Decreased retinal–choroidal blood flow in retinitis pigmentosa as measured by MRI
- 313 Downloads
To evaluate retinal and choroidal blood flow (BF) using high-resolution magnetic resonance imaging (MRI) as well as visual function measured by the electroretinogram (ERG) in patients with retinitis pigmentosa (RP).
MRI studies were performed in 6 RP patients (29–67 years) and 5 healthy volunteers (29–64 years) on a 3-Tesla scanner with a custom-made surface coil. Quantitative BF was measured using the pseudo-continuous arterial spin-labeling technique at 0.5 × 0.8 × 6.0 mm. Full-field ERGs of all patients were recorded. Amplitudes and implicit times of standard ERGs were analyzed.
Basal BF in the posterior retinal-choroid was 142 ± 16 ml/100ml/min (or 1.14 ± 0.13 μl/mm2/min) in the control group and was 70 ±19 ml/100ml/min (or 0.56 ± 0.15 μl/mm2/min) in the RP group. Retinal–choroidal BF was significantly reduced by 52 ± 8 % in RP patients compared to controls (P<0.05). ERG a- and b-wave amplitudes of RP patients were reduced, and b-wave implicit times were delayed. There were statistically significant correlations between a-wave amplitude and BF value (r=0.9, P<0.05) but not between b-wave amplitude and BF value (r =0.7, P=0.2).
This study demonstrates a novel non-invasive MRI approach to measure quantitative retinal and choroidal BF in RP patients. We found that retinal–choroidal BF was markedly reduced and significantly correlated with reduced amplitudes of the a-wave of the standard combined ERG.
KeywordsRetinal diseases Magnetic resonance imaging Electroretinography Retinal degeneration
This work was supported by a Clinical Translational Science Award Pilot Grant and a Translational Technology Resource grant (parent grant UL1TR000149), NIH/NEI (R01 EY014211 and EY018855), and Department of Veterans Affairs MERIT awards to TQD. YZ was supported by a Translational Science Training award through the University of Texas System Graduate Program Initiative.
Conflict of interest
- 3.Gundogan F, Tas A, Sobaci G (2011) Electroretinogram in hereditary retinal disorders. In: Belusic G (ed) Electroretinograms. doi: 10.5772/21704
- 33.Bill A (1984) Circulation in the eye. In: Renkin EM, Michel CC (eds) Handbook of Physiology: Cardiovascular. American Physiological Society, BethesdaGoogle Scholar
- 37.Muir ER, De La Garza B, Duong TQ (2013) Blood flow and anatomical MRI in a mouse model of retinitis pigmentosa. Magn Reson Med 69:221–228Google Scholar
- 42.Ben-Zion I, Harris A, Weizman Y, Ehrlich R, Rechtman E (2008) An updated review of methods for human retinal oximetry measurements and current applications. Harefuah 147(812–817):836Google Scholar
- 43.Harris A, Dinn RB, Kagemann L, Rechtman E (2003) A review of methods for human retinal oximetry. Ophthalmic Surg Lasers Imag 34:152–164Google Scholar
- 46.De La Garza BH, Muir ER, Shih YY, Duong TQ (2012) 3D magnetic resonance microscopy of the ex vivo retina. Magn Reson Med 67:1154–1158Google Scholar
- 60.Li G, De La Garza B, Shih YY, Muir ER, Duong TQ (2012) Layer-specific blood-flow MRI of retinitis pigmentosa in RCS rats. Exp Eye Res 101:90–96Google Scholar
- 61.Nair G, Shen Q, Duong TQ (2010) Relaxation time constants and apparent diffusion coefficients of rat retina at 7 tesla. Int J Imag Syst Tech 20:126–130Google Scholar
- 62.Zhang Y, Wey HY, Nateras OS, Peng Q, De La Garza BH, Duong TQ (2011) Anatomical, blood oxygenation level-dependent, and blood flow MRI of nonhuman primate (baboon) retina. Magn Reson Med 66:546–554Google Scholar
- 63.Nair G, Pardue MT, Kim M, Duong TQ (2011) Manganese-enhanced MRI reveals multiple cellular and vascular layers in normal and degenerated retinas. J Magn Reson Imag 34:1422–1429Google Scholar
- 64.Shih YY, Li G, Muir ER, De La Garza BH, Kiel JW, Duong TQ (2012) Pharmacological MRI of the choroid and retina: blood flow and BOLD responses during nitroprusside infusion. Magn Reson Med 68:1273–1278Google Scholar
- 65.Lavery WJ, Muir ER, Kiel JW, Duong TQ (2012) Magnetic resonance imaging indicates decreased choroidal and retinal blood flow in the DBA/2J mouse model of glaucoma. Invest Ophthalmol Vis Sci 53:560–564Google Scholar
- 66.Muir ER, Renteria RC, Duong TQ (2012) Reduced ocular blood flow as an early indicator of diabetic retinopathy in a mouse model of diabetes. Invest Ophthalmol Vis Sci 53:6488–6494. Google Scholar