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.