What treatment approach is recommended for a patient with beta zone peripapillary atrophy suggestive of glaucomatous damage?

Management of Beta Zone Peripapillary Atrophy in Glaucoma

Patients with beta zone peripapillary atrophy (β-PPA) suggestive of glaucomatous damage should be treated with IOP-lowering therapy targeting at least a 20-25% reduction from baseline, with more aggressive monitoring every 3-6 months due to their significantly elevated risk of rapid disease progression. 1

Recognition of β-PPA as a High-Risk Feature

Beta zone peripapillary atrophy is a well-established independent risk factor for glaucoma progression that warrants heightened clinical concern. The presence of β-PPA increases the risk of visual field progression by 2.59-fold compared to eyes without it, even after controlling for IOP and other risk factors 1. This finding comes from the American Academy of Ophthalmology's 2021 Primary Open-Angle Glaucoma guidelines, which specifically identify both the baseline presence and size of β-PPA as predictive markers for visual field and optic nerve progression 1.

Research demonstrates that eyes with β-PPA progress significantly faster (-0.84 dB/year) compared to those without it (-0.51 dB/year), with moderate to fast rates of progression occurring more commonly in β-PPA eyes 2. The correlation between β-PPA extent and severity of glaucomatous damage is well-documented, with larger β-PPA areas associated with greater visual field defects and more advanced structural optic nerve damage 3, 4.

Treatment Initiation and Target IOP

Any patient demonstrating β-PPA with evidence of optic nerve deterioration, RNFL loss, or visual field changes consistent with glaucomatous damage has progressed to POAG and requires immediate IOP-lowering treatment 1. The decision to treat should not be delayed in these patients.

Target IOP Setting

• Begin with a target IOP of 20-25% below baseline mean IOP based on multiple baseline measurements 1, 5
• For patients with β-PPA showing any progression, lower the target IOP further through downward adjustment of therapy 1
• The presence of β-PPA combined with other high-risk features (older age, disc hemorrhages, thin central corneal thickness <525 μm, higher baseline IOP) necessitates more aggressive IOP targets 1, 2

First-Line Pharmacotherapy

Prostaglandin analogs should be initiated as first-line therapy unless contraindications exist, as they provide the most effective IOP reduction with favorable safety profiles 1. Alternative agents include beta-blockers, alpha-2 agonists, topical carbonic anhydrase inhibitors, or combination therapies if target IOP is not achieved 1.

Laser trabeculoplasty should be strongly considered when medication adherence, cost, convenience, side effects, or medication risks are concerns 1.

Intensive Monitoring Protocol

The presence of β-PPA mandates more frequent surveillance than standard glaucoma management:

Follow-Up Schedule

• Every 3-6 months initially until stability is demonstrated 5
• Three visual field tests per year during the first 2 years to detect rapid progression earlier 1
• More frequent evaluations are required based on severity of damage, rate of progression, and extent to which IOP exceeds target 1

Each Visit Must Include

• Visual acuity measurement 5
• Slit-lamp biomicroscopy 5
• IOP measurement 5
• Periodic optic nerve head and RNFL evaluation using both clinical examination and imaging 1, 5
• Periodic photography to detect disc hemorrhages not visible on examination, which occur more commonly in β-PPA eyes and herald further progression 1

Structural and Functional Assessment

Both structural imaging and visual field testing are essential, as some patients show visual field loss without corresponding structural changes and vice versa 1.

Imaging Modalities

• Stereoscopic optic disc photography for baseline documentation 1, 5
• OCT of optic nerve head, RNFL, and macular ganglion cell complex 5
• Color scanning laser ophthalmoscopy and fundus autofluorescence show highest correlation for β-PPA assessment (correlation coefficient 0.904 for horizontal measurements) 6

Visual Field Testing

• Standard automated perimetry (24-2 or 30-2) as the gold standard 7
• Add 10-2 central field testing when macular involvement is suspected, as central defects may be missed on wider field testing 7
• Confirm any new defects with repeat testing before diagnosing progression 7

Therapy Adjustment Triggers

Adjust therapy downward (lower target IOP) immediately if 1:

• Progressive optic disc, imaging, or visual field changes occur despite achieving initial target IOP
• Target IOP is not achieved
• Patient shows intolerance or non-adherence to current regimen

Critical Clinical Pitfalls

Do not underestimate the significance of β-PPA - it represents actual chorioretinal atrophy with visible sclera and choroidal vessels adjacent to the optic disc, indicating structural vulnerability 1. The correlation between β-PPA location and visual field defect location is significant, with β-PPA being greater in sectors where neuroretinal rim loss is more marked 4.

Do not rely on β-PPA measurement alone for diagnosis - while β-PPA area correlates with glaucoma severity, there is wide overlap between glaucomatous and non-glaucomatous eyes, particularly in myopic populations 8. Always integrate β-PPA findings with comprehensive structural and functional assessment 1, 5.

Monitor for associated risk factors - thin central corneal thickness (<525 μm) shows weak but significant correlation with β-PPA presence and compounds progression risk 2.