Comparison of PMMA, foldable silicone and foldable acrylic hydrophobic intraocular lenses in combined phacoemulsification and trabeculectomy.

PURPOSE To compare the postoperative results of phacotrabeculectomy with implantation of PMMA, foldable silicone or foldable hydrofobic acrylic intraocular lens (IOL). SETTING Glaucoma unit, The Royal Liverpool University Hospital, Liverpool, United Kingdom. METHODS We studied a total of 124 eyes of three consecutive groups of patients with glaucoma and cataract that underwent phacotrabeculectomy with implantation of a PMMA (30 eyes), a foldable silicone (57 eyes) or a foldable acrylic (37 eyes) IOL. Postoperative Snellen visual acuity and intraocular pressure (IOP), and early and late complications were assessed. All data were analyzed by means of chi2 test, Fisher's exact test, ANOVA/MANOVA tests or a combination whenever appropriate. RESULTS In all three groups the early and late mean postoperative IOPs were significantly lower than the preoperative ones (p<0.001), with no intergroup differences (p=0.48). The number of eyes with early postoperative hypertension (IOP>25 mmHg) and hypotony (IOP<7 mmHg) was similar in the three groups (p=0.91 and p=0.92 respectively). All groups showed improvement in mean visual acuity (p<0.001), and the differences among the groups were not significant (p=0.79). By 9-12 months after surgery IOPs lower than 22 mmHg without glaucoma medication were found in 76.9% in the PMMA group, 76.6% in the silicone group and in 76.9% in the acrylic group. At the same interval, best visual acuity of 6/12 or better was attained in 80.8%, 83% and 80.8%, in the PMMA, silicone and acrylic groups respectively. The silicone group had significantly more postoperative fibrin reaction into the anterior chamber (p=0.01) and giant cell deposits on the IOL (p<0.0001) than the PMMA and the acrylic groups. The rate of Yag laser posterior capsulotomy was lower with the acrylic IOL (0%) than with the silicone (12.2%) or PMMA (13.3%) IOLs (p=0.08). CONCLUSION In patients with glaucoma and cataract, phacotrabeculectomy with PMMA, silicone or acrylic IOL was equally effective in lowering the IOP and improving visual acuity. However, incidence of fibrin reaction and lens deposits was higher in those eyes which received a silicone IOL. The PMMA and the acrylic groups did not differ with respect to postoperative complications, but those eyes with an acrylic IOL had a lower rate of posterior capsule opacification.