Macular Degeneration, Regional Blood Flow, Vascular Endothelial Growth Factor
Conditions
Keywords
Age-related macular degeneration, anti-VEGF
Brief summary
Age related macula degeneration is one of the most common sight threatening diseases of the elderly. The so called wet form of AMD is caused by choroidal neovascularisation (CNV) of pathological vessels, which lead to leakage, bleeding and macular edema. Several lines of evidence suggest that vascular endothelial growth factor (VEGF) plays a key role in the induction CNV. Recent evidence indicates that overexpression of VEGF in the retinal pigment epithelium may lead to the development of CNV in experimental models, and intravitreal injection of a VEGF blocker prevents the development of experimental CNV. This hypothesis is also supported by the promising effects of anti-VEGF treatment in patients with choroidal neovascularisation. The substances currently in clinical use include ranibizumab (Lucentis®), bevacizumab (Avastin®) and pegaptanib (Macugen®). However, from a physiological point of view, VEGF also serves as a survival factor for existing vessels and for neuronal cells. Moreover, it has been reported that VEGF induces vasodilatation, most probably by an increased production of nitric oxide. Accordingly one may hypothesize that anti-VEGF treatment is associated with ocular vasoconstriction with unknown long term results. Thus, in the current study, the investigators set out to investigate whether the ocular perfusion is affected by a single intravitreal anti-VEGF.
Interventions
DRUGranibizumab, bevacizumab or pegaptanib
measurements are performed one week before and after anti-VEGF intravitreal injection
Sponsors
Medical University of Vienna
Study design
Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
50 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* 40 subjects ≥ 50 years of age * Subjects with all angiographic subtypes of neovascular wet AMD, already scheduled for intravitreal anti-VEGF therapy in one eye * Good central or eccentric fixation
Exclusion criteria
* History or previous Anti-VEGF therapy * History or previous intravitreal injection with any drug * Intraocular pressure ≥ 25 * Glaucoma * History or presence of thromboembolic events * Diabetes mellitus * Blood donation during the previous 3 weeks * Ametropy ≥ 6 dpt
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Optic nerve head blood flow | before, one week after and three weeks after intravitreal injection with an anti-VEGF drug |
Secondary
| Measure | Time frame |
|---|---|
| Choroidal blood flow | before, one week after and three weeks after intravitreal injection with an anti-VEGF drug |
| Retrobulbar blood flow | before, one week after and three weeks after intravitreal injection with an anti-VEGF drug |
| Intraocular pressure | before, one week after and three weeks after intravitreal injection with an anti-VEGF drug |
| Systemic blood pressure | before, one week after and three weeks after intravitreal injection with an anti-VEGF drug |
Countries
Austria
Outcome results
None listed