Background/purpose: To characterize the progression of structural and functional changes in the retinas of a small cohort of unrelated patients with early late-onset retinal degeneration and evaluate these changes as potential biomarkers for future treatment trials.
Methods: Best-corrected visual acuity, contrast sensitivity, Goldman visual fields, retinal sensitivity measurement by mesopic microperimetry, extent of ellipsoid zone disruption using spectral domain optical coherence tomography, and fundus autofluorescence imaging were performed at each biennial visit.
Patients: Three unrelated patients with molecularly confirmed late-onset retinal degeneration (S163R mutation in C1QTNF5 ) were prospectively followed for 4 years.
Results: The patient's ages were 44, 54, and 62 at baseline. Over the 4-year follow-up period, one patient demonstrated a significant reduction in best-corrected visual acuity (6 Early Treatment of Diabetic Retinopathy Study letters), whereas two patients suffered a significant reduction in contrast sensitivity. Early in the disease, there was a close relationship between ellipsoid zone disruption and a loss in retinal sensitivity. Later in the course of the disease, there were areas outside the zones of ellipsoid zone disruption that also suffered progressive loss of retinal sensitivity, suggesting that ellipsoid zone loss was not the only factor responsible for the loss of retinal sensitivity. Changes in fundus autofluorescence and Goldman visual field loss were not closely related to changes in ellipsoid zone disruption or retinal sensitivity loss.
Conclusion: This study has found that the monitoring of the progression of ellipsoid zone disruption and changes in mesopic microperimetry may be useful biomarkers in future clinical trials in patients with late-onset retinal degeneration.