Purpose: To report a novel spectral-domain optical coherence tomography (SD-OCT) finding in children affected by tilted disc syndrome (TDS), and to correlate it with early visual field defects.
Methods: Patients between 5 and 17 years old with TDS were enrolled in this study. The diagnosis of TDS was made by stereoscopic fundus photography, when the upper edge of the optic disc protruded anteriorly relative to its lower edge. All eyes were examined with 12 radial SD-OCT B-scans of 12 mm centered on the optic disc; the fundus area encompassing the optic nerve was additionally scanned using several vertical and horizontal scans.. C-scan SD-OCT were acquired using the Macular Cube 512 x 128 to create the en face image. Standard automated perimetry 24-2 tests were performed on all patients.
Results: Thirty-eight eyes of 20 pediatric patients with TDS syndrome were enrolled during this 24-months clinical trial. Their mean age was 10.9 ± 2.7 years (range 7-15 years), 12 (60%) were male and eight (40%) were female. The OCT images of the optic discs showed a protrusion of the upper edge of Bruch's membrane and choroid at the nasal edge of the optic disc in 39.5% of the eyes. The retinal nerve fiber tissue appeared to be herniated into this protrusion and bent superiorly in 15 eyes. This severe bending corresponded to early visual field anomalies that were not reduced by corrective lenses in 46.7% of the eyes.
Conclusion: Visual field defects that do not improve by increased myopic correction in TDS may be due to the severe bending of the retinal nerve fiber tissue, which would impair axonal flow.