Evaluate for Glaucoma with Formal Visual Field Testing and Optic Nerve Assessment
After ruling out retinal detachment, the next critical step is to evaluate for glaucoma through comprehensive optic nerve head (ONH) and retinal nerve fiber layer (RNFL) examination, formal automated visual field testing, intraocular pressure (IOP) measurement, and gonioscopy to assess for primary open-angle glaucoma or other optic neuropathies. 1, 2
Algorithmic Approach to Peripheral Visual Field Loss
Step 1: Comprehensive Glaucoma Evaluation
The American Academy of Ophthalmology guidelines for glaucoma suspects and primary open-angle glaucoma provide the framework for evaluation 1, 2:
Essential Components:
- IOP measurement using Goldmann applanation tonometry before any manipulation of the eye
- Gonioscopy to exclude angle closure or secondary causes (angle recession, pigment dispersion, pseudoexfoliation, neovascularization)
- ONH and RNFL examination with documentation—look for cup-to-disc ratio asymmetry, rim thinning, notching, or hemorrhages
- Formal automated perimetry (Humphrey or similar)—not just confrontation fields
- Central corneal thickness measurement, as thin corneas may underestimate true IOP
- Slit-lamp examination for pseudoexfoliation material, pigment dispersion signs (Krukenberg spindle, iris transillumination defects), or inflammatory findings
Step 2: Obtain Targeted History
Focus on specific risk factors 1, 2:
- Family history of glaucoma, particularly with visual loss
- Race/ethnicity (higher risk in African ancestry)
- Prior ocular trauma or surgery (especially LASIK/PRK, which can falsely lower IOP readings)
- Systemic conditions: migraine, vasospasm, cardiovascular disease, diabetes
- Medication history: corticosteroid use (topical or systemic)
Step 3: Consider Neuro-Ophthalmic Causes
If glaucoma evaluation is negative or findings don't match the pattern 3:
- Assess for homonymous field defects suggesting retrochiasmal lesions (stroke, tumor)
- Check for relative afferent pupillary defect indicating optic nerve or severe retinal disease
- Neuroimaging (MRI brain/orbits) if field defect respects vertical midline or other neurologic signs present
- Consider optic neuropathies: demyelinating disease, ischemic optic neuropathy, compressive lesions
Critical Pitfalls to Avoid
Don't rely on confrontation fields alone—they miss subtle but clinically significant defects. Formal automated perimetry is mandatory 1, 2, 3.
Don't assume a single normal IOP rules out glaucoma—IOP fluctuates diurnally and between visits. Multiple measurements at different times may be needed 1, 2.
Don't skip gonioscopy—angle closure can present with peripheral field loss and requires entirely different management than open-angle disease 1, 2.
Don't overlook medication history—prior refractive surgery (LASIK, PRK) causes artificially low IOP readings due to corneal thinning, potentially masking glaucoma 1, 2.
Pattern Recognition
Peripheral field loss patterns guide diagnosis:
- Arcuate defects respecting horizontal midline → glaucoma
- Homonymous defects respecting vertical midline → neurologic lesion 4
- Altitudinal defects → ischemic optic neuropathy or advanced glaucoma
- Concentric constriction → advanced glaucoma, retinitis pigmentosa, or functional loss
The evidence strongly supports that visual field testing is essential for monitoring progression in conditions like idiopathic intracranial hypertension, optic neuropathy from multiple sclerosis, and pituitary lesions 3. These conditions can present with peripheral field loss and must be differentiated from retinal pathology.
Quality of Life Considerations
Visual field defects significantly impair driving (especially at night), reading speed, outdoor mobility, and personal hygiene 2, 3. Early detection through proper testing allows for timely intervention to prevent further vision loss and preserve functional independence.