PURPOSE:To describe the microscopic corneal and conjunctival findings in patients with Fabry disease(FD)related keratopathy by using in vivo confocal microscopy.DESIGN:Prospective observational case series.METHODS:Twelve eyes of six patients affected by Fabry disease,belonging to two different families,underwent in vivo confocal microscopic examination.Corneal and conjunctival morphology were assessed by means of a scanning slit corneal confocal whitelight microscopy and confocal laser-scanning microscope.RESULTS:Confocal microscopy examination evidenced two different types of corneal epithelial changes.The three hemizygous patients presented bright hyper-reflective intracellular inclusions located within the basal epithelial cells,while the three heterozygous patients showed fine diffusion of reflective substance at the level of superficial,basal epithelial cells and basal membrane,in all eyes.The complex basal-Bowman’ s membrane appeared irregular,distorted,and nonhomogeneous in all subjects.Stromal increased reflectivity attributable to haze and epithelial ingrowth with bright intracellular inclusions was noticed in one hemizygous patient.In all patients,conjunctival epithelial involvement represented by bright roundish intracellular inclusions was evidenced,appearing more pronounced in tarsal than in bulbar conjunctiva.CONCLUSIONS:Although FD-related cornea verticillata attributable to glycosphingolipids accumulation is considered to be primarily a corneal disease,in vivo confocal microscopy demonstrated structural alterations throughout the entire ocular surface epithelia.It is still unclear whether the different type of corneal epithelial lesions observed for hemizygous and heterozygous patients is related to different physiopathological mechanisms.Confocal microscopy may assist ophthalmologists in the diagnosis of FD-related ocular surface and corneal manifestations. PURPOSE: To describe the microscopic corneal and conjunctival findings in patients with Fabry disease (FD) related keratopathy by using in vivo confocal microscopy. DESIGN: Prospective observational case series. METHODS: Twelve eyes of six patients affected by Fabry disease, belonging to two different families, underwent in vivo confocal microscopic examination. Corneal and conjunctival morphology were assessed by means of a scanning slit corneal confocal whitelight microscopy and confocal laser-scanning microscope. RESULTS: Confocal microscopy examination evidenced two different types of corneal epithelial changes. the three hemizygous patients presented bright hyper-reflective intracellular inclusions located within the basal epithelial cells, while the three heterozygous patients showed fine diffusion of the reflective substance at the level of superficial, basal epithelial cells and basal membrane, in all eyes. The complex basal-Bowman’s membrane irregular, distorted, and nonhomogeneous in all Stromal increased reflectivity attributable to haze and epithelial ingrowth with bright intracellular inclusions was noticed in one hemizygous patient. In all patients, conjunctival epithelial impressions represented by bright roundish intracellular inclusions was evidenced, appearing more pronounced in tarsal than in bulbar conjunctiva. CONCLUSIONS: Although FD-related cornea verticillata attributable to glycosphingolipids accumulation was considered to be primarily a corneal disease, in vivo confocal microscopy demonstrated structural alterations throughout the entire ocular surface epithelia. It is still unclear whether the different type of corneal epithelial lesions observed for hemizygous and heterozygous Patients are related to different physiopathological mechanisms. Confocal microscopy may assist ophthalmologists in the diagnosis of FD-related ocular surface and corneal manifestations.