Duplication of the Optic Disc: True or Pseudo? A Coloboma or not a Coloboma?

Abstract

We report what we believe to be the first case of pseudoduplication of the optic disc with coexistent bilateral optic disc colobomata.

Pseudodoubling of Optic Disc With Bilateral Serpiginous Choroiditis and Macular Choroidal Neovascularisation- A Case Report

“…Pseudodoubling of the optic nerve head is a rare condition where a lesion resembling an optic disc is situated adjacent to the true optic disc. 1 This pseudoduplication of optic discs maybe caused by lesions such as peripapillary chorioretinal coloboma, optic disc coloboma or inflammatory foci (in our case). Rare cases of true duplication of optic discs with separation of optic nerve into two or more strands have been reported.…”

Pseudo-duplication of the optic disc with maculo-schisis in a 9-year-old patient

“…Previous reports documented various concurrent clinical findings accompanying duplication of the optic disc, such as bilateral serpiginous choroiditis, macular congenital hypertrophy of the RPE and bilateral optic disc pits. 2 , 8 , 9 Pseudo-duplication of the optic disc is readily distinguished from optic pit as the former comprises an adjacent disc-like lesion and the latter appears as a round depression within the optic disc. Nonetheless, our case resembled in some ways the presentation of optic pit maculopathy, however, the fact that the presumed source of the fluid responsible for the retinal schisis was not located precisely at the “second” optic disc, probably represents a major difference between the two entities in terms of mechanism.…”

“…1 The diagnosis of Pseudo-duplication of the optic disc is considered when a disc-like lesion with associated vasculature and occasionally surrounding chorioretinal atrophy and profound cupping, arises adjacent to the normal optic disc. 2 Most cases occur unilaterally and may be associated with decreased acuity in the affected eye. Several developmental defects can simulate the appearance of optic disc pseudo-doubling, including optic disc coloboma, peripapillary chorioretinal coloboma, and scarring.…”

Developmental abnormalities of the optic nerve and chiasm

“…18,19 The second optic disc usually lies below the main disc and has its own set of retinal vessels; it is often connected to the main disc by an arteriolar or a venular connection and a bridge of the coloboma.…”