Outcomes of ab interno trabeculectomy with the trabectome by degree of angle opening

Aim To analyse ab interno trabeculectomy (AIT) with the trabectome and combined phacoemulsification with AIT (phaco-AIT) by Shaffer angle grade (SG). Methods Prospective study of AIT and phaco-AIT with narrow angles of SG <= 2 versus open angles >= 3. Outcomes included intraocular pressure (IOP), medications, complications, secondary surgery and success (IOP < 21 mm Hg and > 20% reduction without further surgery). Exclusion criteria were missing preoperative data and < 1 year follow-up. Results Of 671 included cases, at 1 year AIT SG <= 2 (n=43) had an IOP reduction of 42% from 27.3 +/- 7.4 to 15.7 +/- 3.0 mm Hg (p<0.01) versus AIT SG >= 3 (n=271) with an IOP reduction of 37% from 26.1 +/- 7.8 to 16.4 +/- 3.9 mm Hg (p<0.01). In phaco-AIT with SG <= 2 (n=48), IOP was reduced 24% from 20.7 +/- 7.0 to 15.7 +/- 3.6 mm Hg (p<0.01) versus phaco-AIT with SG >= 3 (n=309) with an IOP reduction of 25% from 22.6 +/- 6.4 to 17.0 +/- 3.4 mm Hg (p<0.01). There was no difference between SG <= 2 and SG >= 3 in reduction of IOP or medications, complications, secondary surgery and success rates (p>0.05). Conclusions SG <= 2 is not associated with worse outcomes in AIT or phaco-AIT.