Bilateral viral keratitis following corneal collagen crosslinking for progressive keratoconus

Herpes Simplex Keratitis Following Corneal Crosslinking for Keratoconus: A One-Year Case Series Follow-Up

Corneal crosslinking (CXL) is a medical procedure used to treat keratoconus. CXL works by strengthening the collagen fibers of the cornea through the application of riboflavin (vitamin B2) and ultraviolet (UV) light, which helps to stabilize the cornea and prevent further deterioration. There is a recognized risk that CXL can trigger the reactivation of dormant herpes simplex virus (HSV), leading to herpetic keratitis even in patients with no history of herpetic disease. We examined the medical history of 52 patients who underwent CXL procedures due to previously diagnosed keratoconus. We reviewed the patient's medical histories to assess whether there was a herpes labialis infection and/or herpetic keratitis. Altogether, 52 eyes (from 52 patients) were analyzed. Of those, four (7.69%) patients were diagnosed with epithelial herpetic keratitis on the 5-8th day after surgery. All four patients had a history of herpes labialis and no prior HSV keratitis infection. Two patients developed herpetic keratitis despite prophylactic therapy with acyclovir 5 days before surgery. A positive history of HSV lip infection before CXL was present in 18/52 (34.62%). During a one-year follow-up period, no patient experienced a recurrence. Close follow-up is crucial for diagnosing herpetic keratitis after corneal crosslinking. The use of prophylactic antiviral therapy in patients who are asymptomatic and have a history of recurrent herpes labialis does not guarantee the prevention of infection.

Herpes simplex keratitis: A brief clinical overview

The aim of our minireview is to provide a brief overview of the diagnosis, clinical aspects, treatment options, management, and current literature available regarding herpes simplex keratitis (HSK). This type of corneal viral infection is caused by the herpes simplex virus (HSV), which can affect several tissues, including the cornea. One significant aspect of HSK is its potential to cause recurrent episodes of inflammation and damage to the cornea. After the initial infection, the HSV can establish a latent infection in the trigeminal ganglion, a nerve cluster near the eye. The virus may remain dormant for extended periods. Periodic reactivation of the virus can occur, leading to recurrent episodes of HSK. Factors triggering reactivation include stress, illness, immunosuppression, or trauma. Recurrent episodes can manifest in different clinical patterns, ranging from mild epithelial involvement to more severe stromal or endothelial disease. The severity and frequency of recurrences vary among individuals. Severe cases of HSK, especially those involving the stroma and leading to scarring, can result in vision impairment or even blindness in extreme cases. The cornea's clarity is crucial for good vision, and scarring can compromise this, potentially leading to visual impairment. The management of HSK involves not only treating acute episodes but also implementing long-term strategies to prevent recurrences and attempt repairs of corneal nerve endings via neurotization. Antiviral medications, such as oral Acyclovir or topical Ganciclovir, may be prescribed for prophylaxis. The immune response to the virus can contribute to corneal damage. Inflammation, caused by the body's attempt to control the infection, may inadvertently harm the corneal tissues. Clinicians should be informed about triggers and advised on measures to minimize the risk of reactivation. In summary, the recurrent nature of HSK underscores the importance of both acute and long-term management strategies to preserve corneal health and maintain optimal visual function.

Atopic Disease as a Risk Factor for Recurrent Herpetic Keratitis

Recurrent herpetic keratitis is a leading cause of blindness worldwide. In this population-based cross-sectional study, the medical records of Israeli adolescents and young adults who underwent systematic preconscription evaluation for mandatory military service were reviewed. The prevalence of atopic conjunctival disease was evaluated in cases with and without documented recurrent herpetic keratitis. The association was tested using uni- and multivariant analyses. Overall, 940,892 adolescents and young adults were included. The mean age was 17.57 ± 1.50 years (range 16-20 years), and 40.70% of participants were female. Recurrent herpetic keratitis was documented in 160 cases, with a prevalence of 0.017% in this age group. Compared to the general population, patients with recurrent herpetic keratitis were significantly more likely to be males (p = 0.003) with a concomitant diagnosis of atopic conjunctival disease (p < 0.0001). Patients with atopic conjunctival disease were 10.60-fold more likely to experience recurrent herpetic keratitis (95% confidence interval (CI): 6.76-16.64, p < 0.0001). Upon multivariate analysis, the results remained significant (p < 0.001). Cases of severe atopic conjunctival disease were more prone to recurrent HSV keratitis compared to mild cases (p < 0.001). These findings suggest that the timely appropriate treatment of atopic conjunctival disease may help reduce the frequency and severity of recurrent HSV keratitis and its complications.

