Comment on: Cataract surgery in herpes simplex virus ocular disease.

Abstract

We read with great interest the study by Al-Ani et al., in which the authors evaluated factors associated with recurrent herpes simplex virus (HSV)-related keratitis after cataract surgery.1 In their retrospective study, the authors reported recurrent HSV keratitis after cataract surgery in 17 (45.9%) of the 37 eyes with previous diagnosis of ocular herpes disease. The risk for recurrent HSV keratitis after cataract surgery was associated with a greater number of recurrences prior to surgery, time quiescent prior to surgery, and iris transillumination defect at preoperative assessment. This study provides a reference for the performance of cataract surgery in eyes with previous HSV keratitis. HSV type 1 seroprevalence in the general adult population was approximately 50% to 60%, with most latently infected with HSV type 1 harboring the dormant virus in their sensory ganglia.2 The annual incidence of all types of new ocular HSV infections has recently been estimated to be approximately 0.01%.2 Given the rising prevalence of pseudophakia combined with the increased life expectancy and ongoing earlier intervention for cataract surgery in the population, it is not uncommon for a surgeon to perform cataract surgery in eyes with a history of HSV keratitis. Furthermore, cataract surgery can trigger the activation of HSV from the latent stage, as well as recurrent infection.3 In our previous study, 11 (1.65%) of 666 eyes that had no history of ocular herpes were diagnosed with HSV keratitis after cataract surgery (Table 1).4 An associated factor of HSV keratitis occurrence after cataract surgery was the method of surgical access. The prevalence was significantly higher with a temporal corneal incision approach than with a superior corneal incision approach; 10 of the 11 patients with HSV keratitis had temporal corneal incisions, and 1 patient had a superotemporal incisional location. There was no documented HSV keratitis complication with a superior corneal incision approach. We suspected that corneal nerves were more likely severed with a temporal incision than with a superior incision, and this can contribute to triggering HSV keratitis reactivation.5 The corneal nerves are derived from the long ciliary nerves of the ophthalmic division of the fifth (trigeminal) cranial nerve; these nerves enter the limbus predominantly at the 9- and 3-o'clock positions. Table 1. - Clinical features of patients with postcataract surgery HSV-K with clear cornea postoperatively and without a history of ocular HSV-K Age (y) Underlying disease Surgery type Time (d) a Incision location Final diagnosis HSV-1 PCR 69 DM Phaco + PCL + PPV 7 Temporal Epithelial HSV-K Positive 71 None Phaco + PCL 5 Temporal Epithelial HSV-K Positive 65 None Phaco + PCL 20 Temporal Epithelial HSV-K Positive 58 DM Phaco + PCL + PPV 14 Temporal Epithelial HSV-K Positive 62 DM Phaco + PCL 21 Temporal Epithelial HSV-K Positive 75 RA Phaco + PCL 10 Temporal Linear endothelitis NA 76 RA Phaco + PCL 20 Superotemporal Epithelial HSV-K Positive 75 None Phaco + PCL 7 Temporal Epithelial HSV-K Positive 68 None Phaco + PCL 20 Temporal Epithelial HSV-K Positive 71 None Phaco + PCL 15 Temporal Epithelial HSV-K Positive 65 None Phaco + PCL 30 Temporal Epithelial HSV-K Positive DM = diabetes mellitus; HSV-1 = herpes simplex type 1; HSV-K = HSV-related keratitis; PCL = posterior chamber lens insertion; PCR = polymerase chain reaction; Phaco = phacoemulsification; PPV = pars plana vitrectomy; RA = rheumatoid arthritisaTime between surgery and presentationReprinted with permission from Cornea 2018; 37:755–759 We concluded that cataract surgery should be performed more carefully in eyes with a greater number of recurrences prior to surgery, a short time quiescent prior to surgery, and iris transillumination defect, with thorough plans for perioperative treatment to decrease the recurrence of HSV keratitis. We would like to ask Al-Ani et al. for their observation and opinion about the associated factors, especially regarding surgical access, which trigger HSV keratitis after cataract surgery in recurrent cases. With maximum prophylaxis, including perioperative antiviral treatment and immunosuppression, the modification of surgical factors such as incision location can potentially decrease or delay recurrence of HSV keratitis after cataract surgery.