Abstract
Purpose: :
Plus disease is a critical sign for identifying treatment-requiring retinopathy of prematurity (ROP), and aggressive-posterior ROP (AP-ROP) is a form of severe disease with high risk of visual loss even with treatment. However, the precise features which characterize and distinguish AP-ROP from other forms of treatment-requiring ROP are unclear. The purpose of this study is to identify quantitative vascular features of plus disease and AP-ROP using computer-based image analysis.
Methods: :
Two ROP experts interpreted a set of 20 wide-angle retinal images to develop a consensus reference standard for presence of AP-ROP and plus disease, and to distinguish arterioles from venules in each image. Vessels were analyzed by a computer-based image analysis system to calculate values of individual system parameters: integrated curvature (IC) and diameter. Mean values of individual parameters for arterioles and venules were compared between images with AP-ROP vs. no AP-ROP, plus disease vs. no plus disease, and images with one diagnosis but not the other.
Results: :
Analysis of images with AP-ROP vs. no AP-ROP showed that images with AP-ROP had greater venular IC (p=0.0003), but no significant difference in arteriolar IC. Analysis of images with plus disease vs. no plus disease showed images with plus disease had greater arteriolar IC (p=0.00002) and venular IC (p=0.0000001). Of the 10 images with AP-ROP, 5 also had plus disease, while 5 had no plus disease. Images with AP-ROP/plus disease had higher arteriolar IC (p=0.0022) and venular IC (p=0.000006) than images with AP-ROP/no plus. Of the 9 images with plus disease, 5 also had AP-ROP and 4 had no AP-ROP. Images with plus/AP-ROP had higher venular IC than images with plus/no AP-ROP (p=0.002), but no significant difference in arteriolar IC. There were no statistically significant differences in diameter between images with AP-ROP vs. no AP-ROP, or in images with plus disease vs. no plus disease.
Conclusions: :
Vascular features of AP-ROP are not identical to those of other forms of treatment-requiring ROP. In particular, venular tortuosity may be more characteristic of AP-ROP than of plus disease. Computer-based quantitative analysis systems may have the ability to provide quantitative definitions of AP-ROP and plus disease in the future.
Keywords: retinopathy of prematurity • imaging/image analysis: clinical