Axial Length Profiles in Inherited Retinal Diseases-A Genotypic and Phenotypic Analysis.

Purpose: The purpose of this study was to unravel the distribution patterns of axial length (AL) in patients with inherited retinal diseases (IRDs) and identify genetic factors as the underlying cause. Methods: In this retrospective multicenter cohort study, we analyzed data from 397 genetically and clinically confirmed patients with IRD (from 349 families) and 605 healthy individuals. Demographic details, phenotypic traits, genotypic profiles, and binocular AL measurements were reviewed. IRDs were categorized by their genetic variants and location of affected retinal cell types. Results: Striking differences in AL profiles emerged across IRD genotypes and phenotypes. Genetically, pathogenic variants, including COL11A1, RP1, and RPGR, were strongly linked to longer AL, whereas variants in genes such as BEST1 correlated with shorter AL. Phenotypically, vitreoretinopathy (odds ratio [OR] = 124.46), choroid/retinal pigment epithelial dystrophy (RPE; OR = 18.35), and cone-dominated dystrophy (CD: OR = 11.04) were significantly associated with long AL. Rod-dominated dystrophy showed a unique bidirectional pattern (OR for short AL = 3.41; OR for medium-long AL = 1.77; and OR for long AL = 6.28), whereas other macular-involved diseases were associated with short AL (OR = 9.03). Notably, AL exhibited strong interocular consistency, although the correlation strength varied by genotype and phenotype. Conclusions: Specific phenotypes correlated with longer and/or shorter AL, with genetic factors serving as an underlying determinant. Pathogenic mutations in COL2A1, RP1, and RPGR correlate with longer AL, whereas variants in BEST1 are linked to shorter AL. Collectively, these findings add evidence that certain genetic etiologies of IRDs disrupt ocular emmetropization.