OBJECTIVE: To demonstrate the methodology and efficacy of using scanning laser ophthalmoscopy (SLO) and dynamic optical coherence tomography (OCT) to identify and treat symptomatic vitreous floaters using yttrium-aluminum garnet laser vitreolysis (YLV).
METHODS: This is a case series highlighted from a cross sectional retrospective study conducted at the Vitreous Retina Macula Specialists of Toronto. Forty eyes from thirty-five patients were treated with YLV between November 2018 and December 2020 for symptomatic floaters and imaged with SLO and dynamic OCT. Patients were re-treated with YLV if they reported ongoing significant vision symptoms during follow-up which correlated to visible opacities on exam and or imaging. Three cases will be highlighted to present the practical applications of SLO and dynamic OCT imaging for YLV treatment.
RESULTS: Forty treated eyes were enrolled in this study, with twenty-six eyes (65%) requiring at least one repeat YLV treatment following the first treatment due to ongoing symptomatic floaters. Following the first YLV, there was a significant improvement in overall mean best corrected visual acuity compared to before treatment (0.11 ± 0.20 LogMAR units vs. 0.14 ± 0.20 LogMAR units, p = 0.02 (paired t test)). Case 1 demonstrates a dense, solitary vitreous opacity that has been localized with dynamic OCT imaging to track its movements and retinal shadowing with the patient\'s eye movements. Case 2 shows the utility of adjusting the fixation target to monitor the movement of vitreous opacities in real-time. Case 3 exhibits an association between decreased symptom burden and vitreous opacity density after YLV.
CONCLUSIONS: Image-guided YLV facilitates the localization and confirmation of vitreous opacities. SLO and dynamic OCT of the vitreous can provide a real-time evaluation of floater size, movement, and morphology, to help clinicians target treatment and monitoring of symptomatic floaters.

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.

Malignant melanoma is an aggressive skin cancer, which can lead to metastasis development. Vascularization enhancement is fundamental for tumor growth, worsening the prognosis. Dynamic optical coherence tomography (D-OCT) enables the in vivo evaluation of vascular patterns in skin lesions.
In vivo evaluation of the melanoma vessel morphology by means of D-OCT and correlation with Breslow index.
Retrospective analysis of histologically proven melanomas, evaluated by D-OCT at three different depths (150, 300 and 500 μm), was performed. Vessels were classified according to morphology (dots, blobs, coiled, line, curved, serpiginous), distribution (regular, irregular) and the presence/type of branches. The data were correlated with Breslow thickness.
A total of 127 melanomas were evaluated. Dotted vessels were recorded at all depths, and their irregular distribution was associated with lesions thicker than 1.0 mm (from 75% to 91%), compared with thin ones (42%) at 150 μm (P = 0.031), and from 33% to 57% vs 18% at 300 μm (P = 0.021). Serpiginous and branching vessels with bulges were predominantly seen in melanomas thicker than 2 mm at 150 μm (from 14% to 27%, P < 0.001) and 300 μm of depth (from 36% to 54%, P < 0.001).
Background noise hampered vessel detection at 500 μm. No correlation with dermoscopy/histology.
Vascular pattern evaluation at 150 and 300 μm provided data on tumor microvascular asset and its pattern of progression in accordance with Breslow thickness. Since vascular progression is theoretically linked with tumor aggressiveness, the study of vascular pattern related with melanoma metastatization capability is warranted.

Acne is an inflammatory disease of the pilosebaceous unit, which can be investigated in vivo using reflectance confocal microscopy (RCM) and optical coherence tomography (OCT).
By means of RCM and OCT to identify morphological characteristics of acne that may be associated with clinical acne severity.
Patients with mild to moderate facial acne (n = 14, Investigators Global Assessment scale, IGA 1-3), and healthy participants (n = 7, IGA 0) were included in this explorative study. A total of 108 RCM image blocks and 54 OCT scans (each RCM and OCT image measuring 6 × 6 mm) were captured from lesional-, perilesional, and lesion-free skin areas. Acne lesions, infundibular regions of follicles and inflammation degree were compared in acne patients and healthy participants.
Combined use of RCM and OCT demonstrated infundibular morphology, acne lesions, and blood flow. RCM images of perilesional- and lesion-free skin in acne patients revealed follicle infundibula with hyperkeratinized borders and abundant keratin plugs, contrasting skin of healthy participants. Higher acne severity related to increased number of follicles with hyperkeratotic borders (P = 0.04) and keratin plugs (P = 0.006), increased infundibulum diameter (P < 0.001), increased density of inflammatory cells (P < 0.001), and blood flow (P = 0.03). Acne lesion morphology was not associated with acne severity.
Combined use of RCM and OCT elucidated distinctive follicle infundibulum characteristics and inflammation degree that were associated with acne severity. Future trials may apply imaging techniques to support clinical acne grading, and monitor treatment efficacy. Lasers Surg. Med. 51:104-113, 2019. © 2018 Wiley Periodicals, Inc.