OCT is a noninvasive system that allows for cross-sectional imaging in vivo, using light waves, which are akin to the sound waves in ultrasonography. The purpose of this article is to discuss the interpretations and limitations of OCT imaging. Hydroxychloroquine retinal toxicity risk factors Chloroquine schedule Plaquenil and pregnancy category In hydroxychloroquine HCQ retinopathy, early detection of asymptomatic retinal changes and the interruption of the drug are essential to prevent permanent vision loss. Our purpose was to investigate the roles of ganglion cell layer GCL and outer nuclear layer ONL thicknesses measured by optical coherence tomography OCT in the early diagnosis of retinopathy. Previous histopathological studies reported that the initial dramatic changes of hydroxychloroquine toxicity were observed in the retinal ganglion cell layer 18, 19. On the other hand, recent OCT studies have suggested that selective thinning of perifoveal inner plexiform and ganglion cell layers was found in patients treated with long-term hydroxychloroquine. Ganglion Cell Analysis Measures thickness for the sum of the ganglion cell layer and IPL using data from the Macular 200 x 200 or 512 x 128 cube scan patterns RNFL distribution in the macula depends on individual anatomy, while the GCL+IPL appears regular and elliptical for most normals. Thus, Low-coherence interferometry was then adapted for use in OCT. The initial application of low-coherence interferometry in ophthalmology was for measurements of axial length. Ganglion cell layer and plaquenil toxicity Retinal Physician - Appropriate Interpretation of OCT Imaging, Effect of Hydroxychloroquine on the Retinal Layers A. Chloroquine and lc3 The exact mechanism of retinal toxicity is still under investigation. Despite the evident clinical changes in retinal pigmented epithelium RPE when the maculopathy is already visible, studies in animals after long exposure to chloroquine demonstrated that the first site of damage is most probably the ganglion cell layer.” COPE Disclosures Plaquenil Toxicity Update. Optical Coherence Tomography OCT The Origins of the OCT. Biomedicines Free Full-Text Outer Nuclear Layer Damage.. Results. Recently published work provides evidence showing a strong relationship not only between the retinal nerve fiber layer and visual threshold in optic nerve disorders, but also between visual sensitivity and the inner layers of the retina in the macula where the cell bodies of ganglion cells reside. Figure 2a and 2b this classic representation of Plaquenil toxicity is a preservation of the outer retinal layers subfoveally with perifoveal loss of the IS/OS junction on both sides of the fovea. Perifoveal IS/OS junction loss is associated with perifoveal outer retinal thinning, resulting in an ovoid appearance in the central retina, creating the flying saucer sign. Hydroxychloroquine Plaquenil and chloroquine cause ocular toxicity to various parts of the eye such as the cornea, ciliary body, and retina. Chloroquine can also induce cataract formation; however, no reports of hydroxychloroquine and cataract have been reported 1.