Four-dot Artifact on Automated Perimetry

A 74-year-old woman was referred to the glaucoma unit for pseudoexfoliative glaucoma. Upon presentation, visual acuity in both eyes was 20/30. Intraocular pressure was 18 mmHg in the right eye and 20 mmHg in the left eye with latanoprost eye drops. Ophthalmoscopy revealed a cup-disc ratio of 0.7 with superior neural rim notching in the right eye and concentric cup-disc ratio of 0.6 in the left eye. She underwent central 24-2 automated perimetry with the Humphrey Visual Field Analyzer (HVFA II, Carl Zeiss Meditec, Dublin, USA) using the SITA-fast program. Although she was instructed before the test, she was unable to respond to the early stimuli efficiently which was reflected in lower threshold values for initial test points. The reliability indices were within normal limits except for higher than normal fixation loss. On repeat visual field testing, reliability indices were within normal limits and thresholds of the four areas with poor sensitivity improved and the artifact disappeared (Fig. 1).