Herpes Simplex Virus Infection
Many surgeons avoid laser vision correction in patients with a history of herpes simplex virus (HSV) keratitis because of the risk of recurrent disease induced by the surgery. Trauma from the lamellar dissection or exposure to the excimer laser may reactivate the virus and cause recurrent HSV keratitis. However, some authors have concluded that the recurrence reflects simply the natural course of the disease rather than reactivation due to excimer laser ablation.
The role of excimer laser ablation in inciting recurrence of HSV keratitis has been investigated in the laboratory. Rabbits infected with HSV type 1 demonstrated viral reactivation after exposure of the corneal stroma to 193-nm ultraviolet radiation during PRK and LASIK. Pretreatment with systemic valacyclovir before the laser treatment decreased the rate of recurrence in the rabbit model. In another study, a rabbit latency model demonstrated that systemic valacyclovir reduced ocular shedding of HSV after LASIK.
Reactivation of HSV keratitis has been reported in humans after radial keratotomy (RK), phototherapeutic keratectomy (PTK), PRK, and LASIK. Fagerholm and colleagues reported a 25% incidence of postoperative HSV keratitis 17 months after PTK for surface irregularities from prior HSV infections, compared with an 18% recurrence rate in an equivalent time period prior to PTK. The authors concluded that the procedure does not seem to significantly increase the incidence of recurrences.
A retrospective review of 13,200 PRK-treated eyes with no history of corneal HSV revealed a 0.14% incidence of HSV keratitis. Of these cases, 16.5% occurred within 10 days of the procedure; the authors postulated that this finding may indicate a direct effect of the excimer ultraviolet laser. In 78% of cases, HSV keratitis occurred within 15 weeks, which could be related to the corticosteroid therapy.
Reactivation of herpes zoster ophthalmicus was also reported in 1 case after LASIK, in association with vesiculo-ulcerative lesions on the tip of the nose. The few cases in which herpes zoster ophthalmicus was reactivated responded to topical and oral antiviral treatment with excellent recovery of vision. There are anecdotal reports of flap interface inflammation resembling diffuse lamellar keratitis after LASIK in patients with herpes simplex or herpes zoster keratitis. In these cases, topical corticosteroids may also be required.
Due to the potential for vision loss from recurrence of HSV keratitis, some refractive surgeons consider prior herpetic keratitis a contraindication to refractive surgery. Others may consider performing PRK, PTK, or LASIK in patients with a history of HSV keratitis who have not had any recent recurrences and who have good corneal sensation, minimal or no corneal vascularization or scarring, and normal best-corrected visual acuity (BCVA; also called corrected distance visual acuity, CDVA). Preoperative and postoperative prophylaxis with systemic antiviral drugs should be strongly considered in these patients. Results of the Herpetic Eye Disease Study (HEDS) showed only a 50% reduction in the risk of recurrence with a prophylactic dose of oral acyclovir over the course of 1 year in patients with latent HSV even with no inciting factors, such as treatment with an excimer laser. Patients with pronounced corneal hypoesthesia or anesthesia, vascularization, thinning and scarring, or recent herpetic attacks should not be considered candidates for refractive surgery. Any patient with a history of herpes simplex or herpes zoster keratitis must be counseled about the continued risk of recurrence and its concomitant potential for vision loss after excimer laser vision correction.
Asbell PA. Valacyclovir for the prevention of recurrent herpes simplex virus eye disease after excimer laser photokeratectomy. Trans Am Ophthalmol Soc. 2000;98:285–303.
de Rojas Silva V, Rodriguez-Conde R, Cobo-Soriano R, Beltrán J, Llovet F, Baviera J. Laser in situ keratomileusis in patients with a history of ocular herpes. J Cataract Refract Surg. 2007;33(11):1855–1859.
Fagerholm P, Ohman L, Orndahl M. Phototherapeutic keratectomy in herpes simplex keratitis. Clinical results in 20 patients. Acta Ophthalmol (Copenh). 1994;72(4):457–460.
Jain V, Pineda R. Reactivated herpetic keratitis following laser in situ keratomileusis. J Cataract Refract Surg. 2009;35(5):946–948.
Levy J, Lapid-Gortzak R, Klemperer I, Lifshitz T. Herpes simplex virus keratitis after laser in situ keratomileusis. J Refract Surg. 2005;21(4):400–402.
Excerpted from BCSC 2020-2021 series: Section 13 - Refractive Surgery. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.