MINIMAL OPTICAL COHERENCE TOMOGRAPHY B-SCAN DENSITY FOR RELIABLE DETECTION OF INTRARETINAL AND SUBRETINAL FLUID IN MACULAR DISEASES.

PURPOSE: To determine the minimal optical coherence tomography B-scan density for reliable detection of intraretinal and subretinal fluid. METHODS: Spectral domain optical coherence tomography raster scanning (Spectralis; Heidelberg Engineering, Heidelberg, Germany) using a scan field of 20° × 20° of 97 B-scans with an interscan distance (ISD) of 60 µm was performed in 150 eyes of 150 consecutive patients at monitoring visits for intravitreal anti-vascular endothelial growth factor therapy. Using custom software, every other B-scan was repeatedly deleted to generate additional data sets with an ISD of 120 µm (49 B-scans), 240 µm (25 B-scans), and 480 µm (13 B-scans). Two independent reviewers evaluated the data sets for the presence of cystoid spaces of intraretinal fluid and subretinal fluid. RESULTS: Treatment diagnoses were neovascular age-related macular degeneration (68.0%), macular edema secondary to retinal vein occlusion (20.7%), diabetic macular edema (10.7%), and other retinal diseases (4.0%). Using the source data sets with an ISD of 60 µm, intraretinal fluid was detected in 56.0%, subretinal fluid in 19.3%, and either/both in 68.7%. Compared with these results, the sensitivity of detection of intraretinal fluid and/or subretinal fluid using an ISD of 120 µm, 240 µm, and 480 µm was 99.0% (95% confidence interval, 94.7-100.0; P = 0.5), 97.1% (91.7-99.4; P = 0.1), and 87.4% (79.4-93.1; P = 0.0001), respectively. CONCLUSION: An increase of ISD up to 240 µm does not significantly impair the detection of treatment-relevant exudative retinal changes in monitoring during intravitreal therapy of macular diseases. These findings are relevant for the choice of optical coherence tomography B-scan density in both routine clinical care and interventional clinical studies.

Longitudinal Analysis of Drusen Volume in Intermediate Age-Related Macular Degeneration Using Two Spectral-Domain Optical Coherence Tomography Scan Patterns.

PURPOSE: To evaluate two different spectral-domain optical coherence tomography (SD-OCT) scan patterns in eyes with intermediate age-related macular degeneration (AMD) for the longitudinal assessment of drusen volume. METHODS: The data of 38 eyes of 38 AMD patients (age 69.97 ± 6.08 years) were included. The longitudinal drusen volume over 4 years was analyzed by annual SD-OCT raster scanning (field size 20 × 15°). Two raster scan patterns (A/B) differed in the distance between neighboring B-scans (240 vs. 30 µm) and in the number of averaged frames (4 vs. 15). RESULTS: The mean drusen volume at baseline was 0.213 ± 0.100 mm3 (pattern A) and 0.219 ± 0.103 mm3 (pattern B) (p = 0.937). Linear mixed-effect models showed no significant difference for the change within 4 years for both pattern A (p = 0.8) and pattern B (p = 0.8). CONCLUSIONS: The results indicate that the performance of interpolation algorithms may be sufficient to balance for less dense raster scanning with regard to quantification of longitudinal drusen volume, which can be used as a surrogate marker for AMD progression in future clinical trials.

LONGITUDINAL CHANGE OF OUTER NUCLEAR LAYER AFTER RETINAL PIGMENT EPITHELIAL TEAR SECONDARY TO AGE-RELATED MACULAR DEGENERATION.

