Electroretinographic patterns of retinitis pigmentosa in a Palestinian cohort: a clinical and functional characterization.

Retinitis pigmentosa (RP) is a progressive rod–cone dystrophy and the most common inherited retinal disease worldwide. Electroretinography (ERG) provides an objective measure of retinal function and is essential for staging severity and guiding therapy. However, ERG data from Middle Eastern populations remain limited. In this cross-sectional study, 71 Palestinian patients with clinically confirmed RP underwent full-field ERG (ffERG) using ISCEV 2022 standards. Responses were classified into mild, moderate, and severe categories. Clinical variables including age, disease duration, best-corrected visual acuity (BCVA), and optical coherence tomography (OCT) findings were analyzed. Global ERG severity grading revealed severe impairment in 40.8% of patients; rod-specific DA 0.01 b-wave amplitude-based classification identified severe rod dysfunction in 32.4%. A strong negative cross-sectional correlation was observed between disease duration and DA 0.01 b-wave amplitude (r = − 0.95, p < 0.0001), consistent with cumulative rod photoreceptor loss over time; visual inspection of the scatter plot confirmed a monotonic relationship without evidence of outlier leverage. BCVA and OCT-derived central macular thickness showed no significant correlation with ERG parameters, underscoring the functional–structural dissociation in RP. Genetic testing (35.2% of cases) identified mutations in RPGR, RHO, USH2A, CRB1, and others; genotype–ERG observations are exploratory given small subgroup sizes. These findings establish baseline ERG profiles for Palestinian RP patients, support ERG-based severity grading, and emphasize the importance of electrophysiology for diagnosis, prognostic counseling, and therapeutic eligibility in underrepresented populations.