Date of Award

January 2013

Document Type


Degree Name

Medical Doctor (MD)



First Advisor

Ron Adelman

Subject Area(s)



Aggressive Posterior Retinopathy of Prematurity: A Quantitative Analysis of Vascular Features and Analysis of Inter-expert Agreement. Rany Woo, R.V. Paul Chan, and Michael F. Chiang. Department of Ophthalmology, Weill Cornell Medical College, New York, New York. (Sponsored by Ron A. Adelman, Department of Ophthalmology, Yale University School of Medicine).

Purpose: Evaluate aggressive posterior retinopathy of prematurity (AP-ROP) with regard to inter-expert diagnostic agreement and quantitative vascular features.

Methods: Eight ROP experts interpreted 15 retinal images for presence of AP-ROP and plus disease. Inter-expert agreement was calculated by absolute agreement for AP-ROP and plus, and κ statistic for each expert compared with all others. Retinal vessels were analyzed by a computer-based image analysis system to calculate parameters: diameter and integrated curvature (IC). Consensus reference standards for presence of AP-ROP and plus disease were developed, and individual quantitative parameters for arterioles and venules were compared among images with AP-ROP vs. not AP-ROP, plus vs. not plus, and AP-ROP vs. plus.

Results: Mean κ for each expert in AP-ROP diagnosis ranged from -0.15 (no agreement) to 0.42 (moderate agreement). Nine (30%) of 30 total AP-ROP diagnoses were also classified as not plus disease. Analysis of images with AP-ROP vs. plus showed that images with AP-ROP had higher venular IC (p=0.04). Arteriolar IC was statistically-significant between images with AP-ROP vs. not AP-ROP (p=0.01) and plus vs. not plus (p=0.00003). There were no statistically-significant differences in arteriolar or venular diameter between image groups.

Conclusions: Inter-expert agreement with regard to AP-ROP diagnosis is imperfect, and some study images were considered by experts to represent AP-ROP without plus disease. Venular curvature may be a distinguishing characteristic between AP-ROP and plus disease. Future studies involving the pathophysiology and quantitative features of AP-ROP will have benefits for clinical diagnosis and management.


This thesis is restricted to Yale network users only. This thesis is permanently embargoed from public release.