Clinical-Evolutionary Staging System of Primary Open-Angle Glaucoma Using Optical Coherence Tomography

Abstract

Background: Primary open-angle glaucoma (POAG) is considered one of the main causes of blindness. Detection of POAG at early stages and classification into evolutionary stages is crucial to blindness prevention. Methods: 1001 patients were enrolled, of whom 766 were healthy subjects and 235 were ocular hypertensive or glaucomatous patients in different stages of the disease. Spectral domain optical coherence tomography (SD-OCT) was used to determine Bruch’s membrane opening-minimum rim width (BMO-MRW) and the thicknesses of peripapillary retinal nerve fibre layer (RNFL) rings with diameters of 3.0, 4.1 and 4.7 mm centred on the optic nerve. The BMO-MRW rim and RNFL rings were divided into seven sectors (G-T-TS-TI-N-NS-NI). The k-means algorithm and linear discriminant analysis were used to classify patients into disease stages. Results: We defined four glaucoma stages and provided a new model for classifying eyes into these stages, with an overall accuracy greater than 92% (88% when including healthy eyes). An online application was also implemented to predict the probability of glaucoma stage for any given eye. Conclusions: We propose a new objective algorithm for classifying POAG into clinical-evolutionary stages using SD-OCT.

miRNAs and Genes Involved in the Interplay between Ocular Hypertension and Primary Open-Angle Glaucoma. Oxidative Stress, Inflammation, and Apoptosis Networks

“…People more predisposed to glaucoma must be early identified to undertake measures for avoiding optic nerve irreversible damage and vision-threatening consequences [ 1 , 2 , 3 , 4 , 5 , 6 ]. Over the years, this concern has continued to shape the thinking of ophthalmologists and researchers worldwide because hypotensive treatment has to be promptly initiated to appropriately control the elevated IOP.…”

“…Oxidative stress, inflammation, and apoptosis are relevant mechanisms involved in POAG [ 3 , 4 , 5 , 6 , 7 , 8 , 12 , 15 , 39 ]. In this regard, oxidative stress can trigger a wide spectrum of transcription factors such as p53, Nrf2, NF-κB, AP-1, PPAR-γ, and β-catenin/Wnt, among others [ 57 , 58 , 59 , 60 ].…”

“…Diagnosis of POAG underlies a variety of clinical hallmarks such as the IOP elevation (the major risk factor) and the optic nerve head changes, as reflected by the structural/functional imaging techniques to appropriately establish the glaucoma stage [ 4 , 5 , 6 ]. Some decades ago, the term ocular hypertension (OHT) arose to catalogue the eyes with elevated IOP but not displaying optic disc damage or altered visual field.…”

“…Among the cellular and molecular processes underlying these diseases, the following have largely been considered: oxidative/nitrosative stress, mitochondrial failure, inflammation and immune response, autophagy/mitophagy, apoptosis, neurotoxicity, ND, etc. [ 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. It is imperative that the above processes are individually and integrally addressed.…”

Global Glaucoma Staging System (GGSS): A New Method to Simultaneously Assess the Severity of Both Functional and Structural Damage in Glaucoma

“…Several staging methods for categorizing glaucomatous functional damage severity, and staging the RNFL damage assessed with the glaucoma diagnosis (GDx) or OCT, are currently available [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. The most popular systems to stage the functional damage include: (1) the three-stage Hodapp–Parrish–Anderson method, which is based on the assessment of the mean deviation (MD) value, number of depressed points in the pattern deviation map, and proximity of defects to fixation point [ 3 ]; (2) the five-stage Mills et al staging system, which is an evolution of the former [ 4 ]; (3) the AGIS method, which takes the number of depressed points in various areas in the central visual field into account, and provides a score ranging between 0 and 20 [ 5 ]; and, the glaucoma staging system 2 (GSS 2), based on the MD and pattern standard deviation (PSD) values plotted in an x-y graph [ 6 ].…”