Wide-field Digital Ophthalmic Imaging in Infants using Nasal Endoscopic System

To report the utility of nasal endoscopic system in viewing the iridocorneal angle and fundus using various nasal endoscopes and light sources and to determine which type suits best to image a given location in the eye.

This is a prospective observational study of 20 eyes of 10 consecutive infants, who were scheduled for irrigation and probing for congenital nasolacrimal duct obstruction under general anesthesia. The pupils were dilated, viscoelastic gel was applied on the cornea and imaging was performed using nasal endoscopes. The endoscopes used were of 2.7 mm and 4 mm diameter, each with various angulations of 0(0), 30(0) and 70(0). Two different cold light illuminators (Xenon and Halogen) were used uniformly in all cases. Images were analyzed for their quality, clarity and extent of the fields captured.

In all the 20 eyes, nasal endoscope provided a clear circular view of the iridocorneal angle and wide-field fundus view in a single glimpse. The 4 mm endoscope offered a wider view while in-air disc analysis was better with the 2.7 mm endoscope. Angulated endoscopes were more useful in imaging the iridocorneal angle, peripheral retina up to the ora serrata and ciliary body. The image quality with the xenon and halogen light sources were found to be comparable. The time taken for a single eye examination did not exceed 5 min.

With good techniques and appropriate selection of nasal endoscopes, viewing of the iridocorneal angle and fundus is easy, possibly less expensive and very useful in infants.