Relationship between optic nerve head microcirculation and visual field loss in glaucoma

PURPOSE: To study the relationship between optic nerve head blood flow velocity and visual field loss in patients with primary open-angle glaucoma (POAG) and normal tension glaucoma (NTG). METHODS: This study included 44 eyes of 44 patients with POAG and 44 eyes of 44 patients with NTG. To evaluate optic nerve head blood flow velocity, the square blur rate (SBR) was measured by means of laser speckle flowgraphy. The correlation between SBR and Humphrey visual field indices was evaluated with linear regression analysis. RESULTS: In the NTG group, the average SBR at the superior and inferior temporal neuroretinal rim was positively correlated with mean deviation (MD) (r = 0.349, p = 0.020). The SBR at the superior or inferior temporal neuroretinal rim was positively correlated with the sum of the total deviations in the corresponding hemifields (r = 0.299, p = 0.049; r = 0.354, p = 0.019, respectively). The correlations between SBR and MD did not differ statistically between the NTG and POAG groups; however, no significant correlation between SBR and visual field indices was observed in the POAG group. CONCLUSION: These results suggested that the change in the circulation of the optic nerve head may be related to visual field damage in the NTG group but may be less involved in visual field damage in the POAG group.     

Microcirculation in eyes after rhegmatogenous retinal detachment surgery

PURPOSE: To investigate the tissue blood flow in the neuroretinal rim of the optic disk and macula after rhegmatogenous retinal detachment (RRD) surgery. METHODS: Tissue blood flow in the neuroretinal rim of the optic disk and macula was measured with the Heidelberg retina flowmeter in 53 eyes of 53 patients who had undergone successful surgery for unilateral RRD. Patients were divided into three groups; those who had the RRD treated by conventional encircling scleral buckling (group E), by local buckling (group L), and by primary vitrectomy (group V). Blood flow measurements were made more than 6 months after surgery in a 10 degrees x 2.5 degrees area of the superior and inferior margins of the neuroretinal disk rim and of the superior and inferior macula area. The mean blood flow (MBF) and the ratio of the MBF in the affected eye to the healthy fellow eye (a/f ratio) were compared among the three groups. The influence of several clinical factors on the MBF was also investigated. RESULTS: The MBF rate and mean a/f ratios of the MBF of the three groups were not significantly different. Multiple regression analysis revealed that the averaged MBF both at superior and inferior disk rims was significantly correlated with only the gas tamponade procedure. CONCLUSIONS: The ocular microcirculation is normal 6 months after scleral buckling or vitrectomy for RRD. However, the use of gas tamponade might have a subclinical adverse effect on the circulation in the neuroretinal disk rim.     

Optic cup deepening spatially correlated with optic nerve damage in focal normal-pressure glaucoma.

PURPOSE: To evaluate whether deepening of the optic cup in patients with focal normal-pressure glaucoma is correlated with the location of most marked loss of neuroretinal rim and visual field. METHODS: Using morphometric evaluation of color stereo optic disc photographs of 102 eyes of 65 patients with focal normal-pressure glaucoma, the superior half of the optic disc was compared with the inferior half. RESULTS: In eyes in which the optic cup was deepest in the inferior half of the disc, the most pronounced rim loss was located inferiorly significantly more often than superiorly, and the most marked visual field loss was located superiorly significantly more often than inferiorly. In eyes in which the optic cup was deepest in the superior half of the disc, the most pronounced rim loss was located superiorly significantly more often than inferiorly, and the most marked visual field loss was located inferiorly significantly more often than superiorly. Correspondingly, in eyes in which the most marked rim loss was located inferiorly, the deepest optic cup part was located inferiorly significantly more often than superiorly, and vice versa. CONCLUSION: In focal normal-pressure glaucoma, location of the most marked deepening of the optic cup is spatially correlated with the location of most pronounced neuroretinal rim loss and visual field damage. Because high-pressure glaucoma is typically associated with optic cup deepening and vascular optic nerve damage is associated with optic cup flattening, the spatial correlation between focal optic nerve damage and focal cup deepening may suggest the presence of a pathogenetic aspect in both high-pressure glaucoma and focal normal-pressure glaucoma.     

