Plant-based low carb diet and other risk factors in relation to incident primary open-angle glaucoma characterized by autonomously determined visual field loss patterns

Abstract

Purpose : Primary open-angle glaucoma (POAG) manifests as distinct visual field (VF) loss patterns localizing to the nerve fiber layer. We used an autonomous algorithm to classify incident visual field VF loss patterns in POAG and evaluated whether a plant-based low carb diet and other risk factors may be differently associated for POAG with paracentral VF loss versus POAG with peripheral VF loss.

Methods : Participants (n=79,906) from the Nurses’ Health Study (NHS), aged ≥40 years and free of glaucoma, were followed from 1980 to 2018. Information on diet, body mass index, smoking, diabetes and other covariates were assessed on biennial questionnaires. Deciles of a plant-based low-carbohydrate-diet (LCD) adherence score were calculated to represent adherence to diets lower in carbohydrate and higher in protein and fat from plant sources. Incident POAG cases with reproducible Humphrey VF loss were confirmed with medical records. The total deviation information of the earliest reliable VF for each eye with POAG was extracted, and a statistical learning method was used to identify optimal solutions for regional vision loss patterns. Each POAG eye was assigned the VF pattern (“archetype”) based on the highest weighting coefficient. Multivariable-adjusted hazard ratios (HRs) for POAG of various archetypes and 95% confidence intervals (CIs) were estimated using per-eye Cox proportional hazards models.

Results : We identified 14 archetypes; of these, 9 archetypes represented early loss. For comparison, we combined 2 archetypes showing paracentral VF loss (n=165 eyes with incident POAG) and combined 7 archetypes showing peripheral VF (n=1145 eyes with incident POAG). The associations for body mass index (BMI; kg/m2), cigarette smoking, and diabetes for the two outcomes were not significantly different (p_contrast≥0.11). However, the association with higher adherence to a plant-based LCD score was stronger for paracentral VF loss (HR=0.79, 95%CI= 0.66, 0.96 per 1 SD increase in diet score) versus peripheral VF loss (HR=1.00, 95%CI=0.98, 1.01), with p_contrast=0.03.

Conclusions : Compared to POAG with peripheral VF loss, POAG with early paracentral VF loss may have common as well as distinct determinants; higher adherence to a plant-based LCD diet was inversely associated only with paracentral VF loss.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.