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Abstract(s)
Introdução: O glaucoma é uma das principais causas de cegueira irreversível em todo
o mundo, sendo uma doença ocular crónica, progressiva e de difícil diagnóstico nas
fases iniciais. Para um controle e diagnóstico do glaucoma, existem algumas métricas
clínicas para a análise da cabeça do nervo óptico. São estas o rácio escavação-disco
(CDR), a regra ISNT e o rácio anel neurorretiniano-disco (RDR).
Objetivo: Este trabalho pretende estudar as diferenças que as diferentes métricas
clínicas têm na análise da cabeça do nervo óptico. Estudou-se também as diferenças
que os eixo fóvea-disco (FONH) e eixo ortogonal têm nessas métricas.
Métodos: Foi utilizada a base de dados de imagens de fundo do olho publicamente
disponível Retinal Fundus Glaucoma Challenge (REFUGE). Esta base de dados é
composta por 400 imagens de fundo de olho (40 glaucomatosas e 360 normais). Foi
criado um algoritmo em MatLab para medir de forma automatizada cada uma das
métricas.
Resultados: O rácio CDR vertical (CDRV) com o eixo FONH apresentou a maior
AUROC (0.940), seguido do CDRV com eixo ortogonal (0.937). O CDR área apresentou
uma AUROC de 0.931. A métrica com pior AUROC foi o RDR (0.850), CDR horizontal
com eixo ortogonal (0.899), CDR horizontal com eixo FONH (0.896) e por fim o RDR
(0.850).
A sensibilidade e especificidade do rácio CDRV com eixo FONH foi de 85% e 93.1%,
enquanto que para o rácio RDR foi de 82.5% e 75.8%. A sensibilidade e especificidade
da regra ISNT quando foi considerado o eixo ortogonal foram de 97.5% e 19.7%,
respetivamente. A sensibilidade e especificidade da regra ISNT considerando o eixo
FONH foram de 97.5% e 18.9%respetivamente.
Conclusão: O rácio CDRV considerando o eixo FONH, é a métrica clínica que
apresenta a maior capacidade para diferenciar olhos normais de glaucomatosos. A
regra ISNT e as suas variantes são as que apresentam os valores mais baixos na deteção
do glaucoma.
Introduction: Glaucoma is one of the main causes of irreversible blindness worldwide, being a chronic, progressive eye disease that is difficult to diagnose in its early stages. For the control and diagnosis of glaucoma, there are some clinical metrics for analyzing the optic nerve head. These are the cup-to-disc ratio (CDR), the ISNT rule and the rim-to-disc ratio (RDR). Objective: This work intends to study the differences that different clinical metrics have in the analysis of the optic nerve head. The differences that the fovea-disk axis (FONH) and the orthogonal axis have in these metrics were also studied. Methods: The publicly available fundus image database Retinal Fundus Glaucoma Challenge (REFUGE) was used. This database consists of 400 fundus images (40 glaucomatous and 360 normal). An algorithm was created in MatLab to automatically measure each of the metrics. Results: The vertical CDR ratio (CDRV) with the FONH axis showed the largest AUROC (0.940), followed by the CDRV with the orthogonal axis (0.937). The area CDR showed an AUROC of 0.931. The metric with the worst AUROC was RDR (0.850), horizontal CDR with orthogonal axis (0.899), horizontal CDR with FONH axis (0.896) and finally RDR (0.850). The sensitivity and specificity of the CDRV ratio with FONH axis was 85% and 93.1%, while for the RDR ratio it was 82.5% and 75.8%. The sensitivity and specificity of the ISNT rule when the orthogonal axis was considered were 97.5% and 19.7%, respectively. The sensitivity and specificity of the ISNT rule considering the FONH axis were 97.5% and 18.9%, respectively. Conclusion: The CDRV ratio considering the FONH axis is the clinical metric that has the greatest capacity to differentiate normal from glaucomatous eyes. The ISNT rule and its variants are the ones that present the lowest values in the detection of glaucoma.
Introduction: Glaucoma is one of the main causes of irreversible blindness worldwide, being a chronic, progressive eye disease that is difficult to diagnose in its early stages. For the control and diagnosis of glaucoma, there are some clinical metrics for analyzing the optic nerve head. These are the cup-to-disc ratio (CDR), the ISNT rule and the rim-to-disc ratio (RDR). Objective: This work intends to study the differences that different clinical metrics have in the analysis of the optic nerve head. The differences that the fovea-disk axis (FONH) and the orthogonal axis have in these metrics were also studied. Methods: The publicly available fundus image database Retinal Fundus Glaucoma Challenge (REFUGE) was used. This database consists of 400 fundus images (40 glaucomatous and 360 normal). An algorithm was created in MatLab to automatically measure each of the metrics. Results: The vertical CDR ratio (CDRV) with the FONH axis showed the largest AUROC (0.940), followed by the CDRV with the orthogonal axis (0.937). The area CDR showed an AUROC of 0.931. The metric with the worst AUROC was RDR (0.850), horizontal CDR with orthogonal axis (0.899), horizontal CDR with FONH axis (0.896) and finally RDR (0.850). The sensitivity and specificity of the CDRV ratio with FONH axis was 85% and 93.1%, while for the RDR ratio it was 82.5% and 75.8%. The sensitivity and specificity of the ISNT rule when the orthogonal axis was considered were 97.5% and 19.7%, respectively. The sensitivity and specificity of the ISNT rule considering the FONH axis were 97.5% and 18.9%, respectively. Conclusion: The CDRV ratio considering the FONH axis is the clinical metric that has the greatest capacity to differentiate normal from glaucomatous eyes. The ISNT rule and its variants are the ones that present the lowest values in the detection of glaucoma.
Description
Keywords
Cabeça do Nervo Ótico Glaucoma Rácio Disco-Anel Neurorretiniano Rácio Escavação-Disco Regra Isnt