Abstract
Purpose: :
To summarize IOP and adjunctive medication outcomes for Trabectome surgeries performed for open-angle glaucomas in the US and Canada 2004-2008.
Methods: :
Trabectome is a new surgical instrument allowing electro-ablation of an arc of nasal trabecular meshwork (trabeculotomy ab interno) with simultaneous infusion (18.5 gauge sleeve) and aspiration (25 gauge) of tissue debris under gonioscopic control via one or two 1.7 mm clear corneal incisions. The device’s ceramic coated footplate is inserted into Schlemm’s canal and functions to feed target tissues into the ablation gap while protecting adjacent tissues from mechanical and thermal injury. Phacoemsulsification is done through one of the expanded incisions. This ongoing retrospective non-comparative case series currently includes 1692 surgeries (366 Trabectome-only with no prior surgery; 506 Trabectome-only with previous LTP; 252 Trabectome-only after prior failed filtering surgery; and 568 combined Trabectome-phacoemulsification cases). Sub-groups analyzed include POAG, pseudoexfoliation, pigmentary, trauma-related, uveitic, low-tension, and congenital glaucomas.
Results: :
Analyses include Kaplan-Meier curves (failure = IOP > 21 and not reduced by 20% below baseline on two consecutive visits beyond 3 months or repeat surgery). Success has remained approximately 70% at two years (N = 79) (Trabectome-only and combined Trabectome-phaco). Ten patients from the original Mexican cohort (N = 37) have achieved five-year follow-up with a mean IOP of 16.4 mm + 2.3 mm Hg, down from a mean preoperative IOP of 28.2 + 4.4 mm Hg. 3/5 congenital glaucomas have benefited. Among adults, uveitis-related (N = 25) glaucomas demonstrated the largest mean decrease in IOP (+ 50%) at six months (n = 11). Vision-threatening complications remain minimal and Trabectome does not appear to accelerate cataract. Adjunctive medications decreased across all sub-groups. Sit and Khaja’s angle photographs (ARVO 2008 P# O102) demonstrated a weak correlation between IOP outcome and the ablation arc. Surgeon-estimated ablation arcs (< or > 90o) have not demonstrated a statistically significant correlation between IOP outcome and degrees treated.
Conclusions: :
Trabectome achieves normalization of IOPs with decrease in adjunctive medications in POAG in spite of prior failed filters or laser trabeculoplasty. Complications remain far less frequent and serious than after trabeculectomy.
Keywords: intraocular pressure • aqueous • outflow: trabecular meshwork