Trans‐zonular delivery of intravitreal triamcinolone acetonide in the management of pre‐existing macular oedema during cataract surgery

Abstract

Editor, T riamcinolone acetonide (TA) is a corticosteroid suspension that has been used as an intravitreal injection to treat macular oedema of various causes (Young et al. 2001; Jonas et al. 2003; Park et al. 2003). Usually, the intravitreal triamcinolone acetonide (IVTA) injection is administered through a pars plana route using a 25or 30gauge needle, predominantly by retinal specialists. We describe a novel technique to deliver an IVTA injection through an anterior trans-zonular approach, which can be performed at the end of routine phacoemulsification cataract surgery in patients with coexisting macula oedema. Patients were selected on a nonrandomized, case-by-case basis. It was difficult to administer any further laser treatment for macular oedema in these patients because of the cataract. They were fully informed that the procedure was new, the natural history of each patient’s eye status was discussed with them, and informed consent was obtained in accordance with the tenets of the Helsinki Declaration. Cataract surgery was performed under local anaesthesia in a standard fashion through a superior clear corneal incision using phacoemulsification and bimanual irrigation and aspiration, with intraocular lens (IOL) implantation in the capsular bag. Then, 1 ml of 40 mg/ml TA (Kenalog; Bristol-Myers Squibb SpA, Princeton, NJ, USA) was drawn into a 1-ml syringe and attached to a Bolger cannula. After lens implantation, the positions of the IOL and continuous curvilinear capsulorhexis (CCC) were noted and the Bolger cannula was introduced into the anterior chamber and advanced under the iris and over the anterior capsule, so that the tip was judged to be passing through the ciliary zonules inferiorly at approximately the 6 o’clock position. Triamcinolone acetonide 0.1 ml (4 mg) was injected into the vitreous cavity through the transzonular route using the Bolger cannula (Fig. 1). The cannula was carefully withdrawn from the anterior chamber and the positions of the IOL and CCC were rechecked. Any TA that had refluxed into the anterior chamber was removed with bimanual irrigation and aspiration. The corneal incision was hydrated with balanced salt solution. No wound leakage was evident at the end of the procedure and no TA was evident in the anterior chamber. Triamcinolone acetonide was seen in the vitreous cavity at the end of the procedure and also in the inferior vitreous at postoperative examination, confirming its presence in the vitreous cavity. This technique was performed prospectively in six patients (Table 1) undergoing cataract surgery with preexisting macular oedema of different aetiologies (three due to diabetes, two to retinal vein occlusion, and one to pars planitis). All cases underwent visual acuity (VA) testing and macular thickness measurements with ocular coherence tomography (OCT) preoperatively and then at 1, 2 and 6 weeks after surgery. The centration of the IOL was observed at each postoperative visit after pupil dilatation. Intraoperatively no change in the position of the IOL or CCC was observed after the trans-zonular IVTA injection and the IOL remained well centred at each postoperative visit in all cases. Visual acuity improved in all six patients and macular thickness, as documented on OCT, was reduced. Intraocular pressure (IOP) was not increased at any of the follow-up visits in this series of patients. There were no cases of infectious or non-infectious endophthalmitis and none of the cases Fig. 1. Triamcinolone acetonide 0.1 ml (4 mg) was injected into the vitreous cavity through the trans-zonular route using the Bolger cannula.