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PURPOSE: Niacin is a B vitamin well-known for causing vasodilation and flushing. The purpose of this study was to investigate its effect on the retinal vasculature of patients with age-related macular degeneration (AMD). METHODS: Twelve patients with AMD were enrolled in a double-blind, randomized, placebo-controlled, crossover trial. Fundus photographs of the posterior pole were taken at baseline, 30 min, and 90 min after a single dose of niacin or placebo. The protocol was repeated after a washout period using the alternate study drug. The diameters of two veins and one artery on each image were measured. RESULTS: An analysis of variance for repeated measures comparing the effects of niacin with those of placebo demonstrated a significant increase in the inferior temporal retinal artery diameter (p = 0.01), with a 5.3 +/- 7.7% increase at 30 min (p = 0.05) and 5.8 +/- 5.0% increase at 90 min (p = 0.003). No significant changes were observed in the temporal retinal veins. CONCLUSIONS: Our results suggest that niacin produces vasodilatation of retinal arterioles. Further studies are needed to ascertain whether niacin treatment may be beneficial in retinal ischemic diseases.

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AIM: To investigate the effect of systemic hypertension (SH) on the foveolar choroidal circulation in patients with age related macular degeneration (AMD). METHODS: This study included 163 study eyes with early AMD characteristics of 124 AMD patients. Study eyes had visual acuity of 20/40 or better, drusen > or =63 microm, and/or RPE hypertrophy. 56 of the AMD patients had a history of SH and 47 of these patients were receiving antihypertensive medications. Laser Doppler flowmetry (Oculix) was used to assess relative choroidal blood velocity (ChBVel), volume (ChBVol), and flow (ChBFlow) in the centre of the fovea of the study eyes. Differences in the mean haemodynamic parameters between groups of eyes were assessed using analysis of variance (ANOVA) and a test of linear trend, with adjustment for the correlation between eyes of the same patient. RESULTS: AMD patients with SH showed decreased ChBFlow in comparison with those without SH (ANOVA, p = 0.02). This association was maintained after adjustments for multiple factors (p = 0.04). CONCLUSIONS: AMD patients with SH have lower ChBFlow than those without SH. This decrease in choroidal blood circulation may help explain the mechanism by which systemic hypertension may contribute to the progression of AMD and the development of choroidal neovascularisation.

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AIM: To investigate the effects of niacin on choroidal blood flow in age related macular degeneration (AMD). METHODS: 12 AMD patients with bilateral drusen and visual acuity of 20/40 or better in the study eye received a single oral dose of niacin (six subjects received 500 mg and six received 250 mg) or matching placebo on two separate occasions. Laser Doppler flowmetry was used to assess relative choroidal blood velocity (ChB(Vel)), volume (ChB(Vol)), and flow (ChB(Flow)) in the foveola of the study eye at baseline, 30, and 90 minutes after dosing. RESULTS: In comparison with placebo, a statistically significant 24% increase in ChB(Vol) was observed 30 minutes after niacin administration (ANOVA, p = 0.01). In comparison with placebo, a significant decrease in ChB(Vel) of 23% was observed in the 500 mg group (p = 0.04) and no significant change in ChB(Vel) was seen in the 250 mg group at 30 minutes. No significant changes in ChB(Flow) were detected at 30 or 90 minutes. Also, there were no statistically significant changes in ChB(Vol) or ChB(Vel) at 90 minutes. CONCLUSION: In comparison with placebo, a significant 24% increase in ChB(Vol) was observed 30 minutes after niacin administration. Owing to simultaneous decrease in ChB(Vel), however, no significant change in ChB(Flow) was detected.

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AIMS: To assess the effect of systemic hypertension on the choroidal circulation in subjects with a normal eye examination. METHODS: Laser Doppler flowmetry was used to determine relative choroidal blood velocity (Ch(vel)), volume (Ch(vol)), and flow (Ch(flow)) in the centre of the fovea. Measurements were obtained in 15 eyes of 15 subjects with systemic hypertension. The mean average duration of hypertension was 11 (SD 6) years. Findings obtained in these patients were compared with those of 15 eyes of 15 age matched healthy controls. All subjects had normal eye examinations. RESULTS: No significant differences in Ch(vel), Ch(vol), and Ch(flow), were found between the subjects with and without systemic hypertension despite a 17% higher perfusion pressure (PP) in patients with hypertension. No significant correlation was found between mean arterial pressure or PP and the choroidal circulatory parameters. It was estimated that there is a 90% power to detect a 35% difference in Ch(flow) between the two groups. CONCLUSION: Systemic hypertension does not seem to have a large effect on the choroidal circulation in hypertensive patients that are controlled by antihypertensive therapy. Further studies are needed to elucidate whether systemic hypertension has an effect on the choroidal circulation in patients with ocular diseases.

