Herpes Simplex DNA Present in Corneal Tissues After Penetrating Keratoplasty

Corneal Herpes With Interstitial Keratitis. (Photo By BSIP/UIG Via Getty Images)
Researchers support additional antiviral treatment following penetrating keratoplasty.

Researchers evaluated the incidence of newly acquired herpetic keratitis in patients who have received corneal buttons in an effort to determine the specific risk of newly acquired herpetic keratitis. This research, published in Acta Ophthalmology suggests antiviral treatment should be administered to patients without clinical history of herpetic keratitis.

Investigators conducted a retrospective review of recipient corneal buttons to determine the prevalence and mean cycle threshold of polymerase chain reaction (PCR) in corneal tissue of patients who have undergone penetrating keratoplasty (PKP), with (HSK positive) and without (HSK negative) previous clinical herpetic keratitis history. 

Clinical data, including patients’ demographics and clinical diagnoses, were collected. In total, 2230 corneal samples (age at the time of the surgery 57.3±19.2 years) of 1860 patients were analyzed. HSV PCR was positive in 137 (6.1%) corneal samples, with a 30.57±6.01 (range 14-39) mean cycle threshold (Ct) value. The 298 corneas (13.4%) of 266 patients were clinically HSK positive, and 1,932 corneas (86.6%) of 1600 patients were clinically HSK negative. HSV DNA was detected significantly more frequently (P <.0001) in HSK positive corneal samples (108 corneal samples; 36.2%) than in HSK negative corneal samples (29 corneal samples; 1.5%). Cycle threshold value was significantly lower in HSK positive than in HSK negative corneal samples (29.8±5.8 vs 32.6±5.9; P =.008).

Researchers note some limitations of their study, including the lack of information about the interval between the last clinical episode and surgery and type of HSK.

“Prophylactic local and oral antiviral therapy should reduce the risk of HSK recurrence and graft failure after PKP,” the study explains.


Tóth G, Berkó-Göttel B, Seitz B, et al. Herpes simplex virus PCR in 2230 explanted corneal buttons. Acta Ophthalmol. Published online June 14, 2021. doi:10.1111/aos.14872.