Coloboma of Optic Nerve Associated With Serous Maculopathy: A Clinicopathologic Correlative Study

• A rhesus monkey with a congenital coloboma of the optic nerve head associated with serous macular detachment underwent intravenous (IV), intrathecal, and retrobulbar fluorescein angiography. No fluorescein leaked beneath the serous detachment after IV or intrathecal injection, although the retrobulbar injection caused a bolus to extravasate from the margin of the optic nerve coloboma, drifting toward the macular region temporally. Histopathologically, glial tissue replaced optic nerve axonal bundles in the temporal coloboma. The intermediary tissue of Kuhnt was disrupted, and fluid from the retrobulbar space diffused into the sub-retinal space temporally, where a localized retinal detachment extended from the optic nerve to the macula. Subretinal fluid in the macula associated with optic nerve coloboma might derive from (1) fluid perfusing into the retrobulbar space from surrounding orbital tissue, (2) peripapillary choriocapillaris, or (3) CSF.