Supplementary Material for: Morphological changes in the saw-tooth pattern of cuticular drusen associated with immune complex-mediated membranous proliferative glomerulonephritis type III: a case report

Background: Patients with membranoproliferative glomerulonephritis (MPGN) type III may exhibit the saw-tooth pattern of cuticular drusen. This study reports a four-and-a-half-year retrospective time-dependent observation of cuticular drusen associated with immune complex-mediated MPGN type III patients.
Case presentation: A 32-year-old woman was referred for ocular evaluation due to systemic steroids used for nephrotic syndrome caused by immune complex-mediated MPGN type Ⅲ. She had no ocular symptoms. The initial examination showed that her best-corrected visual acuity (BCVA) was 1.0 oculi uterque (OU). Color fundus photographs revealed pigmentary abnormalities in the macular and perimacular regions OU. Fundus autofluorescence (FAF) images demonstrated numenous tiny dots with a hypoautofluorescent center surrounded by a rim of hyperautofluorescence. Enhanced depth imaging-optical coherence tomography (OCT) revealed triangular morphologic features, represented by a saw-tooth pattern with internal hyporeflectivity. Over 4.5 years, the internal reflectivity of the drusen gradually increased. Moreover, depigmentation and yellow color changes in the macular and perimacular regions worsened, without obvious changes on FAF. Her BCVA remained at 1.0 OU, without new ocular symptoms or cataract progression during the 4.5 years follow-up period.
Results: Both eyes had a significant positive correlation between OCT-based mean internal reflectivity measured by the Image J software and the observation period. However, no correlation was found between estimated glomerular filtration rate (eGFR) and the observation period or between eGFR and mean internal reflectivity.
Conclusion: The internal reflectivity of cuticular drusen associated with immune complex-mediated MPGN type III showed time-dependent changes on OCT and worsened depigmentation and yellow color changes in the macular and perimacular regions, independent of renal function.