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 abnormal 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.
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.
© 2013 by North American Neuro-Ophthalmology Society
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.