Ezra and coworkers1 studied the ultrastructural features of 18 opercula excised from eyes during vitrectomy for stage 3 idiopathic full-thickness macular holes, and they correlated them with the surgical outcome. Native vitreous collagen was identified on the surface of all 18, while fragments of internal limiting membrane were present in 11 (61%). In 11 (61%) they found only glia, comprising fibrous astrocytes and Müller cells. In the remaining 7 (39%) they found, in addition to glia, neuronal perikarya, neuritic processes containing intracytoplasmic neurotubules, synaptic complexes, and terminals with single neuritic processes synapsing at multiple points with second-order neurones, consistent with cone photoreceptor pedicles in the outer plexiform layer. Not found were abundant cone nuclei, outer limiting membrane junctional complexes, and inner receptor processes that comprise the bulk of the foveola.While they found an association of the presence of neuronal tissue with a worse anatomical result after initial surgery, they found no association between the presence of neurites and the anatomical results of reoperation. There was no statistically significant difference between the type of operculum and the 6-month visual acuity. The authors concluded that the nonneuronal opercula are probably associated with a central foveolar dehiscence, whereas the opercula, "containing both glia and a significant number of avulsed foveal cones (true opercula) arise from a full-thickness foveal tear."
Gass JDM. Macular Hole Opercula: Ultrastructural Features and Clinicopathologic Correlation. Arch Ophthalmol. 1998;116(7):965-966. doi: