Histopathology of optic nerve pit-associated maculopathy

Abstract

Purpose: To describe the histopathologic findings of an eye bank specimen containing an optic nerve pit with associated serous elevation of the macula and cavernous atrophy of the optic nerve.

Methods: An eye bank specimen found to have an optic nerve pit with serous elevation of the macula was grossly examined and photographed. The globe was processed for both light and scanning electron microscopy.

Results: The scanning electron microscopic study of this eye with an optic nerve pit revealed holes in the diaphanous membrane overlying the nerve at the edge of the optic pit. Serial histopathology sections revealed a connection between the holes overlying the optic pit and the subretinal space via a schisis-like cavity in the retina.

Conclusion: The discovery of an optic nerve pit with coexisting serous detachment of the macula in an eye bank eye and subsequent pathological evaluation provides support for current theories into the mechanism of the visual loss in this condition. Our finding supports syneretic vitreous to be the source of the subretinal fluid.

Keywords: electron microscopy; light microscopy; optic nerve pit; retinal detachment.

Figure 1

Fundus photo with a temporally located optic disc pit (arrow) and associated macular detachment. There is chorioretinal atrophy superior to the nerve.

Figure 2

SEM of the optic disc pit with defects in the overlying diaphanous membrane. (A) SEM of the optic disc pit with defects in the overlying diaphanous membrane (arrows). (B) higher magnification allows visualization of the base of the optic pit through these membranous defects. Abbreviation: SEM, scanning electron microscope.

Figure 3

Serial sections through the optic disc pit and adjacent retina. (A) note the schisis cavity and atrophy of the temporal retina adjacent to the optic disc. In this specimen, only ILM remained as a roof of the cavity (arrow). (B) unique to this specimen is extensive cavernous atrophy of the optic nerve (long arrow). Note the intact subarachnoid space (short arrow) without communication to the subretinal space in this section. (C) retinal atrophy has created a schisis cavity adjacent to the optic pit. (D) a lamellar defect below the schisis cavity has resulted in a communication into the subretinal space. Abbreviation: ILM, internal limiting membrane.

Figure 4

Artist’s depiction of our specimen showing the communication between the vitreous cavity to the subretinal space.

Figure 5

SEM showing extensive cavernous atrophy of the optic nerve. (A) SEM showing extensive cavernous atrophy of the optic nerve with an intact subarachnoid space. (B) higher magnification SEM of cavernous atrophy of the optic nerve with a wall of intact glial tissue surrounding this area (upper portion of image). Abbreviation: SEM, scanning electron microscope.