Abstract
Purpose: :
To investigate the relationship between clinical findings at patient presentation with the measured rate of disease progression in patients with Stargardt disease.
Methods: :
A retrospective review of 135 patients with a clinical diagnosis of Stargardt disease was conducted. Demographic and clinical data were collected. Goldmann perimetry was quantified using digital planimetry. Patients were sorted according to type of ERG dysfunction and data was analyzed using SAS statistical software. A subgroup analysis was performed on 36 patients with longitudinal data to model disease progression over time.
Results: :
Fifty-two percent (70/135) of patients had an abnormal ERG result at initial presentation. Eleven percent (15/135) of patients had rod-cone dysfunction, 19% (25/135) of patients had cone-rod dysfunction, and 22% (30/135) patients had isolated cone dysfunction. Patients with abnormal ERG values (photopic b-wave, rod-isolated b-wave, and maximum stimulation a-wave) had worse average logMAR values with p values of 0.0017, 0.0086, and 0.0095, respectively. Patients with cone-rod dysfunction (19%) were found to have significantly worse average logMAR (p = 0.001), larger central scotoma (p < 0.0001) and wider macular atrophy (p = 0.0095) than patients with other types of dysfunction. The progression in central scotoma size was found to be related to the age at symptom onset when applied to a prediction model. Patients with an abnormal photopic b-wave amplitude had a higher rate of central scotoma progression rate than patients with a normal photopic b-wave amplitude (p = 0.019). Patients with central scotoma progression were statistically more likely to have abnormal rod isolated b-wave amplitudes (p = 0.0456).
Conclusions: :
ERG data can provide clinically relevant information regarding the severity of Stargardt disease and disease progression, as on average patients with cone-rod dysfunction experienced more severe disease than patients with other types of ERG dysfunction. Based on our model, patients experience disease progression that quickens with age, and early age of onset is associated with faster disease progression at all ages.
Keywords: retinal degenerations: hereditary