The Effect Of Failed Gatt On The Success Of Sequential Subconjunctuval Surgery- A Matched Analysis

To determine whether failure of gonioscopy-assisted transluminal trabeculotomy (GATT) compromises outcomes of subsequent subconjunctival glaucoma surgery (SGS).

Tertiary referral academic medical center.

This retrospective single-center matched cohort study included eyes that underwent SGS after failed GATT (G-SGS, n=32). These were matched by age, sex, glaucoma type, and SGS procedure (trabeculectomy, Ahmed glaucoma valve, or Preserflo MicroShunt) to eyes undergoing primary SGS (P-SGS, n=32). Primary outcomes were IOP reduction and surgical success after SGS. Secondary outcomes included medication burden, need for additional surgery, and complications.

At baseline, P-SGS eyes had more advanced disease (worse VF MD −19.8 vs −9.6 dB, thinner RNFL 51.6 vs 66.5 µm, higher C/D 0.87 vs 0.72; all p≤0.02) and more advanced glaucoma (97% vs 56%, p=0.003). Preoperative IOP was similar. Final IOP was comparable (12.4 vs 13.8 mmHg, p=0.4), but IOP reduction was greater in G-SGS (14.2 vs 8.9 mmHg, p=0.02). Medication reduction and success rates were similar (78% vs 84%, p=0.5). Further surgery was required in 22% vs 34% (p=0.2). Complications were not increased after prior GATT.

Failure of GATT does not compromise the efficacy or safety of subsequent subconjunctival glaucoma surgery. These findings support a stepwise surgical approach in glaucoma management.