Foveal choroidal blood flow in age-related macular degeneration (AMD) (original) (raw)
Decreased choroidal blood flow associated with retinitis pigmentosa
Eye, 1990
The intraocular pressure pulse has been measured and used to evaluate the ophthal mic arterial pressure and the ocular pulsatile blood flow in 13 retinitis pigmentosa patients and ten similar aged healthy volunteers. The light sensitivity thresholds of the central fields of all persons were recorded using the Heijl-Krakau automated perimeter. The mean pulse amplitudes of 1.2 ± 0.2 (26) and 2.3 ± 0.25 (20) mmHg in the affected and in the control groups respectively differed significantly (p<O.OOI). The corresponding pulsatile blood flows were 310 ± 24 (26) and 628 ± 40 (20) !A-I min-I. The mean ophthalmic arterial pressures in the two groups were equal. The light sensitivities in pairs of eyes of four of the patients differed substantially and in all cases the eye with the better visual performance had the higher ocular pulsatile blood flow. It is concluded that relative choroidal ischaemia is closely associated with visual loss and pigment cell degeneration in patients with retinitis pigmentosa.
American Journal of Ophthalmology, 1999
To study ocular perfusion defects in age-related macular degeneration. Twenty-five subjects with nonexudative age-related macular degeneration were compared with 25 age-matched control subjects in studies of flow velocities in several retrobulbar vessels. Color Doppler imaging, which was performed by an examiner who was masked to the subjects' assignment to the control or age-related macular degeneration group, measured peak systolic and end diastolic velocity in the ophthalmic, central retinal, and nasal and temporal posterior ciliary arteries of one eye. A resistive index was calculated from the peak systolic and end diastolic velocity. Subjects with nonexudative age-related macular degeneration showed a consistent trend toward lower peak systolic and end-diastolic velocities in the posterior ciliary arteries. For example, in the nasal posterior ciliary artery, the mean end diastolic velocity measured 1.45 +/- 0.34 cm per sec in the age-related macular degeneration group compared with 1.96 +/- 0.66 cm per sec in the control group, yielding a 26% decrease in the age-related macular degeneration group, which represented the largest difference and was highly statistically significant (P = .0012). The resistive index was not significantly altered in the nasal or temporal posterior ciliary artery. Subjects with nonexudative age-related macular degeneration did not differ from control subjects in peak systolic velocity, end diastolic velocity, or resistive index in the ophthalmic artery. In the central retinal artery, the end diastolic velocity was lower (1.37 +/- 1.95 cm per sec vs 1.95 +/- 0.66 cm per sec), whereas the resistive index was higher (0.83 +/- 0.05 vs 0.76 +/- 0.06 cm per sec), in the age-related macular degeneration group; these results were highly statistically significant (P = .0007 and P < .0001, respectively). Retrobulbar vascular changes in nonexudative age-related macular degeneration subjects include reduced flow velocities in the nasal and temporal posterior ciliary arteries. The reduced peak systolic velocity, combined with the reduced end diastolic velocity at a constant resistive index, seen in nonexudative age-related macular degeneration, is consistent with reduced bulk flow in these vessels, suggesting that choroidal perfusion is abnormal in this form of age-related macular degeneration. The changes in the central retinal artery suggest there may be a more generalized perfusion abnormality beyond the choroid in patients with age-related macular degeneration or that the central retinal artery exhibits a secondary autoregulatory response to a primary change elsewhere.
Ocular Hemodynamics In Non-Exudative Age Related Macular Degeneration
Duzce Universitesi Tip Fakültesi Dergisi, 2014
Purpose: To explore changes in retrobulbar ocular blood flow dynamics in patients with nonexudative age- related macular degeneration (ARMD). Materials and Methods: 52 patients (M=28, F=24) with ARMD and 45 age-matched healthycontrols (M=23, F=22) were included in our evaluation. Full ophthalmic examination and orbitalcolor Doppler imaging was performed in both eyes. Peak systolic and end-diastolic velocities,resistive and pulsatility indices were considered as Doppler blood flow parameters in ourevaluation. Central retinal, ophthalmic, temporal posterior ciliary and nasal posterior ciliaryarteries measurements were taken. Results: The mean age was 65.90 ± 2.05 in ARMD and 60.95 ± 1.34 in thecontrol group. Pulsatility and resistive indices in ophthalmic arteries of ARMD patients weresignificantly higher than the control group. The peak systolic and end-diastolic velocities innasal and temporal posterior ciliary arteries were significantly lower whereas pulsatility andresistive indic...
