Diagnosis of Glaucoma by Indirect Classifiers

Objectives: Demonstration of the applicability of a framework called indirect classification to the example of glaucoma classification. Indirect classification combines medical a priori knowledge and statistical classification methods. The method is compared to direct classification approaches with respect to the estimated misclassification error.

Methods: Indirect classification is applied using classification trees and the diagnosis of glaucoma. Misclassification errors are reduced by bootstrap aggregation. As direct classification methods linear discriminant analysis, classification trees and bootstrap aggregated classification trees are utilized in the problem of glaucoma diagnosis. Misclassification rates are estimated via 10-fold cross-validation.

Results: Indirect classification techniques reduce the misclassification error in the context of glaucoma classification compared to direct classification methods.

Conclusions: Embedding a priori knowledge into statistical classification techniques can improve misclassification results. Indirect classification offers a framework to realize this combination.

[Diffusion tensor imaging of the visual pathway in glaucomatous optic nerve atrophy]

In Germany more than one million inhabitants suffer from glaucoma, more than 100,000 are threatened with blindness because glaucoma is often diagnosed too late or not at all. Diagnosis and monitoring is usually carried out "only" by examination of the retina and not the whole visual pathway. However, the eye is just "the tip of the iceberg" of the actual visual pathway, which extends through the brain to the visual cortex. The interdisciplinary holistic assessment of the whole visual pathway in glaucoma is of crucial importance because glaucoma is a complex neurodegenerative disease. Subtypes, such as normal tension glaucoma (NTG), seem to originate from primary damage to the intracranial visual pathway with secondary retrograde retinal degeneration. Recent studies including glaucoma patients and healthy controls could show that diffusion tensor imaging with calculation of diffusion coefficients, i.e. fractional anisotropy (FA), mean and radial diffusivity (MD and RD) as markers of axonal integrity, provide the potential to assess the intracranial visual pathway with a high correlation to established ophthalmological examinations. In particular, calculation of FA maps of the visual pathway and accompanying voxel-based approaches, can be integrated into clinical routine. Thus, detection of glaucoma-related intracranial alterations, even in early stages of the disease, as well as differentiation of different glaucoma subtypes, is made possible. Furthermore, the diagnosis of normal tension glaucoma seems to be possible much earlier with these new imaging techniques compared to established ophthalmological work-up. Moreover, holistic imaging provides new insights into the pathophysiology of this form of glaucoma. This review article gives an overview of these novel magnetic resonance imaging techniques for assessment of the visual pathway in glaucomatous optic nerve atrophy and reveals the potential of an interdisciplinary approach.

Addition of liraglutide in patients with Type 2 diabetes well controlled on metformin monotherapy improves several markers of vascular function

AIMS

The aim of this study was to investigate the vascular effects of liraglutide in patients well controlled on metformin monotherapy.

METHODS

Forty-four patients with Type 2 diabetes were included in the study. Main inclusion criteria were: pretreatment with metformin on a stable dosage, HbA(1c) < 53 mmol/mol (7.0%), age 30-65 years. Patients were randomized to receive additional liraglutide or to remain on metformin monotherapy. After 6 weeks (1.2 mg) and after 12 weeks (1.8 mg), venous blood was taken for the measurement of several laboratory markers characterizing vascular and endothelial function. In addition, retinal microvascular endothelial function and arterial stiffness were measured.

RESULTS

HbA(1c) levels declined from 45 ± 4 mmol/mol (6.3 ± 0.4%; mean ± SD) to 40 ± 3 mmol/mol (5.8 ± 0.3%) during liraglutide treatment. Asymmetric dimethylarginin was reduced by liraglutide treatment from 0.39 ± 0.08 to 0.35 ± 0.06 μmol/l, E-selectin from 43.6 ± 15.4 to 40.8 ± 15.1 ng/ml, plasminogen activator inhibitor 1 from 861.6 ± 584.3 to 666.1 ± 499.4 ng/ml and intact proinsulin from 9.0 ± 7.2 to 7.0 ± 4.8 pmol/l at 12 weeks of treatment. The microvascular response to flicker light increased from 7.0 ± 15.1 to 15.4 ± 11.5% after 6 weeks and to 11.1 ± 9.9% after 12 weeks. No change could be observed for high-sensitivity C-reactive protein, monocyte chemotactic protein 1, vascular cell adhesion molecule or arterial stiffness parameters.

CONCLUSIONS

In patients with Type 2 diabetes, well controlled with metformin monotherapy, addition of liraglutide improves several cardiovascular risk markers beyond glycaemic control.

[Retinal microangiopathy in arterial hypertension as an early marker of a cerebral macroangiopathy]

HISTORY AND ADMISSION FINDINGS

A 54-year-old man reported having had nonspecific attacks of dizziness. His BMI was 27.7. Since 11 years he had been treated for arterial hypertension and had received oral medication for type 2 diabetes for one year. The latest blood pressure value was 134/109 mm Hg during treatment with a combination of atenolol, chlortalidone und hydralazine-HCl; furthermore hr received simvastatin, metformin, glimepirid und ramipril. A standardized telemedical imaging of the retina ("talkingeyes (®) ") was undertaken, revealing focal and generalized arteriolar narrowing of the retinal vessels and a retinal microinfarction (cotton wool spot) in the right eye. The arterial/venous ratio was decreased to 0.74 in the right and 0.77 in the left eye.

