This case of a pituitary tumour was originally diagnosed as glaucoma. The visual fields show bitemporal hemianopia. Visual field interpretation is made more difficult by the fact that the defect crosses the vertical midline on the pattern deviation. In this patient there may also be concurrent glaucoma, however the greyscale clearly demonstrates bitemporal hemianopia which respects the midline for the most part. Given the clinical presentation and visual fields, a priority referral to an ophthalmologist is indicated. CT or MRI neuroimaging will be required to confirm the diagnosis.

In the case above, an important screening test was left out, and that is colour vision. This patient had Ishihara testing of 9/17 in the right eye and 11/17 in the left eye. This highlights colour vision as an important screening tool for new glaucoma patients. Glaucoma does not tend to affect colour vision, and reduced colour vision should raise suspicion for a non-glaucomatous optic neuropathy. Reduced visual acuity and a relative afferent pupillary defect (RAPD) should also raise suspicion for non-glaucomatous aetiology.

The appearance of the optic nerves are also atypical for glaucoma. The appearance fits with the pattern of ‘bow-tie’ atrophy, which is bilateral horizontal orientated optic atrophy, and can be associated with compressive chiasmal tumours. The visual field defect is more severe than what you would expect to see, relative to the appearance of the optic nerve and OCT. This is another clue that the aetiology of the visual field defect may be intracranial.