Presión de perfusión ocular en sujetos sin enfermedad ocular / Ocular Perfusion Pressure in Subjects Without Ocular Disease

Objetivo: Describir el comportamiento de la presión de perfusión ocular en sujetos sin enfermedad ocular. Métodos: Se realizó un estudio descriptivo transversal con sujetos sin enfermedad ocular de la consulta externa de Oftalmología del Hospital Universitario "General Calixto García", entre enero y diciembre de 2019. Resultados: La mediana de presión intraocular del ojo derecho osciló entre 13,0-16,0 mmHg, y del ojo izquierdo entre 13,0-15,5 mmHg, durante todo el estudio. El valor máximo para ambos ojos se obtuvo a las 6:00 a. m. (madrugada). La mediana de presión arterial sistólica osciló entre 129,0-138,5 mmHg, y de diastólica entre 79,5-81,5 mmHg. El valor mínimo de presión arterial diastólica fue 53 mmHg a las 6:00 a. m. La mediana de presión de perfusión ocular del ojo derecho osciló entre 46,4 mmHg (12:00 a. m.) y 50,8 mmHg; y del ojo izquierdo entre 47,3 mmHg (6:00 a. m.) y 51,9 mmHg. El valor mínimo específico de presión de perfusión ocular fue 35 mmHg para ambos ojos, a las 6:00 a. m. Conclusiones: La hipertensión arterial es el antecedente patológico personal más frecuente en la población estudiada y en ocasiones se producen cifras fuera de la normalidad, tanto elevadas como disminuidas, capaces de afectar la presión de perfusión ocular, sobre todo la diastólica baja. Sin embargo, las presiones de perfusión ocular se mantuvieron normales, probablemente, por mecanismos de autorregulación individuales(AU)

Objective: To describe the behavior of ocular perfusion pressure in subjects without ocular disease. Methods: A cross-sectional descriptive study was performed with subjects without ocular disease from the Ophthalmology outpatient clinic of the University Hospital "General Calixto García", between January and December 2019. Results: The median intraocular pressure of the right eye ranged between 13.0-16.0 mmHg, and of the left eye between 13.0-15.5 mmHg, throughout the study. The maximum value for both eyes was obtained at 6:00 a. m. (early morning). The median systolic blood pressure ranged from 129.0-138.5 mmHg, and diastolic from 79.5-81.5 mmHg. The minimum diastolic blood pressure value was 53 mmHg at 6:00 a.m. The median ocular perfusion pressure of the right eye ranged from 46.4 mmHg (12:00 a.m.) to 50.8 mmHg; and of the left eye from 47.3 mmHg (6:00 a.m.) to 51.9 mmHg. The minimum specific ocular perfusion pressure value was 35 mmHg for both eyes, at 6:00 a.m. Conclusions: Arterial hypertension is the most frequent personal pathologic antecedent in the population studied, and both elevated and decreased out-of-normal figures capable of affecting ocular perfusion pressure, especially low diastolic, occasionally occur. However, ocular perfusion pressures remained normal, probably due to individual autoregulatory mechanisms(AU)

Ocular doppler imaging: opening a new window in decoding glaucoma

Background: In the aetiopathogenesis of multifactorial glaucoma autoregulation of ocular blood flow plays an important role as failure of autoregulation may lead to progression of disease. Aim of this study to understand this better this study was designed to investigate the quantum of these abnormalities and their likely role in pathogenesis and prognosis of primary open angle glaucoma(POAG).Methods: This is a case control study design which involved 67 POAG patients and 67 matched controls. The parameters assessed includes peak systolic velocity(PSV), end diastolic velocity(EDV) and resistive index(RI) of ophthalmic artery(OA) and central retinal artery(CRA) of patients having POAG with age and sex matched healthy subjects. The data obtained was statistically analysed using IBM SPSS 21.Results: The study showed decreased PSV of 31.7 cm/s vs 42.7 cm/s(p=0.0001) and EDV11.7 cm/s vs 19.8 cm/s(p=0.002) with increased RI 0.63 vs 0.53(p=0.000) in  OA and PSV of 15.2 cm/s vs 21.4 cm/s(p=0.001) and EDV4.7 cm/s vs 11.7 cm/s(p=0.003) with increased RI 0.69 vs 0.45(p=0.000) in CRA in both eyes in POAG patients as compared to healthy controls.Conclusion: The study has shown the promising application of ocular Doppler in evaluating POAG patients. However, more such studies are needed with larger study sample and on follow up basis for better understanding glaucoma hemodynamics and applicability of ocular Doppler in management of glaucoma.

