Optical Coherence Tomography Reflectivity as a Diagnostic Tool and Neurological Biomarker in Sialidosis Type I

in ST-1 patients compared to controls (p < 0.0001), including in those without clinically visible CRS. OCT reflectivity was strongly associated with neurological severity but not with BCVA. Conversely, BCVA correlated with parafoveal and ganglion cell complex thinning and with delayed VEP latency. Age-related declines in reflectivity, retinal thickness, and BCVA were observed in ST-1 but not in controls. These findings highlight OCT reflectivity is a more sensitive biomarker than the CRS for diagnosing ST-1 and reflects neurological severity even in patients without visible CRS. Importantly, the structure-function relationship between OCT parameters and neurological outcomes suggests broader applicability in LSD and other neurodegenerative conditions.