Purpose
To determine the parameters of the eye that are significantly correlated with the amount of residual silicone oil remaining after most of it is removed by vitrectomy.
Methods
Nineteen eyes of 19 patients who had silicone oil removed were studied. The day after the surgery for silicone oil removal, B-scan ultrasonography was performed, and the residual silicone oil droplets were observed as hyper-echoic particles in the ultrasonographic images. The images of the vitreous cavity were binarized, and the ratio of area of hyper-echoic particles to the total vitreous area was quantified and named the silicone oil index (SOI). The correlations between SOI and clinical findings were determined.<br />
Results
The SOI was significantly and positively correlated with the axial length (AL) and the preoperative intraocular pressure (IOP) (AL, R=0.676, P=0.002;preoperative IOP, R=0.771, P<0.001). Partial correlation analysis showed that the AL remained significantly correlated with the SOI but the preoperative IOP was not (AL, R=0.734, P=0.001; preoperative IOP, R=0.417, P=0.096). None of the other clinical factors was significantly correlated with the SOI.<br />
Conclusions
Considering the significant correlation between the amount of residual silicone oil and the AL of the eye, myopic eyes should be carefully scrutinized for residual silicone oil.<br />