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AIM: Previous studies have suggested that laser photocoagulation therapy is associated with the resolution of drusen in some age related macular degeneration (AMD) patients. The main aim of the study was to determine whether low intensity laser treatment applied according to the Complications of AMD Prevention Trial (CAPT) protocol produces changes in the choroidal circulation that may help explain the mechanism leading to the resolution of drusen material. METHODS: This ancillary study included 30 CAPT patients with bilateral drusen that were treated and followed at the University of Pennsylvania. Laser Doppler flowmetry was used to measure relative choroidal blood velocity (Ch(vel)), volume (Ch(vol)), and flow (Ch(flow)) in the centre of the fovea. Measurements were obtained through a dilated pupil in both eyes of each patient at the initial CAPT visit before laser treatment was applied in one eye. Measurements were repeated in both eyes of each subject three months later. Analysis of laser Doppler measurements was performed in a masked fashion. RESULTS: In comparison to baseline, no significant differences in Ch(vel), Ch(vol), or Ch(flow) were observed three months following the application of low intensity laser according to the CAPT protocol in the untreated and treated eyes. In comparison to the untreated eyes, no significant differences were detected in the treated eyes. Based on the variability of flow measurements in the untreated eyes, the authors estimated an 85% power to detect a 15% change in relative blood flow. CONCLUSIONS: The results suggest that large alterations in choroidal blood flow do not occur at three months after low intensity laser therapy following the CAPT protocol.

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AIM: To perform a preliminary assessment of the relation between optic nerve circulatory parameters and glaucomatous visual field progression. METHODS: This study included 29 eyes of 23 patients with open angle glaucoma that had typical glaucomatous nerve fibre bundle visual field defects and increased cup to disc ratios. Laser Doppler flowmetry (Oculix) was used to measure relative optic nerve blood volume (Vol), velocity (Vel) and flow in the superior temporal (ST) and inferior temporal (IT) neuroretinal rim of the optic nerve. After blood flow measurements patients were followed for 6-62 months (mean 33 (SD 17) months) and 2-11 Humphrey visual fields (4.7 (2.6) fields) were obtained. Progression of glaucoma was assessed by the slope of the corrected pattern standard deviation (CPSD) values versus time, which was calculated manually for each eye using regression analysis. RESULTS: A significant negative correlation was observed between Vol in the IT rim and the CPSD slope (r=-0.56, p=0.002); patients with lower Vol tended to show faster progression of glaucomatous field damage than those with higher Vol. When the eyes were arbitrarily divided into two groups according to lower Vol (0.32 (0.06) arbitrary units, AU, n=15) or higher Vol (0.49 (0.06) AU, n=14), those with lower Vol had significantly worse mean CPSD slopes (0.50 (0.48) dB/year) than those with higher Vol (-0.67 (1.38) dB/year; Student's t test, p=0.009). CONCLUSIONS: In the IT rim, the area most prone to develop glaucomatous field damage, lower Vol is associated with subsequently faster CPSD progression. These measurements suggest that circulatory abnormalities may have a role in the development of glaucoma.

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PURPOSE: To assess the acute effects of sildenafil citrate (VIAGRA) on the intraocular pressure (IOP) of patients with chronic open-angle glaucoma. DESIGN: This was a double-blind, randomized, placebo-controlled, crossover study, in which 15 patients received a single oral dose of sildenafil 100 mg or matching placebo on two separate occasions. METHODS: Fifteen subjects aged 63 +/- 14 years (mean +/- SD) with bilateral chronic open-angle glaucoma were administered a single oral dose of sildenafil 100 mg or matching placebo on two separate occasions at least 3 days apart. IOP was measured in both eyes by Goldmann ap-planation tonometry at baseline and then at 1-5 hours after dosing. Brachial artery systolic and diastolic blood pressures were determined by sphygmomanometry, and heart rate was also monitored at baseline and 1-5 hours after dosing. RESULTS: Compared with placebo, no statistically or clinically significant change in IOP was detected after a single dose of sildenafil 100 mg (P =.20). Moreover, no significant change in mean systemic blood pressure (P =.12) or heart rate (P =.72) was detected after treatment with sildenafil. CONCLUSION: At the maximum therapeutic dose of 100 mg, sildenafil did not produce any significant acute change in IOP in men with chronic open-angle glaucoma. This information is of importance for patients with glaucoma receiving sildenafil for treatment of erectile dysfunction.