Clinical Observation of Different Combination Regimens of Latanoprost and Timolol in the Treatment of Primary Open-angle Glaucoma / 中国药房

OBJECTIVE:To observe the clinical efficacy and safety of different combination regimens of latanoprost combined with timolol in the treatment of primary open-angle glaucoma(POAG). METHODS:By 2×2 self-cross controlled regimen,a total of 50 POAG patients were selected from Sanya Municipal People's Hospital during Jan. 2014-Nov. 2016,and then divided into group A and B according to random number tablet,with 25 cases in each group. Group A received traditional regimens (Latanoprost eye drops,once every night,one drop each time+Timolol maleate eye drops,once in the morning and evening,one drop each time);after 8 weeks of treatment and 48 h washout period,group A was given modified regimen(Latanoprost eye drops,once every night,one drop each time+Timolol maleate eye drops,once every morning,one drop each time)for 8 weeks. Group B was given modified regimen;after 8 weeks of treatment and 48 h washout period,then was given traditional regimen for 8 weeks. The 24 h average intraocular pressure,peak and trough intraocular pressure before and after medication,ocular hemodynamics [end diastolic velocity(EDV),peak systolic velocity(PSV),resistance index(RI)] and ADR were recorded in 2 regimens. RESULTS:After received two regimens,24 h average intraocular pressure,peak and trough intraocular pressure, intraocular pressure fluctuation and RI were significantly lower than before treatment,while EDV and PSV were significantly higher than before treatment,with statistical significance(P<0.05). There was no statistical significance between 2 groups(P>0.05). The total incidence of ADR in patients receiving modified regimen was significantly lower than those receiving traditional regimen(4.0% vs. 22.0%),with statistical significance(P<0.05). CONCLUSIONS:In traditional combination regimen of latanoprost combined with timolol,the frequency of timolol use was changed from twice in the morning and evening to once in the morning,which doesn't influence therapeutic efficacy but reduce ADR.

Alteration in ocular blood flow and its effect on the progression of glaucoma / 国际眼科杂志(Guoji Yanke Zazhi)

@#Glaucoma is a multifactorial neurodegenerative disease that can result in permanent vision loss by damaging optic nerves due to higher pressure in the eye. Although most of the fundamental pathophysiological mechanisms involved in glaucoma are undetermined but alteration in ocular blood flow(OBF)in tissues such as optic nerve, retina, choroid and iris is an important risk factor for glaucoma. Various factors such as limited knowledge of the factors causing optic nerve damage, confusion in the measurement assays and lack of therapies, make hindrances in the understanding of glaucoma. Researchers are continuously accumulating evidence to suggest that alterations in OBF play important role in the pathogenesis of glaucoma but most of the times they have diverse and contradictory conclusions regarding changes in the OBF and risk of glaucoma. In this article we have reviewed different aspects of glaucoma and the effect of OBF in the disease progression

Ocular Perfusion Pressure and Pulsatile Ocular Blood Flow in Normal and Systemic Hypertensive Patients.