Use of corneal cross-linking beyond keratoconus: a systemic literature review

PURPOSE

The success of corneal collagen cross-linking in altering keratoconus' clinical course has driven a search for further uses of this procedure. This literature review aims to analyze the scientific evidence available for the benefit of cross-linking in the management of ophthalmic diseases other than progressive keratoconus or ectasia induced by corneal refractive procedures.

METHODS

A systemic literature review.

RESULTS

We reviewed 97 studies. We found that collagen cross-linking can limit the progression of several other corneal ectasias, thus reducing and limiting the need for keratoplasty. Collagen cross-linking also can reduce the refractive power of the cornea and can be considered for a moderate degree of bacterial keratitis or when the organism is unidentified, which is refractive to antibiotics alone. However, the comparative rarity of these procedures has limited the extent of evidence. In fungal, Acanthamoeba, and herpes virus keratitis, the evidence is inconclusive of the safety and efficacy of cross-linking.

CONCLUSION

Current clinical data is limited, and laboratory data has not fully correlated with published clinical data.

Herpetic Keratitis Following Corneal Crosslinking for Keratoconus: A Case Series

Background

Corneal crosslinking is widely applied to enhance corneal biomechanical properties and delay the progression of keratoconus. The surgical procedure and application of ultraviolet A irradiation (UVA) during corneal crosslinking have been recognized to induce the reactivation of simplex herpes virus (HSV) but are rarely reported and poorly analyzed.

Case Presentation

We report the first case series of herpetic keratitis in 4 keratoconus patients undertaking corneal crosslinking, who were all clinically diagnosed at routine follow-up visits 3 days to 1 month after the surgery. Different from the typical new onset of secondary herpetic keratitis that mainly presents with epithelial lesions and severe eye pain, these patients all presented with stromal infiltrates and were generally asymptomatic except for vision blurring in 2 patients. All patients responded well to antiviral therapy, topical steroids, and epithelial nourishment medication, leaving corneal macula or nebula at the last follow-up visit.

Conclusion

Close follow-up is essential and the most effective way to diagnose herpetic keratitis after corneal crosslinking due to the lack of subjective symptoms. The prophylactic use of antiviral therapy on asymptomatic patients is controversial and should be evaluated based on long-term prognosis.

Incidence and Risk Factors of Bilateral Herpetic Keratitis: 2022 Update

Simultaneously occurring bilateral herpetic keratitis is a rare clinical manifestation of ocular herpes. Immunocompromised patients are more susceptible to develop bilateral disease. The purpose of this study is to review recent literature on the topic and to highlight latest updates, regarding risk factors and possible correlations to the disease, as well as new therapeutic options.

Polymicrobial keratitis after accelerated corneal collagen cross-linking in keratoconus: Case reports and literature review

PURPOSE

To report two cases of polymicrobial keratitis following corneal collagen cross-linking for keratoconus and to review the literature.

METHODS

Retrospective case note and literature review.

RESULTS

The first case involved a 27-year-old male who presented with amebic corneal ulcers 3 days after the collagen cross-linking procedure. Some gram-negative (gram-ve) cocci were found upon staining, and cysts were observed by confocal microscopy at 7 days after surgery. Acanthamoeba infection mixed with gram-ve organisms was diagnosed. In the second case, a 14-year male developed Staphylococcus aureus corneal infection with anterior chamber empyema 3 days after the collagen cross-linking procedure for keratoconus. Occasional gram-positive (gram + ve) cocci and gram-ve bacilli were observed under a microscope. The mixed keratitis in the two patients resolved after systemic and topical antibiotic therapy, but the infection ultimately resulted in corneal scarring. Follow-up keratoplasty was needed to improve vision acuity in both patients.

CONCLUSION

Although ultraviolet irradiation and the reactive oxygen released by riboflavin during collagen cross-linking have bactericidal effects, a lack of a corneal epithelial barrier, bandage contact lens usage, perioperative hygiene, and an abnormal immune state are risk factors for infectious keratitis after collagen cross-linking. Perioperative management of collagen cross-linking is important to prevent infection.

