We have studied the effects of dermatochalasis on Humphrey automated p
erimetry of the central 24 degrees visual field. Fifteen visual fields
of 9 ocular hypertensive patients (18 eyes) were found to be incongru
ous with their apparently healthy optic discs. Examination revealed de
rmatochalasis, which was felt to be responsible for the field defects,
This was confirmed by reversal of the defects on repeating the field
test (programme 24-2) with the redundant upper lid skin taped up, or i
n 2 cases following blepharoplasty. The defects always involved the su
perior visual field. The deepest and largest defects were sited in the
supero-temporal quadrant in 13 of the 15 affected fields and the supe
ro-nasal quadrant in 2 fields. The most common pattern was a temporall
y skewed defect which reflected the tendency of the loose upper lid sk
in to be greater in extent temporally than nasally. In 7 fields the su
perotemporal defect extended to fuse with the blind spot, mimicking a
superior arcuate scotoma. Temporal extension of the field defects belo
w the horizontal meridian occurred in 5 fields. In cases where visual
field testing was repeated without taping up the lid inter-test fluctu
ation in scotoma size and depth was observed, although the position of
scotomas when present within the visual field remained constant. We c
onclude that dermatochalasis has the potential to confound diagnostic
automated visual field testing for glaucoma.