INVESTIGATIONS

Optical coherence tomographie (OCT) revealed an ischemic microinfarction of the retina with marked axonal swelling. The digital subtraction angiography of the cerebral vessels revealed a 40 % stenosis of the right internal carotid artery and a proximal, highgrade stenosis of the basilary artery.

TREATMENT AND COURSE

Angioplasty with stent insertion of the basilary artery was performed. Long-term observation showed no restenosis and a reduction in the size of the the retinal microinfarct.

CONCLUSION

Retinal microinfarctions denote localized retinal areas of hypoxia and underperfusion. They may act as markers of a generalized micro- and macroangiopathy. Patients with severe retinal microangiopathic changes should be examined thoroughly to detect early macroangiopathic changes. These can be treated by interventional procedures thus avoiding irreversible end-organ damages.

[Electronic patient records and teleophthalmology : part 1: introduction to the various systems and standards]

Electronic storage of patient-related data will replace paper-based patient records in the near future. Some steps in medical practice can even now not be achieved without electronic data processing. Both systems, conventional paper-based and electronic-based records, have advantages and disadvantages which have to be taken into consideration. The advantages of electronic-based records are e.g. good availability of data, structured storage of data, scientific analysis of long-term data and possible data exchange with colleagues in the context of teleconsultation systems. Problems have to be solved in the field of data security, initial high investment costs and time consumption in learning to use the system as well as in incompatibility of existing IT systems.

[Comparison of early retinal microvascular changes and microalbuminuria as indicators for increased cardioascular risk]

INTRODUCTION

Prevention of cardiovascular disease is an important goal in clinical medicine and public health. In the process, the diagnosis of early end-organ damage is a priority beside the treatment of classic cardiovascular risk factors. To achieve this, the ophthalmoscopic examination of the retinal vessels plays a prominent role. Alternatively, the quantification of low quantities of albumin in the urine (microalbuminuria) allows the detection of early vascular damage in the kidney. The question is addressed as to whether these two methods are interchangeable or are rather complementary.

PATIENTS AND METHODS

We examined 226 members of the staff of the University Hospital Erlangen who volunteered to participate in a preventive campaign. A comprehensive history was taken, and height, weight and blood pressure were measured. Analysis of serum lipids and determination of the urinary albumin/creatinine ratio were performed. Fotos of the central fundus were taken with a non-mydriatic camera and analysed by an experienced ophthalmologist in a standardised fashion. The risk for cardiovascular mortality within the next ten years was estimated from age, sex, blood pressure and serum cholesterol using the euroSCORE tables for Germany.

RESULTS

There was no signficant correlation between the arteriovenous ratio of the retinal vessels and the urinary albumin/creatinine ratio. Neither parameter correlated with the euroSCORE Germany. Arteriovenous crossings and focal narrowing of the retinal vessels were associated signficantly with an elevated euroSCORE risk.

CONCLUSIONS

In large population-based studies, the arteriovenous ratio and the urinary albumin/creatinine ratio have been confirmed as markers of cardiovascular risk. In our study, there was no correlation between these two parameters. Thus, they seem to present independent risk markers. The presence of arteriovenous crossings and focal narrowing seems to be linked more closely to the classic cardiovascular risk factors from which the euroSCORE is calculated. The ophathlmolscopic examination of retinal vessels and the analysis of urinary albumin/creatinine ratio seem to complement rather than replace each other.

[Prevalence of glaucomatous optic nerve atrophy among a working population in Germany diagnosed by a telemedical approach]

PURPOSE

The aim of this study was to determine the prevalence of glaucomatous optic nerve atrophy among a working population in Germany by secondary evaluation of a study conducted to estimate the prevalence of retinal microangiopathic abnormalities by telemedical examination of the retina.

PATIENTS AND METHODS

From August 2002 until January 2004 the retina and optic nerve head were examined in 19,294 Caucasians using a non-mydriatic fundus camera (Kowa, nonmyd-alpha 45), which produces colour images with 45 degrees. The images of the retina and optic nerve head were evaluated telemedically by glaucoma specialists in respect to optic nerve pathologies and microangiopathic abnormalities by a standardised procedure. Glaucomatous optic nerve atrophy was diagnosed when specific glaucomatous morphological alterations of the optic nerve head were present. A complete medical history including reported elevated intraocular pressure (IOP) and blood pressure was obtained.

RESULTS

The intra-observer and inter-observer reliability were 0.884 and 0.740, respectively. Cronbach's alpha for two evaluation cycles each of two observers was 0.870. The prevalences of glaucomatous optic nerve atrophy in the different age groups were 0.07 % (45 - 49 years), 0.40 % (50 - 54 years), 0.45 % (55 - 59 years) and 0.82 % (60 - 64 years). Age could be established as an important risk factor for glaucomatous optic nerve atrophy, while no influence of gender or family history was found.

CONCLUSION

Telemedical evaluation of colour images of the retina and optic nerve acquired by a non-mydriatic fundus camera allows a fast and efficient screening of many subjects with medium reliability.