Papillary blood flow and morphological parameters of the optic nerve head in patients with normal tension glaucoma, primary open angle glaucoma and in healthy volunteers

The aim of the present study was to compare selected morphological parameters of the optic nerve head and papillary blood flow in patients with NTG, POAG and in healthy volunteers, as well as to find any possible correlation between selected morphological parameters and papillary blood flow. 21 glaucomatous and 31 normal eyes were diagnosed using HRT and HRF. Statistically significant differences within many morphological parameters like cup area, cup to disc, cup shape measure, rim volume, RFNL thickness, RFNL cross section and neuroretinal rim blood flow appeared. Nevertheless, in glaucoma patients no statistically significant differences between morphology and flow were found. The conclusion is that blood flow impairment within the neuroretinal rim is connected with glaucoma neuropathy development, nevertheless it is affected by other factors.     

Optic disc blood flow measured by scanning laser-Doppler flowmetry using a new analysis program

PURPOSE: Using a new analysis program for scanning laser-Doppler flowmetry (SLDF) by a Heidelberg retina flowmeter (HRF), we studied the relation between flow and visual field or disc morphology. SUBJECTS AND METHODS: In 42 eyes of 21 patients with normal tension glaucoma (NTG) the mean-flow of the HRF blood flow parameters at the disc rim was measured and analyzed by a new analysis program for perfusion maps (the SLDF analysis tool), to minimize the influence of large vessels or/and artifacts caused by small eye movements. We investigated whether difference of the mean-flow between a pair of eyes had any relation to differences between a pair of eyes in visual field indices and those in disc morphological measurements of the Heidelberg retina tomograph. RESULTS: We found statistically significant correlations between the mean-flow and optic disc parameters (Disk Area, Cup Area, Height Variation Contour, Cup Volume, Rim Volume, Mean RNFL Thickness). We found no statistically significant correlations between the mean-flow and visual field parameters (mean deviation, corrected pattern standard deviation). CONCLUSION: The results suggested that eyes with less flow in the optic disc rim have more advanced glaucomatous morphological changes.     

Microcirculation at optic disc rim is correlated with visual field defects in cases of anterior ischaemic optic neuropathy

We report two cases of anterior ischaemic optic neuropathy in whom tissue blood flow at the disc rim was correlated with the visual field defect. Tissue blood flow of each eye was evaluated with Heidelberg retina flowmeter. Both cases experienced acute visual loss and an altitudinal hemianopsia associated with optic disc oedema in the affected eye. In each case, the tissue blood flow at the affected (upper or lower half) disc rim corresponding to visual field deficit was reduced compared with that at the opposite-sided half disc rim in the affected eye and with the corresponding area in the fellow eye. The reduction of blood flow in the affected half disc rim associated with the visual field defect demonstrated that retina flowmetry can detect differences in tissue blood flow between superior and inferior sectional disc rim areas as well as between eyes non-invasively.     

Optic Disc Blood Flow Measured by Scanning Laser-Doppler Flowmetry Using a New Analysis Program

Purpose: Using a new analysis program for scanning laser-Doppler flowmetry (SLDF) by a Heidelberg retina flowmeter (HRF), we studied the relation between flow and visual field or disc morphology.Subjects and Methods: In 42 eyes of 21 patients with normal tension glaucoma (NTG) the mean-flow of the HRF blood flow parameters at the disc rim was measured and analyzed by a new analysis program for perfusion maps (the SLDF analysis tool), to minimize the influence of large vessels or/and artifacts caused by small eye movements. We investigated whether difference of the mean-flow between a pair of eyes had any relation to differences between a pair of eyes in visual field indices and those in disc morphological measurements of the Heidelberg retina tomograph.Results: We found statistically significant correlations between the mean-flow and optic disc parameters (Disk Area, Cup Area, Height Variation Contour, Cup Volume, Rim Volume, Mean RNFL Thickness). We found no statistically significant correlations between the mean-flow and visual field parameters (mean deviation, corrected pattern standard deviation).Conclusion: The results suggested that eyes with less flow in the optic disc rim have more advanced glaucomatous morphological changes.     