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PURPOSE: The purpose of this study was to evaluate optic nerve blood flow in primary open-angle glaucoma suspect eyes with normal automated visual fields, in an attempt to elucidate how early in the glaucomatous disease process changes in optic nerve blood flow become apparent. METHODS: Twenty-one eyes (21 patients) suspected of having primary open-angle glaucoma were studied prospectively and compared with a previously reported cohort of 22 eyes (22 patients) with primary open-angle glaucoma and 15 eyes (15 subjects) of age-matched controls. Primary open-angle glaucoma suspect eyes had untreated intraocular pressure greater than 21 mm Hg and normal visual fields using Humphrey program 24-2 or 30-2 with a full threshold strategy. Laser Doppler flowmetry was used to measure optic nerve head blood velocity, volume, and flow at four quadrants in the optic nerve, in the cup, and in the foveola of one eye of each patient. The mean flow from the superotemporal rim, inferotemporal rim, and cup was calculated (Flow(3)) and identified as the main outcome measure. Measurements from primary open-angle glaucoma suspect eyes were compared with corresponding measurements from controls and eyes with primary open-angle glaucoma; a Student t test was employed with a Bonferroni corrected P value of.025 to account for comparisons of primary open-angle glaucoma suspects both to controls and to eyes with primary open-angle glaucoma. RESULTS: Compared with controls, Flow(3) was 24% lower in primary open-angle glaucoma suspect eyes (P <.0003). In primary open-angle glaucoma suspect eyes, flow was 16% lower in the superotemporal rim (P <.007), 35% lower in the cup (P <.007), and 22% lower in the inferotemporal neuroretinal rim (P <.029) compared with controls. No significant difference between primary open-angle glaucoma suspect and control eyes was seen in the inferonasal rim, superonasal rim, or foveola. No significant difference was detected at any location between primary open-angle glaucoma suspect eyes and eyes with primary open-angle glaucoma. CONCLUSIONS: Laser Doppler flowmetry detected circulatory abnormalities in primary open-angle glaucoma suspects who did not have any manifest visual field defect. Decreases in flow in glaucoma suspects were similar in magnitude to those of subjects with primary open-angle glaucoma. These data suggest that impaired optic nerve blood flow develops early in the glaucomatous process and does not develop solely as a result of glaucoma damage.

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PURPOSE: Sildenafil citrate induces vasodilation by enhancing the smooth muscle relaxant effects of nitric oxide. We have previously reported that nitrate compounds, a different group of nitric oxide-mediated vasodilators used mainly for the treatment of ischemic cardiac diseases, produce an increase in optic nerve head circulation and retinal venous vasodilation. The purpose of the present investigation was to evaluate the effect of sildenafil on ocular circulation. METHODS: In a double-blind, randomized, crossover trial, 15 healthy male volunteers received 100-mg doses of sildenafil citrate (Viagra; Pfizer, Inc, New York, New York) or matching placebo on 2 separate days. Laser Doppler flowmetry was used to assess foveolar choroidal and optic nerve rim circulatory parameters. Measurements were obtained in one eye at baseline, 1 hour, and 5 hours after dosing. Blood pressure and intraocular pressure were monitored, and perfusion pressure was calculated. RESULTS: Mean optic nerve head blood flow measurements at baseline, 1 hour, and 5 hours were 11.6 +/- 2.2 arbitrary units (+/- SD), 12.5 +/- 2.8, and 12.1 +/- 2.4 after sildenafil and 11.9 +/- 2.5, 12.6 +/- 3.1, and 13.0 +/- 3.0 after placebo, respectively. When compared with placebo, no significant change in mean blood pressure, intraocular pressure, perfusion pressure, or choroidal or optic nerve circulatory parameters were observed after sildenafil treatment. The power to detect a 20% change in optic nerve head and choroidal blood flow after sildenafil was approximately 90%. CONCLUSIONS: In comparison with placebo, no significant change in optic nerve rim or foveolar choroidal blood flow was observed after treatment with sildenafil. This suggests that nitrate compounds and sildenafil may differentially affect ocular circulation. Furthermore, no significant effects on intraocular pressure, systemic blood pressure, or ocular perfusion pressure were detected after sildenafil treatment.

