Typical Indications

• Mild-to-moderate open-angle glaucoma and ocular hypertension (when medical/laser therapy insufficient). (Wills Eye Library)
• Can be performed standalone, but often done combined with cataract surgery (phaco-KDB/phaco-BANG) to leverage dual benefit. (Dove Medical Press)

Extended indications

• Primary angle closure glaucoma with or without synechiolysis
• Secondary glaucoma like angle recession or steroid induced glaucoma
• Post trabeculectomy to further reduce the need for medication

Limitations / Considerations

1. Effectiveness depends on functioning distal outflow system (collector channels).
2. Angle must be accessible and free of extensive peripheral anterior synechiae (PAS) or scarring.
3. Hyphema and early IOP spikes must be anticipated and managed. (PubMed) 

Operating “pearls”:

1. Practice gonio orientation and instrument handling in a wet lab or simulator — the en face gonioscopic view is the most important skill. (Eyetube)
2. Many surgeons perform the KDB /BANG portion before the phaco portion (when combined) because the viscoelastic is fresh and view is clear. (Glaucoma Today)
3. Use gentle, controlled advancement of the blade/bent needle — avoid forcing or “darting” which might damage outer wall of Schlemm’s canal or collector channels.
4. Always verify you have a full TM strip or residual cleft, and note any anatomical variations or resistance.
5. Have backup instruments (microforceps, spare bent needle,spare KDB) and viscoelastic on hand.
6. Post-op, educate patient about mild hyphema (often expected) and the need for head-elevation, blood pressure control and activity moderation
7. Anterior chamber maintainer or infusion line to keep chamber depth stable during angle work .
8. Intraoperative gonioscopic video/documentation capability for teaching or review.
9. Suggested Resources & Further Learning

Video (KDB)

• American Academy of Ophthalmology Master Class – “Kahook Dual Blade Goniotomy” (Dr. Ike Ahmed) — visual step-by-step. (AAO)
• EyeTube Video: “Kahook Dual Blade Goniotomy – Dr. Paul Singh” (with stabilization technique) (Eyetube)

Videos (BANG)

• Goniotomy BANG Technique — demonstration by Dr. Abdelwahhab Azzawi on EyeTube. (Good step-by-step visual). (Eyetube)
• BANG — Bent Ab-Interno Needle Goniectomy — various operative demonstration videos (YouTube/EyeTube/CataractCoach). Search “BANG goniotomy” for multiple examples (e.g., YouTube links). (YouTube)
• BANG! Tips and Tricks — brief pearls video on EyeTube. (Eyetube)

Articles (KDB)

• “A Review of Excisional Goniotomy Performed with the Kahook Dual Blade for Glaucoma Management.” Dorairaj S et al., 2022. (PMC)

• “12-Month Retrospective Comparison of Kahook Dual Blade Excisional Goniotomy with iStent Implantation.” (PubMed)
• “Clinical Outcomes of Excisional Goniotomy with the Kahook Dual Blade: 6-Year Results.” Ophthalmology and Therapy, 2024. (SpringerLink)

Articles (BANG)

• Shute T, et al. An Alternate Technique for Goniotomy — describes needle goniectomy concepts and includes BANG-like approaches. (Free online). (PMC)
• Townsend J, et al. Bent ab-interno needle goniectomy (BANG) — early description and outcomes. (IOVS/ARVO). (IOVS)
• Bukke AN, et al. Outcomes of bent ab interno needle goniectomy with phacoemulsification — recent outcome series. (PMC)
• Jeong J, et al. Comparing outcomes of KDB with bent needle — preliminary comparative data suggesting differences; important when counseling on alternatives. (IOVS)
• Ayub G, et al. RCT protocol comparing BANG vs GATT — describes ongoing trials and rationale. (BioMed Central)