New model to better diagnose dry eye disease integrating OCT corneal epithelial mapping.

PURPOSE: To optimise the objective diagnosis of dry eye disease (DED), the capabilities of wide corneal epithelial mapping using optical coherence tomography (OCT) were studied and subsequently integrated into a new scoring method. METHODS: Fifty-nine patients (118 eyes) with DED and 55 control subjects (110 eyes) were included. All patients underwent a complete ocular surface evaluation. Corneal epithelial thickness was collected using OCT for seven zones. DED and the control group were compared using a t-test, and univariate receiver operating characteristic (ROC) curves were calculated to define the diagnostic ability of OCT epithelial mapping. Multivariate analyses were performed using artificial intelligence (random forest) and logistic regression approaches to define the best way to integrate OCT mapping in the diagnosis of DED. Then, a final multivariable model for diagnosing DED was validated through a bootstrapping method. RESULTS: The DED group had significant epithelial thinning compared with the controls, regardless of location. Superior intermediate epithelial thickness was the best marker for diagnosing DED using OCT (binormal estimated area under ROC: 0.87; best cut-off value: 50 µm thickness). The difference between the inferior and superior peripheral zones was the best marker for grading the severity of DED (analysis of variance, p=0.009). A multivariate approach identified other significant covariables which were integrated into a multivariate model to improve the sensitivity (86.4%) and specificity (91.7%) of this innovative diagnostic method. CONCLUSION: Including OCT corneal epithelial mapping in a new diagnostic tool for DED could allow optimisation of the screening and staging of the disease in current practice as well as for clinical research purposes.

The long-term effects of anti-vascular endothelial growth factor therapy on the optical coherence tomography angiographic appearance of neovascularization in age-related macular degeneration.

BACKGROUND: The short-term effects of anti-vascular endothelial growth factor (anti-VEGF) treatment on macular neovascularization (MNV) morphology is well described, but long-term studies on morphologic changes and correlation of such changes to the type of MNV have not been conducted. This study aims to determine if different types of MNVs in neovascular AMD (nAMD) behave differently with anti-VEGF treatment as visualized on optical coherence tomography angiography (OCTA). METHODS: Treatment-naïve nAMD patients were retrospectively screened for baseline and follow-up OCTA imaging 10 or more months after initial treatment. Images were graded for MNV type, area, activity, mature versus immature vessels, vessel density, presence of atrophy, atrophy location and area. Growth rate was calculated as the percent change in lesion area from baseline over the years of follow-up. In addition, the occurrence of complete regression and the percent of lesions that grew, remained stable, and shrunk per type was also evaluated. RESULTS: Forty-three eyes from 43 patients with a mean follow-up of 2 years were evaluated. On structural OCT, 26 lesions were classified as pure type 1 MNVs, 12 MNVs had a type 2 component, and 5 MNVs had a type 3 component. Of these cases, 2 mixed-type MNVs were considered to have completely regressed. There was no significant differences in MNV area and growth rate between type 1 and type 2 lesions, but all cases of type 3 lesions shrunk in the follow-up period. There was no correlation between the number of injections per year and growth rate, endpoint MNV area or endpoint activity status for any MNV type. There was no significant association between the development of atrophy and the number of injections, baseline MNV area, baseline vessel density, or lesion growth rate. CONCLUSIONS: In nAMD, complete regression of an MNV network exposed to anti-VEGF is rare. This work emphasizes the role of anti-VEGF as anti-leakage rather than vascular regression agents in nAMD.

A Comparison Between Optical Coherence Tomography Angiography and Fluorescein Angiography for the Imaging of Type 1 Neovascularization.

PURPOSE: To determine the sensitivity of the combination of optical coherence tomography angiography (OCTA) and structural optical coherence tomography (OCT) for detecting type 1 neovascularization (NV) and to determine significant factors that preclude visualization of type 1 NV using OCTA. METHODS: Multicenter, retrospective cohort study of 115 eyes from 100 patients with type 1 NV. A retrospective review of fluorescein (FA), OCT, and OCTA imaging was performed on a consecutive series of eyes with type 1 NV from five institutions. Unmasked graders utilized FA and structural OCT data to determine the diagnosis of type 1 NV. Masked graders evaluated FA data alone, en face OCTA data alone and combined en face OCTA and structural OCT data to determine the presence of type 1 NV. Sensitivity analyses were performed using combined FA and OCT data as the reference standard. RESULTS: A total of 105 eyes were diagnosed with type 1 NV using the reference. Of these, 90 (85.7%) could be detected using en face OCTA and structural OCT. The sensitivities of FA data alone and en face OCTA data alone for visualizing type 1 NV were the same (66.7%). Significant factors that precluded visualization of NV using en face OCTA included the height of pigment epithelial detachment, low signal strength, and treatment-naïve disease (P < 0.05, respectively). CONCLUSIONS: En face OCTA and structural OCT showed better detection of type 1 NV than either FA alone or en face OCTA alone. Combining en face OCTA and structural OCT information may therefore be a useful way to noninvasively diagnose and monitor the treatment of type 1 NV.

Chronic central serous chorioretinopathy imaged by optical coherence tomographic angiography.

PURPOSE: To describe optical coherence tomographic (OCT) angiography findings in chronic central serous chorioretinopathy (CSC), and to characterize their OCT B-scans by means of the split-spectrum amplitude-decorrelation angiography algorithm. DESIGN: Evaluation of an imaging technique in a cohort of patients. METHODS: Fluorescein (FA) and indocyanine green (ICGA) angiography (Heidelberg Spectralis, Heidelberg, Germany), OCT angiography, and OCT angiography with the split-spectrum amplitude-decorrelation angiography algorithm (XR Optovue, Fremont, California, USA) were performed. A qualitative analysis of the entire imaging data was done. RESULTS: Twelve eyes of 10 patients were included. Mean visual acuity was 20/30. All eyes presented findings consistent with chronic CSC (lasting more than 6 months) on biomicroscopic examination, autofluorescence, FA, ICGA, and OCT. ICGA showed the characteristic choroidal hyperpermeability, while there was no evidence of choroidal neovascularization (CNV). OCT B-scans showed 2 distinct profiles of the retinal pigment epithelium (RPE): a slight RPE detachment with small undulations was evident in 7 of 12 eyes, while 5 eyes presented a flat RPE profile. OCT angiography in 7 eyes (58%) revealed the presence of a distinct CNV corresponding to the ICGA hyperpermeability. The qualitative analysis of the OCT B-scans compared to the OCT angiographic images demonstrated that the CNV corresponded to the small undulations within the slight RPE detachment, confirming its vascularized nature. On the contrary, OCT angiography showed a normal choroidal circulation in the remaining 5 eyes (42%) with a flat RPE profile. CONCLUSIONS: OCT angiography allows detection of CNV in chronic CSC not visible with other imaging techniques. CNV corresponds to the small undulating RPE detachment on B-scan. This might allow an appropriate treatment resulting in a better visual outcome.