Three-dimensional optical coherence tomography of proliferative diabetic retinopathy.

Fourier-domain optical coherence tomography (OCT) was used to image the three-dimensional (3D) structures of the proliferative membrane in proliferative diabetic retinopathy. The case of a 51-year-old man with retinal detachment of the macula in his left eye is reported. The proliferative membrane covered the entire macular area. In the OCT image, the 3D structure of the proliferative membrane could be clearly visualised. The OCT image showed the presence of multiple adhesions between the retina and the proliferative membrane and separation of the proliferative membrane. The patient underwent three-port vitrectomy, and the extent and locations of the adhesions corresponded well with the findings during vitrectomy. Three-dimensional OCT is an effective tool for understanding the 3D structure of the proliferative membrane in diabetic retinopathy and is useful for training and planning of the surgical procedures in vitrectomy. To view the full report and accompanying video please go to: http://bjo.bmj.com/cgi/content/full/92/5/713/DC1. All videos from the BJO video report collection are available from: http://bjo.bmj.com/video/collection.dtl.

Spectral interferometric optical coherence tomography with nonlinear beta-barium borate time gating.

A high-speed, all optical coherence tomography system was designed and constructed. This tomography system employs spectral interferometry and optical Fourier transformation to reduce the number of mechanical scanning dimensions required for multidimensional profilometry. The system also employs a time gate comprising a beta -barium borate crystal driven by a femtosecond laser pulse to improve measurement time. This system has 43-mum depth resolution and 150-fs temporal resolution and is capable of taking 1000 cross-sectional image frames per second.

Birefringence imaging of human skin by polarization-sensitive spectral interferometric optical coherence tomography.

We have developed a spectral interferometric optical coherence tomography (OCT) system with polarization sensitivity that is able to measure a two-dimensional tomographic image by means of one-dimensional mechanical scanning. Our system, which has an axial resolution of 32 mum , calculates the distribution of each element of the Müller matrix of a measured object from 16 OCT images. The OCT system successfully reveals the birefringent nature of human skin tissue.

Phase-resolved correlation and its application to analysis of low-coherence interferograms.

A new signal-processing technique is proposed that involves a phase-resolved correlation method that one can use to determine the phase distribution of low-coherence interferograms. This method improves the sensitivity and resolution of low-coherence interferometers. The depth structure of an aluminum oxide-coated aluminum mirror was determined by use of a low-coherence interferometer with this method. Three signal peaks were successfully extracted from a noisy interferogram.

Occlusive arterial diseases of the upper and lower extremities found in workers occupationally exposed to vibrating tools.

Hand-arm vibration syndrome (HAVS) is primarily a disorder of the fingers and hands. However, in some cases, vibration-exposed workers are observed to have also episodic blanching of the hands and feet. In latter cases, arteriographies of both the upper and lower extremities are necessary to diagnose the background arterial disorders. In this study, eight HAVS subjects with such disorders were examined by arteriography for differential diagnosis in cases of workers' accident compensation. In three HAVS cases with thromboangiitis obliterans, the arteriographic examination revealed obstructive changes in the palm and forearm as well as three below-knee lesions in the lower extremities. In five HAVS cases with arteriosclerosis obliterans, obstruction kinking or coiling, stenosis and/or tapering-off of the proper digital arteries were observed together with two below-knee lesions and three high lesions in the lower extremities. From the viewpoint of occupational health, palpation of superficial arteries of both the upper and lower extremities should be routinely performed during both pre-placement and periodic medical examinations for workers exposed to vibrating tools for early detection and/or prevention of any worsening of the background disorders.

A new monitor with a zinc-oxide thin film semiconductor sensor for the measurement of volatile sulfur compounds in mouth air.

Halitosis, defined as unpleasant oral odor, is a concern among the general public. Halitosis is generally diagnosed by organoleptic examination and by gas chromatographic analysis of the main source of halitosis, volatile sulfur compounds, such as hydrogen sulfide, methyl mercaptan, and dimethyl sulfide. Gas chromatography requires a large-scale system and a long running time. We investigated the use of a zinc-oxide thin film semiconductor sensor for measuring trace volatile sulfur compounds in mouth air. Mouth air samples collected in teflon bags from 21 volunteers were analyzed by 3 methods: the monitor analysis, gas chromatography, and organoleptic examination by 3 judges. The readings of the monitor were correlated with the values of the total volatile sulfur compounds measured by gas chromatography (r = 0.75, P < 0.01) and also with the organoleptic scores given by the judges (r = 0.76, P < 0.01). The organoleptic scores were correlated with the gas chromatographic values (r = 0.71, P < 0.01). These results suggest that this new monitor with a zinc-oxide thin film semiconductor sensor may be used for the diagnosis of halitosis. Its small size and simplicity of handling may enable its use for routine chair-side study and field surveys of halitosis.

Re-evaluation of capillaroscopy of finger nailfold in vibration-exposed workers.

