocorneal membrane ( n=1) were included. Immediately before a planned penetrating keratoplasty (PKP) noncontact slitlamp-adapted OCT of the cornea was performed. After PKP and following standard histological processing the specimens were examined under LM to compare qualitatively the morphology, and quantitatively the morphometry at selected corneal locations. RESULTS: The cross-sectional optical-reflectivity profiles enabled the reproducible morphological evaluation of the corneal structures and changes. Layers of relative high reflectivity corresponded to the anterior corneal surface and internal stromal layers. In contrast, the deeper corneal epithelial layer demonstrated relative low reflectivity by OCT. An increase in light reflectivity corresponded to corneal scarring, irregularities of the corneal lamellae, and deposition of basal membrane material. Low signal intensity was particularly due to fluid accumulations and shadowing. The most prominent changes were caused by corneal scars or edematous tissue. The morphometric analysis with OCT revealed, in this study, thickness measurements ranging from 31 to 902 micro m. Although the mean OCT thickness values were up to 9% ( P=0.014) higher than those derived from LM, there was a significant positive correlation (r=0.94; P<0.001) between corneal OCT and the light-microscopic measurements. CONCLUSION: Noncontact slitlamp-adapted corneal OCT revealed a good correlation with histological sections. The differences noted were partly related to shrinking processes during preparation. Thus, with certain limitations, OCT allows a non-invasive optical biopsy of pathological structures in corneal diseases.

Aged↗

PubMed2002

Corneal optical coherence tomography before and after phototherapeutic keratectomy for recurrent epithelial erosions(2).

PURPOSE: To study the representation of corneal structures with optical coherence tomography (OCT) before and after excimer laser phototherapeutic keratectomy (PTK) for recurrent epithelial erosions. SETTING: Departments of Ophthalmology, Vivantes Klinikum Neukölln, Berlin, and Medizinische Universität, Lübeck, Germany. METHODS: This prospective study comprised 15 eyes of 14 patients with recurrent epithelial erosions. The central corneal and epithelial thickness as well as the wound-healing response in the anterior corneal stroma were assessed with slitlamp-adapted OCT before and after PTK. RESULTS: After PTK, the symptoms improved in all patients without loss of best corrected, glare, or low-contrast visual acuity. The mean central corneal OCT thickness was 540 microm +/-28 (SD) preoperatively, 492 +/- 36 microm immediately after epithelial debridement and PTK, and 519 +/- 25 microm after 7 weeks (P <.01). The mean central epithelial OCT thickness changed from 70 +/- 13 microm preoperatively to 60 +/- 7 microm after 7 weeks (P >.01). Changes in the light-scattering properties in the anterior subepithelial stroma revealed a hyperreflective area with a mean thickness of 46 +/- 13 microm after 7 weeks. CONCLUSIONS: Using noncontact corneal OCT, corneal and epithelial thickness changes and the wound-healing response in the anterior corneal stroma could be evaluated after PTK in patients with recurrent epithelial erosions.

Cornea↗

PubMedDate not supplied

Experimental imaging of intracorneal ring segments with optical coherence tomography.

PURPOSE: To investigate the imaging of corneal structures with optical coherence tomography (OCT) after implantation of intracorneal ring segments (ICRS). METHODS: In an experimental study with six porcine eyes, qualitative and quantitative imaging with corneal OCT using a wavelength of 1310 nm after implantation of ICRS was performed. The optical results were compared with light microscopy of the histological sections. RESULTS: In corneal OCT, the ICRS revealed marked hyporeflective intrastromal areas, which correlated well with macroscopic and microscopic findings. Corneal OCT enabled precise images of the incision depth for the implantation of ICRS, and the exact intrastromal segment position. CONCLUSIONS: Noncontact slit lamp-adapted corneal optical coherence tomography could be employed to clinically monitor corneal changes after implantation of ICRS, evaluate the depth of the segments to correlate refractive changes, and quantify the stromal wound healing response.

Animals↗