Repeatability Of Retinal And Anterior Segment Measurements With The Nidek Rs3000 Spectral Domain Oct

Abstract

 

Purpose:

 

To evaluate repeatability of the Nidek RS3000 spectral domain optical coherence tomography (SDOCT) (Japan) and assess its agreement to the RTVue SDOCT (Fremont, CA) for measurements of total macular thickness (TMT), average peripapillary retinal nerve fiber layer (RNFL) thickness and central corneal thickness (CCT).

 

Methods:

 

20 healthy eyes, 20 glaucomatous eyes, 20 eyes with corneal abnormalities and 20 eyes with retinal disease were included. For repeatability measurements, 12 eyes of 12 subjects from each group were scanned 3 consecutive times at the same visit by 3 separate experienced operators with the RS3000 SDOCT. The follow-up function was used for measurements of average RNFL and TMT. For agreement, all 20 subjects from each group were scanned with both instruments. Each operator was assigned to a different pair of OCT instruments. The respective scan protocols used for measurements of TMT, average RNFL thickness and CCT were Macula Map, Optic Disc Map and Radial Corneal with the RS3000 and ONH, EMM5 and Pachymetry with the RTVue. All scans were of acceptable quality based on the instruments’ recommended standards. Repeatability was evaluated using CV (coefficient of variation) and ICC (intraclass correlation coefficient). Agreement was assessed by means of Bland Altman plots.

 

Results:

 

Low variability for TMT, average RNFL and CCT measurements were found using the RS3000. Bland Altman plots showed good agreement for RNFL measurements yet consistently and significantly thicker measurements of CCT and TMT with the RS3000. There was good correlation between the two instruments for all measurement types.

 

Conclusions:

 

The repeatability of measurements with the RS3000 was good to excellent in all four groups and for all measurement types. Although agreement between instruments was good for RNFL measurements, the RS3000 provided thicker measurements of CCT and TMT. Measurements with these instruments should not be considered interchangeable.  

 

Clinical Trial:

 

http://www.clinicaltrials.gov NCT01384487

 

Keywords: imaging/image analysis: clinical • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)