Neuro-Ophthalmic
Chiasmal Compression
Also known as: chiasmal compression, optic chiasm compression, bitemporal hemianopia, pituitary field defect, pituitary compression, bitemporal field loss
Filed as: Urgent
Source-cited from the record's own evidence list. Clinical content programme led by Dr Ankit Mathur, PhD, Grad Cert Ocu Thera, B.S. Optom. How the clinical content is governed
Clinical decision support only
Overview
Compression of the optic chiasm, most often by a pituitary lesion, producing field loss that respects the vertical meridian and takes the temporal half of each eye. Acuity and the discs can look entirely normal early, so the field is the finding that matters. A repeatable bitemporal pattern warrants urgent neuro-ophthalmology referral and imaging, because delay costs optic nerve function that does not come back.
Recognition
Symptoms: what patients report
- Bitemporal field loss or difficulty noticing objects to either side.
- Headache may be present.
- Endocrine history or pituitary-related symptoms may coexist.
Signs: what the examination shows
- Bitemporal field pattern on formal testing.
- Defect respects the vertical meridian.
- Optic disc findings may be normal early or show later optic nerve change.
What OptoGuide™ covers for chiasmal compression
- Pattern reasoning: what this combination of findings points to, and its differentiators
- Don't-miss risks and escalation triggers
- Management tiers with linked Australian therapeutics
- Referral urgency, specialty, and letter drafting
Sources
- Compressive Visual Field Defects — EyeWiki
- The Neuro-Ophthalmology Survival Guide (Pane, Miller & Burdon) — standard reference text
Standard texts: Kanski's Clinical Ophthalmology: A Systematic Approach, Oxford Handbook of Ophthalmology, Oxford American Handbook of Ophthalmology, Signs in Ophthalmology: Causes & Differential Diagnosis.