Open-Angle Glaucoma

At the diagnostic visit, document IOP by tonometry, anterior-chamber angle anatomy by gonioscopy, optic nerve head appearance by dilated examination, and baseline structural and functional damage with optic nerve imaging and standard automated perimetry. Open-angle glaucoma is defined clinically by progressive optic nerve rim and retinal nerve fiber layer loss with a compatible open-angle anatomy; IOP is the principal modifiable risk factor but is not itself diagnostic. ScienceDirect+3ScienceDirectOpen Angle Glaucoma - an overviewScienceDirectThe relationship between intraocular pressure and glaucoma: An evolving conceptScienceDirectGlaucomaaaojournalPrimary Open-Angle Glaucoma Preferred Practice Pattern®

Use central corneal thickness as an interpretive modifier for applanation IOP and risk assessment rather than as a stand-alone treatment threshold. The core distinction is ocular hypertension—elevated IOP without established glaucomatous structural or field injury—versus definite glaucoma, in which optic nerve or retinal nerve fiber layer loss and/or reproducible visual-field loss establishes the disease phenotype. ScienceDirect+2ScienceDirectOpen Angle Glaucoma - an overviewaaojournalPrimary Open-Angle Glaucoma Preferred Practice Pattern®aaojournalAlcohol, Intraocular Pressure, and Open-Angle Glaucoma

In suspected or established disease, obtain a reliable baseline visual field using a central threshold automated perimetry strategy and retain the same strategy for subsequent tests when a defect has been detected. Repeat optic nerve head examination or imaging when clinically indicated, because progression may be structural, functional, or both. nice org uknice org ukRecommendations | Glaucoma: diagnosis and management | Guidance | NICE

Set the initial target as a relative and absolute IOP objective based on untreated or pretreatment IOP, current optic nerve and field damage, and subsequent rate of progression. European guidance cites a peak IOP of 8 to 15 mm Hg on a diurnal curve or approximately 30% reduction from baseline in most normal-tension glaucoma cases; the appropriate target should be lowered further if damage progresses at the achieved IOP. BMJBMJEuropean Glaucoma Society Terminology and Guidelines for Glaucoma, 4th Edition - Chapter 2: Classification and terminologySupported by the EGS Foundation | British Journal of Ophthalmology

Measure treatment success against both pressure and disease course. A pressure value that meets the initial target is inadequate if serial OCT or optic nerve assessment shows progressive retinal nerve fiber layer loss or if reproducible visual-field decline continues. Conversely, isolated IOP elevation without documented damage should prompt confirmation, risk assessment, and an individualized decision rather than automatic assignment of a glaucoma diagnosis. ScienceDirect+2ScienceDirectOpen Angle Glaucoma - an overviewnice org ukRecommendations | Glaucoma: diagnosis and management | Guidance | NICEaaojournalPrimary Open-Angle Glaucoma Preferred Practice Pattern®

Recognize that IOP fluctuates over short and long time periods. When office values and progression appear discordant, repeat IOP measurements at different times or obtain a diurnal assessment before declaring a regimen effective or ineffective. BMJ+1BMJEuropean Glaucoma Society Terminology and Guidelines for Glaucoma, 4th Edition - Chapter 2: Classification and terminologySupported by the EGS Foundation | British Journal of OphthalmologyScienceDirectThe relationship between intraocular pressure and glaucoma: An evolving concept

Initial treatment for primary open-angle glaucoma or ocular hypertension can be topical pressure-lowering medication or SLT when the angle is open and trabecular meshwork is adequately visualized. SLT was safe and effective as first-line therapy in the LiGHT trial, and guideline evidence indicates IOP reduction comparable to prostaglandin analogues at 9 to 12 months. BMJ+1BMJEuropean Glaucoma Society Terminology and Guidelines for Glaucoma, 4th Edition - Chapter 3: Treatment principles and optionsSupported by the EGS Foundation | British Journal of OphthalmologyThe LancetSelective laser trabeculoplasty versus eye drops for first- ...