Two hundred and ninety-four vibration-exposed workers were examined for vibration disease (VD) for the worker's accident compensation. Most subjects were male. Their ages ranged from 24 to 68 years. Duration of vibration exposure ranged from 3 to 30 years. After acclimatization at 25 degrees C to 27 degrees C for at least an hour, the nailfold capillaries of the ring (or middle) finger were studied with a light microscope. A cold water immersion test (5 degrees C, 10 min) was then performed. The morphological findings of the nailfold capillaries were classified based on the criteria by Fagrell & Lundberg. A hundred and eighty subjects were diagnosed as VD and 75 as non VD, even without taking the capillaroscopic findings into consideration. The classification of the capillarograms retrospectively investigated were as follows, i.e. in 98 VD subjects 40 cases were stage A, 42 stage B, and 16 cases stage C. In 26 nonVD subjects 13 cases were stage A, 10 stage B, and 3 cases stage C, respectively. When the borderline of VD and nonVD existed between stage A and stages B and C, the sensitivity was 59.2%, specificity was 50.0%, and false positive and negative were 50.0% and 40.8%. Relationship between the capillary stage and recovery (%) of the skin temperature during the cold water immersion test was also studied. The recovery in stage C was not always lower than that in stage A. Among them, arteriography was performed in 57 cases. Despite the use of vasodilator, markedly delayed perfusion of the finger tips was observed in 28 cases. Their capillary stages were A in 12 cases, B in 11 and C in 3. The peripheral microcirculatory state in VD should be carefully evaluated in combination with appropriately selected examinations, including finger nailfold capillaroscopy.

Clinical characteristics of halitosis: differences in two patient groups with primary and secondary complaints of halitosis.

Halitosis, defined as an unpleasant oral odor, has become a health concern among the general public. The objective of this study was to evaluate the diversity of clinical characteristics of halitosis of the patients who visited dental clinics. Sixty-eight patients with primary complaints of halitosis and 19 patients with primary complaints of periodontal diseases but secondary complaints of halitosis were studied by organoleptic examination. The patients with primary complaints were diagnosed as having halitosis in fewer cases than the patients with secondary complaints-25% and 53%, respectively. Patient complaints for halitosis were further categorized, by questionnaire, into three types: Type 1, self-conscious; Type 2, conscious by the indication of others; and Type 3, conscious by presumptions from the attitude of others. Although 80% of the patients of both groups were of Type 1, only 24.1% of the Type 1 patients with primary complaint, in comparison with 50% of the Type 1 patients with secondary complaint, were actually found to have halitosis. The results suggest that the majority of patients with primary complaints of halitosis at the dental clinic did not actually have halitosis, but suffered from an imaginary halitosis due to presumptions based upon others' attitudes. After treatment, these patients were more likely to be dissatisfied than patients who had visited the clinic with halitosis as their secondary complaint.

Hypothenar hammer syndrome in workers occupationally exposed to vibrating tools.

Among 330 vibration-exposed workers, 24 cases of hypothenar hammer syndrome in 29 hands were diagnosed by arteriography. The right hand was involved in 13, the left hand in six, and both hands in five cases. The mean age was 55 years, mean duration of vibration exposure 19.4 years, and mean duration of episodic Raynaud's phenomenon 6.4 years. The vascular lesions of the ulnar arteries were classified into three major types with subtypes. Type 1: stenosis of the superficial palmar arch around the hook of the hamate. Type 2a: occlusion of the superficial palmar arch around the hook of the hamate. Type 2b: occlusion of both superficial and deep palmar arches around the hook of the hamate. Type 3a: occlusion of the ulnar artery at the proximal part of the wrist. Type 3b: occlusion of the ulnar artery near the wrist with the occlusion of the dorsal carpal branch of the ulnar artery.

Construction of a composite thin-element TLD using an optical-heating method.

A composite thermoluminescent dosimeter (TLD), composed of four, thin TL elements with a high-speed reader, has been developed by employing an optical-heating method. Each TL element, which is 15 mg/cm2 thick with a 3 mm dia., is prepared by applying Li2B4O7:Cu or CaSO4:Tm to a plastic substrate 14 mg/cm2 thick. Each element can be heated to 350 degree C within 0.8 sec. by IR radiation from a tungsten lamp. The characteristics of this TLD system include the following: (1) the detection limit of the Li2B4O7:Cu is 3 mR and the limit for CaSO4:Tm is 0.1 mR; (2) the energy-dependence curves are similar to the dose-equivalent curve, showing slight under-responses by 15% near 70 KeV for Li2B4O7:Cu and over-responses by 50% at high energies for CaSO4:Tm; (3) despite quick heating, the residual dose is as low as 0.1% of the last exposure signal; (4) responses are very stable for more than 1,000 cycles of repeated exposure readings; (5) no false signal could be detected, even in the cases of sweat or soil contamination; (6) the thin Li2B4O7;Cu element can be used for skin dose monitoring; and (7) the processing time of the automatic reader for the composite dosimeter is 3 hr/500 dosimeters. This TLD system can be applied to personnel dosimetry, gate monitoring and environmental monitoring.