Supplementary Material for: Stair-Case/Honeycomb Maculopathy in Alport Syndrome: A Case Report

Introduction: Alport syndrome is an inherited disease caused by mutations in COL4A5, COLA3, or COL4A4 resulting in kidney failure, hearing loss and ocular symptoms. We report a patient with Alport Syndrome who has a “stair-case/honeycomb” maculopathy, a rare but distinctive finding in this disease.
Case Presentation: A 53-year-old man with Alport Syndrome was referred for gradual decrease in vision. His ocular history was remarkable for intraocular lens implantation secondary to lenticonus in each eye. Fundus photography showed rare white dots in the temporal midperiphery in each eye and fundus autofluorescence was normal. Optical Coherence Tomography (OCT) B-scans through the fovea showed irregular thinning of the inner retina with peaks and valleys in the macula of each eye. The ellipsoid zone was intact except for mild patchiness centrally. En face retinal structural OCT angiography (OCTA) images showed a mosaic-like honeycomb pattern in the macular region in both eyes, with hyporeflective depressions in areas of focal retinal atrophy. Retinal OCTA scans showed irregular foveal avascular zone (FAZ) areas with capillaries crossing the FAZ in the left eye, corresponding to islands of preserved retinal tissue. There was predominance of capillaries in the deeper retinal layers centrally.
Conclusion: While severe irregular thinning of the macula is not a common feature in Alport syndrome, when it is present in patients who have not been previously diagnosed, particularly in patients with renal disease, it should suggest the diagnosis of Alport syndrome. Its occurrence can be the cause of vision loss which is not commonly associated with Alport central maculopathy.