Histopathological features of vitreous removed at macular hole surgery

Objective: To describe the histopathological features of the vitreous removed at surgery for macular holes in 200 consecutive cases. Methods: The complete vitrectomy specimen in each case was concentrated by means of cellulose membrane filters and stained for light microscopy. The cases were organized into 5 categories: (1) all cases (N = 200), (2) eyes without previous vitrectomy (n = 174), (3) eyes with previous vitrectomy (n = 26), (4) idiopathic cases (n = 143), and (5) traumatic (accidental or surgical) cases (n = 31). The type and frequency of tissue fragments present in the vitreous were determined for each case. Results: Fibrocellular and cellular membrane fragments were found in a minority of cases in all categories. Retinal fragments were a rare finding, present in only 4 cases. Inflammation was present in 57 (28.5%) of all cases. Conclusions: The absence of fibrocellular and cellular membrane fragments in the majority of cases suggests that mechanisms other than cellular proliferation are important in the pathogenesis of macular holes. These fragments are, however, the likely histopathological correlate of the opercula that are often observed clinically in patients with macular hole. Opercula rarely if ever contain retinal fragments, and thus are better termed pseudo-opercula, as has been previously suggested. The cellular proliferation and inflammation that are observed in some of the cases are likely a secondary or reactive process.