Trabeculotomy combined with phacoemulsification and implantation of intraocular lens for primary open-angle glaucoma

Retrospective study examined the surgical effects of lowering intraocular pressure of trabeculotomy combined with phacoemulsification and implantation of an intraocular lens. Included in the retrospective study were 96 eyes of 64 patients with primary open-angle glaucoma. Preoperative mean IOP was 25.6 mmHg. At final examination, the IOP was well-controlled at 21 mmHg or lower without medications in 32 of 96 eyes. In another 62 eyes, the IOP was well-controlled with antiglaucoma medications. The postoperative IOPs were in the high teens after surgery. The life table analysis using Kaplan-Meier methods showed that the success probability after phacoemulsification and implantation of intraocular lens, combined with trabeculotomy (PIT)-I and PIT-II, were 93.9% and 82.6% at 4 years, respectively. Postoperative visual acuity improved by more than two lines in 79 of the 96 eyes. In no case was the visual acuity decreased by more than two lines. Deterioration of the visual field was found in 4 eyes. There were no complications such as shallow anterior chamber, choroidal detachment, malignant glaucoma, hypotonic maculopathy, and endophthalmitis. This triple procedure should be performed in the early stages of glaucoma. Trabeculotomy is thought to relieve the resistance to aqueous outflow by mechanical cleavage of the trabecular meshwork and the inner layer of Schlemm's canal. This technique leads to aqueous outflow the from the opening of the internal trabecular meshwork to the collector channel. For this reason trabeculotomy was developed by a number of surgeons. Recently, however, trabeculotomy has not been selected for those patients with advanced stages of primary open-angle glaucoma because of the disadvantages such as transient intraocular pressure (IOP) elevation several days after surgery and somewhat higher levels (18 mmHg) of postoperative intraocular pressure (Fig. 1). To avoid the IOP spike (transient IOP elevation) after trabeculotomy, we reported previously that the new technique of trabeculotomy combined with outer sclerectomy was a useful surgical option. The results of our previous study indicated that the postoprative intraocular pressure levels after combined trabeculotomy and outer sclerectomy were significantly lower than that of trabeculotomy alone. On the other hand, trabeculotomy with mitomycin C is currently the standard filtration procedure for glaucoma. This technique, however causes severe postoperative complication such as hypotonic maculopathy, bleb leakage and late bleb infection. The major advantages of trabeculotomy preclude these severe complications resulting from creating progressive filtration of aqueous humor from the anterior chamber to the subconjunctival space. The recent advance of small-incision phacoemulsification procedure prompted phacoemulsification and implantation of intraocular lens and trabeculotomy. The theoretical advantages of smaller scleral, conjunctival incision, reduced stimuli to wound healing, and inflammation, could improve long-term IOP control in patients with glaucoma. Therefore several reports have been published on the surgical outcomes of combined trabeculotomy and modern phacoemulsification. These reports suggested that the combined trabeculotomy and a small-incision with intraocular lens implantation is effective in controlling IOP in patients with glaucoma.