Flicker-induced retinal vasodilatation is not dependent on complement factor H polymorphism in healthy young subjects.

Abstract

PURPOSE:

The complement factor H (CFH) tyrosine 402 histidine (Y402H, rs1061170) variant is known to be significantly associated with age-related macular degeneration (AMD). Whether this genetic variant may impact retinal blood flow regulation is largely unknown. This study investigated whether flicker-induced vasodilation, an indicator for the coupling between neural activity and blood flow, is altered in subjects carrying the rs1061170 risk allele.

METHODS:

One hundred healthy subjects (aged between 18 and 45 years) were included in this study. Retinal blood flow regulation was tested by assessing retinal vessel calibres in response to stimulation with diffuse flicker light. Retinal vascular flicker responses were determined with a Dynamic Vessel Analyzer (DVA). In addition, genotyping for rs1061170 was performed.

RESULTS:

Eighteen subjects were homozygous for the risk allele C, 50 were homozygous for the ancestral allele T, and 31 subjects were heterozygous (CT). One subject had to be excluded from data evaluation, as no genetic analysis could be performed due to technical difficulties. Baseline diameters of retinal arteries (p = 0.39) and veins (p = 0.64) were comparable between the three groups. Flicker-induced vasodilation in both retinal arteries (p = 0.38) and retinal veins (p = 0.62) was also comparable between the three studied groups.

CONCLUSIONS:

Our data indicate that homozygous healthy young carriers of the C risk allele at rs1061170 do not show abnormal flicker-induced vasodilation in the retina. This suggests that the high-risk genetic variant of CFH polymorphism does not impact neuro-vascular coupling in healthy subjects.

• Authors: Reinhard Told, Stefan Palkovits, Agnes Boltz, Doreen Schmidl, Katarzyna J Napora, René M Werkmeister, Helmuth Haslacher, Sophie Frantal, Alina Popa-Cherecheanu, Leopold Schmetterer, Gerhard Garhöfer
• Journal: Acta ophthalmologica (Acta Ophthalmol) Vol. 92 Issue 7 Pg. e540-5 (Nov 2014) ISSN: 1755-3768 [Electronic] England
• PMID: 24863099 (Publication Type: Journal Article)
• Copyright: © 2014 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.

Chemical References

• CFH protein, human
• Complement Factor H

Topics

• Adolescent
• Adult
• Blood Flow Velocity
• Blood Pressure (physiology)
• Complement Factor H (genetics)
• Female
• Flicker Fusion (physiology)
• Genotype
• Healthy Volunteers
• Heart Rate (physiology)
• Humans
• Intraocular Pressure (physiology)
• Male
• Middle Aged
• Photic Stimulation
• Polymorphism, Single Nucleotide
• Retinal Vessels (physiology)
• Vasodilation (physiology)
• Young Adult