Reading deficits in diabetic patients treated with panretinal photocoagulation and good visual acuity

PurposePatients with proliferative diabetic retinopathy (PDR) treated with panretinal photocoagulation (PRP) can have abnormal visual functioning that may be missed by Snellen visual acuity alone. We investigated reading deficits in patients treated with PRP for PDR using the Minnesota reading (MNREAD) test.MethodsThirty patients treated with PRP and 15 controls underwent best‐corrected visual acuity (BCVA), the MNREAD, frequency doubling perimetry (FDP), and fundus photography. Panretinal photocoagulation (PRP)‐treated subjects were compared to controls on MNREAD results by two‐sample t‐tests and Wilcoxon tests and Pearson correlations were used to assess the association between performance on MNREAD and other central visual function tests within PRP subjects.ResultsPanretinal photocoagulation (PRP)‐treated patients had reduced MNREAD acuity (p < 0.0001) and increased critical print size (p = 0.01) compared to controls but not a significantly reduced maximum reading speed (p = 0.06). Logmar MNREAD acuity was strongly positive correlated with logMAR BCVA (r = 0.58, p = 0.0098) and strongly negatively correlated with FDP foveal threshold (r = −0.63, p = 0.0030). Maximum reading speed was positively correlated with FDP foveal threshold (r = 0.57, p = 0.0143) and FDP mean deviation (r = 0.51, p = 0.0432). Visual acuity did not correlate with the sensitivities on the FDP.ConclusionThe MNREAD test reveals that PRP reduces reading ability and other aspects of macular function, and thus provides new understanding of how vision‐related quality of life is impaired. These findings may lead to improved means to evaluate and enhance vision following treatment for PDR.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152016/1/aos14097.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152016/2/aos14097_am.pd

High frequency surface acoustic wave resonator-based sensor for particulate matter detection

This paper describes the characterization of high frequency Surface Acoustic Wave Resonator-based (SAWR) sensors, for the detection of micron and sub-micron sized particles. The sensor comprises two 262 MHz ST-cut quartz based Rayleigh wave SAWRs where one is used for particle detection and the other as a reference. Electro-acoustic detection of different sized particles shows a strong relationship between mass sensitivity (Δf/Δm) and particle diameter (Dp). This enables frequency-dependent SAWR sensitivity to be tailored to the size of particles, thus making these types of sensors good candidates for PM10, PM2.5 and ultrafine particle (UFP) detection. Our initial characterisation demonstrated a typical SAWR frequency shift of 60 Hz in response to a deposition of ca. 0.21 ng of 0.75 μm-sized gold particles (∼50 particles) on sensor’s surface. Sensor responses to different size particles, such as ∼30 μm diameter silicon, gold (diameters of ∼0.75 μm and ∼20 μm), ∼8 μm fine sugar, PTFE (∼1 μm and ∼15 μm), ∼4 μm talcum powder, and ∼2 μm molybdenum powder were evaluated, and an average mass sensitivity of 275 Hz/ng was obtained. Based on the results obtained in this study we believe that acoustic wave technology has great potential for application in airborne particle detection. Moreover, acoustic resonator devices can be integrated with CMOS interface circuitry to obtain sensitive, robust, low-power and low-cost particle detectors for variety of applications including outdoor environmental monitoring

Measurements of the Diffuse Ultraviolet Background and the Terrestrial Airglow with the Space Telescope Imaging Spectrograph