正常人不同类型视乳头及早期青光眼患者视乳头形态学研究

目的：探讨正常人不同类型视乳头及早期青光眼患者视乳头形态学特征,以指导青光眼的早期诊断。方法：将收集到的眼底照片分为4组：正常人小视乳头组41只眼,正常人大视乳头组40只眼,正常人大或小视乳头组42只眼,早期开角形青光眼组45只眼。利用计算机图像分析技术,测量视乳头、盘沿、视杯面积向周围（每10^0）盘沿宽度。结果：（1）正常人不同类型视乳头组的盘沿宽度曲线均在下或上方形成双峰,在鼻、颞侧形成谷底。大视乳头组下方盘沿最宽,小视乳头组上方盘沿最宽,鼻侧次之,颞侧最窄。（2）早期青光眼盘沿宽度典线下或上方双峰消失,其曲线低于鼻侧象限、高于颞侧象限。（3）经多因素逐步判别分析,盘沿面积加杯／盘比值的正确判断率为85．7％,以系列盘沿宽度为指标,下方偏颞侧（6：20）和上方偏鼻侧（1：00）两个盘沿宽度最为相关,其正确判断率为90．6％。结论：评价盘沿形态时应以其自身的鼻侧盘沿宽度作为标准,比较其上、下方盘沿宽度是否变窄,有利于生理性大视杯与早期青光眼的鉴别。     

The optic disc hemifield test

PURPOSE: To evaluate whether an optic disc hemifield test comparing the superior half of the optic disc with the inferior disc half is useful for glaucoma diagnosis. METHODS: The clinical observational study included 1268 patients with primary or secondary open-angle glaucoma and 649 normal subjects. The glaucoma group was divided into 1118 patients with glaucomatous visual field defects ("perimetric glaucoma"), and 150 patients with optic nerve head changes and normal visual fields ("preperimetric glaucoma"). Color stereo optic disc photographs were morphometrically evaluated. The optic disc area was divided into four sectors: temporal horizontal (60 degrees), superotemporal (90 degrees), inferotemporal (90 degrees), and nasal (120 degrees). Area and width of the neuroretinal rim were measured, and the ratio of superotemporal-to-inferotemporal rim area, the ratio of superior (12 o'clock)-to-inferior (6 o'clock) rim width, the difference of inferotemporal minus superotemporal rim area, and the difference of inferior rim width minus superior rim width were calculated. RESULTS: For the differentiation between the normal group and the whole glaucoma group, and for the differentiation between the normal group and the preperimetric glaucoma group, respectively, areas under the ROC curves were significantly smaller for the parameters of the optic disc hemifield test (superior-to-inferior rim width ratio: 0.448 and 0.412, respectively; and superotemporal-to-inferotemporal rim area ratio: 0.395 and 0.434, respectively) than for any other rim parameter tested such as inferotemporal rim area (0.827 and 0.745, reps.), total rim area (0.814 and 0.741, respectively), and superotemporal rim area (0.781 and 0.705, respectively). DISCUSSION: An optic disc hemifield test with the parameters superior-to-inferior rim width ratio and superotemporal-to-inferotemporal rim area ratio is not markedly helpful for the morphometric diagnosis of glaucomatous optic nerve damage, either in the preperimetric stage or in the perimetric stage of the disease.     

