Dysthyroid optic neuropathy: update on pathogenesis, diagnosis, and management

Abstract

Introduction Dysthyroid optic neuropathy (DON) is a severe manifestation of thyroid eye disease (TED) that can result in permanent vision loss. Management is complex, multidisciplinary, and involves medical and/or surgical therapies. This review describes current concepts in the epidemiology, pathophysiology, diagnosis, and treatment of DON. Areas covered An extensive review of the literature was performed to detail current concepts on the diagnosis and management of DON. This includes utilization of various medical and surgical modalities for disease management. Expert commentary DON can result in permanent blindness and often requires the use of corticosteroids and surgical decompression. We favor the use of intravenous corticosteroids and a transcaruncular approach when surgical decompression is indicated. The use of orbital radiation for DON is often reserved for patients that are poor surgical candidates and/or patients with refractory disease.

Peripapillary and Macular Vessel Density in Dysthyroid Optic Neuropathy: An Optical Coherence Tomography Angiography Study

“…4 The compression may directly stretch the optic nerve on one hand and reduce the blood flow in short posterior ciliary and peripapillary retinal arteries on the other. 5,6 A report showed that superior ophthalmic vein blood flow velocity was significantly decreased in DON eyes, which implies that the abnormal hemodynamic state may participate in the development of DON. 7 Optical coherence tomography angiography (OCT-A) is a noninvasive technique capable of qualitatively and quantitatively evaluating the retinal and choroidal perfusion.…”

“…19 The mechanism underlying DON appears to be multifactorial, and vascular insufficiency might be an important factor as in other optic neuropathies. 5,6 With the emergence of OCT-A, it is feasible to figure out the correlation between microvascular perfusion and the development of DON. A recent OCT-A study investigating the retinal vessel changes in active TAO eyes initiated the exploration to the contribution of intraocular blood flow in the development of TAO.…”

“…The common exclusion criteria for all subjects were as follows: (1) any systemic diseases rather than thyroid disorders, (2) any history of ocular surgery or ocular trauma, and (3) any ophthalmopathies (e.g., glaucoma, diabetic retinopathy, and uveitis). DON was diagnosed based on clinical findings 6,22,23 : decreased visual acuity (the best-corrected visual acuity [BCVA] in logMAR visual chart, >0.2), apparent visual field (VF) defect (mean deviation [MD] in Humphrey perimetry, <À10 dB), relative afferent pupillary defect when unilaterally affected, abnormal pattern visual evoked potentials test (latency delay and amplitude reduction), and evident apical crowding in orbital computed tomography or and/or magnetic resonance imaging. As image quality was associated with the vessel density measures, 24 OCT-A scans with inadequate quality were excluded: (1) signal strength index of <45, (2) motion artifacts visible on the en face angiogram, (3) local weak signal, and (4) images off-center on fovea or disc.…”

Enduring remission of active and sight-threatening Graves’ orbitopathy with rituximab: report of two cases

“…Visual field testing or visual evoked potentials were not tested for diagnosing DON in our patients. Visual loss is considered a late sign of DON, while color desaturation is an early sign [14]. Prior to rituximab, the first case developed visual decline and loss of color vision, while the second case had visual loss and a relative afferent papillary defect, indicating DON.…”

An atypical case of unilateral vision loss in thyroid eye disease

“…Optic neuropathy is a rare and severe complication of thyroid eye disease (TED), comprising four to eight per cent of all the complications that may manifest due to compression of the optic nerve by hypertrophy of the extraocular muscles, inflammation or compromised blood supply to the optic nerve. 1 Dysthyroid optic neuropathy appears later in the progression of TED and is rarely the presenting feature. Herein is presented a case of 60-year-old female who initially presented with acute painless unilateral diminution of vision, later diagnosed with TED and compressive optic neuropathy.…”