[Validation of telemedical fundus images from patients with retinopathy]

BACKGROUND

The degree of retinal microangiopathy is important foran estimation of the vascular risk and for the optimisation of therapy in hypertensive and diabetic patients. Retinal microangiopathy may be determined by examination of the retinal fundus. We examined the reliability of the ophthalmoscopic diagnosis and of the telemedical judgement of fundus images in relation to the presence and the degree of retinopathy.

PATIENTS AND METHODS

This comparative observational study included 47 inpatient hypertensive and/or diabetic subjects. The fundus was judged ophthalmoscopically and subsequently, a fundus image was generated by use of a KOWA camera. The images were sent to the Interdisciplinary Center of Ophthalmologic Preventive Medicine. The reliability of the two diagnostic methods was calculated for one of the two eyes, which was selected by a random generator.

RESULTS

The largest concordance of the two diagnosis methods was achieved, in descending order, for retinal bleeding, stage of diabetic retinopathy and the papilla findings. Additionally, there were no differences for the stage of hypertensive retinopathy und tortuosity. The reliability of arterio-venous nicking related to the right and the left eye was low or absent, respectively.

CONCLUSIONS

The teleophthalmologic diagnosis achieves good results as compared to the ophthalmoscopic judgement in relation to retinopathy assessment criteria.

A phase I trial of sns-314, a novel and selective pan-aurora kinase inhibitor, in advanced solid tumor patients

2536

Background: Aurora Kinases are a family of serine/threonine kinases (Aurora Kinases (AK) A, B, and C) critical for mitosis. Elevated AKs expression occurs in a high percentage of melanoma, colon, breast, ovarian, gastric, and pancreatic tumors; in a subset of these tumors the AURKA locus (20q13) is amplified. SNS-314 is a selective pan-AK inhibitor with low nanomolar IC50s. Methods: Study design is 3+3 phase 1 dose escalation by modified Fibonacci. Patients (pts) with advanced solid tumors received SNS-314 by 3 hour infusion qweek X 3 (28 day cycle). Primary endpoints: safety, tolerability, and DLT assessment. Secondary endpoints: MTD, pharmacokinetics (PK), pharmacodynamics, and antitumor activity. Pharmacodynamic endpoint was inhibition of Histone H3 phosphorylation (pHH3) evaluated by immunohistochemistry of skin punch biopsies taken pre- and 2 hours post-infusion. Results: Thirty-two pts (16M/16F; median age = 58.5 years) were enrolled into 8 cohorts: dose range 30–1800 mg/m2. Median cycles received =2. SNS-314 was generally well tolerated with Grade 1–2 toxicities ≥ 15% incidence: nausea (31%), fatigue (28%), vomiting, constipation, and pain (16% each), and no Grade 3+ toxicities of ≥ 15% incidence. A DLT of Grade 3 neutropenia preventing administration of all 3 doses was observed at 1440 mg/m2. Plasma PK were dose proportional for exposure with no accumulation of SNS-314 following weekly administration. Clearance was moderate (5.65 L/hr/m2, CV 39.4%); Vss approximated total body water (21.5 L/m2, CV 78.1%); terminal half-life was 10.4 hours (CV 66.8%). Six patients had stable disease as their best response. Inhibition of pHH3 by SNS-314 was observed in skin biopsies of patients treated at doses of 240 mg/m2 and greater. Conclusions: SNS-314 is a novel inhibitor of AKs A, B, and C. The compound has been generally well tolerated; MTD was not established. No objective responses were observed. Pharmacodynamic activity was demonstrated by inhibition of pHH3.

[Table: see text]

Phase Ib/II pharmacokinetic/pharmacodynamic (PK/PD) study of combination voreloxin and cytarabine in relapsed or refractory AML patients

7005

Background: Voreloxin is a naphthyridine analog that intercalates DNA and inhibits topoisomerase II, inducing apoptosis. Clinical activity is observed in ovarian cancer and AML. Voreloxin combined with cytarabine (Ara-C) show supra-additive activity preclinically. Interim results from a phase Ib/II study in relapsed or refractory AML are reported. Methods: Dose-escalation in relapsed/refractory AML patients (pts) with ≤ 3 prior induction regimens; phase II expansion in first-relapse pts (CR1 ≥ 3 months) at MTD. Voreloxin given d1 and d4, combined with: A) continuous infusion 400 mg/m2/d x 5d Ara-C (CIV), or B) bolus 1 g/m2/d IV x 5d Ara-C. Voreloxin starting dose: A) 10 mg/m2/dose; B) 70 mg/m2/dose. Treatment: induction, reinduction if needed, and up to 2 courses for consolidation. DLT, PK, and PD were assessed in cycle 1. Pts’ PBMC were evaluated for induction of DNA damage response markers. Ex vivo sensitivity of pt BMA to voreloxin and Ara-C were evaluated by CellTiter-Glo proliferation assay. Results: 52 pts treated to date (A: 41 pts, dose-escalation; 5 pts Phase 2; B: 6 pts dose-escalation). A) MTD is 80 mg/m2/dose voreloxin. Infections are the most common G3 or higher toxicity. Voreloxin PK were dose proportional to 50 mg/m2, then plateaued. Evaluation of PBMC pre- and posttreatment suggests modulation of pDNA-PKcs and pChk2 may reflect response. Ex vivo BMA assay results suggest that voreloxin is the primary contributor to the majority of CRs observed. Phase Ib: 9 CRs + CRp were observed in multiply relapsed or 1° refractory pts. B) 70 mg/m2/dose voreloxin, no DLT; too early to evaluate activity. Conclusions: Voreloxin in combination with CIV Ara-C is generally well-tolerated, with CR in relapsed/refractory pts. Enrollment continues: A) phase II; B) phase Ib. Ex vivo activity assay results suggest that voreloxin is the primary contributor to the majority of CR. Induction of pDNA-PKcs and pChk2 in PBMCs from treated pts may reflect response.

