Plus disease in retinopathy of prematurity: quantitative analysis of vascular change.

PURPOSE: To examine the relationship between rate of vascular change and plus disease diagnosis.

DESIGN

Retrospective observational case-control study.

METHODS

Wide-angle images were taken bilaterally from 37 infants at 31 to 33 weeks and 35 to 37 weeks postmenstrual age (PMA). The semi-automated Retinal Image multiScale Analysis system was used to measure parameters for all arteries and veins: integrated curvature, diameter, and tortuosity index. A reference standard diagnosis (plus vs not plus) was defined for each eye by consensus of 5 experts at 35 to 37 weeks PMA. Weekly rate of change in parameters was compared in eyes with plus vs not plus disease. Receiver operating characteristic area under the curve (AUC) was calculated for plus disease detection based on 1) weekly rates of parameter change between 31 to 33 weeks and 35 to 37 weeks PMA and 2) parameter values at 35 to 37 weeks only.

RESULTS

Weekly rates of change in all venous parameters were significantly different in eyes with plus vs not plus disease, particularly for tortuosity index (P < .0004) and diameter (P = .018). Using weekly rate of change, AUC for plus disease detection was highest for venous tortuosity index (0.819) and venous diameter (0.712). Using the 35 to 37-week PMA image only, AUC was highest for venous integrated curvature (0.952) and diameter (0.789).

CONCLUSION

Rate of change in venous, but not arterial, parameters is correlated with plus disease development in this data set. This did not appear to contribute information beyond analysis of an image at 35 to 37 weeks PMA only.