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BACKGROUND: In patients with branch retinal vein occlusion (BRVO), we investigated the presence of indocyanine green (ICG) and fluorescein hyperfluorescence at the site of occlusion. We also assessed the association of this feature with the clinical outcome of these patients. METHODS: Both indocyanine green (ICG) videoangiography and fluorescein angiography (FAG) were performed in 21 eyes with BRVO of less than 1 month duration. Deterioration of the disease was defined clinically as an increase in retinal hemorrhages or retinal edema. Capillary nonperfusion was quantified with computer image analysis from the FAG pictures. RESULTS: ICG videoangiography showed focal hyperfluorescence along the venous wall at the site of the affected A-V crossing in 9 of the 21 eyes, and FAG showed this feature in 10 eyes. The ICG hyperfluorescence was more prominently and focally detected than the hyperfluorescence on FAG, which was sometimes diffusely seen throughout the whole occluded area. Eight of the nine eyes showing ICG hyperfluorescence had clinical deterioration with an increase in retinal hemorrhage or edema. This deterioration occurred more frequently in eyes with hyperfluorescence and/or late leakage than in ones without these features. The mean nonperfused area was significantly larger in eyes with hyperfluorescence than in eyes without these features. CONCLUSION: The ICG hyperfluorescence at the site of A-V crossing is associated with disease deterioration in patients with fresh BRVO. The ICG hyperfluorescence was more easily detectable than the hyperfluorescence on FAG, although the difference in sensitivity between the two methods is not great.

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PURPOSE: To assess the short-term effects of sildenafil citrate on intraocular pressure in healthy male volunteers and participants in clinical trials. METHODS: Intraocular pressure and pupil diameter were measured in two placebo-controlled studies. Oral doses of sildenafil citrate (VIAGRA; Pfizer Inc, New York, New York) ranged from 10 mg to 150 mg. RESULTS: No major changes in intraocular pressure or pupillometry were detected at any time (1.0-24 hours) after administration of sildenafil. Additionally, of 36 subjects with a medical history of increased intraocular pressure in the sildenafil safety database, none were reported to have a clinically significant increase of their intraocular pressure. During clinical trials, two glaucoma cases were listed as serious adverse events, but were not considered treatment related. CONCLUSION: No clinical abnormalities were observed in intraocular pressure or pupil diameter in subjects receiving sildenafil. Currently, no evidence suggests that long-term treatment with sildenafil has an effect on intraocular pressure or is associated with the development or worsening of glaucoma.

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PURPOSE: The purpose of this randomized double-masked cross-over study was to determine the effects of 20 mg of 5-isosorbide mononitrate (ISMO) on the retinal hemodynamics of young healthy subjects. METHODS: Monochromatic fundus photography and bidirectional laser Doppler velocimetry (BLDV) were used to determine vascular diameters (D), and blood velocity (V(max)) and flow (Q) in retinal veins, respectively. The diameter of the vein [D((vein))] at the same location where BLDV measurements were made, and the diameter of a neighboring artery [D((art) )], were determined from the fundus photographs. Measurements were carried out one and three hours after ISMO dosing, on twelve and six subjects, respectively. Mean blood pressure (BP(m)) and intraocular pressure (IOP) were also monitored, and ocular perfusion pressure (PP) was calculated. Results are expressed in percentage changes (+/- the standard error of the mean). RESULTS: On average, we observed a moderate increase of Q one hour after ISMO dosing (+8.2 +/- 5.4%), but not after placebo (+2.7 +/- 1.6%). This effect of ISMO, which displayed remarkable interindividual variability (95% confidence interval: -3.9%, +20.4%), did not attain statistical significance. D((vein)) and D((art)) were not appreciably affected. No effect was observed three hours after either ISMO or placebo dosing. PP was reduced one hour following ISMO administration, mainly as a function of reduced BP(m), although this variation was not statistically significant. IOP did not change appreciably throughout the duration of the study. CONCLUSIONS: Our findings suggest that, in contrast to the optic nerve head, in which we previously documented consistent and significant increases in blood flow following ISMO administration at both one and three hours, retinal hemodynamics are not equally responsive to a single dose of ISMO at these time points. Marked interindividual variability to the effects of this long-acting nitric oxide donor was documented one hour after administration, but not at three hours. This study further suggests that distinct vascular tissues of the ocular microcirculation respond differently to identical pharmacological challenges.

