Abstract
Purpose :
To standardize values for retinal thickness and volume for all EDTRS grid subdivisions in healthy individuals using spectral domain optical coherence tomography (SD-OCT).
Methods :
Retrospective study of healthy patients submitted to spectral domain OCT evaluation (Spectralis Eyetracker Tomographer, HRA-OCT, Heidelberg, Germany). Retinal thickness measurements were acquired using a standard 30° x 20° raster scan protocol consisting of 25 horizontal sections (each computed out of 25 frames) with a distance of 240μm between each horizontal scan, covering a square of 30 x 20 degrees on the retina and centered on the foveal region. In order to optimize the accuracy of OCT data, automatic delineation of the inner and outer boundaries of the neurosensory retina generated by OCT built-in software was verified for each of the scans. The OCT machine, according to the geometrical center of the scans, automatically positioned the ETDRS grid.
Results :
OCT scan from 56 eyes of 28 patients with median age of 32,6 (range: 21 to 59) were included in the analysis. Mean CSFT (µm) ± SD was 268.94 ± 15.08. Mean Retina thickness (µm) ± SD was 347.08 ±15.07, 318.34 ±11.69, 330.54 ±15.51, 286.71 ±12.98, 347.97 ±14.41, 304.91 ±11.91, 343.51 ±14.73 , 292.74 ±10.44 at the nasal 3 mm subdivision, nasal 6 mm subdivision, temporal 3 mm subdivision, temporal 6 mm subdivision, superior 3 mm subdivision, superior 6 mm subdivision, inferior 3 mm subdivision, inferior 6 mm subdivision respectively. Mean CSFT (mm3) ± SD was 0.21±0.01. Mean Retinal volume (mm3) ± SD was 0.54 ±0.02, 1.68 ±0.06, 0.51 ±0.02, 1.51 ±0.07, 0.54 ±0.02, 1.61 ±0.05, 0.53 ±0.02 , 1.55 ±0.05 at the nasal 3 mm subdivision, nasal 6 mm subdivision, temporal 3 mm subdivision, temporal 6 mm subdivision, superior 3 mm subdivision, superior 6 mm subdivision, inferior 3 mm subdivision, inferior 6 mm subdivision respectively.
Conclusions :
Standardization of retinal thickness values was performed and may help in the analysis of macular diseases that leads to edema or atrophy. Further studies with larger number of patients stratified by age and ocular refraction are underway.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.