应用海德堡视网膜断层扫描仪检测开角型青光眼的视盘改变

目的探讨海德堡视网膜断层扫描仪(Heidelberg retinal tomography,HRT)检测青光眼性视盘改变是否与视野损害的部位相一致,了解正常眼压性青光眼(normal tension glaucoma,NTG)与原发性开角型青光眼(primary open angle glaucoma,POAG)早或中期视盘形态是否异同.方法对64例(64只眼)仅有半侧视野异常的开角型青光眼(POAG27只眼、NTG37只眼)患者进行HRT检测,将Humphery视野与HRT的检测结果以0°～180°为界,分成上下两部分进行对应分析.结果与正常半侧视野对应的1/2视盘比较,显示异常半侧视野对应的1/2视盘HRT参数中,杯盘面积比、视杯形态测量值显著增大,而盘沿面积、视网膜神经纤维层厚度及视网膜神经纤维层横断面积值显著减少 (t=-2.625～3.025,P=0.003～0.05);NTG眼和POAG眼对应与异常半侧视野的HRT视盘参数差异无显著性(t=-0.98～1.511,P=0.14～0.97).结论 HRT参数能较准确反映与视野损害相一致的视盘变化,其中尤以杯盘面积比、盘沿面积、视杯形态测量、平均视网膜神经纤维厚度及视网膜神经纤维层横断面积测量值较为准确.NTG和POAG眼的视盘形态相似,可能具备某些相似的视神经损害发生机制.     

Polarimetric measurement of retinal nerve fiber layer thickness in glaucoma diagnosis

PURPOSE: To evaluate reliability and diagnostic value of polarimetric measurements of the retinal nerve fiber layer (RNFL) thickness in the diagnosis of glaucoma. METHODS: The study included 81 eyes with perimetric glaucoma with glaucomatous changes of the optic disc and visual field defects; 52 eyes with preperimetric glaucoma with glaucomatous optic disc abnormalities and normal achromatic visual fields; and 70 normal eyes. For determination of reliability, four examiners repeated polarimetric measurements five times in ten normal subjects. RESULTS: The polarimetric variables were significantly correlated with increasing mean visual field defect and decreasing neuroretinal rim area. In correlation analyses with visual field defects, correlation coefficients were highest for the variable "superior/nasal ratio" and "the Number," a variable calculated by the neural network of the device. In correlations with neuroretinal rim area, correlation coefficients were highest for measurements of the inferior nerve fiber layer thickness. The preperimetric glaucoma group and the control group differed significantly in the variables "superior/nasal ratio" and "the Number" and, to a smaller degree, in the variables "superior/temporal ratio" and "superior/inferior ratio." The Number variable had a sensitivity of 82% and 58% at a predefined specificity of 80% in separating perimetric glaucoma patients and preperimetric glaucoma patients, respectively, from control subjects. Reproducibility of the polarimetric measurements ranged between 70% and 89%. CONCLUSION: Polarimetric measurements of the RNFL thickness can detect glaucomatous optic nerve damage in patients with visual field loss, and in some patients with preperimetric glaucomatous optic nerve damage. Considering the fast performance, easy handling, and low maintenance costs, RNFL polarimetry may be helpful in glaucoma diagnosis.     

原发性开角型青光眼不同发展阶段盘沿缺失的形态特征及其临床意义

目的:探讨青光眼病情发展阶段盘沿缺失的形态特征。方法:对青光眼92眼和正常人124眼进行立体彩色视盘照像,侧重分析盘沿的形态。结果:与视力正常眼比较,青光眼不同病情阶段盘沿缺失有其好发区域。早期青光眼盘沿缺失在视盘颞下极明显,中期青光眼盘沿缺失在颞上极较为明显,极晚期青光眼盘沿仅保留视盘鼻侧区域,并且鼻上区大于鼻下区。结论:青光眼盘沿缺失的形态特征与青光眼性视野缺损的发展及筛板的形态密切相关。     

