Vessel Density in nAMD After Longterm Anti-VEGF Treatment Compared to Recently Started Anti-VEGF Treatment

A Cross Sectional Study Assessing the Perifoveal and Peripapillar Vessel Density in nAMD After Longterm Anti-VEGF Treatment Compared to Recently Started Anti-VEGF Treatment - Pilotstudy

Neovascular age-related macular degeneration (nAMD) is characterized by the abnormal growth of blood vessels from the choroid into the subretinal space which leads to sub- and intraretinal fluid accumulation, hemorrhages and subretinal fibrosis with progressive loss of central vision. Intravitreal anti-VEGF treatment is the standard of care. Intravitreal anti-VEGF application might temporarily increase intraocular pressure due to a volume effect. It remains unclear if repeated injections might have an impact on retinal capillary perfusion. Therefore this study aims to investigate the vascular microcirculation differences between patients who received longterm intravitreal Anti-VEGF treatment and patients who recently started Anti-VEGF treatment using Optical Coherence tomography Angiography (OCTA).

Main outcome parameters are:

• Vessel Perfusion Area (%) of central ETDRS subfields and peripapillar region as evaluated by OCTA (single measurement)
• Blood flux index(*) of central ETDRS subfields and peripapillar region as evaluated by OCTA (single measurement).
• Peripapillary and perifoveal retinal nerve fiber layer (RNFL) thickness (µm) as evaluated by OCT (single measurement)
• Intraocular pressure (IOP) (mmHg) (single measurement at study visit) and mean intraocular pressure during anti-VEGF treatment period (evaluated as mean of all retrospectively available IOP measures from the beginning of treatment, mmHg)

(*)Blood flux index is automatically calculated by ARI Network as the mean flow intensity in the vessel area, where the blood flow signal was normalized to 0 to 1 by dividing by the full dynamic range of blood flow signal intensity.

Inclusion Criteria:

To be eligible for participation, patients will be required to

• have been treated for sub- or juxtafoveal CNV due to nAMD with anti-VEGF intravitreal injections either for at least 20 times (longterm treatment eyes) or <5 times (shortterm treatment eyes).
• give written consent to participation

Exclusion Criteria:

• diagnosis of glaucoma/ocular hypertension at baseline of anti-VEGF treatment

  • history of retinal vascular disorders like diabetic retinopathy, retinal vein/arterial occlusive disease, uveitis etc.
  • history of papillary disease which might interfere with interpretation of peripapillary OCT/OCTA evaluation such as severe tilted disc, parapapillar CNV, papillar drusen, optic nerve neuritis, papillar edema etc.
  • inability to perform OCTA examination of sufficient quality.
  • history of any side effects of Tropicamide eye drops