Purpose: Labor-intensive screening of infants in the neonatal intensive care units is the only way presently to detect retinopathy of prematurity (ROP). Our purpose is to determine if RetCam 120 images (Massie Research Laboratories, Inc, Dublin, Calif), acquired by a neonatal nurse, can be used to screen for ROP by performing 2 screening sessions, at 32 to 34 weeks' (examination 1) and 38 to 40 weeks' (examination 2) postconceptional age.
Methods: RetCam examinations were performed by a nurse on infants at examination 1 and examination 2 intervals. At the same time, an examination was performed by an experienced ophthalmologist. Masked readers evaluated the digital images for the presence of ROP and, if ROP was present, estimated the risk of that eye progressing to prethreshold or threshold disease. The data were compared to the eye's clinical course.
Results: A total of 46 eyes were assessed at examination 1 and 50 eyes at examination 2 from July 1, 1999, to December 15, 1999. For detecting ROP, the sensitivity and specificity were 46% and 100% for examination 1 and 76% and 100% for examination 2. Sensitivity and specificity of predicting prethreshold was 64% and 97%, respectively, for examination 1 and 2. Sensitivity for predicting ROP threshold at examination 1 was 0% (only 1 photo was available for grading of sensitivity) and specificity for predicting ROP threshold at examination 1 was 95%. At examination 2, sensitivity and specificity were 100%.
Conclusion: The RetCam examination had insufficient sensitivity to be recommended as a substitute for indirect ophthalmoscopy in screening for ROP. Reasons for low sensitivity are the technical limitation of the camera design itself, which creates difficulty in photographing the peripheral retina in small eyes, and the need for a lid speculum better adapted to the contact camera optical system design. Both of these issues are being addressed as part of an ongoing project to study the feasibility of employing telemetry of digital fundus images from remote, underserved neonatal intensive care units to ophthalmologists capable of diagnosing ROP.