Comparação entre o polarímetro de varredura a laser, a tomografia de coerência óptica 1 e o Stratus-oct na detecção da perda axonal da atrofia em banda do nervo óptico

Abstract

To compare the abilitiy of scanning laser polarimetry (GDx), optical coherence tomography (OCT) 1 and Stratus- optical coherence tomography to discriminate between healthy eyes and eyes with band atrophy of the optic nerve and temporal hemianopsia. Twenty-three eyes with band atrophy of the optic nerve and 23 eyes from healthy subjects were included in this observational prospective case-control study. All eyes underwent retinal nerve fiber layer (RNFL) thickness analysis using GDx, optical coherence tomography-1 and Stratus-optical coherence tomography. Mean values obtained with each equipment were compared between band atrophy and normal eyes. Receiver operating characteristic (ROC) curves and sensitivities at fixed specificities (80% e 95%) were calculated for each parameter calculated with each equipment and compared. When compared with healthy subjects, the parameters corresponding to the global average as well as each of the four quadrant retinal nerve fiber layer thickness in eyes with band atrophy were significantly smaller (p<0.05), than in normal eyes, with the exception of GDx's temporal thickness parameter. Comparison of the areas under ROC curves (AUCs) of the parameters from the three equipments revealed significantly greater values for the Stratus-OCT when compared to the OCT-1 in the global average and in the temporal quadrant thickness measurement. Stratus-OCT was significantly more sensitive than GDx in the global average as well as in the temporal, nasal and inferior quadrant. OCT-1 was superior to GDx only in the temporal quadrant. All three equipments revealed a similar ability to identify retinal nerve fiber layer reduction in the superior quadrant. The Stratus OCT showed the best ability to discriminate between eyes with band atrophy of the optic nerve and healthy eyes although all three equipments were able do identify most of the abnormal eyes. OCT-1 was inferior to Stratus-OCT and superior do GDx in the temporal quadrant. Although GDx was able identify some abnormality in most studied eyes, the equipment showed poor sensitivity in the detection of axonal loss in the nasal and temporal aspect of the optic disc and should be used with caution in neuro-ophthalmic diseases that cause retinal nerve fiber layer loss in those areas of the optic disc.