Application of Novel Down-sampling Method in Retinal Vessel Segmentation / 中国医疗器械杂志

Accurate segmentation of retinal blood vessels is of great significance for diagnosing, preventing and detecting eye diseases. In recent years, the U-Net network and its various variants have reached advanced level in the field of medical image segmentation. Most of these networks choose to use simple max pooling to down-sample the intermediate feature layer of the image, which is easy to lose part of the information, so this study proposes a simple and effective new down-sampling method Pixel Fusion-pooling (PF-pooling), which can well fuse the adjacent pixel information of the image. The down-sampling method proposed in this study is a lightweight general module that can be effectively integrated into various network architectures based on convolutional operations. The experimental results on the DRIVE and STARE datasets show that the F1-score index of the U-Net model using PF-pooling on the STARE dataset improved by 1.98%. The accuracy rate is increased by 0.2%, and the sensitivity is increased by 3.88%. And the generalization of the proposed module is verified by replacing different algorithm models. The results show that PF-pooling has achieved performance improvement in both Dense-UNet and Res-UNet models, and has good universality.

Fellow-eye asymmetry on optical coherence tomography angiography and thickness parameters in unilateral pseudoexfoliation syndrome / Assimetria do olho oposto na angiografia por tomografia de coerência óptica e parâmetros de espessura na síndrome de pseudoexfoliação unilateral

ABSTRACT Purpose: To investigate inter-eye retinal vessel density and thickness asymmetry in unilateral pseudoexfoliation syndrome and understand its use for the early detection of glaucoma. Methods: Thirty patients with unilateral pseudoexfoliation syndrome were enrolled in our study. Optical coherence tomography angiography macular scans were used measure the retinal vessel density, and optical coherence tomography scans were used to assess the thickness parameters of the peripapillary retinal nerve fiber layer and the macular ganglion cell complex. Inter-eye asymmetry was determined by taking the absolute value of the difference in the vessel density and thickness parameters between the pseudoexfoliation syndrome eye and fellow eye. Results: The mean patient age was 64.20 ± 7.05 y in the study group. Inter-eye asymmetry in the peripapillary retinal nerve fiber layer thickness and macular ganglion cell complex measurements were significant in the study group (p=0.03 and p=0.001, respectively). The vessel density of the macular superficial inner region was significantly lower in eyes with pseudoexfoliation syndrome than in fellow eyes (p=0.035). However, there was no inter-eye asymmetry in the central and full region macular superficial vessel density of eyes with pseudoexfoliation syndrome and fellow eyes (p>0.05). Conclusion: Retinal vessel density can be evaluated using optical coherence tomography angiography measurements. There was inter-eye asymmetry in the inner region macular superficial vessel density, peripapillary retinal nerve fiber layer, and macular ganglion cell complex thickness of the unilateral pseudoexfoliation syndrome eyes and fellow eyes. Further studies on a larger number of subjects might provide more clarity regarding the relationship between the inter-eye asymmetry of the retinal vessel density and thickness parameters with early detection of glaucomatous damage.

RESUMO Objetivo: Investigar a densidade dos vasos interoculares da retina e assimetria na espessura na síndrome de pseudoexfoliação unilateral e o seu uso para a detecção precoce de glaucoma. Métodos: Trinta pacientes com síndrome de pseudoexfoliação unilateral foram incluídos no estudo. As varreduras maculares de angiografia por tomografia de coerência óptica mediram a densidade dos vasos da retina, e as varreduras por tomografia de coerência óptica obtiveram parâmetros de espessura da camada de fibras nervosas da retina peripapilar e do complexo macular de célula ganglionar. A assimetria interocular foi determinada tomando o valor absoluto da diferença entre o olho da síndrome de pseudoexfoliação e o olho oposto nos parâmetros de densidade e espessura dos vasos. Resultados: A média de idade foi 64,20 ± 7,05 anos no grupo de estudo. A assimetria interocular na espessura da camada de fibra nervosa da retina peripapilar e as medidas do complexo macular de célula ganglionar foram estatisticamente significativas no grupo de estudo (p=0,03 e p=0,001, respectivamente). Para os olhos com síndrome de pseudoexfoliação, a densidade do vaso da região macular superficial interna foi significativamente menor do que em olhos opostos (p=0,035). No entanto, não houve assimetria interocular estatisticamente significativa na densidade macular dos vasos superficiais da região central e completa entre os olhos da síndrome de pseudoexfoliação e os olhos opostos (p>0,05). Conclusões: A densidade dos vasos da retina pode ser avaliada por medidas de angiografia por tomografia de coerência óptica. Houve assimetria interocular na densidade macular do vaso superficial da região interna, camada de fibra nervosa da retina peripapilar e espessura do complexo macular de célula ganglionar entre olhos com síndrome de pseudoexfoliação unilateral e olhos opostos. Novos estudos com um número maior de indivíduos podem fornecer a relação entre a assimetria interocular da densidade do vaso da retina e os parâmetros de espessura com detecção precoce de dano glaucomatoso.