PURPOSE: To investigate longitudinal changes of outer nuclear layer (ONL) thickness in patients with retinal pigment epithelium tears secondary to neovascular age-related macular degeneration. METHODS: This is an institutional retrospective interventional case series. Twenty-six eyes of 22 patients with retinal pigment epithelium tears identified between April 2009 and March 2015. The patients underwent intravitreal injection of anti-vascular endothelial growth factor agents as needed. Volume scans of optical coherence tomography at first diagnosis of tear (baseline) and after 12 months were analyzed. Outer nuclear layer was segmented, and average ONL thickness inside the tear area, at the border of the tear, and in areas outside the tear was measured. Change of ONL thickness. We also explored several factors for their association with ONL thinning including tear area, number of treatments, and the duration with persistent subretinal fluid. RESULTS: Thinning of ONL was found in all the investigated areas (P < 0.01, respectively). Among the investigated factors, larger tear area was associated with greater ONL thinning outside the tear area (standardized ß = -0.37, P = 0.030), and younger age was associated with greater ONL thinning inside the tear area (standardized ß = 0.37, P = 0.041). CONCLUSION: After an retinal pigment epithelium tear, thinning of ONL occurs in the area devoid of retinal pigment epithelium and also in adjacent areas. Few factors were predictive for the degree of ONL thinning. These results provide new insight in disease progression of this particular neovascular age-related macular degeneration subphenotype.

OCT Angiography-Based Detection and Quantification of the Neovascular Network in Exudative AMD.

Purpose: To investigate the potential of optical coherence tomography (OCT) angiography to detect and quantify the neovascular network in exudative AMD. Methods: Treatment-naïve eyes that were diagnosed with exudative AMD were prospectively examined by OCT angiography (OCT-A). The extent of the neovascular network was measured by three independent readers. Interclass-correlation coefficient and area overlap coefficients (OC) were calculated to assess locally precise agreement between measurements. As a reference for interreader agreement, the extent of the neovascular network was further measured on fluorescein angiography (FA) images. Results: A total of 31 eyes (27 patients, mean age 82.5 years, 15 female) were included in the study. Neovascularization subtype was classified as type I in 5, type II in 11, type III in 9, and mixed in 6 eyes, respectively. Interreader agreement for measurements of the neovascular network was 0.884 for OCT-A and 0.636 for FA. Overlap coefficient was 0.705 (interquartile [IQR]: 0.450-0.76) for OCT-A and 0.704 (IQR: 0.673-0.750) for FA, respectively. Area agreement was weaker in type III and mixed lesions. Conclusions: Optical coherence tomography angiography-based measurements of the new vessel complex in neovascular AMD are feasible with interreader agreement comparable with the values obtained for FA. The results underscore the potential of OCT-A as a noninvasive diagnostic tool in neovascular AMD. Yet, further studies will be required to reveal the origin of poor agreement observed in single eyes and to advance OCT-A toward dependable use (e.g., in a reading center context).

Integrative analysis of head and neck cancer identifies two biologically distinct HPV and three non-HPV subtypes.

PURPOSE: Current classification of head and neck squamous cell carcinomas (HNSCC) based on anatomic site and stage fails to capture biologic heterogeneity or adequately inform treatment. EXPERIMENTAL DESIGN: Here, we use gene expression-based consensus clustering, copy number profiling, and human papillomavirus (HPV) status on a clinically homogenous cohort of 134 locoregionally advanced HNSCCs with 44% HPV(+) tumors together with additional cohorts, which in total comprise 938 tumors, to identify HNSCC subtypes and discover several subtype-specific, translationally relevant characteristics. RESULTS: We identified five subtypes of HNSCC, including two biologically distinct HPV subtypes. One HPV(+) and one HPV(-) subtype show a prominent immune and mesenchymal phenotype. Prominent tumor infiltration with CD8(+) lymphocytes characterizes this inflamed/mesenchymal subtype, independent of HPV status. Compared with other subtypes, the two HPV subtypes show low expression and no copy number events for EGFR/HER ligands. In contrast, the basal subtype is uniquely characterized by a prominent EGFR/HER signaling phenotype, negative HPV-status, as well as strong hypoxic differentiation not seen in other subtypes. CONCLUSION: Our five-subtype classification provides a comprehensive overview of HPV(+) as well as HPV(-) HNSCC biology with significant translational implications for biomarker development and personalized care for patients with HNSCC.