Optic disc surface smoothness and visual field indices

Background: In order to ascertain whether the optic disc surface smoothness (ODSS) could be used to predict the amount of visual field damage in glauc omatous eyes, the correlations between ODSS and visual field indices were e valuated. Methods: One eye was randomly chosen from each of 40 normals and 50 patient s with glaucoma, The morphology of the optic disc surface was analyzed usin g the Topcon IMA-GEnet X Rev-3.51b. In order to define the level of "smooth ness" of the optic disc surface, the differences of the relative position o f each surface point was studied by measuring the standard deviation (SD) f rom the average height of the points (number of points ranged from 623 to 1 883 defending on the size of the disc area) that identify the optic disc su rface, All the subjects were also examined with the Humphrey perimeter (Pro gram 30-2) and the results were analyzed by Mann-Whitney U-test and Spearma n rank correlation coefficient. Results: The difference in ODSS between the glaucomatous and the normal eye s was statistically significant. No significant correlation was found betwe en age and ODSS. A significant correlation was found between ODSS and mean deviation (RID) and between ODSS and corrected pattern standard deviation ( CPSD). In the glaucoma soup there were significant correlations between ODS S and the perimetric indices MD and CPSD; no correlations were found in the normal group, Conclusion: The ability of ODSS to reflect the level of visual field change in glaucomatous eyes appears to be rather limited, even if statistically s ignificant, This fact does not limit the clinical usefulness of ODSS as a d iagnostic parameter in consequence of its strong correlations with the othe r morphometric parameters and its high sensitivity and specificity in separ ating normal from glaucomatous eyes.