Evaluation of cytologic specimens obtained during experimental vitreous biopsy using B-cell lymphoma line.

Purpose: To investigate the role of vitrectomy in the diagnosis of intraocular lymphoma by evaluating the effects of aspiration pressure and cut rate on cell viability and diagnostic yield. Methods: Cells of the human Burkitt lymphoma cell line Namalwa were processed by 20-G vitrectomy under 2 different aspiration pressures and at different cut rates. Some samples were divided into high and low aspiration pressure groups and were then divided into 6 subtypes according to the different cut rates (0, 300, 600, 800, 1500, or 2500 cuts per minute [cpm]). Other samples were treated with dexamethasone sodium phosphate for 48 hours with or without further culturing in cell culture media afterward. The cell viability in each subtype group was determined using trypan blue staining and the Cell Counting Kit-8. Results: The number of viable cells was reduced with increasing cut speed under high aspiration pressure. Cell viability began to decrease at 600 cpm and was lowest at 2500 cpm. Exposure to dexamethasone sodium phosphate induced destruction of cellular structure and a significant reduction in cell viability. However, cell viability could be recovered with further culture in cell culture media for 1 week. Conclusions: A cut rate of 600 cpm or less is recommended during diagnostic vitrectomy to confirm a clinical suspicion of primary intraocular lymphoma. Corticosteroid treatment can lower the diagnostic yield due to reduced cell viability and damaged cellular structure.