Correlation Between Clinical Diagnosis and PCR Analysis of Serum, Aqueous, and Vitreous Samples in Patients with Inflammatory Eye Disease

Purpose: To study the applicability (sensitivity, specificity) of polymerase chain reaction (PCR) tests in the detection of cytomegalovirus (CMV), herpes virus (HSV) and varicella zoster (VZV), Epstein-Barr virus (EBV), Mycobacterium sp and Toxoplasma gondii in the diagnosis of patients with or without AIDS, with presumably infectious uveitis, using serum, aqueous humor and vitreous humor samples.

Methods: Twenty individuals with uveitis of presumed infectious origin were evaluated. Sixteen of them had AIDS, four were immunocompetent individuals. We also evaluated 4 normal controls who underwent vitrectomy surgery. Clinical evaluation of the patients was performed together by three clinicians. PCR evaluations of the serum, aqueous, and vitreous humor were performed in a masked fashion by the laboratory staff.

Results: Twelve patients had a clinical diagnosis of CMV retinitis. Of these 6 (50%) had a positive PCR for CMV in the vitreous, three (25%) had a positive PCR for CMV in the serum, and none were positive in the aqueous. Five patients had a clinical diagnosis of acute retinal necrosis (ARN). Three (60%) of these had positive PCR for HSV/VZV in the vitreous. One of these patients had a positive PCR reaction for both EBV and HSV/VZV in the vitreous samples. One patient with cutaneous herpes zoster had a positive PCR reaction for HSV/VZV in the serum. Four patients had a presumed diagnosis of ocular toxoplasmosis, one patient (25%) had a positive PCR for Toxoplasma gondii in the serum, 3 (75%) had positive results in the aqueous, and 2 (50%) had positive results in the vitreous. One patient with presumed ocular tuberculosis had a positive PCR reaction both in the serum and in the vitreous samples. Finally, none of the four control individuals revealed any positive PCR reaction.

Conclusion: PCR is an auxiliary diagnostic procedure that should be evaluated together with ophthalmological aspects of the patient.