正常人与开角型青光眼患者的视网膜血管内氧饱和度的差异

Purpose:To measure the oxygen saturation(SO2)in retinal arterioles and venules in patients with glaucomatous optic neuropathy.Methods:We examined SO2 in retinal arterioles and venules simultaneously by imaging spectrometry.Oxygen saturationwas evaluated according to the difference of the extinction spectra of haemoglobin and oxyhaemog-lobin.The arterio-venous difference(avD)was calculated by(SO2art-SO2ven).The optic nerve head topography was estimated by Heidelberg retinal tomography and the visual field using the Octopus G1.We examined one eye in each of 58 healthy persons(mean age 58.6 ± 10.7 years;mean rim area 1.52± 0.33mm2;mean defect 0.65± 1.31 dB;mean intraocular pressure IOP 18.5± 2.7 mmHg),49 patients with normal-tension primary open-angle glaucoma(NTG)(mean age 63.0± 8.5 years;mean rim area 0.89± 0.34 mm2;mean defect 5.4± 4.1dB;mean IOP 19.2± 2.9 mmHg),and 45 patients with high-tension primary open-angle glaucoma(POAG)(mean age 62.6± 10.3 years;mean rim area 0.97± 0.47 mm2;mean defect 7.1± 6.4 dB;mean IOP 31.6± 10.8 mmHg).Results:The intraclass correlation coefficients of the SO2 measurement were 0.82(arteriole)and 0.59(venule).In normal eyes,the SO2art,SO2ven and avD were 92.3± 3.4%,55.7 ± 6.8% and 36.6± 7.0%,respectively.Equivalent data were 89.7± 5.4%,56.0± 8.3% and 33.7± 10.6%,respectively,in NTG eyes and 91.4± 4.0%,58.3± 10.5% and 33.1± 11.5%,respectively,in POAG eyes.Over all examined eyes,the arteriolar SO2 and the retinal arterio-venous difference correlated significantly with the rim area.Conclusion:Eyes with NTG showed significantly decreased arteriolar SO2.These changes were not seen in POAG patients.

视网膜血管的远程医疗筛查技术(“能说话的眼”)

Background: Cerebral and retinal vessels behave similarly under the influence of vascular risk factors. Several groups have shown that retinal microvascular abnormalities represent an independent risk factor with regard to strokes and heart attacks. Aim of the Study: The aim of this study was to perform a prospective screening examinationwith regard to retinalmicrovascular abnormalities as well as an extended vessel diagnosis in a subgroup of patients with lower arteriovenous risk values. Methods: In the course of a prospective cross-sectional study (“Talking Eyes”) between 1.9.2001 and 1.8.2002 a telemedical-supported screening of the retina (study 1) was carried out in 7,163 subjects. The patients were selected without any inclusion or exclusion criteria. The mean age was 48.2±8 years (18-83 years) with a sex distribution of 39.2%females to 60.8%males. Digital fundus photos of the right and left eyes were taken for all patients. The pictures were taken without pupil dilation using a CANON-NM camera. The pictures and case histories were stored in a central server using web-based software (MedStage, Siemens). In a central reading centre, the arteriovenous ratio of both eyes was determined telemedically using the Parr-Hubbard formula and the retinas subjected to a standardised examination by an ophthalmologist. The retinal risk factor was calculated on the basis of the arteriovenous ration, the presence of microvascular abnormalities and the case history. The reproducibility of measurement of the arteriovenous ratio (Kronbach alpha coefficient) was evaluated by double measurements on 1,332 images. In a subgroup of study 1 with arteriovenous ratio values < 0.76 (N=107), an extended vessel diagnosis with measurement of 24-h blood pressure and vessel-relevant blood values (homocysteine, cholesterol, LDL, HDL, CRP, TG, HbA1c) was carried out (study II). Results: Study 1: The Kronbach alpha coefficient as a measure of reproducibility amounted to 0.77. The mean arteriovenous ratio of the retinal vessels was 0.83±0.09 and showed a pronounced age dependence (R=0.9, p< 0.0001). On multivariate testing the arteriovenous ratio correlated significantly (R=0.33, p< 0.001) with the factors age, systolic blood pressure, diastolic blood pressure and body mass index. Diastolic blood pressure followed by age had the largest influence. The prevalence of microvascular abnormalities in the right (RE) and left (LE)-eyes, respectively were: cotton wool foci RE 0.0015%, LE 0.003%, retinal haemorrhage RE 0.1%, LE 0.1%, focal stenoses RE 3.4%, LE 3.4%, tortuositas vasorumRE 4.1%, LE 4.0%, arteriovenous crossing signs RE 11.2%, LE 11.2%. On multivariate testing the occurrence of microvascular abnormalities correlated significantly (R=0.38, p < 0.001) with the factors high blood pressure known from case history, body mass index, and gender. Arterial hypertension had the strongest influence followed by diastolic blood pressure. The calculated retinal risk factor correlated with the prevalence of angina pectoris. Study 11: 2/3 of the subjects with arteriovenous risk factor values < 0.76 exhibited pathologically high 24-h blood pressure values. For these patients there were significant correlations between the arteriovenous ratio and the low-density lipoprotein concentration as well as the Framingham risk score. Conclusion: In the course of a prospective, telemedical-supported screening examination of the retinal vessels of more than 7,000 subjects the arteriovenous ratio exhibited a strong dependence on age and blood pressure. Among the subjects with lowered arteriovenous ratio values, 2/3 exhibited arterial hypertension in the 24-h blood pressure determination.