[Table: see text]

A phase II trial of voreloxin in women with platinum-resistant ovarian cancer

5559

Background: Voreloxin is a naphthyridine analog that intercalates DNA and inhibits topoisomerase II, inducing apoptosis. Clinical activity has been observed in ovarian cancer and AML. Results are reported from a fully enrolled phase II study of 3 dose levels of single agent voreloxin in patients (pts) with 1° or 2° platinum-resistant or refractory ovarian cancer. Methods: Pts may have received ≤ 3 prior platinum regimens plus one additional non-platinum regimen. PS of 0–1 was required. Voreloxin regimens: Cohort A 48 mg/m2q3weeks (wk) (N = 65), Cohort B 60 mg/m2q4wk (N = 35), and Cohort C 75 mg/m2q4wk (N = 35) by short IV infusion. BRCA status is reported by pt consent. Results: Cohort A: 2CRs, 5PRs; ORR 11%; median PFS 82 days (52–98 days 95%CI); Cohort B: 1CR, 3PRs; ORR 11%, median PFS too early to evaluate (TETE); Cohort C - TETE. Cohort A: Febrile neutropenia (FN) incidence was low (8%). Other common G3 or G4 AEs reported (≥ 5%) were fatigue (14%) and nausea (5%). Dose delays or reductions (40%) occurred typically at Cycle 1, largely due to neutropenia. Cohort B: Dose was increased to 60 mg/m2 and dosing interval was lengthened to 4 wk, maintaining dose intensity (DI) and allowing adequate time for marrow recovery. ANC dosing criterion was changed from ANC ≥ 1,500 to ≥ 1,000. There was a marked decrease in dose delays and reductions (14%) with only 3% incidence of FN. Common G3 or 4 AEs reported (≥ 5%) were fatigue (11%) and nausea (5%). The safety profile supported further dose escalation to 75 mg/m2q4wk (Cohort C- DI increased by 25%). Data are TETE. Conclusions: Preliminary data suggest Cohorts A and B have similar safety and efficacy profiles as anticipated based on comparable DI. Fewer dose reductions and delays occurred in Cohort B, due to revised dosing criteria and increased cycle length to 4 wk. Accrual to Cohort C is complete. Efficacy and safety data for all cohorts will be reported.

[Table: see text]

[Web-based electronic patient record as an instrument for quality assurance within an integrated care concept]

OBJECTIVE

A prerequisite for integrated care programmes is the implementation of a communication network meeting quality assurance standards. Against this background the main objective of the integrated care project between the University Eye Hospital Erlangen and the health insurance company AOK Bayern was to evaluate the potential and the acceptance of a web-based electronic patient record in the context of cataract and retinal surgery.

METHODS

Standardised modules for capturing pre-, intra- and post-operative data on the basis of clinical pathway guidelines for cataract- and retinal surgery have been developed. There are 6 data sets recorded per patient (1 pre-operative, 1 operative, 4-6 post-operative). For data collection, a web-based communication system (Soarian Integrated Care) has been chosen which meets the high requirements in data security, as well as being easy to handle. This teleconsultation system and the embedded electronic patient record are independent of the software used by respective offices and hospitals. Data transmission and storage were carried out in real-time.

RESULTS

At present, 101 private ophthalmologists are taking part in the IGV contract with the University Eye Hospital Erlangen. This corresponds to 52% of all private ophthalmologists in the region. During the period from January 1st 2006 to December 31st 2006, 1844 patients were entered. Complete documentation was achieved in 1390 (75%) of all surgical procedures. For evaluation of this data, a multidimensional report and analysis tool (Cognos) was used. The deviation from target refraction as one quality indicator was in the mean 0.09 diopter.

CONCLUSIONS

The web-based patient record used in this project was highly accepted by the private ophthalmologists. However there are still general concerns against the exchange of medical data via the internet. Nevertheless, the web-based patient record is an essential tool for a functional integration between the ambulatory and stationary health-care units. In addition to the telemedicine functions of the system, we achieved the export of the data to a data warehouse system in order to provide a flexible and powerful tool for quality assurance analysis and reporting.

Visual field defect during therapy with valproic-acid

Visual field defect because of antiepileptic drug (AED) treatment has been widely reported during the clinical application of vigabatrin. But other gamma-aminobutyric acid (GABA)-ergic and non-GABA-ergic AEDs could also affect the visual field with different mechanisms of action. Here we report a case of a 22-year-old female patient, who suffered from bilateral concentric visual field defect during the long-term therapy with valproic-acid (VPA). A VPA-related metabolic dysfunction was found through blood and urine examination. Reduced B-waves were shown by electroretinography and a bilateral concentric visual field defect was confirmed by both manual and automated perimetry. In conclusion, the concentric visual field defect related to VPA treatment is rare but possible.

