Optical microangiography of retina and choroid and measurement of total retinal blood flow in mice

Abstract Purpose To investigate the relationship of ocular blood flow (via arteriovenous passage time, AVP) and contrast sensitivity (CS) in healthy as well as normal tension glaucoma (NTG) subjects. Design Mono-center comparative prospective trial Methods Twenty-five NTG patients without medication and 25 healthy test participants were recruited. AVP as a measure of retinal blood flow was recorded via fluorescein angiography after CS measurement using digital image analysis. Association of AVP and CS at 4 spatial frequencies (3, 6, 12, and 18 cycles per degree, cpd) was explored with correlation analysis. Results Significant differences regarding AVP, visual field defect, intraocular pressure, and CS measurement were recorded in-between the control group and NTG patients. In NTG patients, AVP was significantly correlated to CS at all investigated cpd (3 cpd: r = − 0.432, p< 0.03; 6 cpd: r = − 0.629, p< 0.0005; 12 cpd: r = − 0.535, p< 0.005; and 18 cpd: r = − 0.58, p< 0.001), whereas no significant correlations were found in the control group. Visual acuity was significantly correlated to CS at 6, 12, and 18 cpd in NTG patients (r = − 0.68, p< 0.002; r = − 0.54, p< .02, and r = − 0.88, p< 0.0001 respectively), however not in healthy control patients. Age, visual field defect MD, and PSD were not significantly correlated to CS in in the NTG group. MD and PSD were significantly correlated to CS at 3 cpd in healthy eyes (r = 0.55, p< 0.02; r = − 0.47, p< 0.03). Conclusion Retinal blood flow alterations show a relationship with contrast sensitivity loss in NTG patients. This might reflect a disease-related link between retinal blood flow and visual function. This association was not recorded in healthy volunteers.

Download Full-text

Central Retinal Vein Occlusion With Further Reduction of Retinal Blood Flow One Year After Radial Optic Neurotomy

American Journal of Ophthalmology ◽

10.1016/j.ajo.2004.10.053 ◽

2005 ◽

Vol 139 (5) ◽

pp. 926-927 ◽

Cited By ~ 6

Author(s):

Naoichi Horio ◽

Masayuki Horiguchi

Keyword(s):

Blood Flow ◽

Retinal Vein Occlusion ◽

Central Retinal Vein Occlusion ◽

Retinal Blood Flow ◽

Radial Optic Neurotomy ◽

Vein Occlusion ◽

One Year ◽

Central Retinal Vein

Download Full-text

Reduced responses of retinal vessels of the newborn pig to prostaglandins but not to thromboxane

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y94-026 ◽

1994 ◽

Vol 72 (2) ◽

pp. 168-173 ◽

Cited By ~ 27

Author(s):

Daniel Abran ◽

Daya R. Varma ◽

Ding-You Li ◽

Sylvain Chemtob

Keyword(s):

Blood Flow ◽

Receptor Agonist ◽

Perfusion Pressure ◽

Retinal Blood Flow ◽

Receptor Subtype ◽

Retinal Vasculature ◽

Receptor Subtypes ◽

Retinal Vessels ◽

Limit Blood Flow ◽

Arteries And Veins

The upper blood pressure limit of retinal blood flow autoregulation is lower in the newborn than in the adult; this suggests an insufficient vasoconstrictor response in the newborn when perfusion pressure is increased. Because prostaglandins (PGs) have an important role in autoregulation of retinal blood flow, we compared the effects of PGE2, PGF2α, carbacyclin (PGI2 analogue), and U46619 (thromboxane analogue), as well as that of agonists for the three different PGE2 receptor subtypes, 17-phenyl trinor PGE2 (EP1), butaprost (EP2), and M&B 28,767 (EP3), on the retinal vasculature of newborn and adult pigs, using isolated eyecup preparations. PGF2α and PGE2 caused a markedly greater constriction of retinal arteries and veins of the adult than of the newborn animals. Further analysis of the response to PGE2, using receptor subtype agonists, revealed that the EP1 receptor agonist, 17-phenyl trinor PGE2, and the EP3 receptor agonist, M&B 28,767, caused a significant constriction of adult arteries and veins but produced minimal effects on newborn vessels; the EP2 receptor agonist, butaprost, caused a small and comparable dilation of newborn and adult arteries and veins. The PGI2 analogue, carbacyclin, caused a greater dilation of the adult than of the newborn arteries, but produced comparable dilation of veins from both newborn and adult animals. In contrast to the effects of PGF2α and PGE2, the thromboxane analogue, U46619, as well as the α1-adrenoceptor agonist, phenylephrine, significantly constricted newborn arteries and veins, and this effect was comparable with that observed on retinal vessels of the adult. Our findings indicate that the retinal vasculature of the newborn responds minimally to prostaglandins, primarily PGF2α and PGE2, compared with the adult, but constricts effectively to thromboxane. Since prostaglandins play an important role in the autoregulation of retinal blood flow, our observations provide an explanation for the inability of the newborn to limit blood flow when perfusion pressure is raised.Key words: retinal vascular responses, prostaglandins, thromboxane, PGE2 receptor subtypes.

Download Full-text