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PURPOSE: To describe the clinical features and complications of diabetic retinopathy, visual acuity, and number of repeat treatments after panretinal photocoagulation for proliferative diabetic retinopathy in a tertiary care center. METHODS: A cohort study was conducted with data collection from medical records of patients undergoing panretinal photocoagulation between 1985 and 1995 at the Scheie Eye Institute; 297 eyes of 186 patients were eligible for study. RESULTS: The presence of neovascularization of the disk at baseline, an earlier onset of diabetes, and a shorter duration of disease before panretinal photocoagulation were the strongest risk factors for needing an additional panretinal photocoagulation treatment. Sixty-two percent of eyes with poor visual acuity (< or =20/200) at baseline still had poor visual acuity at 1 year, and 76% with good visual acuity (> or =20/40) at baseline maintained good visual acuity at 1 year. Poor vision at baseline was the only risk factor for having poor vision at 1 year. Vitreous hemorrhage was present in 44% of eyes at baseline. New vitreous hemorrhage developed in 37% of eyes during the first year after panretinal photocoagulation. A traction retinal detachment was present in 4% of eyes at baseline and newly developed in 6% of eyes during follow-up. A repeat panretinal photocoagulation treatment was performed in 39% of eyes after initial treatment. A vitrectomy was performed in 10% of eyes from baseline through the 1-year follow-up visit. CONCLUSIONS: The data from this study are useful for counseling patients with respect to likely visual outcome, possibility of major complications from proliferative diabetic retinopathy, and the chance of undergoing additional laser treatment after panretinal photocoagulation.

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PURPOSE: To investigate retinal circulatory changes that occur during the third trimester of pregnancy in diabetic patients and control subjects. METHODS: Bidirectional laser Doppler velocimetry and monochromatic fundus photography were used to assess the retinal circulation in seven pregnant diabetic patients and 13 age-matched pregnant control subjects. Retinal venous diameter (D), maximum erythrocyte velocity (Vmax), and retinal volumetric blood flow rate (Q) were measured in one eye of each subject during the third trimester of pregnancy (DPREG, VmaxPREG, and QPREG, respectively). These measurements were repeated during the postpartum period for both diabetic patients (11+/-7 weeks postpartum) and control subjects (16+/-6 weeks postpartum; P = .203; DPOST, VmaxPOST, and QPOST). RESULTS: In control subjects, DPREG was significantly reduced by -4.5%+/-4.4% (mean percent difference +/-1 standard deviation; paired t test, P =.006) relative to DPOST. In diabetic women, DPREG was also significantly reduced by -8.1%+/-3.2% compared with DPOST (P = .001), a change that was significantly larger than that seen in control subjects (unpaired t test; P = .035). Compared with QPOS T, QPREG was reduced by -7.1%+/-14.2% (P = .123), in control subjects. In diabe tic women, QPREG was significantly decreased by -18.4%+/-9.3% compared with QPOST (P = .012). This reduction in QPREG was significantly greater in diabetic patients than in nondiabetic control subjects (unpaired t test, P = .040). No significant differences between VmaxPREG and VmaxPOST were observed in either diabetic patients (-3.1%+/-12.9%; P =.400) or control subjects (+1.9%+/-14.4%; P = .787). CONCLUSIONS: Retinal venous diameter is decreased during the third trimester of pregnancy in both diabetic and nondiabetic mothers. This decrease is significantly larger in diabetic than in nondiabetic mothers. In addition, we observed a reduction in retinal volumetric blood flow in diabetic patients during pregnancy that was significantly larger than that present in nondiabetic women. This fall in retinal volumetric blood flow in diabetic patients may exacerbate retinal ischemia and hypoxia and thus may be associated with the progression of diabetic retinopathy.

