RT Journal Article
A1 Muthiah, Nick Manickam
A1 Chen, Fred Kuanfu
A1 Zhong, Joe
A1 McClelland, Zoe
A1 Sallo, Ferenc
A1 Peto, Tunde
A1 Coffey, Pete
A1 da Cruz, Lyndon
T1 Reliability and Repeatability of a Quality Grading System for Para-foveal Cone Photoreceptor Adaptive Optics Images
JF Investigative Ophthalmology & Visual Science
JO Invest. Ophthalmol. Vis. Sci.
YR 2015
VO 56
IS 7 
SP 4937
OP 4937
SN 1552-5783
AB  To investigate the reliability and repeatability of an image quality - grading system for cone photoreceptors imaged on an adaptive optics (AO) camera. 50 healthy subjects, aged 20-35 years old, with no eye diseases were recruited prospectively. The left eyes of the participants were imaged using an AO camera (rtx1, Imagine Eyes, Orsay, France) at 5 degrees of retinal eccentricity, twice. The 2 images acquired on each subject were anonymized and randomized and the resulting 100 independent unpaired images were graded. A set of AO images validated by two independent experts in AO images and confirmed by a master grader was used as the basis of the 3-level grading system. Two masked independent observers (A and B) graded all the 100 images twice. Grading concordance was assessed by percentage of perfect agreement and kappa statistics. Exact intra-grader agreement on the quality of images for A and B were 90% and 79% respectively, (unweighted k statistics 0.85 and 0.68 respectively, P’s<0.001). Exact inter-grader agreement between A and B’s, 1st grade was 73% and 2nd grade in 76% (unweighted κ statistics 0.59 and 0.63 respectively, P’s < 0.001). The high intra and inter - grader agreement of observer A and B’s 1st and 2nd grades from this study demonstrates a high degree of reproducibility of the grading scores. This AO image grading system can be used as a reliable indicator for assessing the quality of images acquired on this AO camera prior to assessing changes in cone counts. 
RD 4/15/2021