Abstract
Purpose :
The dimensions of a macular hole can help predict the outcome of intervention. The extent of the ellipsoid defect and base diameter can be measured by manual delineation in serial scans. We sought to investigate whether these dimensions are more readily indicated by the Topcon OCT shadowgram.
Methods :
In OCT scans of 50 eyes with idiopathic full-thickness macular holes, we correlated the linear dimensions of OCT sections with those of the shadowgram. We measured the diameter of the total ellipsoid defect, the horizontal extent of intraretinal cysts and the base diameter of the hole using the calliper tool on the OCT section. We measured the linear horizontal diameter of the outer and inner edges of the shadowgram using ImageJ.
Results :
The mean base diameter was 920 μm, and the mean ellipsoid defect was 2338 μm. The diameter of the total ellipsoid defect was correlated positively with the horizontal extent of intraretinal cysts (R2 = 0.67). The horizontal diameter of the outer edge of the shadowgram correlated positively with both the ellipsoid defect (R2 = 0.64) and the extent of intraretinal cysts (R2 = 0.76). The linear horizontal length of the inner edge of the shadowgram correlated positively with the base diameter of the hole (R2 = 0.64).
Conclusions :
The dimensions of the inner and outer edges of the shadowgram provide a potentially useful indication of the dimensions of the base diameter of the hole and the extent of the ellipsoid defect respectively.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.