UNASSIGNED: To develop a noninvasive technique to quantitatively assess the pulsatile deformation due to cardiac contractions of the optic nerve head (ONH).
UNASSIGNED: Evaluation of a diagnostic test or technology.
UNASSIGNED: Healthy subjects with no history of refractive surgery, divided into 2 cohorts on the basis of their axial length (AL).
UNASSIGNED: We present a noninvasive technique to quantitatively assess the pulsatile deformation of the ONH tissue by combining high-frequency OCT imaging and widely available image processing algorithms. We performed a thorough validation of the approach, numerically and experimentally, evaluating the sensitivity of the method to artificially induced deformation and its robustness to different noise levels. We performed deformation measurements in cohorts of healthy (n = 9) and myopic (n = 5) subjects in different physiological strain conditions by calculating the amplitude of tissue displacement in both the primary position and abduction. The head rotation was measured using a goniometer. During imaging in abduction, the head was rotated 40° ± 3°, and subjects were instructed to direct their gaze toward the OCT visual target.
UNASSIGNED: Pulsatile tissue displacement maps.
UNASSIGNED: The robustness of the method was assessed using artificial deformations and increasing noise levels. The results show acceptable absolute errors before the noise simulations grossly exaggerate image degradation. For the group of subjects with AL of < 25 mm (n = 9), the median pulsatile displacement of the ONH was 7.8 ± 1.3 μm in the primary position and 8.9 ± 1.2 μm in abduction. The Wilcoxon test showed a significant difference (P ≤ 0.005) between the 2 paired measures. Reproducibility was tested in 2 different sessions in 5 different subjects with the same intraocular pressure, and an intraclass correlation coefficient of 0.99 was obtained (P < 0.005).
UNASSIGNED: The computational pipeline demonstrated good reproducibility and had the capacity to accurately map the pulsatile deformation of the optic nerve. In a clinical setting, we detected physiological changes in normal subjects supporting its translation potential as a novel biomarker for the diagnosis and progression of optic nerve diseases.

BACKGROUND: The diagnosis of allergic contact dermatitis should be confirmed by skin patch tests. Distinguishing between irritant and allergic reactions is sometimes difficult.
OBJECTIVE: To analyse the in vivo morphological changes in patch test reactions compared to healthy skin, and to detect subclinical changes in doubtful reactions using optical coherence tomography (OCT). To develop an OCT-based algorithm to support patch-test grading.
METHODS: One hundred twenty-nine skin patch-test areas were scanned with OCT to evaluate the following features: architectural and vascular morphology, epidermal thickness, optical attenuation coefficient (AC), and blood flow at 0.1, 0.2, and 0.35 mm depth.
RESULTS: Most common OCT features of acute contact allergic reactions in patch tests were spongiosis with microvesicles (94.8%), macrovesicles (60.3%), and coalescing vesicles (46.6%), the latter useful in differentiating acute allergic from irritant dermatitis (P-value < .05). Objective quantitative parameters correlated well with the severity grade: epidermal thickness due to spongiosis, AC (P-value < .05) and blood flow at 0.2 and 0.35 mm (P-value < .01).
CONCLUSIONS: OCT as a noninvasive diagnostic tool, established for skin cancer diagnosis, is useful for evaluating contact allergic patch-test reactions. Not only morphological but also objective features such as blood flow and AC correlate with the reaction severity. Further studies are needed to explore the differences in irritant and allergic contact dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory disease. Recently, dupilumab was approved for moderate-to-severe AD. D-OCT is a noninvasive tool for the characterization of skin diseases.
OBJECTIVE: To describe the changes observed with D-OCT in lesional and clinically healthy skin of patients with refractory severe AD under dupilumab treatment.
METHODS: We analyzed AD lesions and healthy skin by D-OCT. Clinical scores of AD severity were assessed at baseline (T0) and after 1 and 3 months of treatment (T1, T2). Descriptive statistics, chi-square test, and t test were used to compare the analyzed parameters over time and between AD lesions and clinically healthy skin.
RESULTS: At baseline, average EASI was 45.7. During the follow-up, EASI75 and EASI90 were achieved in 57% and 36% of patients at T1 and 100% and 86% of patients at T2, respectively. Lesional skin D-OCT parameters related to epidermal remodeling and inflammation evidenced a significant improvement after 1 month of treatment. In clinically healthy skin, D-OCT parameters improved significantly after 3 months of treatment, especially for collagen remodeling and inflammation.
CONCLUSIONS: The study demonstrates that the clinical improvement of severe AD patients under dupilumab treatment is correlated with specific D-OCT changes of patients\' lesional and clinically healthy skin.