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* BACKGROUND AND OBJECTIVE: Optical coherence tomography (OCT) was used to evaluate the macular thickness in eyes with advanced glaucoma compared with eyes following a retinal artery occlusion.
* PATIENTS AND METHODS: Ten patients with a retinal artery occlusion and 10 patients with severe glaucoma were evaluated with OCT using the macular thickness map protocol.
* RESULTS: The median thinnest macular sector was 183 microns (range: 152 to 223 microns) in patients with glaucoma versus 143 microns (range: 98 to 177 microns) in patients with arterial occlusion (P = .001). Median macular volume was 5.9 mm^sup 3^ (range: 5.1 to 6.7 mm^sup 3^) in patients with glaucoma versus 5.1 mm^sup 3^ (range: 3.6 to 6.1 mm^sup 3^) in patients with arterial occlusion (P = .015).
* CONCLUSIONS: OCT demonstrates that patients with a retinal artery occlusion have significantly reduced macular thickness compared with those with severe glaucoma.
[Ophthalmic Surg Lasers Imaging 2007;38:392-398.]
INTRODUCTION
The advent of optical coherence tomography (OCT) has allowed reproducible, in vivo, high-resolution imaging and measurement of the retina.1"3 Many pathologic processes of the macula that are not easily discernible on funduscopic examination, such as macular edema, are more distinct on OCT. In many cases, branch and central retinal artery occlusions typically exhibit retinal arteriolar attenuation, reduced central vision, and optic atrophy. Glaucoma is associated with vertical cupping with neural rim atrophy, disc cupping in excess of pallor, preserved central vision, and progressive deterioration. OCT can measure a significant difference in the macula between these two entities.
Acutely, arterial occlusive disease manifests marked edema throughout the inner retinal layers with pyknosis of retinal ganglion cell nuclei.4'5 Coagulative necrosis of the hypoxic retina ensues over several weeks. Wandering microglia invade the necrotic inner retinal layers and phagocytize the dead tissue, replacing the inner retina with glial cells and fibers and leaving a diffuse homogenous acellular scar.5 Because the outer third of the retina is perfused by the choriocapillaris, this portion of the retina remains preserved.
Conversely, the characteristic pathologic retinal finding in glaucoma is degeneration of the retinal ganglion cells and the retinal nerve fiber layer4"6 with preservation of the neuroglia and astrocytes of the inner retina, as well as the outer two-thirds of the retina.4'5
Using low-coherence interferometry, reproducible cross-sectional...