Randomized study of the blood-aqueous barrier reaction after phacoemulsification and extracapsular cataract extraction

Abstract

Purpose: To compare the blood-aqueous barrier (BAB) breakdown after endocapsular phacoemulsification and extracapsular cataract extraction (ECCE).

Methods: Forty-two patients (64-82 years) enrolled for cataract surgery were randomly assigned to phacoemulsification (group I) or ECCE (group II). Patients with pseudoexfoliation syndrome, small pupils, glaucoma, uveitis, dark brown irides, diabetes, treatment with eye drops or anti-inflammatory drugs were excluded. In group I the patients were operated with continuous curvilinear capsulorhexis (CCC), phacoemulsification and implantation of a poly-(methyl methacrylate) (PMMA) intraocular lens (IOL) through a 5.2 mm self-sealing incision. In group II linear capsulotomy, nucleus expression and PMMA IOL implantation through a large incision (10-11 mm) were performed. The incision was sutured. Before surgery and three days and three months after surgery postoperative inflammation and BAB reaction were measured by laser flare photometry and anterior chamber fluorophotometry after intravenous administration of fluorescein. The BAB diffusion coefficient was calculated. Laser flare photometry was performed also after one and two years.

Results: According to fluorophotometry, ECCE induced significantly more postoperative BAB breakdown than did phacoemulsification at three days (p=0.00016) and three months (p=0.00829). Laser flare photometry showed more inflammation in the ECCE group than in the phacoemulsification group at three days postoperatively (p=0.00005).

Conclusions: This study suggests that cataract surgery performed with a small, self-sealing incision, CCC and phacoemulsification induces a reduced surgical trauma with less BAB breakdown compared to ECCE using a large sutured incision, linear capsulotomy and nucleus expression.