Purpose: The purpose was to compare the ocular perfusion pressure (OPP) and the pulsatile ocular blood flow (POBF) in normal and systemic hypertensive patients. Materials and Methods: Totally, 121 individuals (normal n = 60, systemic hypertension patients n = 61) were enrolled in this prospective age-matched comparative study. Intraocular pressure (IOP) and systemic arterial pressure were measured in seated position with 2 min interval between the measurements using Goldmann applanation tonometer (GAT) and tycos sphygmomanometer, respectively. The OPP was calculated as 2/3 of mean arterial pressure (MAP) minus IOP. After 5 min in the seated position POBF measurements were taken with the ocular blood flow (OBF) tonograph. Results: Mean age was 57.5 years (range 35-72 years) in the normal group and 59.6 years (range 36-78 years) in the hypertensive group; majority of the patients were female (68.5% and 71% respectively in each group). Measured parameters in both the groups showed, systolic blood pressure (BP) (143.6 ± 20.5 mmHg vs. 121.9 ± 17.5 mmHg), diastolic BP (90.7 ± 13.5 mmHg vs. 80.1 ± 9.9 mmHg), MAP (108.4 ± 14.2 mmHg vs. 94.2 ± 11.2 mmHg), and OPP (57.6 ± 14.6 vs. 48.7 ± 10.6 mmHg) were significantly greater (P = 0.001) in systemic hypertensive patients in comparison to normals. However, there was no difference in OBF tonograph values in both groups. The IOP measured by the OBF tonograph was higher than GAT in both groups, but the difference was not statistically significant (P = 0.41). Conclusion: Systemic hypertensive patients have a higher OPP in comparison to normal patients, but they do not have higher POBF. More studies are required to evaluate the role of the OPP in different ocular pathologies affecting the POBF.

Choroidal Blood Flow Change in Eyes with High Myopia

PURPOSE: To evaluate choroidal blood flow changes in eyes with high myopia according to the pulsatile components of ocular blood flow analysis. METHODS: A total of 104 subjects (52 males and 52 females) were included in this study. One eye of each participant was randomly selected and assigned to one of four refractive groups, designated as, hyperopes (n = 20; refractive error, > or =+1.00 diopter [D]), emmetropes (n = 28; refractive error, +/-0.75 D), lower myopes (n = 33; refractive error, -1.00 to -4.75 D), and high myopes (n = 23; refractive error, < or =-5.00 D). Components of pulse amplitude (OBFa), pulse volume (OBFv), pulse rate (OBFr), and pulsatile ocular blood flow (POBF) were analyzed using a blood flow analyzer. Intraocular pressure and axial length were measured. RESULTS: Pulsatile components of OBFa, OBFv, and POBF showed positive correlations with refractive error and showed negative correlations with axial length (r = 0.729, r = 0.772, r = 0.781, respectively, all p < 0.001; r = -0.727, r = -0.762, r = -0.771, respectively, all p < 0.001). The correlations of refractive error and axial length with OBFr were irrelevant (r = -0.157, p = 0.113; r = 0.123, p = 0.213). High myopes showed significantly lower OBFa, OBFv, and POBF than the other groups (all p < 0.001). CONCLUSIONS: Axial length changes in high myopes potentially influence choroidal blood flow, assuming the changes are caused by narrowing of the choroidal vessel diameter and increasing rigidity of the choroidal vessel wall. These finding explains the influence of axial length on OBFa, OBFv, and POBF, but not on OBFr. Thus, changes in axial length and the possible influence of these changes on the physical properties of choroidal vessels is the mechanism believed to be responsible for putting high myopes at risk for ocular vascular diseases.

Positional Change of Intraocular Pressure and Its Relationship to Ocular Pulse Amplitude

PURPOSE: To investigate the postural change of intraocular pressure (IOP) from sitting to supine position and determine the relationship to other ocular parameters including ocular pulse amplitude (OPA) in glaucoma suspect and open angle glaucoma patients. METHODS: The present study included 46 eyes of 46 patients. First, we measured IOP and OPA using Goldmann applanation tonometer (GAT), Pascal dynamic contour tonometer and TonoPen(R). Using TonoPen(R), the IOP was measured immediately after the subjects were placed in a supine position and 10 minutes and 30 minutes thereafter. We also investigated the correlation between positional change of IOP and axial length (AL), refractive error (RE), and OPA. RESULTS: IOPs of patients in a sitting position measured with GAT and TonoPen(R) were 15.3 +/- 3.3 mm Hg and 16.6 +/- 2.9 mm Hg, respectively, and OPA was 2.57 +/- 0.89 mm Hg. IOPs measured with TonoPen(R) were 17.6 +/- 2.9 mm Hg immediately after position change, 18.2 +/- 3.7 mm Hg after 10 minutes and 17.5 +/- 2.7 mm Hg after 30 minutes. Each IOP change was statistically significant and the largest change was after 10 minutes. Changes of IOP after 10 minutes were positively correlated with OPA (R = 0.340) and RE (R = 0.330) and negatively correlated with AL (R = -0.410). CONCLUSIONS: When placed in a supine position, the IOP of patients increased and then decreased over time. Positional IOP change was influenced by AL and OPA and variable hemodynamic factors and apparently influenced OPA and ocular perfusion pressure.