原发性开角型青光眼HRT视盘参数和视野缺损的关系

目的 :探讨原发性开角型青光眼视盘参数和视野平均缺损之间的关系。方法 :用海德堡视网膜断层扫描仪和自动视野计测定 5 5名原发性开角型青光眼患者的视盘参数 (杯盘面积比、盘沿面积、盘沿容积、视杯容积、视杯形态测量、视杯高度变异轮廓和平均神经纤维层厚度 )和静态光阈值。视盘参数与视野平均缺损作相关分析和多元线性回归分析。结果 :盘沿面积与平均缺损显著相关 (r =0 3 5 0 ,P <0 0 5 )。盘沿面积每减少 1mm2 ,视野缺损绝对值增加 8 0 81dB。本研究没有发现其它 6个参数与平均缺损相关关系的显著性。结论 :盘沿面积在HRT众多参数中最能反映青光眼的视野平均缺损程度。     

Optic disc morphometry correlated with confocal laser scanning Doppler flowmetry measurements in normal-pressure glaucoma

PURPOSE: To examine the relationship between morphologic optic disc parameters and hemodynamic parameters as measured by confocal laser scanning Doppler flowmetry in patients with normal-pressure glaucoma. METHODS: The study included 91 eyes of 54 patients with normal-pressure glaucoma (mean age: 57.7 +/- 9.8 years), and 136 eyes of 77 age-adjusted normal controls. Color stereo optic disc photographs were morphometrically examined, and confocal laser scanning flowmetry (Heidelberg Retinal Flowmeter) in the neuroretinal rim inside of the optic disc, and in the retina close to the temporal and nasal border of the optic nerve head was performed. RESULTS: Mean confocal laser scanning flowmetric measurements in the neuroretinal rim, temporal parapapillary retina, and nasal parapapillary retina were significantly (P<0.03) lower in the normal-pressure glaucoma group than in the age-adjusted control group. Correspondingly, mean confocal laser scanning flowmetric measurements within the neuroretinal rim decreased significantly, with relatively low correlation coefficients, decreasing neuroretinal rim area (P = 0.016; correlation coefficient r2 = 0.026), and increasing mean visual field defect (P = 0.011; r2 = 0.029). Measurements were statistically independent of alpha zone (P = 0.38; r2 = 0.004) and beta zone (P = 0.57; r2 = 0.002) of parapapillary atrophy. CONCLUSIONS: Confocal laser scanning flowmetric measurements within the neuroretinal rim were lower in eyes with normal-pressure glaucoma than in age-matched normal eyes. Confocal laser scanning flowmetric measurements decrease with increasing glaucomatous optic nerve damage. There is, however, a marked variability preventing a clear relationship between stage of glaucoma and decrease in confocal laser scanning flowmetric measurements. The correlation between parapapillary atrophy and confocal laser scanning flowmetric measurements is not statistically significant in normal-pressure glaucoma.     

Inter-eye differences in chronic open-angle glaucoma patients with unilateral disc hemorrhages

OBJECTIVE: Flame-shaped optic disc hemorrhages are a hallmark of glaucomatous optic neuropathy. The purpose of this study was to evaluate which parameters differ between companion eyes with and without an optic disc hemorrhage in patients with chronic open-angle glaucoma. DESIGN: Comparative (companion eye) observational case series. PATIENTS: The study included 99 white patients with bilateral chronic open-angle glaucoma and unilateral flame-shaped optic disc hemorrhages. METHODS: All patients underwent qualitative and morphometric evaluation of color stereo optic disc photographs. MAIN OUTCOME MEASURES: Size and shape of the optic disc, neuroretinal rim and parapapillary atrophy, diameter of the retinal vessels, intraocular pressure measurements, and both mean value and loss variance value of the visual field examination. RESULTS: In an intraindividual inter-eye comparison, the eyes with disc hemorrhages and the contralateral eyes without disc bleeding did not vary significantly (P > 0.20) in size and shape of the optic disc and neuroretinal rim, optic cup depth, size of alpha and beta zone of parapapillary atrophy, retinal vessel diameter, intraocular pressure measurements, refractive error, and perimetric indices. CONCLUSIONS: In bilateral chronic open-angle glaucoma, the development of unilateral optic disc hemorrhages does not depend on inter-eye differences in size and shape of the optic disc, neuroretinal rim and parapapillary atrophy, diameter of the retinal vessels, intraocular pressure measurements, or visual field loss.     

