Archetypal Analysis Demonstrates Visual Field Patterns of Loss and Evolution in Non-Arteritic Anterior Ischemic Optic Neuropathy

Abstract

Purpose : In non-arteritic anterior ischemic optic neuropathy (NAION), global measures but not quantification of the patterns of visual field (VF) loss have been reported. Further, no prospective trials of optic nerve dysfunction have been conducted using stimulus V. Given the frequency of severe VF deficits in NAION, we incorporated stimulus V VFs, which show important patterns of VF loss with better quality metrics, without sacrificing reliability/sensitivity. We applied archetypal analysis (AA), a machine learning algorithm, to the QRK207 study, the largest prospective study of NAION, to uncover distinct patterns of loss (archetypes, ATs) over time.

Methods : We performed AA on 3157 24-2 VFs (combining stimuli III and V) collected from 728 participants. We used the resulting ATs to track disease progression by examining AT relative weights (RW, total weight = 100%) of 190 untreated eyes at presentation, and at months 2 and 6. We compared 146 pairs of stimulus III VFs at presentation and 2 months, and 107 pairs of stimulus V VFs at presentation and 6 months with a Wilcoxon Rank-Sum Test.

Results : AA revealed 10 distinct ATs, with patterns typically seen in the clinic. The diffuse severe loss AT1 (RW 16%), followed by inferior altitudinal loss AT2 (RW 15%), and diffuse mild loss AT3 (RW 13%) were the most common ATs. From presentation to month 2 (stimulus III), the RW of AT1 increased from 15% to 21% (p = 0.02), the RW of AT2 decreased from 21% to 13% (p < 0.001), and the AT3 RW changed minimally (9%, p = 0.75). Between presentation and month 6 (stimulus V), the change in AT RWs were similar to stimulus III; the RW of AT1 increased from 11% to 16% (p = 0.049), AT2 decreased from 16% to 10% (p = 0.009), and AT3 minimally changed (14%, p = 0.56).

Conclusions : AA identifies recognizable patterns and quantifiable RWs within stimuli III and V VFs in NAION, enabling accurate monitoring of disease changes.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.

 

Figure 1. Archetypes for combined stimuli III and V VFs. The different shades of red within every archetype represent total deviation values. The color scale spans from -30 dB to 0 dB. We show each archetype with its average total deviation value and relative weight, displayed as a percentage within the dataset for both stimulus III and V. The archetypes are numbered and arranged based on their relative weight.