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AIMS: To assess the effects of the nitric oxide donor 5-isosorbide mononitrate (ISMO) on blood flow in the optic nerve head (ON flow) and choroid (Ch flow). METHODS: Laser Doppler flowmetry was used to measure ON flow and Ch flow in 12 normal subjects by aiming the laser beam at the fovea and at the temporal rim, respectively. In a double masked, randomised, crossover design, each subject received orally on separate days either 20 mg of 5-isosorbide mononitrate (ISMO) or placebo. Ch flow and ON flow were determined monocularly at baseline and 1 hour after dosing. In the last six subjects, additional measurements were obtained at 3 hours. Mean arterial blood pressure (BPm), heart rate, and intraocular pressure (IOP) were monitored, and ocular perfusion pressure (PP) was estimated. RESULTS: No significant changes in ON flow, PP, IOP, or BPm were observed following placebo. Following ISMO, ON flow increased from baseline by 19.8% (SEM 9.3%) at 1 hour (paired t test, p = 0.058) and by 33.1% (7.5%) at 3 hours (p = 0.007). Compared with the changes following placebo, statistically significant increases in ON flow were observed both at 1 (p = 0.050) and 3 hours (p = 0.041) after ISMO treatment. Compared with placebo, PP decreased significantly 1 hour after ISMO dosing (p = 0.039), mainly as a function of reduced BPm. A significant inverse correlation (R = -0.618; p = 0.032) was observed between the percentage changes in PP and ON flow 1 hour following ISMO administration, but not after placebo. No significant change in foveal Ch flow was documented. CONCLUSIONS: These results suggest that, in normal subjects, ISMO increases significantly ON flow but not Ch flow. The inverse correlation observed between PP and ON flow suggests that the same mechanism(s) responsible for systemic vasodilatation and blood pressure decrease may also cause the ON flow increase.

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PURPOSE: To investigate optic nerve head blood flow in patients with glaucoma and to assess the effect of systemic hypertension. METHODS: This study included 24 eyes of 24 patients with primary open-angle glaucoma. Eleven of these patients had a history of systemic hypertension. Results in patients with glaucoma were compared with those of 13 eyes of 13 age-matched normal controls. Determinations of relative optic nerve head blood velocity, volume, and flow were obtained with laser Doppler flowmetry in the superotemporal and inferotemporal neuroretinal rim and also in the cup. Means of the velocity, volume, and flow of these three measurement sites were calculated for each subject. RESULTS: Mean overall optic nerve head blood flow was 29% lower in glaucoma patients than in normal controls (t test, P < .001). This decrease in flow was mainly caused by a decrease of 23% in mean blood velocity (P < .001). Mean flow in glaucoma patients without systemic hypertension was 26% lower than that of glaucoma patients with hypertension (Tukey honest significant difference test, P = .05). A significant direct correlation was observed between mean flow and mean blood pressure (R = 0.51, P < .02). CONCLUSIONS: Optic nerve blood flow is reduced in glaucoma patients. Glaucoma patients without systemic hypertension have lower optic nerve blood flow than those with hypertension. Our results raise concerns that treatment of systemic hypertension may further decrease optic nerve blood flow in glaucoma patients.

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PURPOSE: To evaluate the effects of felodipine, a calcium channel blocker, on ocular circulation. METHODS: In a double blind, randomized, crossover design, 10 volunteers received placebo or felodipine on 2 separate days. Bidirectional laser Doppler velocimetry (BLDV), laser Doppler flowmetry (LDF), and monochromatic fundus photography (MFP) were employed to assess retinal, choroidal, and optic nerve rim circulatory parameters. Measurements were obtained at baseline, 1.5, and 3 hours after dosing. Blood pressure, intraocular pressure (IOP), and heart rate were monitored, and perfusion pressure (PP) was calculated. RESULTS: In comparison to placebo, significant average percentage decreases in diastolic blood pressure (BPd; p = 0.001), mean blood pressure (BPm; p = 0.003), and perfusion pressure (PP; p = 0.003) were observed 1.5 hours following felodipine. No significant differences were observed following placebo. Retinal, choroidal and optic nerve rim circulatory parameters showed no significant changes after placebo or felodipine. A significant positive correlation between BPd and optic nerve velocity (ONve1) was observed 3 hours following felodipine (R = +0.654; p = 0.040). In contrast, no significant correlation between BPd and ONve1 was noted (R = +0.198; p = 0.583) following placebo. CONCLUSIONS: No significant change in retinal, optic nerve rim, or foveolar choroidal blood flow were observed, a factor that may be important in the treatment of systemic hypertension in patients with glaucoma.

