Abstract
Purpose: :
Silicone oil tamponade (SOT) produces marked changes in the refraction. However, most reports are based on calculations applied to a model eye, and clinical reports on the refractive changes in pseudophakic eyes with SOT and removal are limited. Recently, as phacoemulsification became popular, more silicone oil-filled pseudophakic eyes are seen. Thus, we examined the refractive changes in pseudophakic eyes with SOT and analyzed whether or not the preoperative target refraction was met following silicone oil removal.
Methods: :
The records of patients who had combined phacoemulsification and posterior chamber IOL implantation, vitrectomy, and SOT at Yongdong Severance Hospital between March 2002 and March 2008 were retrospectively reviewed. Biconvex type foldable acrylic IOL models and 1300 centistoke silicone oil were used. Preoperatively, all had clinically significant cataracts. The IOL power was calculated with the measurements from A-scan ultrasonic biometry (Tomey UD-6000) and an automatic keratometer (Canon RK-3). Manifest refractions were performed using best-spectacle correction based on retinoscopy results at least 1 month after each surgery. Eyes with a history of procedures interfering with the refractive status and eyes with unreliable manifest refraction were excluded.
Results: :
Twenty-six eyes from 23 patients were identified: diabetic tractional retinal detachment in 20 eyes, rhegmatogenous retinal detachment with proliferative vitreoretinopathy in 3, 1 with BRVO and tractional retinal detachment, 1 with uveitis and proliferative vitreoretinopathy, and 1 with choroidal neovascularization and vitreous hemorrhage. The mean age of the patients was 50.2 years and the mean duration of SOT was 9.3 months. Mean spherical equivalent of 3.85 ± 1.63 diopters (D) was observed with SOT. After silicone oil removal, a myopic shift of -4.51 ± 1.79 D was observed resulting in -0.66 ± 1.40 D, which concurred with the preoperative target of -0.47 ± 0.50 D (P = 0.465, paired t-test). Multivariate linear regression analysis demonstrated that the axial length and refractive index of the IOL were significant factors in determining refraction in the oil-filled state(P = 0.000).
Conclusions: :
Pseudophakic eyes with SOT resulted in lesser hyperopic shift than known in phakic eyes, with tolerable hyperopia. After oil removal, refraction returned to the preoperative target diopters. Regarding early postoperative rehabilitation, in cataractogenous patients requiring the use of silicone oil, phacoemulsification with intraocular lens implantation simultaneously with vitreous surgery may be an option.
Keywords: proliferative vitreoretinopathy • intraocular lens • refraction