Correlation of Retinal Thickness and Swept-Source Optical Coherence Tomography Angiography Derived Vascular Changes in Patients with Neovascular Age-Related Macular Degeneration.

Purpose: The aim of this study was to investigate whether structural OCT changes, in specific retinal thickness, is associated with the vascular response within the nAMD CNV lesion. In other words, whether SSOCTA derived parameters may prove suitable to assess CNV activity in future.Methods: During the first 3 months patients were prospectively followed with visits at days 7, and 14 after each anti-VEGF treatment up to day 90. At baseline, day 30 and 60 Aflibercept was administered. OCT-derrived retinal thickness (RT) and OCTA-derived CNV lesion parameters (vessel area [VA]), total vessel length [TVL], total number of junctions [TNJ], junction density [JD]) were determined. Parameters were exported from SSOCT/A (PlexElite, Zeiss) images using the semi-automated AngioTool software. Additionally, the superficial and deep vascular plexus fractal dimension of the para- and perifoveal region were identified. Consequently, all OCTA derived parameters were correlated with RT.Results: 16 consecutive patients presenting with treatment-naïve, SSOCTA-positive CNV lesions were included. A weak to moderate statistically significant correlation was found between the mean RT of the inner as well as the outer ETDRS ring with the SSOCTA-derived vascular markers vessel area (VA; r2 = -0.38, p < .001; r2 = -0.47, p < .001, respectively), total vessel length, (TVL; r2 = -0.38, p < .001; r2 = -0.48, p < .001, respectively) and total number of junctions (TNJ; r2 = -0.35, p < .001; r2 = -0.44, p < .001, respectively). Junctions density (JD), and all variables based on fractal dimension (FD) did not show statistically significant correlations with retinal thickness measurements.Conclusions: In summary, we could confirm a moderate, however, statistically significant correlation between mean para- and perifoveal retinal thickness and the SSOCTA derived vascular parameters VA, TVL, and TNJ. This leads us to the conclusion that an SSOCTA-based activity analysis of the CNV complex is not yet a substitute for retinal thickness or in-depth fluid analysis in patients with nAMD.

Comparative study between a spectral domain and a high-speed single-beam swept source OCTA system for identifying choroidal neovascularization in AMD.

This comparative study between a SD- and SS-OCTA system for visualizing neovascular patterns in AMD, also assessed the influence of cataract on OCTA imaging. 25 eyes with active CNV (AMD) were documented by FA, ICGA and SD-OCT. Two OCTA devices were used: A custom built SS-OCTA (1050 nm, 400,000 A-scans/s, 5 × 5 mm, no image segmentation); AngioVue (OptoVue, CA, USA) SD-OCTA (840 nm, 70.000 A-scans/s, 3 × 3 mm, SSADA technology). Two retina experts graded CNV types and vascular patterns. Cataract influence on OCTA image quality was reported for the superficial retinal plexus (6 eyes). The SS-OCTA prototype showed more CNV lesions compared to the SD-OCTA system (p = 0.01). Overall sensitivity of SD- and SS-OCTA systems to detect CNV lesions was.32 and.68, respectively. The SS-OCTA system was able to detect discrete lesion characteristics better than the SD-OCTA. No significant difference was found in the ability to identify CNV in treatment-naïve eyes. There was no significant influence of cataract. The SS-OCTA prototype detected CNV-associated vascular patterns more reliably than the SD-OCTA system. This is attributed to the SS-OCTA system's longer center wavelength and higher A-scan rate yielding higher definition and contrast of small neovascular structures. The SS-OCTA system used showed no advantage regarding cataract influence.

[Early treatment diabetic retinopathy study (ETDRS) visual acuity]. / ETDRS (Early Treatment Diabetic Retinopathy Study)-Visus.

Human visual acuity is used as an indicator in everyday clinical work and ophthalmological studies to decide on therapy indications and success. This extensively used parameter needs a very structured workflow in order to preserve validity and prevent bias. Therefore, it should be kept in mind that especially in clinical studies investigators should strictly adhere to the study protocol. The intention of this article is to impart interesting facts about the early treatment diabetic retinopathy study (ETDRS) on visual acuity assessment, adhering to the original protocol of the ETDRS dating back to 1979-1989. Furthermore, the history of visual acuity assessment protocols prior to ETDRS, namely those of Snellen and Bailey-Lovie and finally the logMAR system will be discussed.