Anterior chamber paracentesis with PCR not recommended in anterior uveitis

This retrospective study found that anterior chamber paracentesis with polymerase chain reaction (PCR) had a relatively low diagnostic utility and resulted in few management changes in patients with suspected infectious anterior uveitis. Based on these results, the authors do not recommend this procedure as a first-line investigation.

They evaluated 53 patients with anterior uveitis. Most of the patients had either chronic or acute anterior uveitis.

Overall, 7 patients (13 percent) had a change in management because of PCR results from anterior chamber paracentesis. Pigmented keratic precipitates and iris atrophy were associated with a higher likelihood of a positive test for viral DNA by PCR.

There were five complications of paracentesis in four patients, including two hyphemas and one patient who developed a Seidel positive wound and a permanent central scotoma (although the mechanism of the scotoma is not detailed).

There was a low rate of cytomegalovirus (CMV) anterior uveitis. As the authors discuss, it does seem to be population dependent. They recommend a trial of anti-viral medication if herpes simplex or varicella zoster diagnosis is being considered before resorting to paracentesis. This is my approach as well.

On the other hand, oral valganciclovir for CMV is more toxic and expensive than the treatment for the other herpetic viruses, such as valaciclovir, and so perhaps more strong consideration must be given to paracentesis if CMV is suspected. Nonetheless, given that anterior chamber paracentesis is not without risk and there are false negatives, I believe a therapeutic trial can be the way to go even for CMV anterior uveitis if the patient and physician so choose.