Abstract
Purpose :
We recently used archetypal analysis (AA), a form of unsupervised machine learning, to derive quantifiable patterns, or archetypes (AT), of visual field (VF) loss from the optic neuritis treatment trial (ONTT) and idiopathic intracranial hypertension treatment trial (IIHTT) datasets. Our purpose was to derive new AT models for VFs from clinic-based ON and IIH cases. For both ON and IIH, we hypothesized: 1. The new AT model would resemble our prior AT model; 2. Baseline AT1 (normal VF pattern) weight would be associated with outcome VF mean deviation (MD); 3. AA would reveal residual patterns of VF defects in eyes with MD≥-2.00 dB at outcome.
Methods :
We derived two AT models: one based on 446 VFs from 142 patients with acute ON, and the other based on 798 VFs from 120 patients with IIH and VF loss (Fig. 1). We compared these ATs to the ONTT and IIHTT-derived ATs. We compared outcome MD values between patients with baseline AT1 weights above and below the mean using the Mann-Whitney U test. We assessed change in MD over time in each group using the Wilcoxon signed rank test. We determined the number of VFs with abnormal AT weights in eyes with MD≥-2.00 dB at outcome.
Results :
For ON, the two ATs of greatest relative weight (RW; 52.7%, 6.32%) resembled those derived from the ONTT (40.2%, 9.43%). For IIH, the three ATs of greatest RW (51.8%, 8.50%, 7.11%) resembled those derived from the IIHTT (30.9%, 23.9%, 5.89%). For ON VFs with baseline AT1 weights < the mean, the improvement in MD (12.9 dB, p<0.001) was greater than for those with baseline AT1 weights > the mean (2.61 dB, p<0.001). Outcome AT1 weight and MD did not differ between the two groups. For IIH VFs with baseline AT1 weights < the mean, the improvement in MD (2.01 dB, p<0.001) was greater than for those with baseline AT1 weights > the mean (0.77 dB, p<0.001). On average, VFs with baseline AT1 weights > the mean reached better MD values (-1.26 dB vs. -3.69, p<0.001) at outcome than those with baseline AT1 weights < the mean (Fig. 2). For VFs with MD≥-2.00 dB at outcome, 19/45 ON and 44/88 IIH VFs had an abnormal AT.
Conclusions :
AA identified reproducible and quantifiable patterns from “real world” IIH and ON VFs. Baseline AT1 weight is associated with VF outcome. AA can indicate residual defects in VFs at outcome.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.