The 1-2-3 Rule: When to "Consider" Glaucoma Surgery and Discuss It With Patients

Earlier intervention is gaining momentum in glaucoma care, yet delayed referral and delayed consideration of surgery remain concerns in clinical practice. A simple clinical rule may help general ophthalmologists recognize when to discuss procedural options with patients. We propose the Shimane University 1-2-3 rule (SU1-2-3), comprising three prompts: intraocular pressure (IOP) >12 mmHg in progressive advanced glaucoma, with advanced glaucoma defined for this rule as visual field mean deviation ≤ -10 dB or glaucomatous visual field defects within the central 10°; IOP >20 mmHg despite topical treatment in perimetric glaucoma; or use of ≥3 bottles of IOP-lowering eye drops. Oral acetazolamide use is an additional, independent prompt. Meeting any criterion should initiate consideration of surgical options, shared decision-making, and specialist consultation when appropriate, rather than constitute an automatic indication for surgery. SU1-2-3 draws on evidence supporting IOP lowering, treatment-burden assessment, and procedural intervention, but its thresholds and clinical utility have not been prospectively validated. Because its components rely on readily available clinical information, SU1-2-3 may also facilitate consultation when glaucoma subtype classification remains incomplete. It is intended as a minimum safeguard against delayed consideration of surgery, while allowing earlier laser or surgical intervention according to individual needs. SU1-2-3 may serve as a practical clinical and educational reminder for ophthalmologists without glaucoma subspecialty training, general ophthalmologists, and ophthalmology residents.