Purpose: To assess subfoveal choroidal blood flow in patients with early manifest glaucoma (EMG) and to compare blood flow with functional measures of retinal ganglion cell (RGC) integrity. Methods: Subfoveal choroidal blood flow was determined by confocal, real-time laser Doppler flowmetry1,2 in 25 patients with EMG (< -6 dB Humphrey mean deviation, age range: 42-64 years, visual acuity: 0.8-1.0) and in 20 age-matched control subjects. All patients had a therapeutically (topical beta-blockers with or without a prostaglandin) controlled intraocular pressure (IOP < 20 mm Hg). Subfoveal choroidal blood volume (ChBVol), velocity (ChBVel) and flow (ChBF) were determined as the average of three 60 sec recordings with changes in the DC < 10% between the recordings (the DC measures the intensity of the light scattered by the tissue and red blood cells in the illuminated volume). In all patients and controls, pattern electroretinograms (PERGs) were also recorded according to a standardized protocol.3 Results: In EMG patients, average ChBVel and ChBF were reduced by 31 and 35%, respectively (p < 0.01) compared to control values. No significant difference in ChBVol was found between the two groups. PERG amplitudes were reduced by 40% (p < 0.01) in EMG patients compared to controls. No correlation was found between anyone of the choroidal flow parameters and PERG data or IOP values. Conclusions: The results suggest a significant alteration of subfoveal choroidal hemodynamics in EMG patients, involving both ChBVel and ChBF. These changes do not appear to be associated with the severity of functional retinal ganglion cell loss. Our findings may have implications for the pathophysiology of early glaucomatous damage in EMG and its treatment. 1Riva CE, Cranstoun SD, Grunwald JE, Petrig BL. Invest Ophthalmol Vis Sci, 1994 2Geiser MH, Diermann U, Riva CE. J Biomed Opt, 1999 3Falsini B, Marangoni D, Salgarello T, et al. Graefes Arch Clin Exp Ophthalmol, 2008
D. Marangoni, A. Colotto, T. Salgarello, G. Stifano, V. Parisi, C.E. Riva, et al. (2009). Choroidal Blood Flow and Retinal Ganglion Cell Function in Early Glaucoma. s.l : s.n.
Choroidal Blood Flow and Retinal Ganglion Cell Function in Early Glaucoma
RIVA, CHARLES;CAMPOS, EMILIO;
2009
Abstract
Purpose: To assess subfoveal choroidal blood flow in patients with early manifest glaucoma (EMG) and to compare blood flow with functional measures of retinal ganglion cell (RGC) integrity. Methods: Subfoveal choroidal blood flow was determined by confocal, real-time laser Doppler flowmetry1,2 in 25 patients with EMG (< -6 dB Humphrey mean deviation, age range: 42-64 years, visual acuity: 0.8-1.0) and in 20 age-matched control subjects. All patients had a therapeutically (topical beta-blockers with or without a prostaglandin) controlled intraocular pressure (IOP < 20 mm Hg). Subfoveal choroidal blood volume (ChBVol), velocity (ChBVel) and flow (ChBF) were determined as the average of three 60 sec recordings with changes in the DC < 10% between the recordings (the DC measures the intensity of the light scattered by the tissue and red blood cells in the illuminated volume). In all patients and controls, pattern electroretinograms (PERGs) were also recorded according to a standardized protocol.3 Results: In EMG patients, average ChBVel and ChBF were reduced by 31 and 35%, respectively (p < 0.01) compared to control values. No significant difference in ChBVol was found between the two groups. PERG amplitudes were reduced by 40% (p < 0.01) in EMG patients compared to controls. No correlation was found between anyone of the choroidal flow parameters and PERG data or IOP values. Conclusions: The results suggest a significant alteration of subfoveal choroidal hemodynamics in EMG patients, involving both ChBVel and ChBF. These changes do not appear to be associated with the severity of functional retinal ganglion cell loss. Our findings may have implications for the pathophysiology of early glaucomatous damage in EMG and its treatment. 1Riva CE, Cranstoun SD, Grunwald JE, Petrig BL. Invest Ophthalmol Vis Sci, 1994 2Geiser MH, Diermann U, Riva CE. J Biomed Opt, 1999 3Falsini B, Marangoni D, Salgarello T, et al. Graefes Arch Clin Exp Ophthalmol, 2008I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
