Viral nucleic acid analysis with PCR in lacrimal tissue and nasal swab samples of primary acquired nasolacrimal duct obstruction cases

Yanik, Özge; Hosal, Banu; Tekeli, Alper; Nalci, Hilal

This was a pilot study, and the major study limitations were the small sample size and the low number of viral positives in the DCR samples, which prevented us from establishing a definitive association between PANDO and viral infections. Sexual differences in cytokine responses to infection may also have a role in determining susceptibility to viruses. 27 Therefore, further studies including large number of cases with equal gender and age distribution and usage of quantitative real-time PCR analysis for suspected viruses to decide the clinical stage of the infection are needed. Animal models in which virus inoculation is performed directly into the lacrimal sac may also help to assess the mucosal changes that viruses can reveal in this region. Moreover, populationbased studies with a long follow-up time that evaluate the time period prior to the disease development may help to elucidate the precise pathogenesis of PANDO.