The existence of the plus disease in retinopathy in prematurity is one of the most crucial elements in identifying the treatment-requiring disease. But the procedure of diagnosis of the plus disease is significantly variable. The objective of this research is to compare eye-based and quadrant-based diagnoses for the plus disease in retinopathy of prematurity.

This is a multi-center cohort study that included a database of 197 wide-angle retinal images from 141 preterm infants (65 female, 76 male). Six readers diagnosed each quadrant (cropped image), and the primary outcomes and measures were intragrader and intergrader reliability and accuracy compared to standard diagnosis.

The researchers found a variable agreement between eye-based quadrant-based diagnoses among six graders. Four graders showed underdiagnosis of the plus disease, and the intergrader agreement of quadrant-based diagnosis was lower than the eye-based diagnosis. The accuracy of eye-based diagnosis was substantial to near-perfect when compared to reference standard diagnosis. Quadrant-based diagnosis, on the other hand, was moderate to substantial for each grader. 

The research concluded that graders had lower accuracy and reliability using quadrant-based diagnosis when compared to eye-based diagnosis. The findings suggested that eye-based diagnosis has advantages over quadrant-based diagnosis.