17.2Telemedicine and ROP

17.2.1Potential Benefits of Telemedicine for ROP

Telemedicine for ROP consists of capturing retinal images by trained neonatal personnel (e.g., nurse or technician) with a wide-angle camera (e.g., RetCam; Clarity Medical Systems, Pleasanton, CA). Images are stored in the medical record and transferred for subsequent interpretation by a remote ophthalmologist [26, 39]. Examples of wide-angle retinal images are shown in Fig. 17.2. As the number of newborns at risk for developing ROP continues to increase, especially in areas where access to appropriate ophthalmic care may be difficult, telemedicine could be a cost-effective screening strategy to provide expert care while ensuring high accuracy for detection of treatment-requiring ROP [9, 28]. It may also decrease the physiological stresses and behavioral changes resulting from ROP screening involving BIO with scleral depression [15, 17].

From the standpoint of providing high-quality clinical care, there are many potential benefits to having archived images in a telemedical model. Imaging preterm infants can facilitate more objective documentation of disease findings and likely identification of disease progression by comparison of serial images. Patient photographs may be compared formally with published ROP images, such as the standard definition of plus disease [18]. Consultation for second opinions could be obtained from experts throughout the world [4]. Furthermore, these images would facilitate the creation of digital image libraries for educational and research purposes, leading to improvements in the uniformity and quality of ROP diagnosis and training of neonatology staff [14, 26]. The advantages of telemedicine are particularly important because studies have shown

b

c

Fig. 17.2 Examples of ROP images captured by a trained neonatal nurse during routine ROP screening using a wideangle camera (RetCam; Clarity Medical Systems, Pleasanton, CA). Images demonstrate retinas with (a) no ROP disease, (b) type 2 prethreshold ROP based on the presence of stage 3 disease in zone II with pre–plus disease, and (c) type 1 treatment-requiring ROP based on the presence of plus disease (peripheral stage 3 disease was visible in temporal and nasal photographs which are not shown)

that there may be significant disagreement, even among expert examiners, in diagnosis of plus disease and treatment-requiring ROP [2, 25, 37].

In contrast, retinal findings from BIO rely solely on the judgment of individual examiners during a brief bedside examination, which can be somewhat subjective and limited by infant cooperation, and may not be easily verified.

17.2.2Accuracy and Reliability of Telemedicine for ROP Diagnosis

Telemedicine for ROP has been evaluated in numerous studies of diagnostic accuracy and reliability. Virtually all of these studies to date have used wide-angle digital images (e.g., RetCam; Clarity Medical Systems, Pleasanton, CA) to compare the performance of remote telemedicine experts to a reference standard of dilated ophthalmoscopic examination by an ROP expert. An initial study demonstrated that moderate to severe ROP could be identified using digital imaging [29]. Subsequent research projects have demonstrated that telemedicine for ROP can achieve relatively high diagnostic accuracy over a broad range of disease severity (Table 17.1). For diagnosis of any ROP regardless of severity, studies have demonstrated sensitivity of 0.46–0.97 and specificity of 0.49–1.00 compared to BIO [3–5, 27, 32, 39]. Generally, lower accuracy has been found while examining infants at lower postmenstrual ages. This is presumably because infants at lower postmenstrual

ages may have ROP at earlier stages with more subtle diagnostic features and because it may be technically more difficult to image eyes that are smaller and have increased media opacities [4, 39]. For moderate to severe ROP, many studies have achieved higher diagnostic accuracy (Table 17.2). These studies demonstrated sensitivity of 0.57–1.00 and specificity of 0.37–1.00 [3–5, 7, 16, 19, 20, 23, 33, 38] compared to a reference standard of BIO.

Scott et al. designed a study to control for interphysician diagnostic variability by comparing ophthalmoscopic and telemedicine diagnoses by the same experts in 67 infants [30]. There was substantial to near-perfect agreement in these diagnostic modalities, with absolute agreement of 86% (178/206 eyes) and kappa of 0.66– 0.85 between ophthalmoscopy and telemedicine. Among the 14% (28/206 eyes) discrepancies in this study, some cases provided photographic documentation suggesting that ophthalmoscopic examination may have failed to detect mild ROP that was detected using telemedicine by the same experts. In addition, there were discrepancies between presence of zone 1 ROP and presence of plus disease, in which telemedicine may have provided theoretical advantages by allowing examiners to review their diagnoses, make more exact measurements of anatomical landmarks such as zone I of the retina, and directly compare images to the standard photograph for plus disease [30].

Other studies have also measured the interand intragrader reliability of telemedical diagnosis using metrics such as kappa statistic. Among pairs of graders viewing the same images, two studies demonstrated substantial to near-perfect agreement with weighted intergrader kappa of 0.67–0.83 [3] and 0.55–0.89 [4]. Intragrader reliability of telemedical diagnosis has also been evaluated by analyzing the diagnoses of randomly repeated images presented to the same grader. For example, in one study, three ROP specialists demonstrated near-perfect to perfect agreement with intragrader kappa of 0.91–1.00 for detection of mild or worse ROP and intragrader kappa of 0.79–1.00 for detection of treatment-requiring ROP [4].

17.2.3Operational ROP Telemedicine Systems

Based on these principles, several operational telemedicine programs have been implemented throughout the world, with the goals of improving accessibility to expert ROP diagnosis while improving efficiency of examination. These programs have typically used trained nonexpert personnel, such as technicians or neonatal nurses, to capture images and transfer data for interpretation by ophthalmologists at remote locations. Infants found to have clinically significant disease are either examined locally by an expert ophthalmologist or transferred to an outside center for evaluation.