Journal of Neuro-Ophthalmology, December 2013, Volume 33, Issue 4

Optic Disc Doubling or Pseudo-Optic Disc in Colobomatous Retinal Abnormality?

Optic Disc Doubling or Pseudo-Optic Disc in Colobomatous Retinal Abnormality? In their Photo Essay, Padhi et al (1) described a patient with optic disc doubling. We examined a similar case (Fig. 1) and believe that the case reported by Padhi et al, like ours, has a coloboma located inferiorly to the true optic disc. First, the optical coherence tomography (OCT) image in the report by Padhi et al shows naso-temporal asymmetry of the nerve fiber characteristic of a true optic disc, but convergence of the inner retinal layers toward the second disc. This finding is typical of retinal coloboma (2). Second, inferior retinal colobomas often are associated with abnor-mal retinal vasculature. Third, on OCT imaging, typically there is a discontinuation of the IS/OS junction near a coloboma (3). This finding may be present in the patient of Padhi et al, although it is difficult to assess due to the quality and angulation of the scan. Christina Gerth-Kahlert, MD Hannes Wildberger, MD Department of Ophthalmology, University Hospital Zurich, Zurich, Switzerland [e-mail] The authors report no conflicts of interest. REFERENCES 1. Padhi TR, Samal B, Kesarwani S, Basu S, Das T. Optic disc doubling. J Neuroophthalmol. 2012;32:238-239. 2. Schubert HD. Schisis-like rhegmatogenous retinal detachment associated with choroidal colobomas. Graefes Arch Clin Exp Ophthalmol. 1996;233:74-79. 3. Judson CH, Vuong LN, Gorczynska I, Srinivasan VJ, Fujimoto JG, Duker JS. Intact retinal tissue and retinal pigment epithelium identified within a coloboma via high-speed, ultrahigh resolution optical coherence tomography. Retin Cases Brief Rep. 2011;5:46-48. FIG. 1. Spectral domain optical coherence tomography images show normal appearance of true optic disc (left), whereas series of scans through coloboma (right) demonstrates discontinuation of inner/outer segment boundary (white line) and convergence of retinal layers. (A, B, C) Coloboma area in different section as illustrated in the red-free image (above). 412 Letters to the Editor: J Neuro-Ophthalmol 2013; 33: 412-423 Letters to the Editor Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.