Specular microscopy ancillary study methods for donor endothelial cell density determination of Cornea Donor Study images.
OBJECTIVE
To describe reliable methods for determining central corneal endothelial cell density (ECD) in a multicenter eye bank study.


METHODS
The Specular Microscopy Reading Center utilized a dual-grading procedure and adjudication process to classify image quality and determine ECD for a subset of donor endothelial images obtained in the Specular Microscopy Ancillary Study, which is part of the Cornea Donor Study. Two certified readers classified images as analyzable (excellent, good, fair) or unanalyzable and determined the ECD using a variable frame technique. An adjudicator also evaluated the images if quality classifications by the two readers differed by one grade, if any reader found the image unanalyzable, and/or if the ECD determination between the two readers was >or= 5%.


RESULTS
Image quality categorization by the two readers was identical for 441 (64%) of 688 donor images. The ECD differed by < 5% for 442 (69%) of the 645 analyzable images. The ECD determined by the adjudicator was < 5% different than the ECD determined by at least one reader for 193 (95%) of the 203 remaining images.


CONCLUSIONS
The dual-grading and adjudication procedures produce reliable, reproducible assessments of image quality and ECD. The importance of two independent readings is evident in that image quality ratings differed between the two readers by one grade in 36% of all images and ECD counts differed by >or=5% for 31% of analyzable images.
Benetz
Beth Ann
BA
Specular Microscopy Reading Center, Department of Ophthalmology, Case Western Reserve University and University Hospitals of Cleveland, Cleveland, Ohio, USA.
Gal
Robin L
RL
Ruedy
Katrina J
KJ
Rice
Carmella
C
Beck
Roy W
RW
Kalajian
Andrea D
AD
Lass
Jonathan H
JH
D002452:Cell Count; D004728:Endothelium, Corneal / Q000166:cytology*; D005125:Eye Banks; D006801:Humans; D008853:Microscopy / Q000379:methods*; D015588:Observer Variation; D009885:Ophthalmology / Q000379:methods*; D011786:Quality Control; D015203:Reproducibility of Results; D014019:Tissue Donors