Base de datos normativa del grosor de las capas retinianas maculares segmentadas usando el algoritmo de polo posterior 8x8 de la SD-OCT Spectralis

Abstract

Background: Normative databases contain data values from control subjects and permits the comparison of the thickness values obtained with spectral domain optic coherence tomography (SD-OCT). At present, however, there is not a normative database for the posterior pole algorithm (PPA) of the Spectralis™ SD-OCT. Purpose: To provide reference thickness values for all macular layers in a healthy caucasian population using the Spectralis™ PPA and to analyze the effect different variables such as age, gender and axial length and laterality on thickness values of the different macular layer. Methods: This is an observational cross-sectional study in which we included 300 eyes of 300 healthy caucasian subjects with ages between 18 and 85 years (both genders represented equally). The inclusion and exclusion criteria predetermined the size and gender of the sample for the different age groups and prevented the inclusion of individuals that could affect macular layer thickness. All patients received a complete ophthalmological examination and were examined with the Spectralis™ PPA that is composed of a grid of 64 (8x8) cells. The macular thickness of the following retinal layers was automatically segmented: retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), retinal pigment epithelium (RPE), inner retina (INNER), outer retina (OUTER) and full retina (RETINA). Results: Mean values and the percentiles 1, 5 and 95 values were calculated for each cell and for the different macular layers. We found a significant negative correlation between age and thickness for most of the macular layers, except the RNFL, OPL and RPE. Most macular layers were significantly thicker in men than in women, except the RNFL, OPL and RPE. The thickness of most of macular layers did not show a significant correlation with axial length, except for the RNFL that showed a significant positive correlation. However, the thickness of the GCL, IPL and INL showed a significant positive correlation with axial length in the central cells and a significant negative correlation in the cells near the optic disk. The RNFL, INL and OPL were significantly thicker in the right eyes than in left eyes, but the other macular layers showed similar thickness between the right and left eyes. Conclusions: This is the first normative database of the thickness of the different macular layers for the Spectralis™ 8x8 PPA in a caucasian population. Our study documents that age, sex and axial length influence macular retinal layer thickness.