Título

REPRODUCIBILITY OF PARAPAPILLARY RETINAL NERVE FIBER LAYER THICKNESS AND MINIMUM RIM WIDTH MEASUREMENTS USING THE SPECTRALIS AND THE RTVUE SPECTRAL DOMAIN OPTIC COHERENCE TOMOGRAPHERS

Objetivo

The purpose of the present study is to evaluate and compare the reproducibility of retinal nerve fiber layer (RNFL) thickness measurements obtained by the Spectralis OCT2 (Heidelberg Engineering, Heidelberg, Germany) and the RTVue (Optovue Inc, Fremont, USA) spectral domain optic coherence tomographers (OCT). In addition, we evaluated the reproducibility of the minimum rim width (MRW) optic nerve parameters using the Spectralis.

Método

109 eyes (healthy, glaucomatous and suspects of having glaucoma) were included in this cross-sectional observational study. Three consecutive peripapillary RNFL thickness scans (average and sectors) were obtained from each eye, by the same operator, using both instruments in the same visit. Three consecutive MRW scans were also obtained from each participant using the Spectralis. Inter-operator reproducibility of RNFL and MRW measurements were evaluated using intraclass correlation coefficient (ICC) and coefficient of variation (CV).

Resultado

The parameters with the highest ICC obtained with the Spectralis were 0.99 for the average thickness and 0.99 for the superior temporal and inferior temporal sectors. For the RTVue, the parameters with the highest ICC were 0.97 for the average thickness and 0,94 for the superior temporal sector. The average CV obtained for the average RNFL thickness parameter was 0.88% and 2.08% for the Spectralis and RTVue, respectively. The evaluation of global MRW measurements obtained by the Spectralis showed a CV of 1.19%. The MRW parameters with the highest ICC were global thickness (0.99), temporal thickness (0.97) and superior temporal thickness (0.96).

Conclusão

Both instruments showed excellent reproducibility for the average RNFL thickness parameters. The lower coefficient of variation obtained with the Spectralis, both for RNFL and MRW thickness, indicates that the instrument may provide lower measurement variability when compared to the RTVue.