Professor Gonzalez de la Rosa (GR), prime inventor of the Laguna ONhE/RetinaLyze Glaucoma algorithm, was invited to lecture at two recent meetings in Madrid.
The first was the annual congress of the Spanish Glaucoma Society and consisted of a general description of the design and results of the Laguna ONhE program for the analysis of the perfusion of the optical disc by automated analysis of color photographs. This program has been designed by the company INSOFT S.L under the direction of Professor GR and marketed by the company RetinaLyze System.
The second conference took place during a meeting called "International Symposium of Controversies in Glaucoma" that for 19 years has been organized by Professors Julián García Sanchez, Julian García-Feijoó and Jose María Martinez de la Casa, in collaboration with Allergan laboratories.
Approximately 500 glaucoma specialists attended each of them. As a result of these conferences, the Ramón y Cajal hospital in Madrid, the Hospital Clínico in Barcelona, two new groups from the Hospital Clínico San Carlos in Madrid and the Hospital Miguel Servet de Zaragoza have been added to the centers that use and carry out studies on the method.
At the first conference, GR recalled that the Glaucomas are a group of optical neuropathies with a common general characteristic: the death of retinal ganglionic cells that lead to a progressive and irreversible visual loss, mainly due to poorly tolerated intraocular pressure from the nerve, but also to a number of additional factors including poor blood perfusion. The current technology for measurement of the ganglion cell fiber layer thickness and the shape and appearance of the optic nerve head as well as the for peripheral visual function, currently needed for reliable diagnosis, are expensive, as well as, time consuming and subjective.
The Laguna ONhE application was conceived as a relatively inexpensive and simple method to analyze the state of the optic nerve, studying color fundus images, analyzing its characteristics and comparing them to a wide series of normal nerves and Glaucomas. It automatically identifies the nerve edge, using Deep Learning techniques, and calculates its hemoglobin content and cupping, providing a Globin Distribution Factor (GDF) index.
The Laguna ONhE/RetinaLyze Glaucoma program uses Artificial Intelligence(DL) techniques to identify the edges of the optical disc and its vessels. The color of the vessels is used to estimate the perfusion (hemoglobin) of the tissue. Their distribution and DL classifiers are also used to compare results with normal patterns. The results can be used for screening, obtaining risk warnings, or providing specialists with more detailed graphical and numerical information.
Deep Learning techniques were applied for vessel segmentation and to obtain classifiers that identify the differences between results in normal and glaucoma eyes. 1397 normal cases and 1434 confirmed and suspected Glaucomas have been used to verify the method’s capabilities. The most recent version of the program has reached high sensitivity figures, of the order of 84.6%, for a very high specificity, namely 99%.
High specificity is essential, especially for screening purposes, to avoid obtaining a high number of false diagnoses that would saturate the health systems, which must confirm the diagnosis.
With this recent version we have re-analyzed the data obtained in previous studies in which we have compared the results of the GDF index of Laguna ONhE with the perimetry and the OCT Cirrus and Spectralis.These new evaluations are pending publication, but in summary we can synthesize them in two conclusions. Sensitivity and specificity figures and ROC areas higher than the OCT indices have been obtained. In some cases, statistical significance has been reached and in others not, but what seems evident is that the results are not inferior.
In the second of the lectures, the results obtained by associating the Laguna ONhE GDF index or the OCT indices with perimetric indices were analyzed, especially those analyzing the irregularity of the visual field. Among them are the PSD of the Humphrey and Oculus perimeters and their equivalent (sLV) in the Octopus perimeter, and a new irregularity index that we have described and patented, called Thresholds Coefficient of Variation (TCV) that studies the harmony and symmetry of 18 points of the central visual field.
The results obtained indicate that, in this case, the association of Laguna ONhE with perimetry provides significantly superior results to any of the associations made between the OCT indexes and perimetry, with high statistical significance.
Finally, and in addition to these conferences, we can report that, after more than 60,000 examinations on the Retinalyze platform, the images could be analyzed in the first attempt in approximately 89.3% of the cases. An additional 8.9% needed a second image, due to excessive lighting or insufficient quality and only a small percentage of cases could not be analyzed because of dense cataracts or other problems.
Finally, the new version of the program will provide information about the size of the optical disc. As it is well known, large optical discs have larger cups. The user is given the Disc Area in percentiles with respect to the frequency in the population studied (range 0-1) to interpret with caution the results obtained in unusually large optical discs, the same way that this information should be taken into account when analyzing the indices of an OCT.
Reception of both lectures was quite good and at the one of the Spanish Glaucoma Society there was time to make a live analysis using the RetinaLyze platform. Attendees were quite impressed with the system, especially since all other speakers in the panel did not present actual products but ideas for future products or services.
