A novel photoplethysmography technique to derive normalized arterial stiffness as a blood pressure independent measure in the finger vascular bed.

Stiffening of the small artery may be the earliest sign of arteriosclerosis. However, there is no adequate method for directly assessing small arterial stiffness. In this study, the finger arterial elasticity index (FEI) was defined as the parameter n which denotes the curvilinearity of an exponential model of pressure (P)-volume (V(a)) relationship (V(a) = a - b exp (-nP)). For the original estimation, the FEI was calculated from a compliance index from the finger photoplethysmogram whilst occluding the finger. A simple estimation of the FEI was devised by utilizing normalized pulse volume instead of the compliance index. Both estimations yielded close agreement with the exponential model in healthy young participants (study 1: n = 19). Since the FEI was dependent on finger mean blood pressure, normalized finger arterial stiffness index (FSI) was defined as standardized residual from their relationship: mean and standard deviation (SD) of the FSI were 50 ± 10 (study 2: n = 174). The mean coefficient of variation of the FSI for four measurements was 5.72% (study 3: n = 6). The mean and SD of the FSI in seven arteriosclerotic patients were 100.0 ± 13.5. In conclusion, the FEI and FSI by simple estimation are valid and useful for arteriosclerosis research.

Ocular blood flow levels and visual prognosis in a patient with nonischemic type central retinal vein occlusion.

We look at the case of a 39-year-old female patient suffering from a sudden decrease in her left visual acuity (0.08). Her macular edema was examined using optical coherence tomography, and her optic disc blood flow was examined with laser speckle flowgraphy (LSFG). Additionally, the degree of seriousness of the central vein occlusion was evaluated through fluorescein angiography (FA). Ocular fundus findings revealed central vein occlusion associated with macular edema, and FA determined her disease type as a nonischemic-central vein occlusion. Daily doses of 100 mg of aspirin were administered orally to the patient. Upon administration, her ocular blood flow almost immediately increased. In this study, we demonstrate the potential of LSFG as a means to investigate ocular blood flow.

[Examination of the optic nerve head blood flow in patients with proliferative diabetic retinopathy treated with vitrectomy].

PURPOSE: To evaluate the optic nerve head blood flow level of a patient with proliferative diabetic retinopathy before and after vitrectomy, using laser speckle flow graphy (LSGF) for noninvasively ocular blood flow analysis. METHODS: Twenty three eyes of 23 patients were recruited in the present study who underwent vitrectomy at Sapporo Medical University hospital. We measured optic nerve head blood flow before and 2 weeks after operation. The average blood pressure and ocular perfusion pressure were measured before and after surgery. RESULTS: Blood flow in the central retinal artery and on both the nasal and temporal sides of the optic nerve head significantly increased after surgery in all cases. In cases where the post-operative blood flow in the optic disk temporal side increased by more than 59%, visual acuity was also ameliorated. CONCLUSION: LSFG is an effective method for evaluating the optic nerve head blood flow noninvasively, and may be useful for prediction of postoperative visual acuity prognosis.

Analysis of sFas IL-6 levels in thyroid-associated ophthalmopathy: Pre- or poststeroid pulse treatment.

PURPOSE: To investigate whether serum levels of soluble Fas (sFas) and interleukin-6 (IL-6) could function as an index of the efficacy of steroid pulse treatment, we examined the serum level of these proteins before and after steroid pulse treatment in thyroid-associated ophthalmopathy patients. METHODS: We gathered the blood of thyroid-associated ophthalmopathy patients before or after steroid pulse treatment, obtained serum with a centrifuge, and measured the serum levels of sFas and IL-6 by enzyme-linked immunosorbent assay (ELISA). RESULTS: There was no difference in serum IL-6 value between pre- and poststeroid pulse treatment. Serum sFas value was significantly decreased in both pre- and poststeroid pulse treatment. Furthermore, there was a recognizable improvement in the degree of the extraocular muscle thickening after treatment in cases in whom the serum sFas value was lower than 3 ng/ml prior to the beginning of the therapy. In patients who had a serum sFas value of more than 3 ng/ml, there was no improvement in the degree of thickening of the extraocular muscle. CONCLUSIONS: Serum level of sFas is an accurate index of the outcome of steroid pulse treatment in thyroid-associated ophthalmopathy and may become a useful index to gauge the status of convalescence.