Comparison of Ocular Pulse Amplitude Measured Using Dynamic Contour Tonometry and Ocular Blood Flow Analyzer

PURPOSE: To compare ocular pulse amplitude (OPA) measured using dynamic contour tonometry (DCT) and ocular blood flow analyzer (BFA). METHODS: Thirty-five eyes of 35 patients were enrolled in this cross-sectional and retrospective study. OPA was measured using DCT. Pulse amplitude (PA) and pulsatile ocular blood flow were measured using BFA. RESULTS: OPA measured using DCT (2.79 +/- 0.89 mm Hg) was not significantly different from PA measured with BFA (3.02 +/- 0.90 mm Hg; p = 0.082) and both were significantly correlated (r = 0.663, p < 0.001). Mean difference +/- limit of agreement was -0.22 +/- 1.44 mm Hg between OPA and PA. OPA correlated significantly with intraocular pressure (IOP) measured using Goldmann applanation tonometry (r = 0.330, p = 0.047) but not PA (r = 0.057, p = 0.745). Both PA and OPA did not show significant correlation with the spherical equivalent of refractive error and central corneal thickness. CONCLUSIONS: Although both OPA and PA measure IOP fluctuation and are not significantly different, they showed different relationships with IOP.

Short-Term Effects of Ginkgo biloba Extract on Peripapillary Retinal Blood Flow in Normal Tension Glaucoma

PURPOSE: Based on the vascular theory of glaucoma pathogenesis, we wanted to evaluate the effect of Ginkgo biloba extract (GBE) on peripapillary blood flow in patients with normal tension glaucoma (NTG). METHODS: Thirty patients with NTG were randomly placed in the GBE-treated or control groups. The GBE-treated group received 80 mg GBE orally, twice a day for four weeks, and the control group received a placebo twice a day for four weeks. Complete ocular examinations including visual field, Heidelberg retina flowmeter, and systemic examinations were performed on the first study day and on the day treatment was completed. RESULTS: After GBE treatment, the mean blood flow, volume, and velocity increased at almost all points, and there was a statistically significant increase in blood flow at almost all points, in comparison to the placebo. Blood volume significantly increased only in the superior nasal and superior temporal neuroretinal rim areas. GBE also significantly increased blood velocity in areas of the inferior temporal neuroretinal rim and superior temporal peripapillary area. CONCLUSIONS: GBE administration appears to have desirable effect on ocular blood flow in NTG patients.

Short-Term Effects of Ginkgo biloba Extract on Peripapillary Retinal Blood Flow in Normal Tension Glaucoma

PURPOSE: Based on the vascular theory of glaucoma pathogenesis, we wanted to evaluate the effect of Ginkgo biloba extract (GBE) on peripapillary blood flow in patients with normal tension glaucoma (NTG). METHODS: Thirty patients with NTG were randomly placed in the GBE-treated or control groups. The GBE-treated group received 80 mg GBE orally, twice a day for four weeks, and the control group received a placebo twice a day for four weeks. Complete ocular examinations including visual field, Heidelberg retina flowmeter, and systemic examinations were performed on the first study day and on the day treatment was completed. RESULTS: After GBE treatment, the mean blood flow, volume, and velocity increased at almost all points, and there was a statistically significant increase in blood flow at almost all points, in comparison to the placebo. Blood volume significantly increased only in the superior nasal and superior temporal neuroretinal rim areas. GBE also significantly increased blood velocity in areas of the inferior temporal neuroretinal rim and superior temporal peripapillary area. CONCLUSIONS: GBE administration appears to have desirable effect on ocular blood flow in NTG patients.

