Slow recruitment

In colorectal cancer therapy anti-angiogenic strategies have become a cornerstone of treatment regimens in the metastatic setting. Addition of bevacizumab to conventional chemotherapeutic combination regimens has improved the median overall survival of advanced colorectal cancer patients by approximately 5 months. Selecting patients, who will benefit from anti-angiogenic approaches, would be highly desirable in order to optimize treatment strategies. Changes in ocular blood flow may be an attractive biomarker for predicting treatment response. In light of the given alternative first line treatment options such a predictive biomarker would be of clinical benefit. In the proposed study the investigators will assess potential changes in the ocular blood flow of mCRC patients after treatment with standard of care anti-angiogenic/cytotoxic therapy as an early predictive marker of treatment response as assessed by standard CT-scan

Inclusion Criteria:

• Male or female patients (age 18 and over) suffering from mCRC.
• Normal findings in ophthalmic examination (except the investigator finds an abnormality irrelevant for the purpose of the study.)
• Patients, which are scheduled for standard of care treatment with chemotherapy plus bevacizumab

Exclusion Criteria:

• Refusal to give informed consent
• Severe hypertension (RR ≥180/110)
• Epilepsy
• Pregnancy and breastfeeding women

Patients, who are treated at the Medical University of Vienna