Single nucleotide polymorphisms in LOXL1 as biomarkers for progression of exfoliation glaucoma in Sweden

Exfoliation glaucoma is a common and aggressive type of glaucoma with high prevalence in Scandinavia. The aim of this study was to elucidate whether the allele frequencies of two single nucleotide polymorphisms (SNPs) located in LOXL1 were associated with the progression of exfoliation glaucoma in Swedish patients.

In this non-randomised cohort study, we enrolled patients with exfoliation glaucoma, and they performed at least five reliable visual field tests. Blood samples were collected, and genotyping was performed using competitive allele-specific PCR genotyping. Glaucoma progression was evaluated using the guided glaucoma progression analysis (GPA), mean deviation (MD) difference and rate of progression (ROP). In addition, associations between allele frequencies and glaucoma progression were tested using logistic regression for GPA and linear regression for MD and ROP.

We enrolled a total of 130 patients in the study. The general genetic model showed statistical significance for LOXL1_rs2165241 (p = 8 × 10^-7 , Fisher's exact test) and LOXL1_rs1048661 (p = 2 × 10^-6 , Fisher's exact test). Regression analyses using an additive genetic model showed significant values for LOXL1_rs2165241SNP in relation to GPA, MD and ROP as outcomes (p = 1.8 × 10^-4 , 4 × 10^-2 , 6 × 10^-4 ) and for LOXL1_rs1048661 SNP in relation to GPA, MD and ROP (p = 7 × 10^-5 , 8 × 10^-3 , 2 × 10^-4 ).

This was the first study to show an association of the SNPs LOXL1_rs2165241 and LOXL1_rs1048661 with the progression of exfoliation glaucoma. Further large-scale studies are required to verify these findings.