Favor SLT when avoiding long-term drop burden, adherence dependence, ocular-surface exposure, or medication cost is important, provided the anticipated pressure reduction is sufficient. SLT is repeatable, but its effect is variable and generally greater when baseline IOP is higher. BMJ+2BMJEuropean Glaucoma Society Terminology and Guidelines for Glaucoma, 4th Edition - Chapter 3: Treatment principles and optionsSupported by the EGS Foundation | British Journal of OphthalmologyWolters KluwerPredictors of Success in Selective Laser Trabeculoplasty... : MedicinePubMedOutcome After Selective Laser Trabeculoplasty for Glaucoma Treatment in a Thai Population - PMC

Favor or retain topical therapy when laser access is delayed, the angle cannot be treated adequately, the required pressure reduction exceeds the expected laser response, or a patient prefers medication. Pharmacologic classes used in glaucoma include prostaglandin analogues, beta-blockers, alpha agonists, and topical carbonic anhydrase inhibitors; select agents based on achieved IOP reduction and tolerance rather than assuming equivalence across patients. Wolters Kluwer+1Wolters KluwerPredictors of Success in Selective Laser Trabeculoplasty... : MedicinePubMedCarbonic Anhydrase Inhibitors - StatPearls - NCBI Bookshelf

Reserve systemic carbonic anhydrase inhibition for situations in which topical therapy does not sufficiently reduce IOP or when urgent pressure lowering is needed, recognizing that systemic agents have renal effects including urinary alkalinization and kidney-stone risk. In open-angle glaucoma, systemic therapy is generally a bridge or adjunct when topical, laser, or procedural control is inadequate. PubMedPubMedCarbonic Anhydrase Inhibitors - StatPearls - NCBI Bookshelf

Refer for incisional glaucoma surgery when IOP remains above the individualized target despite tolerated medical therapy and/or SLT, or when structural or field progression continues at the achieved IOP. Available procedural pathways include trabeculectomy with mitomycin, tube shunt surgery, trabecular stent bypass procedures, ab interno trabeculotomy, canaloplasty, and subconjunctival gelatin-stent approaches. JAMA+1JAMACost-effectiveness of Tube vs Trabeculectomynice org ukInterventional procedure overview of trabeculectomy with a ...

When a very low target pressure is required, trabeculectomy with mitomycin remains a central filtering procedure; comparative evidence in primary open-angle glaucoma indicates that trabeculectomy with mitomycin may provide IOP lowering similar to tube shunt surgery. Procedure choice should therefore incorporate prior ocular surgery, conjunctival status, disease severity, complication tolerance, and the magnitude of pressure reduction needed. JAMAJAMACost-effectiveness of Tube vs Trabeculectomy

Do not use a microinvasive procedure merely to postpone adequate pressure reduction in a progressing eye. The required target, trajectory of visual-field loss, and prior response to medications or SLT should determine whether a trabecular procedure, filtering operation, or tube procedure is appropriate. nice org uk+2nice org ukInterventional procedure overview of trabeculectomy with a ...nice org ukRecommendations | Glaucoma: diagnosis and management | Guidance | NICEaaojournalPrimary Open-Angle Glaucoma Preferred Practice Pattern®

At follow-up, measure IOP and compare it with the individual target; repeat optic nerve head examination or imaging and automated perimetry when clinically indicated. In eyes with a prior visual-field defect, use the same perimetric measurement strategy at each assessment to make serial change interpretable. nice org uknice org ukRecommendations | Glaucoma: diagnosis and management | Guidance | NICE

Treat discordance as a signal for reassessment. Progression on OCT or visual fields despite apparently controlled IOP requires a lower target and more intensive therapy; an IOP increase without confirmed structural or functional change requires confirmation of measurement, assessment of adherence or treatment delivery, and reassessment of risk. BMJ+3BMJEuropean Glaucoma Society Terminology and Guidelines for Glaucoma, 4th Edition - Chapter 2: Classification and terminologySupported by the EGS Foundation | British Journal of OphthalmologyScienceDirectThe relationship between intraocular pressure and glaucoma: An evolving conceptnice org ukRecommendations | Glaucoma: diagnosis and management | Guidance | NICEaaojournalPrimary Open-Angle Glaucoma Preferred Practice Pattern®

For treated ocular hypertension or suspected glaucoma without demonstrated damage, repeat visual-field testing when clinically indicated and reassess optic nerve status. If glaucoma is no longer suspected or ocular hypertension does not require treatment, discharge to primary eye care with ongoing routine surveillance may be appropriate. nice org uknice org ukRecommendations | Glaucoma: diagnosis and management | Guidance | NICE