The Results of B-scan Ultrasonography in Different Positions after Vitrectomy and Gas Tamponade

PURPOSE: To determine the proper time frame in which to assess retinal attachment status and to evaluate the superior retinal attachment status by performing B-scan ultrasonography in different positions on patients who have undergone pars plana vitrectomy and gas tamoponade. METHODS: In this prospective study, 23 patients (23 eyes) who had undergone pars plana vitrectomy and gas tamponade were investigated between June 2005 and February 2006. SF(6) (18%) was injected into the vitreous cavity of 15 eyes, and C(3)F(8) (14%) was injected into the vitreous cavity of 8 eyes. At postoperative day 1, day 3, week 1, week 2, and week 4, B-scan ultrasonography was performed in the supine, sitting, prone, right decubitus, and left decubitus positions. RESULTS: The proper time to evaluate the retinal attachment status was three days post-operatively in 10 eyes (66.7%) with SF(6) (18%) injections and two weeks post-operatively in six eyes (75%) that had C(3)F(8) (14%) injections. The superior retinal attachment status can be evaluated from the summation of B-scan ultrasonography results performed in the right decubitus and left ducubitus positions. CONCLUSIONS: The proper time to evaluate the retinal attachment status was related to the degree of the gas absorption when performing B-scan ultrasonography after pars plana vitrectomy and gas tamponade. To evaluate the entire retina, it is useful to perform B-scan ultrasonograhy in the prone, right decubitus and left decubitus positions.