Evaluation of corneal damage by combined phacoemulsification and passive efflux of silicone oil in vitrectomized eyes.

PURPOSE: To evaluate the effect on the corneal endothelium of phacoemulsification combined with passive silicone oil removal and intraocular lens (IOL) implantation under topical anesthesia after pars plana vitrectomy. SETTING: Department of Ophthalmology and Otolaryngology, University of Bari, Bari, Italy. METHODS: This retrospective study evaluated the corneal endothelium in 17 consecutive patients (17 eyes) who had phacoemulsification with transpupillary passive silicone oil washout (1300 centistokes) through a posterior capsulorhexis and single clear corneal incision and foldable acrylic IOL implantation. The findings were compared with those in a control group of 17 patients (17 eyes) who had phacoemulsification with acrylic IOL implantation through a single clear corneal incision. All procedures were performed by the same surgeon using topical anesthesia. The preoperative and postoperative endothelial cell densities, coefficient of variation (CV), and percentage of hexagonal cells at the corneal center and peripheral temporal position, evaluated by noncontact specular microscopy, were compared between the 2 groups. The central corneal thickness and occurrence of keratopathy were also noted. RESULTS: The mean phacoemulsification and total ultrasound times did not differ significantly between the 2 groups. At 6 months, the mean endothelial cell loss was 284.50 cell/mm(2) +/- 462.3 (SD) (11.2%) in the study group and 200.15 +/- 117.9 cell/mm(2) (8.3%) in the control group (P=.87, unpaired t test). There were no significant between-group differences in the increase in the mean CV and the percentage of hexagonal cells. The mean pachymetry remained at preoperative values, with no difference between groups. Keratopathy was not observed in any patient. CONCLUSIONS: Passive silicone oil efflux caused significant endothelial cell loss and changes in endothelial morphology. Nevertheless, these modifications were well tolerated and minimally different from the results of trauma caused by standard phacoemulsification with posterior chamber IOL implantation