Effect of flavone on the ocular blood flow and formation of choroidal neovascularization / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To investigate the effect of flavone on ocular blood flow in rabbit eyes and the formation of choroidal neovascularization(CNV)in rat model of age-related macular degeneration(AMD).METHODS:In in vivo studies,colored microsphere technique was used to determine the ocular blood flow in ocular hypertensive rabbit eyes.The rat eyes were treated with 5g/L flavone eye drops 3 times a day for 1 week before and 4 weeks after laser-induced injury of Bruch's membrane.The development of CNV was determined by fluorescein angiography(FA)performed on weeks 2 and 4.In in vitro studies,the effect of flavone on the viability of HUVECs was measured by MTT assay.RESULTS:The ocular blood flow in rabbit eyes was significantly increased after flavone instillation.Flavone significantly inhibited the formation of laser induced CNV.In vitro resultsshowedthat fiavoneinhibited the proliferation of HUVECs.CONCLUSION:Flavone could increase ocular blood flow and inhibit the formation of CNV.

Effects of naringenin on ocular blood flow and choroidal neovascularization in experimental animals / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the effects of naringenin on laser-induced experimental choroidal neovascularization (CNV) in rat models,ocular blood flow in rabbit eyes and retinal function recovery after ischemic insults in rat eyes.membrane. Naringenin 10g/L(20mg/kg) was given once-daily through intraperitoneal injection for 4 weeks after laser treatment. The development of CNV was determined by fluorescein angiography(FA) performed on weeks 2 and 4. The colored microsphere technique and electroretinography method were used for the study of ocular blood flow and retinal function recovery,respectively.RESULTS: The choroidal blood flow in elevated intraocular pressure (IOP) rabbit eyes was significantly increased by 10g/L naringenin solution as compared to control group(P<0.05) . The retinal function recovery after ischemic insults in rat eyes indicated significant increase of b-wave recovery in treated group,as compared to control group(P<0.05).The intensity of fluorescein leakage from the photocoagulated lesions decreased significantly in treated group,compared to the control group(75.8%-95.0%,P<0.01). CONCLUSION: Naringenin could prevent the development of CNV on laser-induced experimental rat models,increase the choroidal blood flow in elevated IOP rabbit eyes and be beneficial on retinal function recovery in ischemic rat eyes.

Effects of enantiomers(R,R)-XY and(S,S)-XY on ocular blood flow in rabbits / 国际眼科杂志(Guoji Yanke Zazhi)

·AIM: To evaluate the effects of two series of enantiomers [(R, R)-XY-1 through (R, R)-XY-12 and (S,S)-XY-1 through (S, S)-XY-12] on ocular blood flow in rabbits.·METHODS; Colored microsphere technique was used for in vivo experiments to determine the ocular blood flow in various tissues of ocular hypertensive (40mmHg) rabbit eyes.·RESULTS; Of the twelve compounds of ( R, R)-XY series examined, four increased choroidal blood flow at 10g/L, 50uL instilled into eyes. All compounds of (S, S)-XY series were not effective on ocular blood flow.·CONCLUSION; Some compounds of (R, R)-XY series increased the ocular blood flow, which might be useful for the prevention and treatment of ocular blood flow related eye diseases. Among all twenty-four compounds, (R, R)-XY-1and (R, R)-XY-9 seem to be the most potent ones.KEYWORDS; ocular blood flow; ischemia; enantiomer

Pulsatile Ocular Blood Flow in Healthy Koreans

PURPOSE: To determine the normal reference range of pulsatile ocular blood flow (POBF) values in healthy Korean subjects and to find out the factors that may affect them. METHODS: A total of 280 eyes of 280 normal subjects were included in this study. Best corrected visual acuity (BCVA), intraocular pressure (IOP), axial length, POBF, systemic blood pressure, and pulse rate were measured. The mean, standard deviation, range, and the 5th and 95th percentiles of POBF were calculated, and the influences of various parameters to POBF were determined by multiple regression analyses. RESULTS: The mean POBF value was 766.0+/-221.6 microliter/min in men and 1021.1+/-249.5 microliter/min in women. The 5th and 95th percentiles for POBF values were 486.0 microliter/min and 1140.0 microliter/min in men and 672.0 microliter/min and 1458.0 microliter/min in women. The POBF values were significantly influenced by gender, mean blood pressure, pulse rate, and axial length. CONCLUSIONS: Even though the POBF values were influenced by gender, BP, and axial length, we could define the normal reference range of POBF in healthy Koreans.

