Structural abnormalities associated with glaucoma using swept-source optical coherence tomography in patients with systemic sclerosis

PurposeVasospasm represents an early event in systemic sclerosis (SSc). Ocular vasospasm may induce optic nerve head (ONH) damage and has been involved in the pathogenesis of glaucoma, especially normal-tension glaucoma (NTG). We aimed to investigate the presence of structural abnormalities associated with NTG using swept-source optical coherence tomography (SS-OCT) and to correlate the OCT parameters with clinical, capillaroscopy and digital blood flow measures in patients with SSc. MethodsIn this cross-sectional study, 40 patients with SSc and 23 age-matched controls were included. The following parameters were measured using SS-OCT: mean and sectoral retinal nerve fiber layer (RNFL) thickness, macular ganglion cell layer complex (GCC) thickness and ONH morphology. Nailfold capillaroscopy (NFC) and digital blood flow measurements using laser Doppler imaging (LDI) were performed in all subjects. ResultsPatients with SSc showed a thinner temporal RNFL than the controls (69.23 ± 11.74 versus 83.35 ± 20.19 µm, p=0.001). The other parameters were similar between the two groups. In SSc patients, there was an inverse correlation between the disease duration and the average, superior and inferior RNFL thickness and the GCC thickness and between Raynaud’s phenomenon duration and the average RNFL and GCC thickness (p<0.05). NFC and LDI measurements did not show correlations with OCT parameters.ConclusionA thinner temporal RNFL and the correlation between Raynaud’s phenomenon and disease duration and structural abnormalities on OCT suggest the presence of early ganglion cell damage in patients with SSc. Although mild, these findings indicate the need to monitor ocular abnormalities in SSc.

Caffeine consumption does not have an effect on digital microvascular perfusion assessed by laser doppler imaging on healthy volunteers: a pilot study

Caffeine is one of the most commonly consumed pharmacologically active ingredients in the Western world. It is postulated to cause peripheral vasoconstriction and decreased digital blood flow. As a result, many hand surgeons forbid caffeine consumption post-operatively by patients undergoing replantation surgery for fear of compromising healing. We hypothesized that caffeine has no effect on digital microvascular perfusion. Healthy volunteers were recruited and digital microperfusion was assessed using laser Doppler probes attached to the finger pulp, both before and after ingestion of 100 mg of caffeine. A total of 34 patients were included in the final study. The mean flow before the consumption of caffeine was 226.15 PU. The mean flow following the consumption of caffeine was 197.7 PU. This decrease was not statistically significant. This study revealed no decrease in digital blood flow following the ingestion of 100 mg of caffeine by healthy volunteers, as measured by laser Doppler flow monitoring. Level of Evidence: 3

Diagnosis of Raynaud’s Phenomenon by 99mTc-Hydroxymethylene Diphosphonate Digital Blood Flow Scintigraphy After One-hand Chilling

Objective.We introduce the use of 99mTc-hydroxymethylene diphosphonate (HDP) digital blood flow scintigraphy to diagnose Raynaud’s phenomenon (RP).Methods.Fifty-seven patients with RP and 60 healthy controls were recruited. One hand was chilled by immersion into water at 4°C, and then an intravenous bolus of 740 MBq of 99mTc-HDP was injected. The radioactivity from the second to the fifth fingers of both hands was recorded. Acquisition was performed at a rate of one frame per 2 seconds until 155 frames. We calculated 4 ratios by comparing the activity curves of the chilled hand with those of the ambient hand.Results.The chilled to ambient hand ratio of the initial slope was significantly lower in the patients with RP (0.28 ± 0.18) than in the controls (0.78 ± 0.20) (p < 0.001). The chilled to ambient hand ratio of the first peak height, 30-second area under the curve, and blood pool uptake were also lower in the patients with RP than in controls (p < 0.001 for each). The initial slope ratio of 0.51, used as a cutoff value, showed a sensitivity of 91.2% and specificity of 93.3%. The loss of the initial spike curve, the presence of a slowly progressing radioactivity curve, and the inhomogeneous radioactivity uptake in the blood pool image in either hand were characteristic findings of the patients with RP (p < 0.001).Conclusion.99mTc-HDP digital blood flow scintigraphy after one-hand chilling is a noninvasive, accurate, and quantitative method to evaluate RP.