Session Title: Imaging III
Session Date/Time: Saturday 13/09/2014 | 14:30-16:00
Paper Time: 15:50
Venue: Boulevard C
First Author: : H.Almuhtaseb SPAIN
Co Author(s): : J. Badal M. Biarnés J. Monés
The purpose of this study is to describe the appearance of reticular pseudodrusen on multicolor imaging and to evaluate its diagnostic accuracy as compared with the two modalities that may be considered the current reference standard, blue light and infrared imaging. We used the STARD guidelines (STAndard for the Reporting of Diagnostic accuracy studies), aimed at improving the reporting of diagnostic test studies.
Although there is no reference (“gold”) standard for diagnosis of reticular pseudodrusen, blue light was originally used to describe it, and infrared has been recently shown to provide high sensitivity in its detection, whereas SD OCT provides an adequate means to confirm their presence.
A retrospective study reviewing all multicolor images of a series of consecutive patients visited between 01/12/2012 and 28/02/2013. Inclusion criteria involved the presence of > 1 reticular pseudodrusen (RPD) on a 30º x 30º image centered on the fovea as seen with the blue light channel derived from the multicolor imaging of the Spectralis HRA+OCT ®. The diagnosis of RPD was confirmed by the identification of subretinal debris on a tracking-assisted SD OCT Heidelberg. Recruited patients were only those with Age-Related Eye Disease Study (AREDS) AMD categories 1 to 3. A circle with a diameter equivalent to 3.0 mm divided in 4 fields (superior, nasal, inferior and temporal) was overlaid on each image and manually centered on the foveola. Three experienced observers, masked to their own results with other imaging modalities, independently classified the number of reticular pseudodruesen in each field in each image with each modality, according to this classification: Category 0: 0-5 RPD ; Category 1: 6-20; Category 2: 21-35; Category 3: 36-49; and Category 4: >50. Friday 12 Septemberedman and Wilcoxon tests were used for the comparison between different imaging modalities per field by the same observer. The kappa (K) coefficient was used to measure interobserver agreement.
45 eyes of 45 patients met the inclusion criteria and were finally recruited. The p value corresponding to the Friday 12 Septemberedman test always showed to be statistically significant when comparisons were made between the Category (RPD number categories) means allocated in each field for each imaging modality performed by the same observer. The inter-observer agreement ( kappa) gave a value of 0.58 (0.59) using blue light; 0.65 (0.64) using infrared, and 0.64 (0.61) when multicolor images were analyzed. A kappa coefficient representing moderate to substantial agreement according to Landis and Koch . Multicolor and infrared modalities detected a higher number of RPD than blue light modality in all fields in all observers (p <0,0001) ; however, results were not statistically significant when multicolor and infrared were compared together (p≥0.28).
Multicolor and infrared modalities showed higher sensitivity and interobserver agreement in RPD detection than blue light. No clinically significant differences were found between multicolor and infrared. Multicolor imaging modality (the new index test) can play an important role in the identification, quantification and categorization of RPD when compared to the reference standard test (the images of blue and infrared light), a result which is still the subject of much debate.