2M.D. Asistant, Erciyes University Faculty of Medicine, Department of Ophthalmology, Kayseri/TURKEY Purpose: To evaluate spectral domain optical coherence tomography (SD-OCT) in differentiating optic disc edema (ODE) due to papilledema and other optic neuropathies from optic nerve head drusen (ONHD).
Material and Methods: Optical coherence tomographic images from 42 subjects (18 with ONHD: group 1, 24 with ODE: group 2,) were examined qualitatively and quantitatively. Qualitative criteria for ODE were an elevated optic nerve head with smooth internal contour and subretinal hyporeflective space (SHYPS) with recumbent “lazy V” pattern. Optic nerve head drusen showed a “lumpybumpy” internal optic nerve contour and a rapid decline in SHYPS thickness. Quantitative comparisons included optic nevre head thickness (ONHT) and SHYPS thickness.
Results: All of the eyes matched the qualitative criteria for ONHD in group 1 and for ODE in group 2. The mean age of group 1 was 27.44±15.01 and in group 2 was 32.66±11.48 and there was no significance between groups (p>0.05). The mean ONHT measurement was 747.33±50.35 μm in group 1, and 820.07±150.78 μm in group 2. Although the ONHT was greater in ODE patients, there was not a statistically significant difference between groups (p>0.05). When we evaluate the SHYPS thickness, the mean value was 478.77±53.77 μm in group 1 and 596.01±126.37 μm in group 2. The difference between the measurements was statistically significant (p<0.005).
Conclusions: SD-OCT is a viable instrument to differentiate optic nerve pathologies. The qualitative criteria and SHYPS as a quantiatative measurement seems to be useful for differentiation.
Keywords : Optic nerve drusen, optic disc edema, optic coherence tomography