A phase 1, pharmacokinetic (PK) and pharmacodynamic (PD) study of CHIR-258, a novel oral multiple receptor tyrosine kinase (RTK) inhibitor

3043

Background: CHIR-258 is a potent small molecule inhibitor of VEGF, FGF, PDGF and c-KIT RTKs with IC50≤10nM that demonstrates activity in a variety of angiogenesis, tumour and metastasis models. Methods: Patients (pts) with histologically confirmed advanced solid tumors, ECOG PS 0–2 were treated in cohorts of 3–6 with CHIR-258. Treatment was as single daily doses on a repeated 7 days (d) on/7d off schedule (25–100mg), with a subsequent protocol amendment to continuous (cont) daily dosing. The objectives were to determine maximum tolerated dose (MTD) and dose limiting toxicity (DLT), evaluate PK and PD endpoints - ERK phosphorylation in PBL - and describe anti-tumour activity. Results: 35pts (median age 56.5 yrs; 15F/20M) were treated in 4 intermittent dosing cohorts (25, 50, 75, 100 mg/d) and 3 continuous dosing cohorts (100,125, 175 mg/d). The most common drug related adverse events were (grade [gr], number of pts): nausea (gr 1–3, 12); fatigue (gr 1–2, 9); headache (gr 1–3, 8); vomiting (gr 1–2, 7); anorexia (gr 1–2, 7); diarrhoea (gr 1–2, 6); dysgeusia (gr1–2, 6); anaemia (gr 2–3, 4); hypertension (gr 1–3, 3) and reversible asymptomatic drop in left ventricular ejection fraction (gr 2, 2). DLTs were gr 3 hypertension (HTN) in 1 pt with pre-existing HTN (100mg, cont); asymptomatic uncomplicated grade 2 elevation in cardiac troponin I (125mg); gr 3 anorexia/fatigue and gr 3 rise in alkaline phosphatase (both at 175mg). 3 pts have had prolonged stable disease (all 4m+; parotid, renal and imatinib-refractory GIST). The plasma PKs of CHIR-258 were linear over the dose range of 25–175 mg with respect to Cmax and AUC. On d1, the mean Cmax was 13.5(5.3) ng/mL to 109 (26) ng/mL, the mean AUC (0–24) was 224(97.4)ng*h/mL to 1740(466)ng*h/mL, and the t½ was 17h. Trough CHIR-258 concentrations at doses >50 mg/d were above the concentrations known to inhibit target receptor activation in vitro. Data on evaluable samples demonstrate up to 90% inhibition of basal ERK phosphorylation. Conclusions: CHIR-258 was safely administered at continuous daily doses up to 175mg/d. Modulation of p-ERK was demonstrated. Treatment is associated with disease stabilization.

[Table: see text]

Phase I trial of chir-258 in multiple myeloma

17502

Background: CHIR-258 is an orally active small molecule receptor tyrosine kinase (RTK) inhibitor which has potent activity against multiple RTKs involved in tumor growth and angiogenesis (IC50 ≤13 nM for FGFR, VEGFR, PDGFR, C-KIT, and FLT3). Approximately 15% of newly diagnosed MM patients harbor a t(4;14) translocation, which results in ectopic expression of FGFR3 and MMSET and is associated with poor treatment outcome [0]and reduced survival. CHIR-258 inhibits proliferation and induces apoptosis in FGFR3-expressing MM tumor xenografts as well as FGFR3-expressing primary MM cells (Trudel et al, Blood 2005). CHIR-258 was synergistic with dexamethasone (dex) in vitro. Methods: CHIR-258 was administered once daily in a dose-escalating phase 1 study to patients with relapsed/refractory MM. Drug tolerability and safety, pharmacokinetics (PK) and pharmacodynamics (PD) were assessed. Results: as of December 2005, 9 total pts have been treated (50, 100, and 200mg qd cohorts) [6M, 3F; median age: 58 (range: 44–68), median of 3 prior therapies(range:1–7)]. Prior tx: 9/9 pts-thalidomide; 8/9 -Velcade; 8/9-transplant; 8/9- had progressed through dex. 4 of 9 pts treated were FGFR3+ and 4 pts remain on study (3 are FGFR3+). No CR or PR have been observed; stable disease has been noted. CHIR-258 has been generally well tolerated, and most drug related AEs were CTC grade 1 or 2, including: headache, dysgeusia, fatigue and anorexia. No neuropathy. One DLT has been observed to date: neutropenia (200mg cohort). Five pts had dex added to CHIR-258 of which 3 are ongoing (all FGFR3+). FGFR3+ pts receiving dex and CHIR-258 have a greater decline in urine and serum paraproteins (pp) vs CHIR-258 alone. Plasma exposure and Cmax increased proportionally across the doses. Conclusions: CHIR-258 is a novel inhibitor of RTKs involved in MM growth and proliferation. FGFR3+ pts have a more marked reduction in pp than FGFR3- pts. CHIR-258 has generally been well tolerated and further accrual continues.

