In USH2A patients, RP severity score is correlated with age and additional morpho-functional parameters not included in the international staging system and can reliably predict their abnormality at different stages of disease. CS was also negatively correlated (rho = -0.7) with log10 ERG amplitudes and positively correlated (r = 0.5) with SRI. RP cumulative score (CS) was positively correlated (r = 0.6) with age. The cumulative staging score was correlated with patients' age, amplitude of full-field and focal flicker ERGs, and the OCT-measured area of sub-Retinal Pigment Epithelium (RPE) illumination (SRI). In 26 patients with established USH2A genotype, RP was staged according to recent international standards. The aim of this study was to retrospectively determine RP stage in a cohort of patients with USH2A gene variants and to correlate the results with age, as well as additional functional and morphological parameters. According to a recent collaborative study, RP can be staged considering visual acuity, visual field area and ellipsoid zone (EZ) width. While several methods, including electroretinogram (ERG), describe retinal function in USH2A patients, structural alterations can be assessed by optical coherence tomography (OCT). Usher syndrome type 2A ( USH2A) is a genetic disease characterized by bilateral neuro-sensory hypoacusia and retinitis pigmentosa (RP).

Usher syndrome type 2a carrier