Deliberate dietary adjustments may not mitigate the progression of glaucoma: A two-sample Mendelian randomization study

Abstract

Ocular diseases, including glaucoma, are significant contributors to visual impairment and irreversible blindness, impacting individuals' socioeconomic opportunities and quality of life. This study aimed to investigate the causal relationship between dietary components and glaucoma progression. We conducted Mendelian randomization studies to assess the effects of 4 dietary components (protein, carbohydrates, sugar, and fat) on glaucoma. A total of 11,417,548 single nucleotide polymorphisms (SNPs) were screened, and after applying a stringent threshold, we retained relevant SNP markers for each dietary group. We employed 4 regression models: MR-Egger regression, a weighted median estimator, an inverse-variance weighted random-effects model, and a weighted model to analyze the data. The analysis revealed that all obtained P-values were greater than .05, indicating no significant association between dietary components and glaucoma. Additionally, sensitivity analyses using the leave-one-out method confirmed the robustness of these findings, showing that the removal of any SNP did not alter the conclusions. The findings suggest that deliberate dietary adjustments may not mitigate the progression of glaucoma. For now, adhering to prescribed medications and considering early surgical intervention when necessary may represent more effective treatments for glaucoma.

Keywords: Mendelian randomization; carbohydrate; dietary; fat; glaucoma; protein; sugar.

Figure 1.

The schematic diagram of this Mendelian randomization study illustrates the process clearly. It demonstrates how Mendelian randomization utilizes representative genome wide association study data from different dietary components and glaucoma to explore their causal relationships. This approach aims to analyze further whether dietary regulation could potentially mitigate the progression of glaucoma.

Figure 2.

This figure presents a Manhattan plot of glaucoma SNP data. The x-axis represents the chromosomal positions across the genome, while the y-axis shows the –log 10 (P-value), which indicates the significance of the association between each SNP and glaucoma. Notably, the highest values are observed on chromosome 1 and chromosome 9. SNP = single nucleotide polymorphism.

Figure 3.

None of the regression equations for the 4 dietary components show a significant association with glaucoma. Additionally, the intercepts of the MR-Egger regression lines with the y-axis are all below 0.05, indicating the absence of significant pleiotropic effects in this study.

Figure 4.

Sensitivity analysis results of the SNP information. All markers observed exhibit a span across the coordinate zero, and the exclusion of any individual marker does not lead to changes in the conclusions. This underscores the robustness of the study’s findings. SNP = single nucleotide polymorphism.

Figure 5.

In the heatmap, SNPs are plotted on the x-axis, beta values on the y-axis, and standard errors are indicated by the color fill. Results shown in blue indicate high reliability and stability, while those in red indicate the opposite. It is observed that in all 4 scenarios, blue lines are distributed around the zero value, indicating that dietary components do not influence the onset or progression of glaucoma. SNP = single nucleotide polymorphism.