“Pattern Reversal” Can Indicate Paracentral Visual Field Loss

Paracentral pattern reversal may be associated with paracentral visual field (VF) loss and is not consistently associated with increased false positive (FP) rates, according to an investigation published in Ophthalmology Glaucoma. 

VF measurement using standard automated perimetry (SAP) is a central component of the diagnosis and management of patients with glaucoma. According to the research, VFs with additional test points outside normal limits on the pattern deviation map than on the total deviation map have been assumed to indicate an unreliable VF. Researchers propose the term “pattern reversal” to characterize this VF finding and sought to investigate its association with paracentral loss.

The investigation consisted of 2 studies: retrospective cohort and case-control. Patients with glaucoma and glaucoma suspects that finished VF testing in Veterans Affairs ophthalmology or optometry clinics were eligible for enrollment. In the cohort study, the calculated false positive (FP) error rates were compared between groups classified by area of pattern reversal. In the case-control study, rates of pattern reversal were compared between groups with and without paracentral loss.

The cohort study included 217 eyes of 145 patients who showed pattern reversal. The patients’ mean age was 71.3 years and most were men (95.7%). Researchers found that FP rates were significantly higher for VFs with pattern reversal and mixed loss compared with paracentral or peripheral loss only (16.25% vs 6.26% and 8.15%, respectively, P <.001). 

The case control study included 55 eyes of 41 patients in the case group and 55 eyes of 41 patients in the control group. The patients’ mean age in the case and control groups were 70.7 and 70.4, respectively, and mostly men (92.7%) in both groups. Researchers found that patients with paracentral loss were more likely to have a history of pattern reversal compared with control patients without paracentral loss (58.2% vs 29.1%, P =.004). In the case group, 12 eyes with paracentral loss had 24-2 VFs that demonstrated defects on the pattern deviation map, but not on the total deviation map. 

“Paracentral VF loss is particularly important to identify because paracentral defects are associated with decreased quality of life in glaucoma patients,” according to the study. “Clinicians should be aware that a paracentral defect that appears only on the pattern deviation map may be an early sign of paracentral VF loss as opposed to a sign of poor reliability.”

Limitations of the study include the overwhelming male population, as is typical for Veterans Affairs-based studies. Additionally, not all patients with paracentral loss in the cohort study had 10-2 VFs available to distinguish between true paracentral loss and artifactual loss. 

“For patients showing repeatable paracentral pattern reversal, one should consider macular structural imaging and/or obtaining a 10-2 VF to better ascertain whether or not there is significant macular damage,” according to investigators. 

Reference

Chang AC, Camp AS, Patella VM, Weinreb RN. Association of visual field pattern reversal with paracentral visual field loss. Ophthalmol Glaucoma. Published online October 21, 2021. doi:10.1016/j.ogla.2021.10.009