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PURPOSE: To investigate the circulation of the optic nerve head and choroid in patients with glaucoma. METHODS: Laser Doppler flowmetry was used to determine optic nerve head relative blood velocity (ONVel), volume (ONVol), and flow (ONFlow) in 19 primary open-angle glaucoma patients and 15 age-matched healthy control subjects. In each subject, determinations were obtained from four sites on the neuroretinal tissue and from the center of the cup. A mean of the ONVel, ONVol, and ONFlow for these five measurement sites were calculated for each subject and defined as ONVel5, ONVol5, and ONFlow5. Circulatory parameters were correlated with measures of disease progression such as cup-to-disc ratio and Humphrey visual field indices. Measurements of relative choroidal blood velocity, volume, and flow were also obtained from the foveola. RESULTS: In glaucoma patients, mean ONFlow5 was significantly lower than in control subjects (24%; P = 0.001; independent, two-tailed Student's t-test). This decrease was caused by a significant decrease in ONVol5 (15%; P = 0.04) and a nonsignificant decrease in ONVel5 (10%; P = 0.07). In glaucomatous eyes, mean ONFlow was significantly reduced from normal, by 28% in the inferior temporal neuroretinal rim location (P = 0.001) and by 24% in the superior temporal location (P = 0.001). Although mean ONFlow was also decreased by 33% in the cup, the difference was not statistically significant after a Bonferroni correction was applied. No significant differences from normal were observed in the superior and inferior nasal rim tissues. In glaucoma patients, ONFlow5 was significantly and inversely correlated with the corrected pattern standard deviation (R = -0.53; P = 0.02) and with the cup-to-disc ratio (R = -0.65; P = 0.002). Choroidal blood flow measurements obtained in the foveola of glaucomatous eyes showed no statistically significant differences from normal. CONCLUSIONS: ONFlow5 is reduced by approximately 24% in glaucoma patients. In the inferior temporal rim, the area in which nerve bundle defects most commonly occur, blood flow is reduced by 28%. Patients with more advanced glaucomatous damage, as detected by visual field corrected pattern standard deviation and measurement of the cup-to-disc ratio, tend to have lower ONFlow5. These results suggest a decrease in optic nerve blood flow that is correlated with functional and morphologic measures of glaucomatous progression. However, from these results we cannot conclude whether this decrease in flow has a primary role in the etiology of glaucoma or whether it is the result of the loss of neural components caused by this disease.

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OBJECTIVE: To determine the effect of aging on choroidal blood flow (ChBFlow) in the foveolar region of the normal ocular fundus. METHOD: Choroidal blood flow was determined using laser Doppler flowmetry. Twenty-nine eyes of 29 normal subjects whose ages ranged from 15 to 76 years (mean+/-SD, 42+/-18 years) were included in this study. Relative choroidal blood velocity (ChBVel), choroidal blood volume (ChBVol), and ChBFlow were determined in the foveolar region by asking the subjects to fixate on the probing laser beam. RESULTS: Significant negative correlations were observed between ChBVol and the subject's age (R=-0.52, P=.004) and between ChBFlow and the subject's age (R=-0.54, P=.003). No significant correlation was detected between ChBVel and the subject's age (R=0.07, P=.70). Significant differences were observed in ChBVol and ChBFlow between the younger subjects aged 15 to 45 years (mean+/-SD, 0.48+/-0.20 arbitrary units [AU] and 18.9+/-5.8 AU, respectively) and the older ones aged 46 to 76 years (mean+/-SD, 0.34+/-0.11 AU and 13.3+/-3.3 AU, respectively; unpaired Student t test, P=.04 and P=.007, respectively). CONCLUSION: In the subjects studied, foveolar ChBFlow decreases with age. This change is probably related to the decrease in density and diameter of the choriocapillaries that occurs with increasing age.

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