Ocular Manifestations in MPGN (C3 Dense Deposit Disease) on the island of Ireland

Abstract

Purpose : To determine the retinal features of membranoproliferative glomerulonephritis (MPGN) C3 Dense Deposit Disease (DDD) in a cohort of patients on the Island of Ireland and to correlate this with age of onset of retinal findings

Methods : Thirty-six individuals were identified as having MPGN C3 DDD from renal clinics in Belfast and Dublin, 21 from Northern Ireland and 15 from Republic of Ireland. Each individual had a full ophthalmic assessment, review of the histopathological diagnosis, colour retinal imaging (a subset also had OCT) and had a venous sample taken for genotyping. Retinal images were graded by the Belfast Ophthalmic Reading Centre and a consultant ophthalmologist. Drusen were graded as hard distinct, soft distinct, soft indistinct and reticular within the regions. All data were collated into an excel spreadsheet and statistical analysis was conducted.

Results : Of the 36, 28 (77.8%) had retinal images and 6 (16.7%) had OCT. The mean age was 67.6 years, and the average age of onset was 17 years. There were 23 females (63.9%) and 13 males (36.1%). Some, 25% had had more than 1 renal transplant. Only 2 described visual symptoms.

Nearly all, 98% showed various degrees of RPE atrophy and 100% of individuals showed disease involvement in the macular region. A majority, 68% showed one or more categories of drusen with 44% showing soft indistinct drusen. The most common type of distribution was in the temporal macular area with the drusen being distributed in a cone shape in the temporal macula. (34%). Only 9% of individuals showed evidence of fibrosis. In addition, 42% showed pigmentary changes. On OCT, 27% of all cases had an epi-retinal membrane, of these 56% lacked the presence of drusen.

Conclusions : All individuals with MPGN C3 DDD had some degree of retinal involvement. Generalised atrophy of the RPE is the most common finding. The majority of cases have shown lipoid depositions in the form of soft indistinct drusen which were distributed in a cone-like configuration towards the temporal end of the macula. However other features such as fibrosis and pigmentary changes have been observed at a relatively lower percentage. Following analysis of the retinal findings we propose the following grading for MPGN C3 DDD retinopathy (Table 1).

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.