Reliability of Visual Field Testing in Children With Glaucoma Is Less Than Ideal

Investigators evaluated the reliability of Humphrey visual field (HVF) testing and longitudinal change over time in children with glaucoma or glaucoma suspect, a population in which standard automated perimetry tests are not widely given.

Study Design

This was a retrospective case series of 136 children aged ≤18 years (247 eyes) with glaucoma or glaucoma suspect who had undergone at least 1 HVF test. Fifteen percent of the children were aged 0–8 years, 50% were aged 9–13 years, and 35% were aged 14–18 years. Test reliability was based on the manufacturer’s metrics of false positives (≤33%), false negatives (≤33%), and fixation losses (≤20%).

Outcomes

In total, 647 HVF tests were administered, and only 51.3% were determined to be reliable based on the fulfillment of all 3 metrics. Fixation loss showed the least reliability. Older age, better best-corrected visual acuity at the first test, and English as a primary language were associated with greater odds of overall test reliability; number of prior tests was not a factor.

Limitations

Limitations of the study include its retrospective nature and the fact that the mean participant age at the first test was 12 years, so the applicability of the results to grade school children is limited. Furthermore, the study included both Swedish Interactive Threshold Algorithm (SITA) Fast and SITA Standard HVF tests, although no significant difference in reliability was found between them. The study included children with glaucoma suspect as well as those with diagnosed glaucoma, and there are likely differences between these groups. The applicability of these findings to other diagnoses is unknown.

Clinical Significance

While VF testing is standard of care in adults with glaucoma, its use in children is more challenging. Interpretation of VF test results is hampered by reliability and poor correlation with optic nerve findings (OCT and optic nerve cupping). In this study, HVF testing showed an overall reliability of 51% of children with glaucoma or glaucoma suspect. Not surprisingly, reliability increased with older age and better visual acuity. The use of VF testing in young children and those with poorer vision is likely limited, making it difficult to rely on these tests when making clinical decisions.

Financial Disclosures: Dr. Brenda Bohnsack discloses no financial relationships.