[Table: see text]

[Diagnostics and therapy for normal tension glaucoma]

Pooled data from "The Baltimore Eye Survey", "The Blue Mountains Eye Study", "The Beaver Dam Eye Study", "The Rotterdam Study" and "The Melbourne VIP" showed a strong age-dependent prevalence of open angle glaucoma. Patients younger than 60 years have a prevalence of open angle glaucoma of less than 1 %. Beginning with the age of 60 the prevalence increases exponentially. The prevalence of open angle glaucoma in persons in the 8(th) age decade reaches up to 5 %. Among these patients, 30-50 % have normal intraocular pressure. The diagnostics and therapy for open angle glaucoma with normal intraocular pressure (IOP), also called normal tension glaucoma, is a complex and often interdisciplinary challenge. Established causative factors for developing a glaucomatous optic nerve atrophy in normal tension glaucoma are: relatively increased IOP, older age, non-dippers (0-10 %) or extreme dippers (> 20 %) concerning nocturnal arterial blood pressure drop, small vessel disease with cardiovascular disease and cerebral microgliosis (white matter lesions), decreased blood flow in the optic nerve head, extreme dip of the optic nerve head blood flow in the morning, cerebral blood flow dysregulation and the epsilon4-allele polymorphism of the apolipoprotein E-gene. Clinical pathways are presented for the diagnostics and therapy for normal tension glaucoma.

[TalkingEyes-and-more]

To avoid the clinical manifestation of a vascular disease like stroke it is necessary to detect early vascular signs, to begin a therapy before the outbreak of the vascular disease happens. "TalkingEyes-and-more" is an interdisciplinary and quality-assessed program for prevention of vascular diseases. In several "screening-centers" in Germany interested citized were examined by non-invasive and fast methods to estimate the vascular risk. The examinations were performed on site, the medical evaluation of the data and images were performed centrally in the reading center of the Private Center of Preventive Medicine and Eye Diagnostics" in Erlangen by medical doctors. Alterations of the microvessels become often at first visible in retinal vessels. "TalkingEyes-and-more" examined telemedically the retinal vessels by a patented approach regarding microangiopathic abnormalities. In addition other risk factors like arterial blood pressure, intima media thickness of the carotid artery, cholesterol, fasting glucose, extended bodymass index, and others were documented. By these data a risk index is calculated and a proposal for improving the risk factors is generated.

Automated segmentation of the optic nerve head for diagnosis of glaucoma

Glaucoma is the second most common cause of blindness worldwide. Low awareness and high costs connected to glaucoma are reasons to improve methods of screening and therapy. A well-established method for diagnosis of glaucoma is the examination of the optic nerve head using scanning-laser-tomography. This system acquires and analyzes the surface topography of the optic nerve head. The analysis that leads to a diagnosis of the disease depends on prior manual outlining of the optic nerve head by an experienced ophthalmologist. Our contribution presents a method for optic nerve head segmentation and its validation. The method is based on morphological operations, Hough transform, and an anchored active contour model. The results were validated by comparing the performance of different classifiers on data from a case-control study with contours of the optic nerve head manually outlined by an experienced ophthalmologist. We achieved the following results with respect to glaucoma diagnosis: linear discriminant analysis with 27.7% estimated error rate for automated segmentation (aut) and 26.8% estimated error rate for manual segmentation (man), classification trees with 25.2% (aut) and 22.0% (man) and bootstrap aggregation with 22.2% (aut) and 13.4% (man). It could thus be shown that our approach is suitable for automated diagnosis and screening of glaucoma.

Telemedizinisch unterstütztes Screening der retinalen Gefäße („Talking Eyes”)

BACKGROUND

Cerebral and retinal vessels behave similarly under the influence of vascular risk factors. Several groups have shown that retinal microvascular abnormalities represent an independent risk factor with regard to strokes and heart attacks.

AIM OF THE STUDY

The aim of this study was to perform a prospective screening examination with regard to retinal microvascular abnormalities as well as an extended vessel diagnosis in a subgroup of patients with lower arteriovenous risk values.

METHODS

In the course of a prospective cross-sectional study ("Talking Eyes") between 1.9.2001 and 1.8.2002 a telemedical-supported screening of the retina (study I) was carried out in 7,163 subjects. The patients were selected without any inclusion or exclusion criteria. The mean age was 48.2 +/- 8 years (18 - 83 years) with a sex distribution of 39.2 % females to 60.8 % males. Digital fundus photos of the right and left eyes were taken for all patients. The pictures were taken without pupil dilation using a CANON-NM camera. The pictures and case histories were stored in a central server using web-based software (MedStage, Siemens). In a central reading centre, the arteriovenous ratio of both eyes was determined telemedically using the Parr-Hubbard formula and the retinas subjected to a standardised examination by an ophthalmologist. The retinal risk factor was calculated on the basis of the arteriovenous ration, the presence of microvascular abnormalities and the case history. The reproducibility of measurement of the arteriovenous ratio (Kronbach alpha coefficient) was evaluated by double measurements on 1,332 images. In a subgroup of study I with arteriovenous ratio values < 0.76 (N = 107), an extended vessel diagnosis with measurement of 24-h blood pressure and vessel-relevant blood values (homocysteine, cholesterol, LDL, HDL, CRP, TG, HbA1c) was carried out (study II).

