Doubling of the optic disc is rare and is seen as true doubling or pseudodoubling. We describe a peculiar case with multiple anomalies involving a single optic disc: a coloboma involving the optic nerve along with a pit and sensory detachment, and pseudodoubling of the optic disc with a disclike lesion within the coloboma.
A 34-year-old man was referred to our institute as a case of a “peculiar optic disc.” Examination revealed a right eye that was within normal limits and a left eye that had a coloboma involving the optic disc. A small, craterlike depression was seen in the center of the coloboma. A thin blood vessel along with a tuft of whitish glial tissue extended down from the optic disc and entered the crater on its superior aspect. Several thin vessels emerged from the lesion, thereby simulating another optic disc (FigureA and B). Since we found it difficult to photograph the entire optic disc and coloboma without loss of detail of the simulated optic disc with a standard fundus camera (VISUPAC FF 450PlusIR; Carl Zeiss Meditec, Jena, Germany) (Figure, A), another fundus photograph using a digital slitlamp camera (VISUPAC Digital Archiving system; Carl Zeiss Meditec) and a Mainster ultrawide field lens (Western Ophthalmics, Lynnwood, Wash) placed over the patient’s cornea was taken with satisfactory results (Figure, B). The inferotemporal portion of the coloboma lodged an optic pit. Sensory detachment was confined to the temporal part of the coloboma. Peripapillary pigmentary changes surrounded the temporal aspect of the disc and the coloboma. The macula was normal. Optical coherence tomography disclosed a craterlike depression corresponding to the simulated optic disc, which suggested a doubling of the papilla (Figure, C and D). A B-scan ultrasonogram showed a single optic nerve head shadow.
A, Color fundus photograph of patient’s left eye taken with standard fundus camera, showing optic disc (arrowhead) with coloboma in its inferior aspect. Central disclike lesion (arrow) with vessel clothed in glial tissue entering it in its superior aspect from optic disc and thin vessels emerging from lateral and inferior aspects are seen, as is sensory detachment confined to temporal part of coloboma (asterisk). Inset, optic pit (arrow) in inferotemporal part of coloboma. B, Color fundus photograph of patient’s left eye taken with digital slitlamp camera and Mainster ultrawide field lens in place, showing optic disc and coloboma in their entirety. Arrow denotes central disclike lesion. Vessels in relation to lesion are not as clear as in earlier fundus photograph. Asterisk denotes sensory detachment confined to temporal part of coloboma, which is also less clear than in earlier fundus photograph. Inset, optic pit (arrow) in inferotemporal aspect of coloboma, which is clearer than in earlier fundus photograph. C, Optical coherence tomographic picture of patient’s left eye (oblique line scan through disclike lesion and temporal aspect of coloboma), showing coloboma and craterlike depression (arrow) corresponding to disclike lesion. Glial tissue surrounding vessel entering lesion superiorly (arrowhead) and sensory detachment in temporal aspect of coloboma (asterisk) are obvious. D, Optical coherence tomographic picture of patient’s left eye (horizontal line scan through temporal aspect of coloboma and adjacent temporal peripapillary retina), showing sensory detachment in temporal aspect of coloboma (asterisk). Arrow denotes confinement of sensory detachment to temporal margin of coloboma, with sparing of adjacent peripapillary retina.
A diagnosis of true doubling is made with direct or indirect evidence of twin optic nerves.1 Our patient had only a single optic nerve as imaged by B-scan ultrasonography, though magnetic resonance imaging would have been more informative. Pseudodoubling of the optic disc is also rare and is commonly caused by optic disc colobomas or peripapillary colobomas.1- 3 Our patient had the interesting finding of an optic disc–like lesion within a coloboma. Additional abnormalities such as an optic pit, serous detachment confined to the coloboma, peripapillary altered pigmentation, and a glial tuft were observed. The latter 2 abnormalities are usually seen in association with the morning glory syndrome that occurs owing to embryologic insults to the distal optic stalk.4 The coloboma involves an injury to the proximal embryonic fissure. The origin of the pit is debated, with some speculating it to be owing to an improper closure of the superior end of the embryonic fissure.4 Our patient had a spectrum of hybrid disc anomalies, suggesting an instance of early embryonic injury involving both the proximal embryonic fissure and the distal optic stalk. To our knowledge, there is no other such case described in the literature.
Correspondence: Dr Vedantham, Retina-Vitreous Service, Aravind Eye Hospital & Postgraduate Institute of Ophthalmology, 1, Anna Nagar, Madurai 625-020, Tamilnadu, India (email@example.com).
Financial Disclosure: None.
Vedantham V. Double Optic Discs, Optic Disc Coloboma, and Pit: Spectrum of Hybrid Disc Anomalies in a Single Eye. Arch Ophthalmol. 2005;123(10):1450-1452. doi:10.1001/archopht.123.10.1450