Clinical application of new membrane filter for cytopathological diagnosis in ophthalmology

In order to evaluate the clinical usefulness of a new membrane filter method, PORETEC, for cytopathological diagnosis in ophthalmology, we performed a comparative study on conjunctival cell specimens using this method and a previously developed cytocentrifugation method. The subjects were 5 normal male volunteers (6 eyes) with an average age of 33 years. The conjunctival cells were obtained by brush cytology, and processed for both the new membrane filter and the cytocentrifugation methods. The total numbers of epithelial cells obtained by both methods were counted under a light microscope. The number of cells obtained by the cytocentrifugation method was 4933 +/- 2338 for each specimen, whereas that by the new membrane filter method was 12436 +/- 5281 (mean +/- SD). The difference was statistically significant (Wilcoxon signed-rank test, P < 0.05). The new membrane filter diagnostic method was also applied to specimens of aqueous humor from patients with uveitis or vitreous body from patients with proliferative diabetic retinopathy or endophthalmitis. The new method provided excellent cytopathological specimens which were also applicable for special staining and immunocytochemical study. We concluded that the new membrane filter is quite useful for cytopathological diagnosis of ocular fluid specimens.