Abstract
Purpose: The purpose of the study is to evaluate the efficacy of ultrasound elastography (USE) in differentiating optic disc drusen (ODD) from optic disc edema (ODE) and to investigate the relationship between corneal biomechanics and optic nerve elasticity. Methods: This prospective, clinical study included 28 eyes of 16 ODD patients (Group 1), 23 eyes of 18 ODE patients (Group 2) and 30 eyes of 15 healthy controls (Group 3). Best corrected distance visual acuity (BDVA), corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated intraocular pressure (IOPcc), Goldmann-correlated IOP (IOPg) and optic nerve head (ONH)-elasticity were measured. Results: The mean BDVA value was significantly lower in Group 2 compared to Groups 1 and 3 (p<0.001), there was no significant difference between Groups 1 and 3 (p=0.089). The mean intraconal fat to ONH ratio was significantly higher in Group 1 compared to Group 2 (p=0.008) and 3 (p=0.002), there was no significant difference between Group 2 and 3 (p=0.182). The receiver operating characteristic curve areas for ONH-elasticity in differentiating group 1 and group 2 was 0.728 (p=0.008) with 80% sensitivity and 60% specificity when the cut-off point was set at 2.29. Corneal biomechanics (CH, CRF, IOPcc, IOPg) were not different between the three groups (p>0.05), however there was a significant correlation between corneal and ONH biomechanics in drusen group (p<0.05). Conclusion: The evaluation of the ONH with USE seems to provide useful data in differentiating ODD from ODE. Significant correlation was revealed between corneal and ONH biomechanics in drusen group.
Differentiating Optic Disc Edema From Optic Nerve Head Drusen on Optical Coherence Tomography