To elucidate the mechanism of acquired pseudoduplication of the optic disc and its association with pathologic myopia.
The prevalence of pseudoduplication of the optic disc was estimated by reviewing 128 consecutive patients diagnosed as having pathologic myopia between January 2010 and December 2012. The pseudodisc was investigated at the scleral level using enhanced depth imaging spectral-domain optical coherence tomography to elucidate pathologic changes. Fluorescein angiography or indocyanine green angiography was performed to identify the vessel origin.
Among 128 patients with pathologic myopia, 3 patients (2.3%) showed pseudoduplication of the optic disc. Enhanced depth imaging optical coherence tomography showed chorioretinal atrophy and focal scleral excavation in the area showing the pseudodisc. The round scleral excavation gave the underlying visible peribulbar tissue a pinkish appearance, which could be mistaken as the optic disc. Fluorescein angiography or indocyanine green angiography showed that the vessel within the pseudodisc was the short posterior ciliary artery.
Although not a common presentation, scleral excavation associated with pathologic myopia accompanied by a ciliary artery penetrating the excavation’s center could make a lesion mimicking pseudoduplication of the optic disc.