RESULTS

Study I: The Kronbach alpha coefficient as a measure of reproducibility amounted to 0.77. The mean arteriovenous ratio of the retinal vessels was 0.83 +/- 0.09 and showed a pronounced age dependence (R = 0.9, p < 0.0001). On multivariate testing the arteriovenous ratio correlated significantly (R = 0.33, p < 0.001) with the factors age, systolic blood pressure, diastolic blood pressure and body mass index. Diastolic blood pressure followed by age had the largest influence. The prevalence of microvascular abnormalities in the right (RE) and left (LE) eyes, respectively were: cotton wool foci RE 0.0015 %, LE 0.003 %, retinal haemorrhage RE 0.1 %, LE 0.1 %, focal stenoses RE 3.4 %, LE 3.4 %, tortuositas vasorum RE 4.1 %, LE 4.0 %, arteriovenous crossing signs RE 11.2 %, LE 11.2 %. On multivariate testing the occurrence of microvascular abnormalities correlated significantly (R = 0.38, p < 0.001) with the factors high blood pressure known from case history, body mass index, and gender. Arterial hypertension had the strongest influence followed by diastolic blood pressure. The calculated retinal risk factor correlated with the prevalence of angina pectoris. Study II: 2/3 of the subjects with arteriovenous risk factor values < 0.76 exhibited pathologically high 24-h blood pressure values. For these patients there were significant correlations between the arteriovenous ratio and the low-density lipoprotein concentration as well as the Framingham risk score.

CONCLUSION

In the course of a prospective, telemedical-supported screening examination of the retinal vessels of more than 7,000 subjects the arteriovenous ratio exhibited a strong dependence on age and blood pressure. Among the subjects with lowered arteriovenous ratio values, 2/3 exhibited arterial hypertension in the 24-h blood pressure determination.

Telematisch assistierte Selbsttonometrie (TAS)

BACKGROUND

Close supervision of intraocular pressure (IOP) means monitoring an important risk factor for glaucoma.

METHOD

After instruction in its use, patients measure their own IOP several times a day with the Drager self-tonometer. The measurements are subsequently transmitted to a server via the telephone keypad and recorded separately for each patient. The software enables statistical evaluation of the pressure levels collected.

RESULTS

Up to now 30 of 35 patients transmit measurements or had done so for at least 6 months. Registration of measurement levels covering months and years provides the opportunity for optimizing treatment and hence can be considered a start toward quality assurance in the treatment of glaucoma patients.

CONCLUSION

TAS is a cost-efficient method for obtaining long-term profiles of eye pressure. Thus, the possibility exists for early therapeutic intervention in patients at risk. The compliance gained by the close relationship between the physician and the patient represents a positive prognostic factor.

Multimodal retinal image registration for optic disk segmentation

OBJECTIVES

The analysis of the optic disk morphology with the means of the scanning laser tomography is an important step for glaucoma diagnosis. A method we developed for optic disk segmentation in images of the scanning laser tomograph is limited by noise, non-uniform illumination and presence of blood vessels. Inspired by recent medical research, we wanted to develop a tool for improving optic disk segmentation by registration of images of the scanning laser tomograph and color fundus photographs and by applying a method we developed for optic disk segmentation in color fundus photographs.

METHODS

The segmentation of the optic disk for glaucoma diagnosis in images of the scanning laser tomograph is based on morphological operations, detection of anatomical structures and active contours and has been described in a previous paper. The segmentation of the optic disk in the fundus photographs is based on nonlinear filtering, Canny edge detector and a modified Hough transform. The registration is based on mutual information using simulated annealing for finding maxima.

RESULTS

The registration was successful 86.8% of the time when tested on 174 images. Results of the registration have shown a very low displacement error of a maximum of about 5 pixels. The correctness of the registration was manually evaluated by measuring distances between the real vessel borders and those from the registered image.

CONCLUSIONS

We have developed a method for the registration of images of the scanning laser tomograph and fundus photographs. Our first experiments showed that the optic disk segmentation could be improved by fused information from both image modalities.

Diagnosis of glaucoma by indirect classifiers

OBJECTIVES

Demonstration of the applicability of a framework called indirect classification to the example of glaucoma classification. Indirect classification combines medical a priori knowledge and statistical classification methods. The method is compared to direct classification approaches with respect to the estimated misclassification error.

METHODS

Indirect classification is applied using classification trees and the diagnosis of glaucoma. Misclassification errors are reduced by bootstrap aggregation. As direct classification methods linear discriminant analysis, classification trees and bootstrap aggregated classification trees are utilized in the problem of glaucoma diagnosis. Misclassification rates are estimated via 10-fold cross-validation.

RESULTS

Indirect classification techniques reduce the misclassification error in the context of glaucoma classification compared to direct classification methods.

CONCLUSIONS

Embedding a priori knowledge into statistical classification techniques can improve misclassification results. Indirect classification offers a framework to realize this combination.

Functional imaging of the retinal microvasculature by scanning laser Doppler flowmetry

PURPOSE

to image functionally perfused retinal vessels and to assess quantitatively the intercapillary space of the retinal microvasculature.

