Directional Reflectivity of the Ellipsoid Zone in Dry Age-Related Macular Degeneration
Shane Griffin, Yali Jia, Alicia J. Johnson, Bhavna Antony, H. Richard McDonald, Robert N. Johnson, Brandon J. Lujan
Abstract
BACKGROUND AND OBJECTIVE: Ellipsoid zone (EZ) reflectivity on optical coherence tomography (OCT) is affected by the orientation of the scanning beam. The authors sought to determine how directional reflectivity changes in dry age-related macular degeneration (AMD). PATIENTS AND METHODS: Retrospective image analysis included 17 control and 20 dry AMD subjects. Directional OCT (D-OCT) was performed using multiple displaced pupil entrance positions. EZ pixel values and apparent incidence angles were measured. RESULTS: EZ reflectivity decreased in off-axis scans in controls ( P < .001), AMD areas between drusen ( P < .001), and AMD areas overlying drusen ( P < .001). The magnitude of decrement in EZ reflectivity was significantly higher when incidence angles exceeded 10° in controls than in AMD areas between drusen ( P = .024). CONCLUSION: EZ reflectivity in dry AMD may vary by incident angle of light less than in controls, possibly indicating alteration of photoreceptor orientation or integrity. [ Ophthalmic Surg Lasers Imaging Retina. 2021;52:145–152.]