Choroidal Thickness in Acute Non-arteritic Anterior Ischemic Optic Neuropathy.

Homayoun Nikkhah,Saeed Karimi,Mohadeseh Feizi,Hamed Esfandiari,Mehdi Yaseri,Naser Abedi

doi:10.18502/jovr.v15i1.5946

Abstract

PurposeTo compare the choroidal thickness in eyes with acute non-arteritic anterior ischemic optic neuropathy (NAION) with healthy contralateral eye and normal controls.MethodsThirty-eight eyes with NAION, thirty-eight unaffected fellow eyes, and seventy-four eyes from 37 healthy, age- and sex-matched subjects were included in this prospective comparative case-control study. Choroidal thickness was measured by enhanced depth imaging (EDI) of spectral domain optical coherence tomography (SD-OCT). Peripapillary choroidal thickness (PCT) was measured at 1000 and 1500 m from Bruch's membrane opening (BMO). Subfoveal choroidal thickness (SFCT) was measured in central subfoveal area, and 500 microns apart in temporal and nasal sides. Choroidal thickness among NAION eyes, uninvolved fellow eyes, and control eyes were compared.Results The mean of PCT at 1000 m was significantly thicker in NAION and fellow eyes compared to control eyes (169.7 47, 154.4 42.1, and 127.7 49.9 m, respectively, P 0.001 and P = 0.42). The mean PCT at 1500 m was also significantly thicker in NAION and fellow eyes compared to control eyes (178.6 52.8, 162.6 46.1, and 135.1 59 m, respectively, P = 0.007 and P = 0.048). The mean PCT at 1000 and 1500 m was significantly greater in NAION compared to fellow eyes (P = 0.027 and P = 0.035, respectively). The mean of SFCT was significantly thicker in NAION compared to control eyes (P = 0.032); however, there was no significant difference between uninvolved fellow and control eyes (P = 0.248).ConclusionThicker choroidal thickness in acute NAION and uninvolved fellow eyes compared to normal eyes suggests a primary choroidal role in NAION pathophysiology.

Highlights

Choroidal Thickness in Acute non-arteritic anterior ischemic optic neuropathy (NAION); Nikkhah et al the role of choroid in several sight-threatening ocular conditions such as polypoidal choroidal vasculopathy or choroidal neovascularization[1,2,3,4] is well-studied, it is only recently that the details of the choroid have been evaluated with enhanced depth imaging optical coherence tomography (EDI-OCT)
Since choroid is located adjacent to optic nerve and shares interconnected blood supply with optic disc, investigators have started to look at its possible role in two of the most common optic neuropathies, that is, non-arteritic anterior ischemic optic neuropathy (NAION) and glaucoma.[6,7,8,9]
The diagnosis of NAION was based on the presence of a history of sudden painless visual loss associated with a relative afferent pupillary defect that was not attributed to any other ocular, neurologic, or systemic disease, optic disc swelling detected by biomicroscopic examination at the time of presentation and confirmed by peripapillary retinal nerve fiber layer thickness measurement using OCT, visual field testing compatible with ischemic optic neuropathy, and resolution of disc swelling and appearance of optic atrophy within two months

Summary

Introduction

The role of choroid in several sight-threatening ocular conditions such as polypoidal choroidal vasculopathy or choroidal neovascularization[1,2,3,4] is well-studied, it is only recently that the details of the choroid have been evaluated with enhanced depth imaging optical coherence tomography (EDI-OCT). Evaluating choroidal thickness in acute NAION may help identify choroidal role in NAION and clarify if the choroidal thickness changes in NAION is a predisposing factor for this condition or the consequence of acute optic neuropathy. The purpose of this case-control study was to evaluate the peripapillary choroidal thickness (PCT) and subfoveal choroidal thickness (SFCT) in eyes with acute NAION and compare them with uninvolved fellow eyes and eyes of healthy controls Since choroid is located adjacent to optic nerve and shares interconnected blood supply with optic disc, investigators have started to look at its possible role in two of the most common optic neuropathies, that is, non-arteritic anterior ischemic optic neuropathy (NAION) and glaucoma.[6,7,8,9] NAION is the most common acute optic neuropathy[10] and, as the name implies, it is presumed to be secondary to the vascular insufficiency within optic disc space, but the nature of the vasculopathy and its pathophysiologic mechanism is not definitely known yet.[11]

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Conclusion