Effect of hydroxy groups in natural flavones on ocular blood flow of rabbits and retinal function recovery after ischemia insult in rat eyes / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To determine the effect of hydroxy (OH) group on the ocular blood flow and retinal function recovery.METHODS: Colored microsphere technique was used to determine the ocular blood flow in rabbit eyes and electroretinography was used to measure the retinal function recovery.RESULTS: Flavones with four free OH groups seemed to produce the optimal effects in ocular blood flow increase and retinal function recovery. When there were 3OH groups (Apigenin), rapid increment in ocular blood flow and retinal function recovery was found. When the number of OH groups was below two (7-Hydroxyfiavone,Chrysin), no effect was observed on the ocular blood flow. The attachment of rutinose group in the fiavone (Diosmin) with two free OH groups and methoxy group did not affect the ocular blood flow or retinal function recovery, but the attachment of glucose group in the fiavone (Luteolin-7-glycoside) with catechol group affected the ocular blood flow one way or the other. The attachment of methoxy group in the fiavone (Acacetin)with two free OH groups affected ocular blood flow and retinal function recovery after ischemic insult.CONCLUSION: Ocular blood flow and retinal function recovery are increased significantly with the increase in the number of OH groups attached in the flavone molecule, with the 7-OH group and the catechol group in the B ring the most efficient to enhance the ocular blood flow and retinal function recovery after ischemic insult.

The Short Term Effects of Bimatoprost on Optic Nerve Head and Peripapillary Retinal Blood Flow

PURPOSE: To demonstrate the effects of bimatoprost on the optic nerve head (ONH) and peripapillary retinal blood flow. METHODS: Sixteen healthy volunteers were recruited. In a randomized, double-blind design, one eye received a drop of bimatoprost and the other eye a drop of placebo. ONH and peripapillary retinal blood flow parameters (flow, volume, velocity) were measured with HRF before, and at 1, 6 and 24 hours after eyedrops and blood pressure (BP), heart rate (HR), and intraocular pressure (IOP) were recorded. RESULTS: The 16 subjects comprised 13 males and 3 females with a mean age of 27.3 +/- 2.4 years. IOP decreased significantly in the bimatoprost-treated eyes at 1, 6 and 24 hours after eyedrops (p<0.05). BP and HR were unchanged after bimatoprost eyedrops. The flow was significantly higher in the temporal peripapillary retina in the bimatoprost-treated eyes 1 hour after eyedrops and the velocity was also higher 6 hours after eyedrops at the same location. At the optic disc, there was a significant increase of the volume in the bimatoprost group 1 hour after eyedrops. There was no significant decrease of HRF parameters in the bimatoprost-treated eyes. CONCLUSIONS: These results suggest that bimatoprost does not have any adverse effect on ONH or peripapillary retinal blood flow.

Pulsatile Ocular Blood Flow Measurements in Ocular Trauma Patients

The objective of this study was to ascertain the elationship between the various ocular traumas and the change of pulsatile ocular blood flow[POBF] measured with Ocular Blood Flow Tonograph[OBF Laboratories, UK Ltd.]. We tested POBF with Ocular Blood Flow Tonograph 3 times repeatedly within 48 hours after trauma in the 33 ocular trauma patients.In all the trauma eyes, heart rate[HR]and intraocular pressure[IOP]were higher and pulse amplitude [PA], pulse volume[PV], POBF were lower than in all the fellow eyes.In the hyphema group, HR, IOP, PA, PV, POBF were higher, especially IOP and OBF%S.D.were statically significant, than in non-hyphema group.In the orbital fracture group, only POBF and OBF%S.D.were higher than those of in non-fracture group. Therefore, these results show the change of POBF after various ocularinjuries in the ocular trauma patients.The further studies to follow up the serial change of POBF are necessary.