Correlation study of retinal vascular morphological parameters with ischemic stroke / 中华眼底病杂志

Objective:To observe the morphological characteristics of retinal vessels in patients with ischemic stroke, and to preliminary analyze the correlation between retinal vascular morphological parameters and ischemic stroke.Methods:A retrospective study. From May 2015 to May 2017, 73 patients with ischemic stroke (ischemic stroke group) confirmed by examination at the Beijing Friendship Hospital, Capital Medical University were included in this study. In addition, 146 patients were included in the control group. A total of 146 patients with acute stroke who were excluded by head CT and/or magnetic resonance imaging were selected as the control group. Fundus images of patients were collected by nonmydriatic fundus camera. Retinal vascular parameters were measured by artificial intelligence fundus image analysis system, included retinal artery and vein caliber as well as vascular curvature, branching angle, fractal dimension, and density. The morphological characteristics of retinal vessels were compared between the control and ischemic stroke groups, and correlation between the retinal vascular parameters and ischemic stroke was analyzed using binary logistic regression.Results:Compared with the control group, the ischemic stroke group had thinner retinal artery caliber, smaller retinal vascular fractal dimension, and lower retinal vascular density; moreover, these differences were statistically significant ( t=3.232, 3.502, 3.280; P<0.05). Vascular fractal dimension [odds ratio ( OR)=0.291, 95% confidence interval ( CI) 0.160-0.528] and retinal artery caliber ( OR=0.924, 95% CI 0.870-0.981) were strongly correlated with ischemic stroke ( P<0.01). Conclusion:Compared with the control group, the retinal artery caliber, fractal dimension and retinal vascular density in ischemic stroke group are smaller; decreased retinal artery caliber and fractal dimension are correlated with ischemic stroke.

Segmentation of retinal vessels by fusing contour information and conditional generative adversarial / 生物医学工程学杂志

The existing retinal vessels segmentation algorithms have various problems that the end of main vessels are easy to break, and the central macula and the optic disc boundary are likely to be mistakenly segmented. To solve the above problems, a novel retinal vessels segmentation algorithm is proposed in this paper. The algorithm merged together vessels contour information and conditional generative adversarial nets. Firstly, non-uniform light removal and principal component analysis were used to process the fundus images. Therefore, it enhanced the contrast between the blood vessels and the background, and obtained the single-scale gray images with rich feature information. Secondly, the dense blocks integrated with the deep separable convolution with offset and squeeze-and-exception (SE) block were applied to the encoder and decoder to alleviate the gradient disappearance or explosion. Simultaneously, the network focused on the feature information of the learning target. Thirdly, the contour loss function was added to improve the identification ability of the blood vessels information and contour information of the network. Finally, experiments were carried out on the DRIVE and STARE datasets respectively. The value of area under the receiver operating characteristic reached 0.982 5 and 0.987 4, respectively, and the accuracy reached 0.967 7 and 0.975 6, respectively. Experimental results show that the algorithm can accurately distinguish contours and blood vessels, and reduce blood vessel rupture. The algorithm has certain application value in the diagnosis of clinical ophthalmic diseases.

