Spectral domain optical coherence tomography and in vivo confocal microscopy imaging of a case of Bietti's crystalline dystrophy

Background: The aim was to describe the morphology and localisation of crystals in a case of Bietti's crystalline corneo-retinal dystrophy (BCD) by means of spectral domain optical coherence tomography (SD-OCT) and in vivo confocal microscopy (IVCM). Methods: Clinical examination, SD-OCT and IVCM evaluation of a 35-year-old woman with BCD. Results: Optical coherence tomography examination of the macular region revealed multiple crystals in the retinal pigment epithelium (RPE)-choriocapillaris, some crystals within the full thickness of the neurosensory retina and less numerous crystals in the choroid. Crystals were present peripherally in areas of retinal atrophy, predominantly in the choroid and to a lesser extent in the RPE-choriocapillaris and the neuroepithelium. In vivo confocal microscopy showed multiple crystals of varying morphology in the peripheral and paralimbal cornea, mainly located in the anterior stroma over 360°. Conclusions: SD-OCT provided greater precision in the localisation of crystals, found mainly in the choroid and RPE-choriocapillaris rather than the neuroepithelium. In vivo confocal microscopy revealed a higher number of crystals compared to those visible using conventional slitlamp biomicroscopy and showed a different crystal morphology.