It is with great joy and pride that we can publish that a paper about Laguna ONhE / Retinalyze Glaucoma has been accepted in the acclaimed British Journal of Ophthalmology.
The study compares the diagnostic capability of Optical Coherence Tomography Angiography (OCT-A) and Colorimetric assessment of ONH haemoglobin (RetinaLyze Glaucoma) in open-angle glaucoma (OAG) patients. The conclusion is that the RetinaLyze Glaucoma program and OCT-A have similar diagnostic validity in open-angle glaucoma patients.
This means that RetinaLyze Glaucoma can be used, not only as a screening programme by optometrists and clinical personnel, but that it also presents as much clinical interest to an ophthalmologist as an OCT or visual field study.personnel
The article is authored by several Spanish ophthalmologists from the University Hospital of San Carlos (Madrid) and Complutense University (Madrid). Optic nerve perfusion depends on three factors, namely, oxygen saturation, blood flow and Hb content. It has been suggested that changes in ONH reflectance can detect variations in Hb levels, which may be useful for indirectly measuring ONH perfusion. Optic nerve ischemia and reduced ocular blood flow have been shown to be associated with the development and progression of glaucoma.
The OCT-A Nidek RS-3000 Advance allows the quantification of vascular areas and vessel density, and it is capable of identifying changes in the papilar, circumpapilar and macular vessel density in glaucoma patients. Decreased vessel density has been associated with the severity of visual field damage independently of the structural loss.9 Its use in the clinic is increasingly widespread and its diagnostic yield in glaucoma has been demonstrated.
In the prospective observational cross-sectional study, 67 OAG patients and 41 healthy age-sex frequency matched subjects were examined with OCT-A and retinal photos.
The circumpapillary (wcpVD), optic nerve head (iVD) and macular (wmVD) capillary vessel density of OCT-A and ONH (optic nerve head) colorimetric assessment to determine the ONH Hb amount using the RetinaLyze Glaucoma program were evaluated. The area under the receiver operating characteristic (ROC) curve (AUROC) for discriminating between healthy and glaucomatous eyes was highest for wcpVD (0.93; 95% CI 0.86 to 0.97, p<0.0001), followed by GDF (0.92; 95% CI 0.86 to 0.97, p<0.0001), iVD (0.79; 95% CI 0.70 to 0.86; p<0.0001) and ONH Hb (0.78; 95% CI 0.69 to 0.85, p<0.0001).
Pair wise comparisons showed that the AUROC of wcpVD (0.93) was not significantly different than GDF (0.92) (p=0.855) ie. OCT-A and RetinaLyze Glaucoma have similar similar diagnostic validity in open-angle glaucoma patients.
The colorimetric analysis procedure offers some advantages over OCT-A. The first is related to the length of the OCT-A examination. One of the disadvantages of OCT-A is the duration of the exam, which is longer than the scanning time with SDOCT, which may imply a limitation when exploring uncooperative patients. In this study, four patients could not be included in the final data analysis, three of them due to lack of collaboration that made it impossible to complete the analysis with OCT-A.
Poor OCT-A image quality due to segmentation errors made OCT-A unreadable. However, the RetinaLyze Glaucoma program can be used in patients that either because of their low visual acuity or their age are not able to maintain their sight in a pre-established fixation point, since the analysis of the amount of ONH Hb only requires a good quality retinography, even if the image of the papilla is off-centre.
An additional advantage of RetinaLyze Glaucoma over OCT-A is its price, which is determined by the cost of the fundus camera, a fundamental device in any ophthalmological clinic. RetinaLyze Glaucoma is a non-invasive method that is not expensive since it is performed on retinographies. Diagnostic devices such as OCT-A are inaccessible to many ophthalmologists globally due to the price.
Title: Diagnostic validity of optic nerve head colorimetric assessment and optical coherence tomography angiography in patients with glaucoma.
Authors: Carmen Mendez-Hernandez, Surina Wang, Paula Arribas-Pardo, Liseth Salazar-Quiñones, Noemi Güemes-Villahoz, Cristina Fernandez-Perez, Julian Garcia-Feijoo
RetinaLyze System A/S is a medical technology company established in 2013, which is represented in 35 countries all over the world. The company delivers groundbreaking decision support tools to eye-screening professionals to enable efficient, accessible and fast eye-screenings. All our algorithms and services are CE-marked, clinically validated and patented.
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