Far-UV observations in and near the Hubble Deep Fields demonstrate that the Space Telescope Imaging Spectrograph (STIS) can potentially obtain unique and precise measurements of the diffuse far-ultraviolet background. Although STIS is not the ideal instrument for such measurements, high-resolution images allow Galactic and extragalactic objects to be masked to very faint magnitudes, thus ensuring a measurement of the truly diffuse UV signal. The programs we have analyzed were not designed for this scientific purpose, but would be sufficient to obtain a very sensitive measurement if it were not for a weak but larger-than-expected signal from airglow in the STIS 1450-1900 A bandpass. Our analysis shows that STIS far-UV crystal quartz observations taken near the limb during orbital day can detect a faint airglow signal, most likely from NI\1493, that is comparable to the dark rate and inseparable from the far-UV background. Discarding all but the night data from these datasets gives a diffuse far-ultraviolet background measurement of 501 +/- 103 ph/cm2/sec/ster/A, along a line of sight with very low Galactic neutral hydrogen column (N_HI = 1.5E20 cm-2) and extinction (E(B-V)=0.01 mag). This result is in good agreement with earlier measurements of the far-UV background, and should not include any significant contribution from airglow. We present our findings as a warning to other groups who may use the STIS far-UV camera to observe faint extended targets, and to demonstrate how this measurement may be properly obtained with STIS.Comment: 7 pages, Latex. 4 figures. Uses corrected version of emulateapj.sty and apjfonts.sty (included). Accepted for publication in A

Atomic position localization via dual measurement

We study localization of atomic position when a three-level atom interacts with a quantized standing-wave field in the Ramsey interferometer setup. Both the field quadrature amplitude and the atomic internal state are measured to obtain the atomic position information. It is found that this dual measurement scheme produces an interference pattern superimposed on a diffraction-like pattern in the atomic position distribution, where the former pattern originates from the state-selective measurement and the latter from the field measurement. The present scheme results in a better resolution in the position localization than the field-alone measurement schemes. We also discuss the measurement-correlated mechanical action of the standing-wave field on the atom in the light of Popper's test.Comment: 6.5 pages and 5 figure

Impaired Retinal Vasoreactivity: An Early Marker of Stroke Risk in Diabetes

Diabetes is a common cause of small vessel disease leading to stroke and vascular dementia. While the function and structure of large cerebral vessels can be easily studied, the brain’s microvasculature remains difficult to assess. Previous studies have demonstrated that structural changes in the retinal vessel architecture predict stroke risk, but these changes occur at late disease stages. Our goal was to examine whether retinal vascular status can predict cerebral small vessel dysfunction during early stages of diabetes. Retinal vasoreactivity and cerebral vascular function were measured in 78 subjects (19 healthy controls, 22 subjects with prediabetes, and 37 with type‐2 diabetes) using a new noninvasive retinal imaging device (Dynamic Vessel Analyzer) and transcranial Doppler studies, respectively. Cerebral blood vessel responsiveness worsened with disease progression of diabetes. Similarly, retinal vascular reactivity was significantly attenuated in subjects with prediabetes and diabetes compared to healthy controls. Subjects with prediabetes and diabetes with impaired cerebral vasoreactivity showed mainly attenuation of the retinal venous flicker response. This is the first study to explore the relationship between retinal and cerebral vascular function in diabetes. Impairment of venous retinal responsiveness may be one of the earliest markers of vascular dysfunction in diabetes possibly indicating subsequent risk of stroke and vascular dementia.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/136050/1/jon12412.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/136050/2/jon12412_am.pd

Particle Sensor Using Solidly Mounted Resonators

This paper describes the development of a novel particle sensing system employing zinc oxide based solidly mounted resonator (SMR) devices for the detection of airborne fine particles (i.e., PM2.5 and PM10). The system operates in a dual configuration in which two SMR devices are driven by Colpitts-type oscillators in a differential mode. Particles are detected by the frequency shift caused by the mass of particles present on one resonator with while the other acts as a reference channel. Experimental validation of the system was performed inside an environmental chamber using a dust generator with the particles of known size and concentration. A sensor sensitivity of 4.6 Hz per μg/m3 was demonstrated for the SMRs resonating at a frequency of 970 MHz. Our results demonstrate that the SMR-based system has the potential to be implemented in CMOS technology as a low-cost, miniature smart particle detector for the real-time monitoring of airborne particles