The macular hole: histopathologic studies.

OBJECTIVE To delineate the light and electron microscopic features of tissue removed at the time of macular hole surgery. METHODS The ocular fluid specimens were concentrated using Millipore filters and stained with a modified Papanicolaou and the periodic acid-Schiff stains in 697 cases. In 92 cases, surgically isolated tissue was processed and examined by electron microscopy. RESULTS The findings in the specimens studied by the Millipore filter technique included vitreous strands; cellular fragments in 108 cases (13.3%); fibrocellular fragments in 75 (9.2%); and fragments of internal limiting lamina (ILL) of the retina in 104 (12.8%). Findings in the 92 specimens with tissue studied by electron microscopy included native vitreous collagen in 48 cases (52.2%); new collagen in 6 (6.5%); native and new collagen in 1 (1.2%); ILL of the retina in 54 (58.7%); and a variety of cells in 22.5% of cases, including fibrocytes, myofibrocytes, fibrous astrocytes with and without myoblastic features, Mueller cells, retinal pigment epithelium with and without myoblastic features, and inflammatory cells. The organization of the tissue elements included a cellular layer along one surface of a layer of cortical vitreous in 18 cases, cortical vitreous along the inner surface of the ILL of the retina in 10, and cortical vitreous sandwiched between the ILL of the retina and a layer of cells in 9. CONCLUSIONS Tangential traction induced by fluid movements affecting the cortical vitreous is a major factor in the pathogenesis of idiopathic macular holes. Cellular proliferation is a secondary change seen in 22.2% of cases.