Anterior Segment OCT and Specular Microscopy Study in Pediatric Patients: Normal Versus Glaucomatous Eyes

Abstract

Purpose : Anterior segment anatomy evaluation in children is challenging and has been restricted to high-frequency ultrasound, that requires immersion technique. Anterior segment optical coherence tomography (AS-OCT) and specular microscopy are important noninvasive imaging tools, however their role in ocular pediatric diseases has not been well reported. In this study, AS-OCT and specular microscopy were used to evaluate and compare the iridocorneal angles and corneal parameters in normal versus glaucomatous eyes in a pediatric population

Methods : AS-OCT of the temporal iridocorneal angle and specular microscopy were performed on a total of 90 pediatric subjects (70 glaucomatous eyes and 20 normal eyes) from the Children Hospital of Los Angeles using a noncontact technique. AS-OCT images were graded for the ability to visualize Schwalbe’s line (SL), the superior iris surface, and the angle recess. Image J software (1.49v) was used to measure the angle opening distance at SL (SL-AOD) and trabecular-iris-space-area 500 µm posteriorly from SL (SL-TISA) in gradable images. Specular microscopy images were manually analyzed using the center method to determine the endothelial cell density, hexagonality, and coefficient of variation. Student t-test was used to calculate the p-value from the means (statistical significance if <0.05)

Results : OCT and specular microscopy imaging of the anterior segment in the study patients was well tolerated . The mean temporal SL-AOD in the normal eyes is 0.76 +/- 0.22 mm compared with 0.81 +/- 0.26 mm in glaucomatous eyes, with no statistically significant difference between the 2 study groups (P- value: 0.8). The mean temporal SL-TISA in normal eyes is 0.30+/- 0.17 mm² compared with 0.28 +/- 0.12 mm² in glaucomatous eyes with no statistically significant difference between the 2 groups (P- value: 0.92).
Data obtained from further analysis of the glaucoma subtypes and specular microscopy are summarized in table-1 & 2

Conclusions : In the present study, there does not appear to be a clinically significant difference in iridocorneal angle biometrics between normal and glaucomatous eyes, however, the endothelial cell density is observed to be lower in glaucomatous eyes. Noncontact AS-OCT and specular microscopy demonstrated to be effective techniques to evaluate the anterior segment providing anatomic details and are useful to clarify diagnoses in the pediatric population.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.