Abstract
Purpose :
CIRRUS and PRIMUS are two distinct SD-OCT devices developed by Carl Zeiss Meditec Inc. Both devices are having normative database for quantitative comparison of patient data with normal representative population. PRIMUS normative limit is derived from CIRRUS by appropriate correction using regression analysis based on data obtained from an agreement analyses and repeatability & reproducibility assessment study. The purpose of this study is to assess the level of agreement (by Cohen’s kappa method) achieved on normative limits provided by PRIMUS & CIRRUS for Macula and ONH/RNFL measurement parameters obtained from normal, retinal disease & glaucoma subjects.
Methods :
Macular scans were obtained from 46 normal subjects & 39 subjects with retinal disease whereas ONH/RNFL scans were obtained from 45 normal subjects & 43 subjects with glaucoma. All the subjects underwent scanning on both PRIMUS & CIRRUS and had 11 macular, 4 ONH and 3 RNFL measurement parameters obtained from both the devices.
The classification results for the measurement parameters; 11 Macular parameters – Cube Volume, Cube Average Thickness, ETDRS Subfields (Central, Inner Inferior, Inner Superior, Inner Nasal, Inner Temporal, Outer Inferior, Outer Superior, Outer Nasal, Outer Temporal); 4 ONH parameters – Rim Area, Average Cup to Disc Ratio, Vertical Cup to Disc Ratio , Cup Volume; 3 RNFL parameters – Average RNFL Thickness, Superior RNFL Thickness, Inferior RNFL Thickness; were generated using latest PRIMUS as well as CIRRUS software. The classifier provided the appropriate color code for each parameter according to the classification criteria. Cohen’s Kappa statistical test was used for the calculation of Percentage Agreement and Cohen’s Kappa Agreement Specificity.
Results :
The Percentage Agreement specificity and Cohen’s Kappa Agreement specificity for each of the measurement parameters are presented in Table 1.
Conclusions :
All the Macular, ONH and RNFL measurement parameters listed above had Percentage Agreement of >=83% and Cohen’s Kappa Agreement of >=64%. Based on the results of this study, it can be concluded that there is substantial level of agreement in normative limits between normative databases of PRIMUS & CIRRUS for the measurement parameters obtained from a given subject.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.