Purposes: To identify a new method of choroidal blood flow analysis in glaucomatous patients. Methods: Twenty-four glaucomatous patients (G), 15 subjects with normal tensional glaucoma (NTG) and 26 age-matched controls were recruited for the study. They were submitted to dynamic indocyanine green angiography (ICGA) with a scanning laser ophthalmoscope (SLO) (Rodenstock, Munchen, Germany). The choroidal filling phases were digitized and stored in a computer. Twenty-five frames per second were obtained. Each frame was elaborated by means of a “ threshold technique ” in order to obtain black or white pixels. The area occupied by the white pixels in a field of 35° of the choroid surrounding the disc was measured. The data obtained from each frame were plotted versus time in order to obtain a “ frame-by-frame ” dilution curve. The 10% filling time and the 55% filling time were compared among the three groups. Results: NTG and G groups showed a significantly delayed filling time of the posterior choroid when compared to the controls (10% filling time, p<0.01; 55% filling time, p<0.05). No statistical difference between NTG and G could be observed. Conclusions: These data suggest that an altered choroidal blood flow can play a role in the pathogenesis of glaucoma. CR: None -'
Frame by frame dilution analysis of ICG angiography: a new method to measure choridal blood flow in glaucoma
PIERMAROCCHI, STEFANO;
1999
Abstract
Purposes: To identify a new method of choroidal blood flow analysis in glaucomatous patients. Methods: Twenty-four glaucomatous patients (G), 15 subjects with normal tensional glaucoma (NTG) and 26 age-matched controls were recruited for the study. They were submitted to dynamic indocyanine green angiography (ICGA) with a scanning laser ophthalmoscope (SLO) (Rodenstock, Munchen, Germany). The choroidal filling phases were digitized and stored in a computer. Twenty-five frames per second were obtained. Each frame was elaborated by means of a “ threshold technique ” in order to obtain black or white pixels. The area occupied by the white pixels in a field of 35° of the choroid surrounding the disc was measured. The data obtained from each frame were plotted versus time in order to obtain a “ frame-by-frame ” dilution curve. The 10% filling time and the 55% filling time were compared among the three groups. Results: NTG and G groups showed a significantly delayed filling time of the posterior choroid when compared to the controls (10% filling time, p<0.01; 55% filling time, p<0.05). No statistical difference between NTG and G could be observed. Conclusions: These data suggest that an altered choroidal blood flow can play a role in the pathogenesis of glaucoma. CR: None -'Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
