Optical coherence tomography (OCT) of the macula in patients with primary optic neuropathy has revealed the presence of structural changes in the neurosensory retina in addition to the nerve fibre layer. Subretinal fluid has been documented in papilloedema and non-arteritic ischaemic optic neuropathy, and may account for decreased visual acuity in affected patients. Subretinal fluid has also been described from other causes of optic nerve head swelling including diabetic papillopathy and papillitis. Drugs used in the treatment of multiple sclerosis, such as corticosteroids and fingolimod can cause decreased vision due to central serous and cystoid macular oedema sometimes confused with recurrent optic neuritis. A subset of patients with various types of optic atrophy show microcystic changes in the inner nuclear layer on spectral domain OCT imaging. The pathophysiology and visual significance of these retinal changes remain unclear, but may affect the diagnosis and management of optic nerve disorders.

The objective of this study was to describe the changes in the retinal ganglion cell complex (GCC) relative to the retinal nerve fibre layer (RNFL) over time in Leber hereditary optic neuropathy (LHON) patients. Average RNFL and GCC thickness was measured in seven patients in the early acute (123, 68.4 μm), late acute (113.5, 57.4 μm), and chronic (72.7, 50.8 μm) phases. Patients showed thinning of the GCC with RNFL swelling in the early acute phase. GCC thinning became severe within weeks and persisted. RNFL swelling normalised during the late acute phase with eventual thinning in the chronic phase. GCC changes appear at the commencement of visual loss and in some cases prior to vision loss. These findings define an optical coherence tomography (OCT) profile in LHON.ARTICLE HISTORY

BackgroundBirdshot chorioretinopathy is a chronic bilateral inflammatory disease of unknown etiology characterized by bilateral retinal vasculitis, mild to moderate vitritis, retinal vascular leakage, cystoid macular edema (CME), and typical “birdshot” chorioretinal lesions. Typically, patients with birdshot chorioretinopathy are treated with systemic immunosuppressive and/or corticosteroid therapy in an effort to minimize loss of vision. Spectral-domain OCT (SD-OCT) has shown regional or generalized photoreceptor loss in addition to both retinal as well as choroidal thinning in these patients. The present study describes anatomical changes of the retina and alterations in choroidal thickness and vasculature on sequential spectral-domain optical coherence tomography (SD-OCT) in 4 patients with birdshot chorioretinopathy treated with local corticosteroids.MethodsA retrospective observational case series identified 4 consecutive patients (8 eyes) at New England Eye Center, Boston diagnosed with birdshot chorioretinopathy according to the research criteria of the international consensus conference that were managed by a single retina specialist and treated exclusively with local corticosteroid therapy (intravitreal/sub-tenon injections) without systemic immunosuppression. All patients underwent longitudinal SD-OCT imaging with both the 512 × 128 cube scan and the 1-line raster protocol. A chart review was performed to review the visual response to treatment. Two independent observers analyzed sequential SD-OCT images for retinal parameters such as occurrence of CME at any time during the course of disease, presence of retinal thinning and presence of hyper-reflective foci within the retina, and choroidal parameters including its thickness and its vasculature.ResultsMean age of the patients at diagnosis was 47 years (26–60 years). Mean duration of follow-up was 96 months. All patients were HLA-A29 positive. Visual acuity remained stable in 75 % of eyes, 63 % eyes had central retinal thinning, 75 % eyes had hyper reflective foci within the retina and 75 % eyes had CME during follow-up. Mean total sub-foveal choroidal thickness of all 8 eyes at the time of the last SD-OCT was significantly lower than at initial SD-OCT (p = 0.03).ConclusionsThis case series suggests that treatment with local corticosteroids may have good visual outcome despite retinal and choroidal thinning. Future longitudinal studies are necessary to further determine the benefits of local corticosteroid therapy.