Electron microscopy for the diagnosis of ocular viral infections

Tear samples obtained from patients with suspected viral conjunctivitis were examined by virus culture and by the pseudoreplica method for electron microscopy (EM). Adenoviruses were isolated in 13 of the 34 cases (38%) clinically diagnosed as adenovirus conjunctivitis. Characteristic adenoviral particles were demonstrated by electron microscopy in seven of the culture-positive, and two of the culture-negative samples. In cases of herpes simplex virus ocular infection, tears were virus positive by culture in one-third of the patients; two-thirds of the culture positive specimens were also positive by EM. This study demonstrates the potential of electron microscopy as a rapid, specific, and relatively inexpensive method for the laboratory diagnosis of ocular viral infections.