Eva Koch

Evaluation of early anatomical changes following canaloplasty with anterior segment spectral-domain optical coherence tomography and ultrasound biomicroscopy

To analyse structural changes in conjunctiva, sclera and Schlemms canal (SC) following canaloplasty with optical coherence tomography (AS‐OCT) and ultrasound biomicroscopy (UBM).

Blood Pressure and Heart Rate Variability to Detect Vascular Dysregulation in Glaucoma

Purpose. To investigate blood pressure and heart rate variability in patients with primary open-angle glaucoma (POAG) to detect disturbed blood pressure regulation. Methods. Thirty-one patients with POAG (mean age 68 ± 10 years) and 48 control subjects (mean age 66 ± 10 years) were included in a prospective study. Continuous blood pressure and heart rate were simultaneously and noninvasively recorded over 30 min (Glaucoscreen, aviant GmbH, Jena, Germany). Data were analyzed calculating univariate linear (time domain and frequency domain), nonlinear (Symbolic Dynamics, SD) and bivariate (Joint Symbolic Dynamics, JSD) indices. Results. Using nonlinear methods, glaucoma patients were separated with more parameters compared to linear methods. In POAG, nonlinear univariate indices (pW113 and pW120_Sys) were increased while the indices pTH10_Sys and pTH11_Sys reflect a reduction of dominant patterns. Bivariate indices (JSDdia29, JSDdia50, and JSDdia52; coupling between heart rate and diastolic blood pressure) were increased in POAG. The optimum set consisting of six parameters (JSDdia29, JSDdia58, pTH9_Sys, pW231, pW110_Sys and pW120_Sys) revealed a sensitivity of 83.3% and specificity of 80.6%. Conclusions. Nonlinear uni- and bivariate indices of continuous recordings of blood pressure and heart rate are altered in glaucoma. Abnormal blood pressure variability suggests disturbed autonomic regulation in patients with glaucoma.

Long term effect of trabeculectomy on retrobulbar haemodynamics in glaucoma

Previous reports showed increased flow velocities in retrobulbar vessels after glaucoma surgery in the first weeks. Colour Doppler imaging was performed to investigate the long‐term effects of trabeculectomy on retrobulbar haemodynamics in patients with primary open–angle glaucoma (POAG).

Arteriovenous Passage Times and Visual Field Progression in Normal Tension Glaucoma

Purpose. Fluorescein angiographic studies revealed prolonged arteriovenous passage (AVP) times and increased fluorescein filling defects in normal tension glaucoma (NTG) compared to healthy controls. The purpose of this study was to correlate baseline AVP and fluorescein filling defects with visual field progression in patients with NTG. Patients and Methods. Patients with a follow-up period of at least 3 years and at least 4 visual field examinations were included in this retrospective study. Fluorescein angiography was performed at baseline using a confocal scanning laser ophthalmoscope (SLO, Rodenstock Instr.); fluorescein filling defects and AVP were measured by digital image analysis and dye dilution curves (25 Hz). Visual field progression was evaluated using regression analysis of the MD (Humphrey-Zeiss, SITA-24-2, MD progression per year (dB/year)). 72 patients with NTG were included, 44 patients in study 1 (fluorescein filling defects) and 28 patients in study 2 (AVP). Results. In study 1 (mean follow-up 6.6 ± 1.9 years, 10 ± 5 visual field tests), MD progression per year (−0.51 ± 0.59 dB/year) was significantly correlated to the age (P = 0.04, r = -0.29) but not to fluorescein filling defects, IOP, or MD at baseline. In study 2 (mean follow-up 6.6 ± 2.2 years, 10 ± 5 visual field tests), MD progression per year (−0.45 ± 0.51 dB/year) was significantly correlated to AVP (P = 0.03, r = 0.39) but not to age, IOP, or MD at baseline. Conclusion. Longer AVP times at baseline are correlated to visual field progression in NTG. Impaired retinal blood flow seems to be an important factor for glaucoma progression.

