Pituitary Tumors Do Not Compromise 24-2 Visual Field Testing

Pituitary tumors do not compromise clinical exams conducted with 24-2 pattern visual fields (VF) tests, according to research published in Acta Ophthalmologica. The investigation shows no patients with radiologically confirmed tumor compression of the visual pathway in the pituitary region was perimetrically overlooked when only 24-2 tests were evaluated, compared with full 30-2 VF tests.

Participants (N=79) with pituitary tumors underwent VF testing at a median of 7 days (range 1 to 91 days) before surgery at an academic or regional hospital in Sweden, from 2000 to 2020. After initial 30-2 testing, automated programming withdrew the outer ring of points except the 4 nasal-most sites closest to horizontal midline. Researchers defined a field defect as any significantly depressed point (SP) (P <.05 to P <.005) on the total deviation probability plot.

Maps of most participants showed more than 15 SPs, but more than 50% of patients with pituitary tumors presented mild depression and similarly, more than half showed only mild depression of visual field index (VFI) above 80%. Thus, researchers suggest MD and VFI may not dependably indicate compression-associated defects.

No patient’s field deficits were missed using the 24-2 pattern. Investigators also found an unanticipated result. “Although the majority of the visual field defects were located in the temporal portion of the visual field, a significant minority of the patients in the present study exhibited most of their visual field defects in the nasal half of the visual field, which is contradictory to many textbook examples,” researchers explain. Also, a large proportion of patients with pituitary tumors had normal visual acuity

Previous studies have reported results such as a majority of participants with optic nerve disorder having comparable 24-2 and 30-2 tests, as well as that in patients with pituitary adenoma, visual field defects were identified in 85% of 30-2 patterns vs 80% of 24-2, although the latter evaluation did not indicate whether deficiencies could be missed in assessments including both eyes. Current investigators considered SPs found in print-outs of fellow eyes.

A potential study limitation may have involved using only highest sensitivity for uncovering VF defects with 24-2 vs 30-2 in those with radiologically-confirmed visual pathway compression.

Disclosure: One study author declared affiliations with the biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.