|Year : 2022 | Volume
| Issue : 1 | Page : 332
Piggyback optic disc
Aditi Parab1, Priya Sivakumar2, Harsh Vardhan Singh3
1 Department of Ophthalmology, Aravind Eye Hospital, Puducherry, India
2 Department of Neuro Ophthalmology and Low Vision Services, Aravind Eye Care, Puducherry, India
3 Department of Vitreo-Retinal Services, Aravind Eye Hospital, Puducherry, India
|Date of Web Publication||07-Jan-2022|
Dr. Priya Sivakumar
Department of Neuro Ophthalmology and Low Vision Services, Aravind Eye Care, Puducherry - 605 007
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Parab A, Sivakumar P, Singh HV. Piggyback optic disc. Indian J Ophthalmol Case Rep 2022;2:332
Double optic disc is a rare entity and is seen in lower vertebrates. True optic disc duplication is still rarer than a pseudoduplication. Pseudoduplication is characterized by the duplication of the retinal vasculature and optic disc but with a single optic nerve. Pseudoduplication is most commonly misdiagnosed as optic disc coloboma. Diagnosis can be made by the fundus appearance [Figure 1]a, ultrasonography, optical coherence tomography (OCT). Computed tomography orbit [Figure 1]c shows single optic canal in case of pseudoduplication, thereby confirming the diagnosis. Fundus fluorescein angiography shows bridging retinal vessels originating from the true optic disc to the pseudooptic disc in case of pseudoduplication. OCT [Figure 1]b shows localized retinal layer atrophy adjacent to the true optic disc with hyperreflective ring indicating vessels at outer retina presenting as pseudooptic disc.
|Figure 1: (a) Color fundus photograph of the left eye showing a true optic disc (black arrow head) with a pseudooptic disc (black arrow) nasally, bridging retinal vessels from the true optic disc to the pseudooptic disc. (b) OCT line scan through the optic nerve head (white arrow head) showing localized retinal layer atrophy nasal to disc (white arrow) with hyperreflective ring (white asterisk) indicating vessels at outer retina presenting as second optic disc. (c) Plain computed tomography scan of brain and orbit, mid axial view showing single optic canal (black asterisk) in both orbits|
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