Histological examination of primary posterior capsule plaques

To understand the source and evolution of the cellular elements of posterior capsule plaques.

Department of Ophthalmology, University of Sciences, Faculty of Medicine, Pécs, Hungary.

In 24 eyes of 24 patients, the primary fibrotic plaques were carefully peeled off the posterior capsule with forceps and sent for histological examination. The samples were stained with hematoxylin-eosin and with picrosirius to demonstrate collagen content.

Most plaques were found in elderly patients with mature cataracts. However, one was found in a patient with congenital cataract. The histological examination revealed different stages of plaques, permitting discrimination of early (cellular), transitional, and late (fibrotic) stages. The plaques in the early stage contained cuboidal cells with nuclei; collagen deposition led to the development of the transitional stage; and further collagen deposition led to the fibrotic stage. There was no significant correlation between the maturity of the cataract and the plaque stage, but other factors such as previous eye surgery (vitrectomy, glaucoma surgery), long-standing diabetes mellitus (DM), and a high degree of myopia appeared to contribute to the development of plaques.

Primary posterior capsule plaques were found primarily in elderly patients with mature cataracts but were also present post vitrectomy in those who had DM from a young age and had early stages of cataract. In the early plaque stage, cells with nuclei were found. It follows that plaques are capable of proliferation at this stage, aggravating visual disturbance. Therefore, removing the plaques by peeling from the posterior capsule or by posterior capsulorhexis during surgery is suggested.