Abstract
Purpose: :
To determine the agreement between peripapillary retinal nerve fiber layer (RNFL) thickness measurements by Stratus time domain optical coherence tomography (OCT) and Spectralis spectral domain SLO/OCT in patients without and with glaucoma
Methods: :
A prospective study with 85 patients (range 40-90 years of age) visiting the Eye Clinic and the glaucoma clinic was performed. Patients were divided in two groups: group 1 was composed of 44 patients without glaucoma and group 2 was composed of 41 patients with moderate to advanced glaucoma. After informed consent, time-domain OCT (Humphrey Zeiss Stratus, Dublin CA), and spectral-domain SLO/OCT (Spectralis, Heidelberg Engineering, Heidelberg), of both eyes were obtained. The measurements were analyzed and the two OCTs were compared in patients without and with glaucoma. One eye was randomly selected for each patient. Student’s t-test was performed to compare both groups
Results: :
The mean age of group 1 was 59±12 and group 2 was 68±10 years old. The means of the RNFL measurements in group 1 using Stratus OCT were: superior 119.17±14.24µm, nasal 71.93±21.02µm, inferior 124.16±15.94µm, temporal 70.37±9.75µm and the average 96.91±12.16µm. The Spectralis OCT/SLO measurements for same subjects were: superior 125.53±20.96µm, nasal 72.55±19.70µm, inferior 119.89±20.92µm, temporal 71.89±15.14µm and the average 98.21±12.66µm. In group 2 the Stratus OCT showed: superior 84.99±19.94µm, nasal 55.69±15.36µm, inferior 86.68±25.88µm, temporal 61.53±13.30µm, average 72.43±13.59µm, and the measurements with spectral-domain OCT/SLO were: superior 85.74±25.12µm, nasal 56.37±15.45µm, inferior 80.26±30.92µm, temporal 55.34±15.39µm and the average 68.94±16.32µm. There were no statistically significant differences between RNFL measurements with Stratus versus Spectralis, although the Spectralis consistently produced thicker RNFL measurements than the Stratus in normal subjects, except for the inferior quadrant. The mean temporal and inferior RNFL measurements were significantly thicker when measured with Stratus than with Spectralis in glaucomatous subjects
Conclusions: :
There were no statistically significant differences between RNFL measurements by Stratus and Spectralis OCT, except for temporal and inferior quadrants in glaucomatous subjects. There was a positive correlation between the two machines
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • nerve fiber layer