Changes of microvascular diameter in non-proliferative diabetic retinopathy / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To investigate the changes of microvascular diameter in non-proliferative diabetic retinopathy(NPDR)at different stages.<p>METHODS: Prospective case-control study. Patients with type 2 diabetes mellitus complicated with diabetic retinopathy(DR)who were hospitalized in the Endocrine Department of our hospital from September 2020 to March 2021 were selected and divided into diabetic non-retinopathy group(50 cases and 50 eyes), DR stage Ⅰ group(50 cases and 50 eyes), DR stage Ⅱ group(50 cases and 50 eyes), DR stage Ⅲ group(50 cases and 50 eyes)according to the “Clinical Diabetic Retinopathy Disease Severity Scale” formulated by the Chinese Medical Association in 1985. In addition, 50 cases and 50 eyes of a control group with normal physical examination were selected, totally 250 cases and 250 eyes. The fundus color photos were taken and entered into the ARIA1.0 automatic analysis software to record the diameters of arterio-venous and capillary vessels in different ranges, with 4 segments in each range and 200 segments in each group for statistical analysis.<p>RESULTS: There was no significant difference in the diameter of retinal artery between different stages of NPDR(<i>P</i>>0.05), and there was significant difference in the diameter of retinal vein and diameter of perimacular capillary amorg different stages of NPDR(<i>P</i><0.05). The multiple comparison of retinal vein diameter and perimacular capillary diameter in different groups was statistically significant(<i>P</i><0.01). The average score of retinal vein diameter in the range of 0-0.5PD was “stage Ⅲ course > stage Ⅱ course>stage Ⅰ course>normal group>control group”. The average score of retinal vein diameter group in the range of 0.5-1.0PD(including 0.5)was “stage Ⅲ course > stage Ⅱ course > stage Ⅰ course > normal group > control group”, the average score of perimacular capillary diameter group was “stage Ⅲ course > stage Ⅰ course > control group; Stage Ⅲ course > normal group; Stage Ⅱ course > stage Ⅰ course > control group; Stage Ⅱ course > normal group; The diseased normal group > the control group”, while there was no significant difference between the stage Ⅲ course and the stage Ⅱ course, the stage Ⅰ course and the diseased normal group(<i>P</i>>0.05).<p>CONCLUSION: Retinal artery diameter has no obvious change in NPDR stages. The retinal vein and perimacular capillary in diabetic patients are dilated. In different stages of NPDR, the diameter of the vein and perimacular capillary is gradually widened.

Retinal Vessel Segmentation Based on Multiscale Matched Filtering / 中国医疗器械杂志

Retinal vascular function is complex, morphological structure varies from person to person, and is susceptible to vascular diseases and systemic vascular diseases. Its accurate segmentation is of great significance for disease diagnosis and identification. In this paper, a multi-scale matching filtering algorithm is proposed for the uneven size of retinal blood vessels. On the basis of the traditional singlescale Gaussian matching filter, multiscale Gaussian matched filters with two sizes are used to enhance grayscale images. Enhancement is performed, and the superimposed image is binarized using a twodimensional maximum entropy threshold segmentation algorithm. The algorithm is tested in the DRIVE database with sensitivity, specificity and accuracy of 0.803, 0.959, 0.981, respectively. Comparing with the traditional algorithm, the algorithm has high sensitivity, fast running speed and rich details of segmentation results.

Application of optical coherence tomography angiography in retinal vein occlusion / 眼科新进展

Optical coherence tomography angiography (OCTA) is a novel,non-invasive,and high-resolution technique for imaging of the retinal vessel.OCTA has the unique advantages to observe retinal vascular morphology at different levels and quantify vascular perfusion,so now OCTA has been widely applied to make diagnosis and follow up in various types of retinal vascular diseases.Retinal vein occlusion (RVO) is a com mon fundus vascular disease,and this paper will give a brief review on the application of OCTA in RVO.

Vascular behavior characteristics in degenerative retinopathy and its influence factors / 眼科新进展

Vascular morphology and function changes exist in degenerative retinopathy,which have an important influence on the development and prognosis of the disease.The literature has been reported that retinal vascular structure and function change can be found early by using the retinal oximeter,color Doppler flow imaging,ocular pulse amplitude and so on,as well as exploring the primary and secondary factors affecting the development of retinal blood vessels.This article reviews the vascular behavior characteristics in degenerative retinopathy and their influence factors.

Application of optical coherence tomography angiography in retinal vein occlusion / 眼科新进展

Optical coherence tomography angiography (OCTA) is a novel,non-invasive,and high-resolution technique for imaging of the retinal vessel.OCTA has the unique advantages to observe retinal vascular morphology at different levels and quantify vascular perfusion,so now OCTA has been widely applied to make diagnosis and follow up in various types of retinal vascular diseases.Retinal vein occlusion (RVO) is a com mon fundus vascular disease,and this paper will give a brief review on the application of OCTA in RVO.