Blood Pressure and Heart Rate Variability in Primary Open-Angle Glaucoma and Normal Tension Glaucoma

ABSTRACT Purpose: Vascular dysfunction and ischemia are believed to play an important part in the pathogenesis of glaucoma and especially of normal tension glaucoma (NTG). The aim of the present study was to analyze the blood pressure (BP) and heart rate variability patterns in patients with primary open-angle glaucoma (POAG) and NTG compared with controls. Methods: In total, 37 patients with POAG, 27 patients with NTG, and 82 control subjects were included in a prospective clinical validation study. Continuous BP and heart rate were simultaneously recorded over 30 min (Glaucoscreen, aviant GmbH, Jena, Germany) under resting conditions. Time series of heart rate, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were extracted and analyzed calculating univariate linear (time domain, frequency domain), nonlinear (symbolic dynamics), and bivariate (joint symbolic dynamics) indices. Results: Overall, 12 parameters could be identified that were significantly different when comparing POAG patients and controls, whereas 80 parameters were significantly different in NTG patients compared with controls. The optimum set consisting of three indices showed a sensitivity of 81.5% at a specificity of 86.6% for NTG patients compared with a sensitivity of 62.2% at a specificity of 82.9% for POAG patients. Conclusions: Alterations in BP variability and coupling with heart rate suggest impaired patterns of autonomic cardiovascular regulation in glaucoma patients especially in patients with NTG.

Identifying glaucoma patients by applying multivariate analyses of cardiovascular signals

Glaucoma is a disease that damages the eyes optic nerve. However, the exact cause of this optic nerve damage is not yet fully understood. Besides the factors of age, genetics and others, such as obesity, medication and migraines, a vascular dysfunction is believed to be a significant factor leading to glaucoma. This studys objective was to investigate whether these vascular dysfunctions could be recognized by analyzing cardiovascular regulation in glaucoma patients. Linear and nonlinear methods were applied to the extracted heart rate (HR), and systolic/ diastolic blood pressure (DBP) time series to discriminate between 35 healthy controls and 20 glaucoma patients. The combination of indices from 30-min analysis of time domain (Renyi entropy of systolic blood pressure) and nonlinear dynamics (segmented Poincare plot analysis of DBP, high-resolution joint symbolic dynamics of DBP/ HR) were able to differentiate between controls and patients with a specificity and sensitivity of > 95%. Since changes in short-term blood pressure regulation patterns and heart-rate coupling are clear signs of a vascular dysfunction, this approach could be useful for providing an earlier diagnosis of glaucoma in clinical practice.

Sensitivity and Specificity of the Nerve Fibre Imaging Using Scanning Laser Ophthalmoscopy and of Optic Nerve Analysis Using Heidelberg Retina Tomography in Glaucoma

PURPOSE Imaging of the optic nerve head and the nerve fibre layer are used in the diagnosis of glaucoma. We have investigated the diagnostic precision of nerve fibre layer imaging using a manually operated scanning laser ophthalmoscope and analysis of the optic nerve head using the Heidelberg Retina Tomograph II (HRT). PATIENTS AND METHODS 42 patients with glaucoma, 16 patients with ocular hypertension (OHT) and 24 healthy control subjects were included in a clinical study. Nerve fibre layer imaging was performed using a scanning laser ophthalmoscope (SLO, Rodenstock Instr. argon laser 488 nm). Nerve fibre layer defects were analysed peripapillarily for every single degree (defect or no defect) at 1.7 mm (near) and at 3.4 mm (far) distance to the optic nerve head. Specificity and sensitivity of the HRT II were calculated using the Moorfields regression analysis (MRA). RESULTS Patients with glaucoma were found to have 109 ± 92° (near) and 109 ± 92° (far) defects of the nerve fibre layer. Patients with OHT (8 ± 14° [far] and 6 ± 11° [near]) and control subjects (0 ± 0° [far] and 0 ± 1° [near]) showed significantly smaller defects (p < 0.0001). Sensitivity at > 90 % specificity for POAG and controls was 85.7 % (far) and 82.9 % (near). Sensitivity at > 90 % specifity for OHT and POAG was 85.7 % (far) und 82.9 % (near). Specificity of controls for the MRA was 83.3 % (borderline classified as normal). Specificity of OHT patients was 93.8 % (borderline classified normal). Sensitivity of the MRA for POAG was 80.9 % (borderline classified normal) and 90.5 % (borderline classified glaucoma). CONCLUSIONS Nerve fiber layer imaging using a manually operated scanning laser ophthalmoscope was found to achieve a higher diagnostic precision as compared to optic disc evaluation using the HRT II.