Supplementary Material for: Long-Term Structural and Functional Assessment of Doyne Honeycomb Retinal Dystrophy Following Nanosecond 2RT Laser Treatment. Case Series.

Introduction. Doyne honeycomb retinal dystrophy (DHRD), or autosomal dominant radial drusen, is a genetic disease caused by pathogenic variants of the epidermal growth factor-(EGF)-containing fibulin-like extracellular matrix protein 1 EFEMP1 gene and is characterized by the formation of subretinal drusenoid deposits. In a previous study, we reported the short-term beneficial effects of nanosecond laser treatment (2RT) on retinal function in DHRD. The aim of the present report is to describe the findings of a long-term follow-up of retinal structure/function in a small case series of patients with DHRD who underwent 2RT treatment. Case presentation. Three DHRD patients (case 1, male, and cases 2 and 3, two sister females, age range 41-46) with EFEMP1 pathogenic variant (c.1033C>T; p.R345W) and drusenoid deposits at the posterior pole were examined at baseline and after 2RT treatment, at regular intervals (every 2-4 months) up to 30 months. All three patients underwent one or two treatment sessions in one or both eyes during the follow-up period. Case 3 was treated with only the left eye (LE). Each patient underwent a full ophthalmologic examination, spectral domain optical coherence tomography (OCT), central perimetry with frequency doubling technology (FDT), and mesopic and photopic Ganzfeld electroretinograms. Compared to baseline findings, during follow-up, visual acuity improved in both eyes in case 1 and LE in case 2, while it decreased in the right eye (RE) in case 2 and LE in case 3; perimetric sensitivity was stable in case 1 and improved in both eyes in cases 2 and 3; and electroretinogram amplitude improved in cases 1 and 2, and was stable in case 3 (both eyes). OCT central macular thickness and retinal structure were stable in all cases. None of the patients had treatment-related side effects. Conclusion. This is the first report showing that in a long-term follow-up, 2RT treatment in DHRD may improve or stabilize some retinal function parameters without significant structural changes.