Optical coherence tomography of macular lesions associated with optic nerve head pits.

PURPOSE

Although optic pits were described more than a century ago, the pathogenesis and pathologic nature of the associated macular lesions remain controversial. The authors used the technique of optical coherence tomography (OCT) to further define the anatomic relation that exists between optic pits, macular schisis-like spaces, and macular detachments.

METHODS

Four eyes of three consecutive patients with optic pit-related macular pathology were evaluated. Cross-sectional OCT images were correlated with findings from slit-lamp biomicroscopy and stereo fundus photography. All eyes previously had undergone unsuccessful photocoagulation to the temporal juxtapapillary retina. One eye had undergone vitrectomy and intraocular gas tamponade, resulting in partial resorption and displacement of the submacular fluid.

RESULTS

Retinal edema and cystic degeneration were present, overlying macular neurosensory detachments in all four eyes. The most prominent edema was present in the outer retina at the level of the outer plexiform layer. This mimicked a true retinoschisis cavity, although bridging retinal elements were identifiable. A lesser degree of edema was present in the inner retina, predominantly located between the disc and fovea. In one eye, a lamellar hole was shown to be a defect in the outer neurosensory retina. In another eye, a macular detachment developed under a pre-existing schisis-like cavity. The schisis-like cavity or edematous retina communicated with the optic disc in all eyes, whereas none of the eyes demonstrated a direct connection between the macular detachment and optic pit.

CONCLUSION

These findings support the concept of a bilaminar structure in which a macular detachment develops secondarily to a pre-existing schisis-like lesion consisting of severe outer retinal edema. Fluid may enter from the optic pit into the retinal stroma and not directly into the subretinal space, explaining the prolonged recovery and frequency of treatment failure after photocoagulation to the juxtapapillary retina.