Performance of an algorithm for glaucoma diagnosis based on the optic nerve cup/disc ratio

Los algoritmos para tamizaje de glaucoma determinan la presencia o ausencia de enfermedad basados en la relación excavación/disco (Clasificación de Armaly). Sin embargo, se podrían pasar por alto hallazgos sugestivos de daño del nervio óptico clasificándolo incorrectamente. La escala de probabilidad de daño del disco de Spaeth puede ser útil identificando cambios tempranos de neuropatía óptica glaucomatosa. Objetivo Determinar el rendimiento de un algoritmo para tamizaje de glaucoma analizando fotografías de nervio óptico. Métodos Estudio transversal de prueba diagnóstica. Se diseñó un algoritmo para identificar características sugestivas de daño en imágenes del nervio óptico. Se clasificaron las imágenes según las escalas de Armaly y Spaeth. El algoritmo segmenta el nervio y la excavación mediante análisis de tono, saturación e iluminación; extrae los contornos con el método de Otsu de múltiples umbrales y cada contorno es representado mediante series de Fourier, alimentando una red neuronal de dos capas. Resultados La concordancia del algoritmo con el criterio del especialista fue de 80% (p menor a 0.05) para determinar la relación excavación/disco, 91% (p menor a 0.05) para la escala DDLS de Spaeth, 92% (p menor a 0.05) para la escala DDLS de Spaeth modificada, y de 99% (p menor a 0.05) para la clasificación de severidad de daño por glaucoma. El criterio de los dos especialistas coincidió en 94% (p menor a 0.05) para la clasificación de severidad de daño por glaucoma, 40% para la relación excavación/disco, en 12,4% para la escala DDLS de Spaeth y en 12,5% para la escala DDLS de Spaeth modificada. Conclusiones Se propone un algoritmo de inteligencia artifical basado en una red neuronal de 2 capas que alcanza alta precisión en resultados preliminares para clasificar riesgo de glaucoma usando las escalas de Armaly, DDLS de Spaeth y la clasificación de severidad de daño por glaucomaGlaucoma screening algorithms determine the presence or absence of disease based on the cup/disc ratio (Armaly’s classification). However, findings suggestive of optic nerve damage may be missed and misclassified as healthy in affected eyes. Spaeth’s Disc Damage Likelihood Scale helps to identify early changes of glaucomatous optic neuropathy. Objective To determine the performance of an algorithm for glaucoma screening based on Armaly’s classification and Spaeth’s Disc Damage Likelihood Scale by analyzing optic nerve images. Methods Cross-sectional diagnostic test study. An algorithm was designed to identify findings suggestive of optic nerve damage and not only the presence or absence of glaucoma. Optic nerve photos were classified using Armaly’s classification and Spaeth’s scale. The algorithm segments the optic nerve and cup by analyzing hue, saturation, and lighting values, then extracts contours using Otsu’s method with multiple thresholds. Each contour is represented using Fourier series. All the information feeds a two-layer neural network. Results The agreement of the algorithm with the specialist's criteria was 80% (p less than 0.05) for determining the cup/disc ratio, 91% (p less than 0.05) for Spaeth’s Disc Damage Likelihood Scale (DDLS), 92% (p less than 0.05) Spaeth’s modified DDLS and 99% (p less than 0.05) for the glaucoma damage classification. The agreement between the two specialists was 94% (p less than 0.05) for the glaucoma damage classification, 40% for the excavation/disc ratio, 12,4% for Spaeth’s DDLS and 12.5% for Spaeth’s modified DDLS. Conclusions We propose an algorithm based on a 2-layer neural network that in preliminary results achieves high accuracy to estimate glaucoma risk based on Armaly’s classification, Spaeth’ original and modified DDLS scales and glaucoma damage classification

Efficacy and safety of sodium hyaluronate/chondroitin sulfate preservative-free ophthalmic solution in the treatment of Dry Eye: a clinical trial

Purpose: The present study was designed to evaluate the efficacy and safety of sodium hyaluronate/chondroitin sulfate, preservative-free ophthalmic solution (SH/CS-PF) in patients with mild-moderate dry eye disease (DED). Methods: This was a randomized phase IV, multicenter, prospective, double-blind, clinical trial. A total of 217 subjects were randomized (1:1:1) and completed the study. Subjects were assigned to receive either SH/CS-PF (n=72), PEG/PG (n=64) or PEG/PG-PF (n=81). Subjects instilled a drop four times a day (QID) for 90 days. The primary efficacy endpoints were conjunctival goblet cell density, Nelson’s grades, fluorescein tear break-up time (TBUT), Ocular Surface Disease Index (OSDI), and, Schirmer’s test. The tolerability was measured by the ocular symptomatology, and safety was assayed by corneal staining, intraocular pressure (IOP), visual acuity (VA) and adverse events (AE)