24-hour Ambulatory Blood Pressure in Normal Tension Glaucoma: Associations with Retinal Vessel Diameter and Visual Field Defect Progression

PURPOSE: To investigate the correlation between 24-hour ambulatory blood pressure (BP) monitoring and peripapillary retinal vessel width and visual field (VF) defect progression in normal tension glaucoma (NTG) patients. METHODS: All patients were classified by 24-hour ambulatory BP monitoring as non-dipper (nocturnal dip < 10%) and dipper (nocturnal dip ≥ 10%) group. Vessel diameter, mean deviation (MD) value by VF test and VF progression from Glaucoma Progression Analysis (GPA) were compared among non-dipper and dipper groups. RESULTS: Retinal arterial diameter was wider in the non-dipper group compared to the dipper group (p = 0.015), while retinal venous diameter had no significant relationship between the two groups (p = 0.131). The MD value at baseline and 2 years after was worse in the non-dipper group than the dipper group, respectively (p = 0.006, p = 0.030). But, there was no significant relationship between nocturnal dip and GPA progression (p = 0.658). CONCLUSIONS: There was a statistically significant correlation between nocturnal dips and retinal arterial diameter and MD values. These results suggest that non-invasive fundus photography can predict hemodynamic features like nocturnal dip.

Correlation study of cerebral small vessel disease and retinal vascular network parameters / 中国神经精神疾病杂志

Objective To investigate the correlation of cerebral small vessel disease with retinal vascular network parameters using fully automatic retinal image analysis of fundus photographs. Methods A total of 121 patients undertak?ing fundus photography in a sitting position were included. They were divided into either a cerebral small vessel disease group (n=80) or an artery atherosclerotic cerebral infarction group (n=41) according to their cerebral MRI findings. The clinical data and retinal vascular network parameters were compared between the two groups. We used logistic regression to analyse risk factors of the small vessel disease. Results The percentage of males, the incidence of smoking and serum uric acid level in the small vessel disease group were lower than those in the artery atherosclerotic cerebral infarction group(P<0.05). The bifurcation coefficient and asymmetry index of venule in the small vessel disease group were lower than those in the artery atherosclerotic cerebral infarction group(P<0.05). Logistic regression analysis showed that after adjusting vascular risk factors, decreased asymmetry index of venule was associated with cerebral small vessel disease (OR=1.16,95% CI:1.05-1.38,P<0.05). Conclusions The decreased asymmetry index of venule is associated with small vessel disease which can be used as an early diagnotic indicator.

Analysis of Retinal Vascular Calibers with Cardiovascular Risk Factors

PURPOSE: To analyze the association between retinal vascular caliber and cardiovascular risk factors including smoking, blood pressure, diabetes and age. METHODS: This study included 60 Korean male participants 40-69 years of age. The retinal vessel caliber was measured using computer-assisted fundus photography. Four vessels coursing through the area of one half disc diameter from the optic disc margin were measured. Additionally, we analyzed the association between the retinal vessel caliber and risk factors including smoking, diabetes, hypertension and age. RESULTS: Smoking was not significantly associated with retinal vessel calibers. The diabetes group showed larger average retinal vessel calibers than normal group, but veins were significantly wider (p < 0.05). The average retinal vessel caliber was wider and inferior vein and artery were significantly larger in the hypertension group (p < 0.05). Although the retinal vessel caliber increased with age, significance was observed only in the superior artery (p < 0.05). CONCLUSIONS: In our study, retinal vessel caliber was easily measured using a semi-automatic computer program. This method should prove useful in further studies examining the correlation among retinal vessel caliber variations in many localized ophthalmologic disorder.

Analysis of Factors Associated with Retinal Vascular Caliber in Normal Korean Subjects

PURPOSE: To measure the diameter of the retinal arterial and venous caliber of normal Korean subjects and evaluate the factors affecting these diameters. METHODS: Fundus photography was performed on 152 normal Korean subjects. Central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE) were measured with a computer-based program (IVAN), and were used to investigate the relationship between the diameter and factors including age, gender, hypertension, diabetes, and smoking. RESULTS: Among the study subjects, the CRVE was 209.33 +/- 12.40 microm and the CRAE was 149.70 +/- 9.01 microm. The CRVE and CRAE decreased with increasing age in all study subjects (both p 0.05). CONCLUSIONS: In our study group, retinal vascular caliber of normal Korean subjects decreased with aging. Retinal vascular caliber was affected by gender and hypertension, but not by smoking and diabetes.

