Plus disease in retinopathy of prematurity: diagnostic impact of field of view.

PURPOSE: To examine the impact of retinal field of view and magnification on interexpert reliability of plus disease diagnosis in retinopathy of prematurity. METHODS: Fifteen wide-angle images from infants with retinopathy of prematurity were cropped and adjusted in magnification to create 2 additional image categories: medium angle (40°-50°) and narrow angle (20°-30°). These 45 images were uploaded to a Web-based system and interpreted independently by 13 experts of retinopathy of prematurity using a 3-level (plus, preplus, neither) and 2-level (plus, not plus) classification. Absolute agreement and kappa statistics were calculated to compare interexpert reliability. RESULTS: In the 3-level classification, ≥ 70% experts agreed on the same diagnosis in 8 of the 15 wide-angle images (53%), but only in 3 of the 15 medium-angle (20%) and 3 of the 15 narrow-angle (20%) images. In the 2-level classification, ≥ 80% experts agreed on the same diagnosis in 11 of the 15 wide-angle images (73%), but only in 9 of the 15 medium-angle (60%) and 3 of the 15 narrow-angle (20%) images. Mean kappa of each expert compared with all other experts was 0.40 to 0.59 in 8 of 13 experts (62%) using wide-angle images, was 0 to 0.19 in 7 of 13 experts (54%) using medium-angle images, and was 0.20 to 0.39 in 9 of 13 experts (69%) using narrow-angle images. CONCLUSION: Interexpert agreement in plus disease diagnosis in wide-angle images is higher than from medium-angle and narrow-angle images. Plus disease is defined using a narrow-angle standard published photograph, yet this study suggests that peripheral findings also contribute to diagnosis.

Computer-based image analysis for plus disease diagnosis in retinopathy of prematurity.

Presence of plus disease in retinopathy of prematurity (ROP) is an important criterion for identifying ROP requiring treatment. Plus disease is defined by a standard published photograph selected more than 20 years ago by expert consensus. However, diagnosis of plus disease has been shown to be subjective and qualitative. Computer-based image analysis using quantitative methods has potential to improve the objectivity of plus disease diagnosis. The objective was to review the published literature involving computer-based image analysis for ROP diagnosis. The PubMed and Cochrane library databases were searched for the keywords "retinopathy of prematurity" AND "image analysis" AND/OR "plus disease." Reference lists of retrieved articles were searched to identify additional relevant studies. All relevant English-language studies were reviewed. There are four main computer-based systems-ROPtool (area under the receiver operating characteristic curve [AUROC], plus tortuosity 0.95, plus dilation 0.87), RISA (AUROC, arteriolar TI 0.71, venular diameter 0.82), Vessel Map (AUROC, arteriolar dilation 0.75, venular dilation 0.96), and CAIAR (AUROC, arteriole tortuosity 0.92, venular dilation 0.91)-attempting to objectively analyze vessel tortuosity and dilation in plus disease in ROP. Some show promise for identification of plus disease using quantitative methods. This has potential to improve the diagnosis of plus disease and may contribute to the management of ROP using both traditional binocular indirect ophthalmoscopy and image-based telemedicine approaches.