Case-matched comparison of combined phacoemulsification with ab-interno trabeculectomy via Kahook dual blade and trabectome in a Caucasian population

The purpose of this retrospective study was to compare the outcomes after combined phacoemulsification and ab-interno trabeculectomy via Kahook Dual Blade (KDB) and Trabectome, being represented in two groups of patients of Caucasian ethnicity with matched baseline criteria. We included 60 eyes of 49 participants being treated for cataract, of which 30 eyes underwent additional ab-interno trabeculectomy via KDB (Kahook group) and 30 eyes received additional Trabectome surgery (Trabectome group). For this comparative analysis, the Kahook group and Trabectome group were matched at a 1:1-ratio, based on the following criteria: preoperative IOP, maximum known preoperative IOP, preoperative medication score, cup/disc-ratio, follow-up time, best-corrected visual acuity and age. Successful surgery was defined by three scores: IOP at longest follow-up < 21 mmHg (Score A) or < 18 mmHg (Score B) without re-surgery and an IOP reduction > 20% or IOP ≤ 15 mmHg without re-surgery and an IOP reduction ≥ 40% (Score C). Furthermore, we compared postoperative IOP, as well as medication score, and side effects between both groups. Both surgical techniques led to a relative IOP reduction of 29% within their respective groups. Specifically, preoperative IOP decreased from 19.5 ± 5.0 mmHg to 13.8 ± 3.9 mmHg in the Kahook group, and from 19.8 ± 4.5 mmHg to 14.0 ± 3.9 mmHg in the Trabectome group during an average follow-up period of 23–24 months. There was no statistical significant difference noted. Both the KDB and Trabectome yielded similar success rates, according to Score A (67% vs. 70%), Score B (63% vs. 67%) and Score C (33% vs. 23%). There were no severe side effects notes in either group. In conclusion, the KDB and Trabectome showed similar IOP-lowering properties and safety profiles within our two matched groups of Caucasian patients.