The Effect of Bevacizumab on Retinal Vessel Diameter, Intraocular Pressure, Retinal Nerve Fiber Layer and the Optic Disc

PURPOSE: To evaluate the effects of a single intravitreal bevacizumab injection on retinal vessel diameter, intraocular pressure (IOP), retinal nerve fiber layer (RNFL) thickness and the optic disc in patients with diabetic macular edema (DME). METHODS: In this retrospective study, 63 eyes with DME were included. All patients received an intravitreal injection of 1.25 mg bevacizumab. We reviewed retinal vessel diameter, IOP RNFL thickness and vertical cup-to-disc (C/D) ratios at the baseline and 7 days, 1 month, 3 months and 6 months after injection. The diameter of the central retinal arteries and veins were measured using retinal photographs. The central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) were calculated using the revised Parr-Hubbard formula. RNFL thickness was obtained using optical coherence tomography. The vertical C/D ratio of the optic disc was evaluated using stereoscopic optic disc photography. RESULTS: After bevacizumab injection, the CRAE significantly decreased at 7 days and 1 month postoperatively compared to baseline (p < 0.001 and p = 0.036, respectively). However, the changes in the CRAE at 3 months and 6 months were not statistically significant (p = 0.992 and p = 0.342, respectively). There were no statistically significant changes in the CRVE, mean IOP, RNFL thickness and vertical C/D ratios of the optic disc. CONCLUSIONS: A single intravitreal bevacizumab injection transiently decreased the diameters of central retinal arterioles, but induced no significant changes in central venular diameter, mean IOP, RNFL thickness or vertical C/D ratios of the optic disc.

Feasibility assessment for the observation of murine retinal vessel by retro-orbital injection of fluorescein isothiocyanate-dextran / 中华实验眼科杂志

Background The incidence of retinal vascular diseases increase annually,such as diabetic retinopathy,retinopathy of prematurity and age-related macular degeneration.The key of treatment for these diseases is how to evaluate retinal vascular change effectively and objectively.Retro-orbital injection of fluorescein isothiocyanatedextran (FITC-dextran) is a simple and effective method for observing C57BL/6J mouse retinal vessels.But,whether it is suitable for other mice and rats is seldom reported.Objective This experiment was to assess the feasibility of the observation of retinal vessels by retro-orbital injection of FITC-dextran in different genus of mouse and offer the reference for relevant study.Methods Twelve animals of C57BL/6J mice,Kunming mice,SD rats and Wistar rats were selected,respectively and divided into the experimental group and control group at average.The right eyes of the animals of the experimental group received the retro-orbital injection of 9 ml/kg FITC-dextran,and the right eyes of animals of the control group received PBS solution at the same volume and way.All the animals were sacrificed 10 seconds after injection and both eyes of each animal were obtained for retinal stretched preparation.The retrobulbar tissue and whole-mount retina were viewed under a fluorescence microscope.The use of the animals complied with Regulation for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission.Results Retinal blood vessels labeled by FITC-dextran could be observed in both eyes of C57BL/6J mice and Kunming mice to present with a green fluorescence in experimental group under a fluorescence microscope,but no any fluorescence-labeled retinal blood vessel was exhibited in the control mice.The retinal blood vessel could not be observed in all eyes of SD rats and Wistar rats after the injection of FITC-dextran both in the experimental group and the control group under a fluorescence microscope.The surrounding tissues of the right eyes of mice and rats dyed with green fluorescence of FITC-dextran in the experimental group,however,green fluorescence could not be seen in the surrounding tissues of the left eyes of mice and rats.Conclusions Retro-orbital injection of FITC-dextran is a suitable method of observing the retinal vessels of mouse but not rat.

The influence of the duration of type 2 diabetes mellitus on retinal vessel diameter / 中国基层医药

Objective To observe the signs of retinal vessel diameter among different clinical characteristic groups such as sex,age,BMI,the duration of DM. Methods200 diabetic patients were selected.Using face to face questionnaire survey forms filled in the questionnaire in order to collect the general situation of all subjects selected.The diameters of vessels were measured using a computer-assisted imaging program. ResultsIn type 2 diabetes mellitus,there was no significant difference in the retinal arteriolar and veular diameters between the groups with different sex.In type 2 diabetes mellitus,as age increased,both the retinal arteriolar diameters and the retinal veular diameters declined.In type 2 diabetes mellitus,there was no significant difference in the retinal arteriolar and veular diameters between the groups with different BMI.In type 2 diabetes mellitus,as the duration of DM increased,the retinal veular diameters dilated and the retinal arteriolar diameters declined.After storied in accordance with age,we can draw the sameConclusion . ConclusionIn type 2 diabetes mellitus,as the duration of DM increased,the retinal veular diameters dilated and the retinal arteriolar diameters declined.