Reproducibility of Pulsatile Ocular Blood Flow Measurement by OBF Tonograph

To evaluate the reproducibility of pulsatile ocular blood flow(POBF), bilateral POBFs of 10 volunteers were measured 3 times serially by OBF tonograph system(OBF laboratories, UK Ltd.). The POBFs were recorded in sitting position using pneumotonometer attached at slit lamp. After measurement of POBF, intraoculat pressure(IOP) was measured by Goldmann applanation tonometry. Mean values of pulse amplitude(PA), pulse volume(PV), POBF, IOP were 2.0+/-0.4mmHg, 5.1+/-1.5microliter, 701+/-197microliter/min, 13.9+/-2.5mmHg, respectively. Average of standard deviation of POBF was 7.0+/-1.9%. Mean value of IOP using Goldmann applanation tonometry was 12.8+/-2.6mmHg. Coefficient of reliability of the repeated measurement of POBF was 83%, analyzed by intraclass correlation. Coefficient of variation of the repeated measurement of POBF was 5.2%. Linear regression analysis of the Goldmann applanation tonometer on the measurements of IOP witn the tonograph showed a regression coefficient of 0.91. In conclusion, reproducibility of POBF measurement by OBF tonograph was acceptable and compatible with conventional technique. Further studies are required to measure the POBF in glaucoma patients.

Effects of Topical 2% Dorzolamide(Trusopt(R)) in Q-switched Nd:YAG Laser Induced Glaucoma Rabbits

The purpose of this study is to evaluate the effects of 2% dorzolamide(Trusopt(R)) on the ocular blood flow and retinal microcirculation. To creat an experimental glaucoma model in rabbits and to study the effects of elevated intraocular pressure(IOP), ocular blood flow, retinal effects of elevated intraocular pressure(IOp), ocular blood flow, retinal microcirculation on rabbits eyes, we treated trabecular meshwork of 6 adult pigmented rabbits with Q-switched Nd;YAG laser. And then we investigated the IOP lowering effect, ocular blood flow, and the microcirculation on retina of 2% dorzolamide(Trusopt(R)) in experimental glaucoma model. The IOP, ocular blood flow and the microcirculation were measured with applanation pneumotonography(Alcon, Texas), pneumotonometric probe linked to Langham ocular blood foow system(OBF, Blue mountain) and Heidelberg Retina Flowmeter(HRF). During sustained IOP elevation, 2% dorzolamide(Trusopt(R)) was instilled in one eye and normal saline in the fellow eye. The IOP and ocular blood flow were measured 1, 2, 4 and 8 hours after instillation. The retinal microcirculation was measured 2 and 8 hours after instillation. The retinal microcirculation was measured 2 and 8 hours after instillation at 200micrometer apart from the superior optic disc margin. There were statistically significant reductions in IOP in both 2% dorzolamide(Trusopt(R)) and normal saline-treated eyes(P0/1). From the above results, we concluded that 2% dorzolamide(Trusopt(R)) reduced the IOP but did not alter ocular blood flow and peripapillary retinal microcirculation.

The Effect of Oral Calcium Channel Blockers on the Ocular Blood Flow

Pulsatile ocular blood flow(POBF) System can measure the ocular blood flow easily and reliably. We attempted to investigate if oral calcium-channel blockers such as nifedipine and verapamil used for treatment of normal tension glaucoma increase the ocular blood flow in normal eyes by using above instrument. Twelve normal volunteers who have no ocular and systemic disorder history were involved in this study, and their ocular blood flow, intraocular pressure, systolic and diastolic blood pressure and pulse rate were measured. We performed the same study for 14 normal volunteers using verapamil. Systolic and diastolic blood pressures were decreased significantly after administration of calcium-channel blockers(P0.05). The intraocular pressure did not vary after administration of verapamil, but elevated in mean by 1.1mmHg after administration of nifedipine(P<0.05). Our study showed oral calcium-channel blockers, nifedipine and verapamil, did not increase the ocular blood flow in normal subjects with use of POBF.