To determine the risk factors for transient hypotony after silicone oil removal in rhegmatogenous retinal detachment and to analyze changes in intraocular pressure and visual acuity after silicone oil removal.

The medical records of 54 eyes of 52 patients who underwent pars plana vitrectomy, silicone oil tamponade followed by silicone oil removal due to rhegmatogenous retinal detachment, were reviewed.

The incidence of transient hypotony after silicone oil removal was 18.5%. Young age ( p = 0.011) and axial length ( p = 0.002) were risk factors for transient hypotony based on univariate analysis. In multivariate analysis, axial length longer than 26 mm was the only risk factor for transient hypotony ( p = 0.005). Seven hypotony patients recovered to normal intraocular pressure spontaneously within 2 weeks. In 2 patients, intraocular pressure was normalized after intravitreal injection of C3F8 gas and 1 patient recovered after a balanced salt solution injection into the anterior chamber. Two weeks after silicone oil removal, there was no significant difference in intraocular pressure between the hypotony group and normal intraocular pressure group. Additionally, there was no statistically significant difference in best corrected visual acuity between the 2 groups after 2 weeks.

Although transient hypotony after silicone oil removal in rhegmatogenous retinal detachment was frequently observed in the present study, the final best corrected visual acuity and intraocular pressure was not always affected. Ocular hypotony should be examined thoroughly in the early postoperative period.