Intraocular pressure changes after phacoemulsification and foldable silicone lens implantation using Healon GV

The authors studied the intraocular pressure (IOP) changes after phacoemulsification with two different kinds of foldable silicone lens implantation using Healon GV as viscoelastic substance. One hundred patients undergoing cataract surgery were enrolled in this study. Inclusion criteria were: absence of ocular hypertension or glaucoma. Patients were randomly assigned to plate haptic (Silens PH, Domilens Chiron Vision, Lyon, France) or three-piece (CeeOntrade mark& ;920, Pharmacia spa, Milano, Italia) silicone intraocular lens (IOL) implantation. Following phacoemulsification and cortical aspiration, the capsular bag was reinflated with Healon GV. After foldable silicone IOL insertion residual Healon GV was removed from the anterior chamber. IOP was measured preoperatively and at 6, 24 h and 1 week postoperatively. Six hours postoperatively IOP was higher in the Silens PH group than in the CeeOn group (20. 85+/-5.42 vs. 18.88+/-2.95 mm Hg, p= 0.026). The difference was confirmed after 24 h (21.02+/-5.18 vs. 17.34+/-3.18 mm Hg, p < 0.01). Despite the medical treatment (acetazolamide 250 mg orally every 6 h), at the 24-hour control 2 eyes with plate haptic silicone lens showed IOP values higher than 30 mm Hg. Slitlamp examination showed in both eyes a shallowing of the anterior chamber together with the evidence of capsular bag hyperdistension and capsular block resulting from the occlusion of the circular anterior capsule opening by the plate haptic IOL. Residual Healon GV removal from the anterior chamber was performed. At 1-week control both eyes showed normalization of IOP. The use of a plate haptic silicone lens may be associated with a more consistent retention of Healon GV in the eye with trapping in the capsular bag. Retained viscoelastic may cause either trabecular meshwork blockage by viscoelastic substance or postoperative capsular bag hyperdistension, anteroplacement of the IOL optic and capsular block from occlusion of the circular anterior opening by the IOL optic.