Beyond corneal structure in Noonan syndrome: topographic, tomographic, and optical findings

This study aimed to evaluate corneal topographic, tomographic, and wavefront characteristics in individuals with Noonan syndrome (NS) and to compare these findings with those of healthy controls.

This prospective, case-control study included 18 patients with NS (36 eyes) and 19 age- and sex-matched controls (38 eyes). All participants underwent anterior segment tomography and corneal wavefront analysis. Both eyes were included in the analysis, and inter-eye correlation was addressed using generalized estimating equation (GEE) models.

Keratometric values, central corneal thickness, and anterior and posterior corneal elevation parameters were comparable between groups (all p > 0.05). Cylindrical refractive error was greater in the NS group (-0.92 ± 0.19 vs - 0.41 ± 0.12 D; p = 0.022). Corneal wavefront analysis demonstrated significantly higher total corneal high-order aberration root mean square (HOA RMS) (0.54 ± 0.03 vs 0.44 ± 0.03 μm; p = 0.004), coma RMS (0.37 ± 0.01 vs 0.27 ± 0.03 μm; p = 0.001), and trefoil RMS (0.27 ± 0.03 vs 0.19 ± 0.02 μm; p = 0.012) in the NS group.

Individuals with NS demonstrated preserved corneal structure but exhibited heterogeneous alterations in corneal optical quality, characterized by increased asymmetric high-order aberrations and greater cylindrical refractive error in a subset of patients. These findings suggest variable and predominantly subclinical corneal involvement rather than a uniform ectatic phenotype.