METHOD

The base of functional imaging and the quantitative assessment of the retinal vasculature is the two-dimensional map of the retina encoded by the laser Doppler frequency shift. By Scanning Laser Doppler Flowmetry (HRF. Heidelberg Engineering) the laser Doppler frequency shift of 16.384 retinal sites (256 pixels x 64 lines, spatial resolution 10 mum) of a retinal area of 2.7 x 0.7 mm was gained. The image processing was performed by a recently described algorithm (AFFPIA). Using the data of the laser Doppler frequency shift of every retinal site, a color-coded retinal image was established showing perfused vessels and capillaries. By automatic pattern analysis of this image vessels and capillaries were identified and segmented. Based on this image the distances in [microm] of every retinal site to the next vessel or capillary were calculated ("distance to next capillary"). The functional imaging of the retinal perfusion was demonstrated in (1) normal retina, (2) retinal arterial occlusion, and (3) proliferative retinopathy. Intraobserver reliability of the quantitative assessment of the parameter "distance to next capillary" was estimated by measuring 10 eyes of 10 subjects at 5 different days by one observer. Interobserver reliability of the quantitative assessment was evaluated by analysing 10 perfusion maps by 5 different operators. In 93 eyes of 71 normal subjects (mean age 40.4 mu 15 years) the juxtapapillary retina was quantitatively evaluated.

RESULTS

QUALITATIVE EVALUATION: The functional images of the retinal perfusion of eyes with normal retina, with retinal arterial occlusion, and with proliferative retinopathy corresponded well with the fluorescein angiography. Perfused vessels and capillaries became visible in a high local resolution. QUANTITITATIVE ASSESSMENT: The coefficient of reliability of the introobserver and interobserver reproducibility of the parameter 'mean distance to next capillary" was 0.74, and 0.95, respectively. The quantitative assessment of the perfusion showed that the major part of the retinal sites (>700%) had distances to the next capillary lower than 30 microm 46% of the retinal area had distances to the next capillary from 0-20 microm 26% of the retina had distances from 20-30 microm, 12% of the retina had distances from 30-40 microm 7% of the retina had distances from 40-50 microm, 4% of the retina had distances from 50-60 microm, and 4% of the retinal sites showed distances to the next capillary greater than 60 mum. The mean distance to the next capillary or vessel was calculated with 21 +/- 6.5 microm.

CONCLUSION

By non-invasive Scanning Laser Doppler Flowmetry in combination with adequate software it is possible to perform a functional imaging of the retinal vasculature and to measure all index for the functional density of retinal capillaries and vessels.

Retinal microcirculation correlates with ocular wall thickness, axial eye length, and refraction in glaucoma patients

PURPOSE

To examine the correlations of refraction, axial eye length, and posterior eye wall thickness with retinal microcirculation.

PATIENTS AND METHODS

In a prospective study, 25 patients with primary open-angle glaucoma, 12 patients with ocular hypertension, and 12 healthy subjects were examined; only one eye of each participant was considered in the analysis. Posterior eye wall thickness and axial eye length were measured with standardized A-scan ultrasonography. Retinal microcirculation temporal to the optic disc was determined by a scanning laser Doppler flowmeter using automatic full-field perfusion image analyzer software.

RESULTS

In glaucoma patients, temporal retinal mean flow exhibited significant correlation to the eye wall thickness (r = 0.470, P = 0.042), axial eye length (r = -0.570, P = 0.011), and refraction of the eye (r = 0.520, P = 0.022). In glaucomatous eyes, the temporal retinal mean flow was significantly lower than in healthy subjects or in ocular hypertensive patients (P = 0.01).

CONCLUSIONS

Myopic eyes have longer axial eye length and thinner ocular wall than emmetropic eyes. In glaucoma patients, the longer the axial eye length and the thinner the ocular wall, the more reduced the retinal microcirculation. The reduced microcirculation found in myopic glaucomatous eyes might contribute to the development of glaucomatous damage in these eyes.

Changes in ocular blood flow velocities during external counterpulsation in healthy volunteers and patients with atherosclerosis

BACKGROUND

External counterpulsation (ECP) is a new noninvasive means of augmenting organ perfusion by applying ECG-triggered diastolic pressure to the vascular bed of the lower limbs. In this study, effects of ECP on changes of ocular blood flow velocities were studied.

METHOD

Mean, systolic and diastolic flow velocities of the ophthalmic artery were measured by Doppler sonography before and during ECP. Twelve healthy volunteers (age 31.3+/-4.3 years) and 12 patients with severe atherosclerosis (inclusion criteria: two atherosclerotic risk factors, at least one severe coronary stenosis, age 62.1+/-5.3 years) were included in the study.

RESULTS

In healthy subjects, ECP changed diastolic flow velocity of the ophthalmic artery nonsignificantly from 21.6+/-7.7 to 23.7+/-10.5 cm/s. Systolic flow velocity decreased significantly from 36.1+/-13.6 to 28.9+/-10.2 cm/s (P<0.01). Mean flow velocity changed nonsignificantly from 28.1+/-9.4 to 26.5+/-9.9 cm/s. In atherosclerotic patients, mean flow velocity increased significantly from 26.3+/-11.4 to 29.3+/-11.2 cm/s (P<0.001), which was caused by significant diastolic flow augmentation from 19.7+/-9.1 to 23.9+/-9.7 cm/s (P<0.001). Systolic flow velocity was not changed significantly (from 34.2+/-12.8 to 32.6+/-11.8 cm/s).

CONCLUSION

No significant change of mean blood flow velocity in the ophthalmic artery was found in young healthy subjects. In elderly patients with atherosclerosis, ECP significantly increased blood flow velocity in the ophthalmic artery by 11.4%. This may indicate an ocular perfusion benefit in these patients as a result of ECP and could also explain the increase of perfusion found in patients with retinal ischemia after ECP.