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Choroidal blood flow and retinal ganglion cell function in early glaucoma
Author(s) -
MARANGONI D,
COLOTTO A,
SALGARELLO T,
STIFANO G,
PARISI V,
RIVA CE,
CAMPOS EC,
FALSINI B
Publication year - 2009
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2009.4416.x
Subject(s) - ophthalmology , medicine , blood flow , glaucoma , ganglion , intraocular pressure , choroid , visual acuity , retinal , hemodynamics , retinal ganglion cell , laser doppler velocimetry , retina , cardiology , anatomy , biology , neuroscience
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 flowmetry in 25 EMG patients (<‐6 dB Humphrey mean deviation, age range: 42‐64 years, visual acuity: 0.8‐1.0) and in 20 age‐matched controls. All patients had a therapeutically (topical beta‐blockers with or without a prostaglandin) controlled intraocular pressure (IOP <20 mmHg). 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 (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 recorded according to a standardized protocol. 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. Conclusion 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 and its treatment.