Disc excavation in dominant optic atrophy: differentiation from normal tension glaucoma

OBJECTIVE: In patients with dominant optic atrophy (DOA, Kjer type), excavation of the optic nerve develops, and these patients may be misdiagnosed as having normal tension glaucoma (NTG). This study examined disc morphologic features in patients with DOA and explored features that help distinguish this condition from NTG. DESIGN: Noncomparative, observational case series. PARTICIPANTS: Patients with DOA who were seen at the Duke University Eye Center between 1987 and 1996 and who had bilateral optic nerve photographs. METHODS: Retrospective chart review of the results of visual acuity testing, visual field testing by Goldmann perimetry, color vision testing, intraocular pressure measurement, and observation of bilateral optic nerve photographs. MAIN OUTCOME MEASURES: Appearance of the optic disc and peripapillary zone in patients with DOA. RESULTS: Nine patients were identified. The mean age at the time of evaluation was 28 years (range, 11-62 years). Most patients had a mild to moderate reduction in visual acuity. Color vision as tested with Hardy-Rand-Rittler plates was reduced (4.0/10 +/- 4.2/10). A cup-to-disc ratio of more than 0.5 was observed in at least one eye of eight patients. A temporal wedge-shaped area of excavation was observed in 14 of the 18 eyes studied. Moderate to severe temporal pallor was observed in all of the eyes. Pallor of the remaining (noncupped) neuroretinal rim was also observed consistently, ranging from mild to moderate. A gray crescent and some degree of peripapillary atrophy were noted in all eyes. CONCLUSIONS: Several clinical features, including early age of onset, preferential loss of central vision, sparing of the peripheral fields, pallor of the remaining neuroretinal rim, and a family history of unexplained visual loss or optic atrophy, help to distinguish patients with DOA from those with NTG.     

原发性开角型青光眼视乳头盘沿高度与视野的一致性研究

探讨原发性开角型青光眼（开青）相对视乳头盘沿高（ｎｅｕｒａｌ ｒｉｍ ｄｅｐｈｔｈ,ＮＲＤ）与视野检查结果的一致性。方法利用计算机图像分析技术测量开青患者颞下方的ＲＮＤ值,比较ＮＲＤ值较大部位与视野缺损较重部位的一致性。结果早、中期开青患者有视野缺损或视野缺损较重部位所对应区域的ＮＲＤ值较无视野缺损或视野缺损较轻部位所对应区域的ＮＲＤ值明显增大,且５４只眼中有４６只眼的ＮＲＤ值较大部位与视野缺损较     

Parapapillary retinal vessel diameter in normal and glaucoma eyes. II. Correlations

The juxtapapillary diameters of the superior temporal and inferior temporal retinal artery and vein have been shown to be significantly smaller in glaucomatous eyes than in normal eyes. They had been measured in 473 eyes of 281 patients with chronic primary open-angle glaucoma and in 275 eyes of 173 normal subjects. In the current study the vessel diameters were correlated with intra- and parapapillary morphometric data and visual field indices. Only one eye per patient and subject was taken for statistical analysis. The retinal vessel calibers were significantly (P less than 0.001) correlated with: (1) the area of the neuroretinal rim as a whole and in four different optic disc sectors; (2) the rim width determined every 30 degrees; (3) the optic cup area and diameters; (4) the horizontal and vertical cup/disc ratios and (5) the quotient of them; (6) the retinal nerve fiber layer score; (7) the area of the parapapillary chorioretinal atrophy; and (8) the visual field indices. In the same eye the vessel caliber was smaller in that sector where the neuroretinal rim loss was highest and the retinal fiber layer score lowest. In intraindividual comparison the vessels were smaller in that eye with less neuroretinal rim tissue and lower nerve fiber layer score. No significant correlations were found with the form of the optic disc, the area of the peripapillary scleral ring, side, sex and refraction. The correlation coefficients were not significantly different when the control group was matched for age. The parapapillary retinal vessel diameter decreases with advancing glaucomatous optic nerve damage. It is correlated with morphometric intra- and parapapillary glaucomatous changes and perimetric defects.     

