A survey of vitreous cell components performed using liquid-based cytology

To confirm the efficacy of liquid-based cytology (LBC) method in the observation of vitreous cells in various vitreoretinal diseases in human.

Vitreous fluid samples from 30 eyes were obtained by 23-gauge 3-port pars plana vitrectomy. After making three ports, we collected vitreous specimen from the core vitreous cavity without infusion. We divided the samples into a quiescent group and an active group based on clinical signs of inflammation. To confirm availability of LBC preparation slides for immunostaining, we also performed immunocytochemistry (ICC) for CD68, RPE65 and DEC-205 (CD205) using LBC slides of 10 cell-rich cases including retinal detachment and endophthalmitis.

Using LBC method, small amounts of vitreous cells were observed efficiently. Vitreous cells were observed in inflammatory quiescent cases including macular pucker and macular hole. The number of vitreous cells increased significantly in the cases with clinically active inflammation (2297 versus 207 cells/ml, respectively, p < 0.01, Mann-Whitney U-test). The ICC results showed the presence of CD68(+) cells in all 10 cases. Large numbers of DEC-205(+) cells were observed in one case with infectious endophthalmitis. In the cases with retinal detachment, the predominant cell type was RPE65(+) . Neutrophils and lymphocytes were also observed.

The LBC method makes it possible to examine vitreous specimens easily and efficiently, facilitating the expedient diagnosis of vitreoretinal diseases, and the preparation slides are available for immunocytochemistry. This study also showed that vitreoretinal disease involves the migration of various types of cells including macrophages, neutrophils, lymphocytes, RPE65(+) pigmented cells and DEC-205(+) cells.