Repeatability of high-resolution laser Doppler images of the hands in patients with systemic sclerosis and secondary Raynaud's phenomenon.

OBJECTIVES: The objective of the study was to establish the repeatability of baseline diagnostic images of the dorsum of the hands acquired using a high-resolution laser Doppler imager in patients with Raynaud's phenomenon secondary to systemic sclerosis (SSc). METHODS: The dorsal side of the hands of 22 patients (8 male 14 female), age range 29-73, median 62, with SSc and secondary Raynaud's phenomenon were imaged over two consecutive days at approximately the same time using a Moor Instruments' high-resolution laser Doppler imaging unit. The images were analysed by taking regions of interest at discrete locations in the images to calculate dimensionless values of flux (PU). Repeatability of the diagnostic investigation was assessed using methods described by Bland and Altman and by also plotting the results from visit 1 against visit 2 and calculating the line of best fit. RESULTS AND CONCLUSIONS: Based on the criteria that 95% of all measurement differences should be within a factor of 1.96 of the standard deviations of the mean values, then high-resolution laser Doppler imaging technique is probably repeatable when acquiring and analysing baseline images of patients with Raynaud's phenomenon secondary to SSc. However, a larger study with more patients is required to prove this conclusively-as only data from 19 patients were analysed (3 patients were not included due to technical issues)-and was therefore susceptible to marked clinical variations in patients presenting on different days for the investigations.

An investigation of different types of eyewear and face shields in protecting patients and operators from the harmful effects of ultraviolet radiation.

BACKGROUND: Phototherapy and photochemotherapy are commonly used treatment modalities for a range of chronic skin conditions. Whilst undergoing ultraviolet radiation exposure, patients can wear personal protective equipment. Face shields in combination with other forms of skin cover may be worn to provide both skin and eye protection. There are a number of different types of eyewear and face shields available for purchase. Some of these have clear identifications that show the levels of protection provided whilst others may not have any. METHODS: A series of similar experiments has been undertaken independently at two phototherapy treatment centres-Chapel Allerton Hospital, Leeds and Ninewells Hospital, Dundee-to investigate the effectiveness of different face shields and eye protection that are available for purchase in the United Kingdom (UK). Two similar examples of one face shield were tested at both centres, and another was transferred between the units. RESULTS: Not all examples of the face shields and protective eyewear provided the wearer full protection between 300 nanometres and 400 nanometres (nm). Cost and conformance to different standards was not always a good indicator. Some inexpensive examples tested also met British Association of Dermatology protective sunglasses guidelines. CONCLUSIONS: It is incumbent on all centres to check the properties of protective face shields and eyewear provided to patients and operators to guard against the effects from ultraviolet radiation. There is no correlation between price of the protective equipment and level of protection offered, and there may be opportunity for cost savings.

A Multicenter Study of the Validity and Reliability of Responses to Hand Cold Challenge as Measured by Laser Speckle Contrast Imaging and Thermography: Outcome Measures for Systemic Sclerosis-Related Raynaud's Phenomenon.

OBJECTIVE: Reliable and objective outcome measures to facilitate clinical trials of novel treatments for systemic sclerosis (SSc)-related Raynaud's phenomenon (RP) are badly needed. Laser speckle contrast imaging (LSCI) and thermography are noninvasive measures of perfusion that have shown excellent potential. This multicenter study was undertaken to determine the reliability and validity of a hand cold challenge protocol using LSCI, standard thermography, and low-cost cell phone/mobile phone thermography (henceforth referred to as mobile thermography) in patients with SSc-related RP. METHODS: Patients with RP secondary to SSc were recruited from 6 UK tertiary care centers. The patients underwent cold challenge on 2 consecutive days. Changes in cutaneous blood flow/skin temperature at each visit were imaged simultaneously using LSCI, standard thermography, and mobile thermography. Measurements included area under the curve (AUC) for reperfusion/rewarming and maximum blood flow rate/skin temperature after rewarming (MAX). Test-retest reliability was assessed using intraclass correlation coefficients (ICCs). Estimated latent correlations (estimated from multilevel models, taking values between -1 and 1; denoted as rho values) were used to assess the convergent validity of LSCI and thermography. RESULTS: In total, 159 patients (77% with limited cutaneous SSc) were recruited (84% female, median age 63.3 years). LSCI and standard thermography both had substantial reliability, with ICCs for the reperfusion/rewarming AUC of 0.67 (95% confidence interval [95% CI] 0.54, 0.76) and 0.68 (95% CI 0.58, 0.80), respectively, and ICCs for the MAX of 0.64 (95% CI 0.52, 0.75) and 0.72 (95% CI 0.64, 0.81), respectively. Very high latent correlations were present for the AUCs of LSCI and thermography (ρ = 0.94; 95% CI 0.87, 1.00) and for the AUCs of standard and mobile thermography (ρ = 0.98; 95% CI 0.94, 1.00). CONCLUSION: This is the first multicenter study to examine the reliability and validity of cold challenge using LSCI and thermography in patients with SSc-related RP. LSCI and thermography both demonstrated good potential as outcome measures. LSCI, standard thermography, and mobile thermography had very high convergent validity.

Variability of pulsed energy outputs from three dermatology lasers during multiple simulated treatments.

BACKGROUND: Dermatology laser treatments are undertaken at regional departments using lasers of different powers and wavelengths. In order to achieve good outcomes, there needs to be good consistency of laser output across different weeks as it is custom and practice to break down the treatments into individual fractions. Departments will also collect information from test patches to help decide on the most appropriate treatment parameters for individual patients. OBJECTIVES: The objective of these experiments is to assess the variability of the energy outputs from a small number of lasers across multiple weeks at realistic parameters. METHODS: The energy outputs from 3 lasers were measured at realistic treatment parameters using a thermopile detector across a period of 6 weeks. RESULTS: All lasers fired in single-pulse mode demonstrated good repeatability of energy output. In spite of one of the lasers being scheduled for a dye canister change in the next 2 weeks, there was good energy matching between the two devices with only a 4%-5% variation in measured energies. CONCLUSIONS: Based on the results presented, clinical outcomes should not be influenced by variability in the energy outputs of the dermatology lasers used as part of the treatment procedure.