Acta Ophthalmologica, 2008
Purpose To assess the short-term changes in choroidal blood flow after photodynamic therapy (PDT) in patients with neovascular age-related macular degeneration (AMD).Methods Fourteen patients with exudative AMD were included after complete ophthalmologic examination, fluorescein and indocyanine green angiography and optical coherence tomography. Subfoveal choroidal blood flow was assessed using laser Doppler flowmetry (LDF) in both treated (n=14) and nontreated controlateral (n=8) eyes, 1 h and 1 week after PDT. Ocular perfusion pressure was calculated.Results The detection sensitivity of the LDF measurements at 2-min intervals before PDT in treated eyes was 7.4% for volume, 6.3% for velocity, and 10.4% for choroidal blood flow. Initial mean visual acuity was 0.68±0.3 logMar. Macular thickness at baseline as measured by OCT3 was at median [interquartile range], 326.5 mm[188–367]. One hour and 7 days after PDT, a significant increase in velocity (15.8% and 24.4%, respectively) and a significant decrease in volume (11% and 17.9%, respectively) were noted in treated eyes. Choroidal blood flow and ocular perfusion pressure remained similar during follow-up. No significant change in flow parameters was reported in untreated eyes.Conclusion The LDF technique provides feasible and reliable measurements of blood flow parameters before and after PDT in a selective population of patients with exudative AMD. The prognostic value of these early blood flow parameter changes also needs to be assessed.
Correlation Between Choroidal Thickness and Ciliary Artery Blood Flow Velocity in Normal Subjects
Ophthalmic surgery, lasers & imaging retina, 2015
To study the correlation between the choroidal thickness (CT) measured by spectral-domain optical coherence tomography (SD-OCT) and retrobulbar blood flow measured by color Doppler flowmetry (CD) in normal subjects. Healthy subjects underwent enhanced-depth imaging SD-OCT and CD using a linear 6 MHz to 18 MHz transducer. The maximal peak systolic velocity and resistance index (RI) were obtained for the ophthalmic artery (OA), short posterior ciliary artery (SPCA), and central retinal artery (CRA) and correlated with the subfoveal CT measured by SD-OCT. Twenty-seven eyes of 27 healthy patients were enrolled (mean age: 40.6 ± 12.4 years; range: 27-68 years). An inverse proportional relationship (P = .0496) was identified between the RI of the SPCA (mean, 0.6117 ± 0.07911) and the subfoveal CT (319.9 µm ± 83.79 µm) but not between the RI and the OA (mean: 0.7019 µm ± 0.07317 µm) or the CRA (mean: 0.68843 µm ± 0.08994 µm). The results of this study suggested there is an inverse proporti...
Ocular blood flow measurements and their importance in glaucoma and age-related macular degeneration
The Israel Medical Association journal: IMAJ
This survey of methods for assessing ocular hemodynamics in glaucoma and age-related macular degeneration is not complete, but it does cover those likely to be encountered in the literature. A fundamental problem in getting to grips with the ocular blood flow literature is the difficulty in comparing the results of similar studies employing different assessment techniques. As evident from the discussion above, each technique evaluates a portion of the ocular circulation in a distinct way. Some of the methods overlap with regard to the tissues that can be used for examination, while others are directed at entirely different parts of the ocular vasculature. Despite these difficulties, hemodynamic studies of glaucoma and AMD are likely to grow in importance. On the basis of accumulating epidemiological and clinical evidence, it is becoming apparent that intraocular pressure is not the sole etiological factor in glaucoma, and retinal pigment epithelium senescence is not the sole etiolog...
Pulsatile ocular blood flow in asymmetric exudative age related macular degeneration
British Journal of Ophthalmology, 2001
Background/aims-Decreased perfusion or increased vascular resistance of the choroidal vessels had been proposed as the vascular pathogenesis for age related macular degeneration (AMD). This study planned to answer the question whether pulsatile ocular blood flow (POBF) was diVerent in patients with asymmetric exudative AMD between eyes with drusen, choroidal neovascularisation (CNV), or disciform scar. Methods-37 patients with asymmetric exudative AMD were enrolled in this observational case series study. POBF were measured in both eyes of each subject. Eyes with high myopia, anisometropia, recent laser treatment, and glaucoma were excluded. Results-After adjusting for ocular perfusion pressure, intraocular pressure, and pulse rate, multivariate regression analysis with generalised estimating equation showed POBF was significantly higher in eyes with CNV (1217 (SD 476) µl/min) than the contralateral eyes with drusen (1028 (385) µl/min) (p = 0.024). Eyes with disciform scar had lower POBF than the contralateral eyes with drusen (999 (262) µl/min and 1278 (341) µl/min, respectively, p<0.001). There was no significant correlation between the POBF and the lesion size of the CNV. Conclusion-The POBF in eyes with drusen was lower than their fellow eyes with CNV, but higher than their fellow eyes with disciform scar. This finding suggests that haemodynamic diVerences between fellow eyes in individuals are relevant to the development of CNV and the formation of disciform scar. Further studies on the follow up patients might shed light on the pathogenesis of exudative AMD.