AMOUNT OF RESIDUAL SILICONE OIL IN VITREOUS CAVITY IS SIGNIFICANTLY CORRELATED WITH AXIAL LENGTH. Issue 1 (January 2016) - Shiihara, Hideki
Abstract : 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 hyperechoic particles in the ultrasonographic images. The images of the vitreous cavity were binarized, and the ratio of area of hyperechoic particles to the total vitreous area was quantified and named the silicone oil index (SOI). The correlations between SOI and clinical findings were determined. Results: The SOI was significantly and positively correlated with the axial length (AL) and the preoperative intraocular pressure (AL, R = 0.676, P = 0.002; preoperative intraocular pressure, R = 0.771, P < 0.001). Partial correlation analysis showed that the AL remained significantly correlated with the SOI but the preoperative intraocular pressure was not (AL, R = 0.734, P = 0.001; preoperative intraocular pressure, R = 0.417, P = 0.096). None of the other clinical factors was significantly correlated with the SOI. Conclusion: 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. Abstract : The quantification of residual silicone in vitreous cavity by an image processing technique of the ultrasonographic images showed that eyes with longer axial lengths had a significantly greater chance of having larger amounts of residual silicone oil. Eyes with long axial length should be carefully treated in removing silicone oil.