Clinicopathologic features of excised mitomycin filtering blebs.

Using light and electron microscopy, we examined two conjunctival filtering blebs that had been treated with mitomycin just prior to trabeculectomy and were later excised due to ocular hypotony. Light microscopy showed attenuated epithelium, loosely arranged subepithelial connective tissue, and scattered acute and chronic inflammatory cells. Electron microscopy also showed these findings and demonstrated the presence of presumably viable activated fibrocytes in the subepithelial connective tissue. The presence of inflammatory cells in the blebs was attributed to concurrent infections and suggests that mitomycin does not completely suppress, but may attenuate, the inflammatory response. The mechanism of hypotony and bleb failure in the two eyes was most likely a combination of over-filtration and a persistent wound leak due to a lack of postoperative subconjunctival fibrosis secondary to treatment with mitomycin.

Occupational noise exposure in the printing industry.

The noise exposures of 274 printing production workers in 34 establishments in the New York city area were monitored. Results showed that 43% were exposed to 8-hr time-weighted average (TWA) noise exposures of 85 dBA or greater and that 14% were exposed to 8-hr TWAs of 90 dBA or greater. Within the press department, web press workers were exposed to significantly greater mean 8-hr TWAs than sheetfed press workers. In general, a greater percentage of the workers in the bindery departments were exposed to potentially harmful noise than workers in the press departments. Results of this study indicate that many workers in the printing industry may be at risk of occupational hearing loss. Further research is needed to determine the extent of hearing impairment in this group of workers.