OCT III imaging of whiplash maculopathy

Sir,

I read with interest the remarkable description of whiplash maculopathy in a 24-year-old woman following a motor vehicle accident.¹ The authors point out that the patient noted a paracentral scotoma within hours of the accident. During the examination and on visual field testing 6 months later, a nasal parafoveal annular whitish lesion was noted and the scotoma could be documented by visual field assessment with laser beam and a Maddox cross, and quantified Octopus automated perimetry (10° centromacular field). Furthermore, the authors describe a change on optical coherence tomography (OCT) at the vitreoretinal interface.

After a careful review of the imaging, including the OCT, I note an additional finding that may be a more likely cause of the scotoma in this patient. The OCT image demonstrates a severe disorganization of the inner segment–outer segment (IS–OS) retinal pigment epithelial (RPE) layer signals. Parafoveally, on the side closest to the visual field images in the composite figure, and presumably representing the nasal macula, the outer retina-RPE layers are not separately visible. Specifically, the IS–OS junction is obscured in this area, while it is distinctly visible elsewhere on this OCT image.

The integrity of the IS–OS junction has increasingly become recognized as important for visual function. Reports in several conditions have shown that abnormalities in this layer are associated with poor visual function in the abnormal region, with decreased measured acuity or corresponding scotomata.^{2, 3, 4}

Reinterpretation of the OCT image would thus suggest that the cause of the scotoma in this case of whiplash maculopathy may be disruption of the outer segment architecture, and not a small area of increased reflection at the vitreoretinal junction. This interpretation is supported by the findings of Parsons et al in an autopsy case of whiplash maculopathy, which demonstrated the pathologic features of retinoschisis between the photoreceptor nuclei and the intact, but folded, photoreceptor inner and outer segments and RPE detachment.⁵ This alternative interpretation of the OCT image may more plausibly explain the scotoma in this patient and in whiplash maculopathy in general.