Investigating the blue sclera in osteogenesis imperfecta by in vivo confocal microscopy

Abstract

PurposeThe blue sclera appearance is a distinctive clinical sign for osteogenesis imperfecta (OI), a connective tissue disorder caused by an abnormality of type I collagen. It is a challenging diagnosis because multiple bone fractures, occurring in early childhood, can be the only sign of the non‐lethal forms of OI. In these situations, child abuse is a major concern for Paediatricians.AimTo investigate the in vivo confocal microscopy (IVCM) of the sclera and its characteristics as a diagnostic test for OI.MethodsA father and his daughter suffering from OI gave informed consent for non‐invasive ocular examination. The cornea and sclera were examined with a handheld dermatological IVCM (VivaScope 3000, MAVIG GmbH/Lucid), which we pioneered for ophthalmological examination. The examination of two age matched healthy volunteers and corneoscleral donor tissues served as a control.ResultsThe IVCM in OI shows a very specific and reproducible pattern where the collagen fibres have a well organised parallel alignment as would be expected within the clear corneal stroma. Collagen fibres were cross striated in the control.ConclusionsThese findings were consistent with the electron‐microscopic features previously described. The blue appearance results from the visualisation of the underlying choroid through the translucent sclera, which displays a specific parallel orientation of the collagen fibres. To the best of our knowledge, this is the first report of IVCM of the blue sclera. This rapid and non‐invasive imaging technique is an interesting diagnostic tool for challenging cases, especially in children, with multiple bone fractures.GRANT: GIRCI RAA