Treatment success of canaloplasty and trabeculectomy by the same surgeon with the same level of experience in the long-term course

Abstract

Trabeculectomy (TE) with the use of antimetabolites is the standard procedure in glaucoma surgery, whereas canaloplasty (CP) is anonpenetrating and potentially less invasive alternative. The aim of this retrospective case series was to compare the long-term success of CP and TE under the same conditions and with the same levels of experience of the surgeon as well as to investigate whether preoperative intraocular pressure (IOP) and postoperative IOP correlate with eachother. The study included 57eyes that underwent either CP or TE (CP n = 27; male = 50.0% age 60.7 ± 13.2 years; TE n = 30; male = 55.6% age 68.0 ± 9.1years). Each of the procedures was performed by the same surgeon with comparable levels of experience. The comparison included preoperative and postoperative visual field damage, preoperative and postoperative IOP (mm Hg) after 1 and 6weeks, 6and 12months as well as in the long-term course (1-3years) and the necessary local treatment at the corresponding times. With both methods no worsening of the visual field could be detected and the patient groups showed comparable preoperative and postoperative mean deviations (MD). The CP showed apositive correlation between preoperative and postoperative 1‑year IOP (r = 0.4; p = 0.022), whereas TE showed no significant correlation between preoperative and postoperative IOP. The count of local antiglaucoma medication in long-term comparison (1-3years after surgery) was higher after CP than after TE (1.5 ± 1.6 vs. 0.5 ± 0.8; p = 0.003). In both groups there were no severe postoperative complications. The overall success rates (without treatment) were higher at all time points after TE. With both methods conducted by the same surgeon with the same levels of experience, an effective reduction of the IOP was achieved. It seems that the higher the preoperative IOP before CP, the higher the achievable pressure after 1 year and in the long term. In contrast, after TE the IOP was effectively reduced in the long term regardless of the initial IOP. The CP seems to be inferior to TE under the same conditions with respect to complete surgical success (without local treatment).