Comparison of the Central Retinal Vessel Diameter Between Glaucomatous and Normal Eye

PURPOSE:To compare the diameter of central retinal vessels between patients with normal-tension glaucoma, primary open-angle glaucoma and healthy (control) eyes. METHODS: The authors reviewed 30 eyes of 30 normal-tension glaucoma patients, 20 eyes of 20 primary open-angle glaucoma patients and 30 eyes of normal persons who had no systemic vascular diseases. The diameters of the central retinal arteries and veins were measured and calculated using a revised Parr-Hubbard formula, and results were compared between the groups. RESULTS: The diameter of the central retinal vessel showed no statistical differences between the eyes with normal-tension glaucoma and primary-open angle glaucoma. However, there were significant differences between the eyes of patients with glaucoma and the normal control eyes (p<0.05). Conclusion: The diameter of the central retinal vessels in glaucoma patients were narrower than that in the control group. Our results suggest that the diameter of the central retinal vessels may affect the development of glaucoma both in normal tension and primary open-angle types, or that glaucomatous damage may influence the diameter of the central retinal vessels.

A Case of Nonspecific Normal Retinal Vessels in Foveal Avascular Zone

PURPOSE: To report a case of a young man with nonspecific normal retinal vessels found in foveal avascular zone. METHODS: We experienced a 20-year-old man with decreased visual acuity of left eye. In anterior segment there was no abnormality, but there were unusual vessels in foveal avascular zone that appeared to be normal vessels. RESULTS: In fluorescein angiography, dye was exhibited on the vessel of foveal avascular zone in 14-15 sec after injection, and there were no leaking or abnormal findings. CONCLUSIONS: Normal retinal vasculature in foveal avascular zone is known to be an extremely unusual case in normal adult, and it is to report a case with review of available papers.

Morphological Changes of Retinal Vessel Under Tissue Culture

PURPOSE: This study was performed to investigate the growth pattern of the retinal vessel including retinal vascular endothelial cell and pericyte. METHODS: The sensory retina was detached from the eyecup obtained from donor's eye. The retinal vessel which was separated from the sensory retina was cultured in tissue culture media for 2, 3 and 4 weeks separately and examined by transmission electron microscopy. RESULTS: On the second week of tissue culture, both the retinal vascular endothelial cells and pericyte were intact in morphology in nuclear and cytoplasmic pattern. Both cells were partially detached from the surrounding basement membrane. On the third week of tissue culture, the cytoplasm of the retinal vascular endothelial cells and pericyte were degenerated, whereas the vascular endothelial cell were intact in nuclear and cytoplasmic profiles which were still partially surrounded by the basement membrane. CONCLUSIONS: These findings suggest that the survivability of the retinal vascular endothelial cells and pericyte may be limited for 2 and 3 weeks, separatedly under the ordinary culture medium.

Retinal Vessel Diameter: 1. Comparison of Normal and Glaucoma Eyes

Narrowing of the retinal vessels in chronic glaucoma has been recognized only recently. We performed this study to evaluate the vessel diameter in normal and glaucoma eyes, addressing whether the retinal vessel diameters differ with the degree of glaucomatous optic nerve damage. The diameters of the superior temporal and inferior temporal retinal artery and vein were measured at the optic disc border from optic disc photographs of 234 eyes of 141 patients with primary open-angle glaucoma and 139 eyes of 86 normal subjects. The photographic magnification was corrected according to Littmanns method. Only one eye per patient and subject was taken for statistical analysis. According to the neuroretinal rim/disc area ratio, the glaucoma group was divided into four stages(early; more than 0.61, medium; 0.60~0.41, advanced; 0.40~0.21, far advanced; less than 0.20). In the normal group the diameter of the inferior temporal vein(0.130+/-0.020mm) was the largest, followed by the superior temporal vein(0.117+/-0.017mm), the inferior temporal artery(0.102+/-0.016mm), finally the superior temporal artery(0.093+/-0.012mm). The retinal vessel diameter decreased significantly with decreasing of the neuroretinal rim/disc area ratio. In the glaucomatous eyes as compared to the normal eyes, the diameters of the inferior temporal and superior temporal retinal artery were significantly smaller at the early and medium stages(p<0.03, p<0.02, respectively). Whereas both inferior temporal and superior temporal retinal vein diameters were significantly samller at the far advanced stage(p=0.01, p=0.005, respectively). The results indicate that generalized reduction of the retinal vessel diameter throughout the retina is related to the severity of glaucoma. From a diagnostic point of view, evaluation of artery diameter rather than vein diameter may be helpful for the differentiation between normal and glaucomatous eyes.