Neuroretinal rim width ratios in morphological glaucoma diagnosis

AIMS—To evaluate the inferior to temporal neuroretinal rim width ratio and superior to temporal rim width ratio as measures of rim shape for diagnosis of glaucoma.
METHODS—Colour stereo optic disc photographs of 527 normal subjects, 100 ocular hypertensive individuals with normal visual fields, and 202 open angle glaucoma patients with a mean perimetric defect of less than 10 dB were morphometrically evaluated. Eyes with an optic cup area of < 0.2 mm² were excluded.
RESULTS—In the normal subjects, inferior to temporal rim width ratio (1.67 (SD 0.53)) was significantly (p<0.0001) higher than superior to temporal rim width ratio (1.56 (0.49)). Both ratios were significantly (p<0.0001) higher the more vertically the optic disc was configured. In the normal eyes, both ratios were statistically independent of disc size, rim area, refractive error, age, and sex. With the differences being more marked for the inferior to temporal ratio than for the superior to temporal ratio, both rim width ratios were significantly (p<0.005) lower in the ocular hypertensive group than in the normal group. Despite the high significance of the differences, diagnostic power of the inferior ratio and the superior ratio was 59% and 58%, respectively, indicating a marked overlap between the groups.
CONCLUSIONS—Abnormally low inferior to temporal and superior to temporal rim width ratios can indicate glaucomatous optic nerve damage in some ocular hypertensive eyes. Being independent of optic disc size and ocular magnification, the rim width ratios may be taken as one among other variables for the ophthalmoscopic optic disc evaluation, taking into account, however, a pronounced overlap between normal eyes and ocular hypertensive eyes.

Keywords: neuroretinal rim width ratios; glaucoma; ocular hypertension     

Measurement of microcirculation in optic nerve head by laser speckle flowgraphy in normal volunteers

PURPOSE: To report blood flow in the optic nerve head between the right and left eyes or the superior and inferior neuroretinal rims in normal volunteers using laser speckle flowgraphy. METHODS: This prospective study included 120 eyes of 60 normal volunteers (mean age, 50.0 +/- 16.9 years; range, 21 to 77 years). The square blur rate was measured by laser speckle flowgraphy (Kyushu Institute of Technology, Iizuka, Japan). The sequence of eye measurements was randomized. In each eye, measurements were taken at the neuroretinal rim away from visible vessels. Linear regression analysis, paired two-tailed t test, and two-way analysis of variance were used for statistical analysis. P values less than.05 were accepted as statistically significant. RESULTS: There was a significant correlation in square blur rate between the right and left eyes (r = 0.587, P <.001). Square blur rate in the superior temporal neuroretinal rim significantly correlated with that in the inferior temporal neuroretinal rim in each of the right (r = 0.546, P <.001) and left (r = 0.465, P <.001) eyes. Square blur rate in the right eye was higher than that in the left eye (P =.049). Square blur rate in the superior neuroretinal rim was higher than that in the inferior neuroretinal rim in both the right (P =.035) and left (P =. 005) eyes. CONCLUSION: There were statistically significant differences of optic nerve head blood flow in normal volunteers using laser speckle flowgraphy between the right and left eyes and between the superior and inferior temporal neuroretinal rims. These normal data can be used for understanding physiological ocular hemodynamics.