Purposes: To evaluate the multimodal imaging findings in retinal deep capillary ischemia (DCI).
Methods: This was a retrospective review of 5 eyes of 4 patients with sudden onset of paracentral scotomas caused by DCI. Multimodal imaging techniques, including color and red-free photographs, near-infrared reflectance, fluorescein angiography, and spectral-domain optical coherence tomography, were performed in all eyes, and the findings were correlated with microperimetry in two eyes. Imaging findings in DCI were compared with those of a cotton wool spot caused by superficial capillary ischemia (SCI).
Results: Unlike SCI, the imaging findings in DCI were subtler during both the acute and chronic phase, but specific optical coherence tomographic findings could readily differentiate these entities. Acute SCI showed inner retinal whitening, edema, and increased reflectivity, whereas acute DCI showed increased reflectivity of middle retinal layers. Chronic DCI showed retinal thinning with middle layer atrophy, whereas chronic SCI showed inner layer atrophy. In one patient, microperimetry showed a paracentral dense scotoma that corresponded well to the optical coherence tomographic findings.
Conclusion: Deep capillary ischemia may represent a nonspecific finding of retinal ischemia and produces characteristic changes within the middle retinal layers, analogous to a deep cotton wool spot, but with distinct features differing from the superficial cotton wool spot which is seen in SCI. Among the various multimodal imaging techniques, optical coherence tomography seemed to be the most sensitive and specific technique in detecting DCI in both the acute and chronic phases.