Infectious keratitis after corneal crosslinking for keratoconus caused by levofloxacin-resistant microorganisms

Introduction

We present seven cases of infectious keratitis after corneal crosslinking (CXL) to attenuate keratoconus progression.

Methods

Of 524 consecutive patients who underwent CXL, 7 cases (4 males and 3 females; 21.5 ± 7.1 years) developed postoperative infectious keratitis were retrospectively reviewed. CXL was performed using the Dresden protocol or an accelerated protocol involving epithelial removal.

Results

All cases appeared normal on the day after surgery, but subsequently developed eye pain, blurred vision, corneal infiltration, inflammation of the anterior chamber, and ciliary injection on day 2 or 3. Methicillin-resistant Staphylococcus aureus was cultured from two eyes, methicillin-sensitive Staphylococcus aureus from two eyes, and Streptococcus pneumoniae from one eye. All detected bacteria were resistant to levofloxacin (LVFX). Five of the seven cases, especially four of the five severe cases with hypopyon, had a history of atopic dermatitis. All cases were observed after 2015.

Conclusions

Infectious keratitis after CXL caused by microbes resistant to LVFX is increasing. In addition to careful postoperative observation of the cornea, preoperative evaluation of bacteria within the conjunctival sac evident on nasal swab cultures may be useful to identify potentially problematic microbes and inform the selection of appropriate antibiotics.

Infectious keratitis after corneal crosslinking: systematic review

Corneal crosslinking is a U.S. Food and Drug Administration--approved therapy to stiffen the cornea and prevent progression of corneal ectasia in patients with keratoconus. The standard procedure involves removal of the corneal epithelium (epithelial-off) prior to treatment. Variations to the standard procedure include accelerated crosslinking and transepithelial procedures. This study reviewed what is known regarding the risk for infection after epithelial-off crosslinking, the spectrum of pathogens, and clinical outcomes. 26 publications were identified. All eyes were fit with a bandage contact lens postoperatively. Available data indicate that the overall frequency of infectious keratitis after epithelium-off crosslinking is low. Bacterial infections are the most common, with a mean time of presentation of 4.8 days postoperatively. The use of steroids and bandage contact lenses in the immediate postoperative period and/or a history of atopic or herpetic disease were associated with infection. These patients require intense postoperative care with prophylactic antiviral therapy when appropriate.

Corneal Cross-Linking: The Evolution of Treatment for Corneal Diseases

Corneal cross-linking (CXL) using riboflavin and ultraviolet A (UVA) light has become a useful treatment option for not only corneal ectasias, such as keratoconus, but also a number of other corneal diseases. Riboflavin is a photoactivated chromophore that plays an integral role in facilitating collagen crosslinking. Modifications to its formulation and administration have been proposed to overcome shortcomings of the original epithelium-off Dresden CXL protocol and increase its applicability across various clinical scenarios. Hypoosmolar riboflavin formulations have been used to artificially thicken thin corneas prior to cross-linking to mitigate safety concerns regarding the corneal endothelium, whereas hyperosmolar formulations have been used to reduce corneal oedema when treating bullous keratopathy. Transepithelial protocols incorporate supplementary topical medications such as tetracaine, benzalkonium chloride, ethylenediaminetetraacetic acid and trometamol to disrupt the corneal epithelium and improve corneal penetration of riboflavin. Further assistive techniques include use of iontophoresis and other wearable adjuncts to facilitate epithelium-on riboflavin administration. Recent advances include, Photoactivated Chromophore for Keratitis-Corneal Cross-linking (PACK-CXL) for treatment of infectious keratitis, customised protocols (CurV) utilising riboflavin coupled with customised UVA shapes to induce targeted stiffening have further induced interest in the field. This review aims to examine the latest advances in riboflavin and UVA administration, and their efficacy and safety in treating a range of corneal diseases. With such diverse riboflavin delivery options, CXL is well primed to complement the armamentarium of therapeutic options available for the treatment of a variety of corneal diseases.

A Retrospective Study of Herpetic Keratitis in Patients with Keratoconus after Crosslinking Surgery

Background: The aim of this study was to perform a retrospective analysis of patients who underwent cross-linking for keratoconus, in the Department of Ophthalmology of the Medical University of Silesia in Katowice, between 2011 and 2020, regarding the occurrence of herpetic keratitis after the procedure. Methods: We analyzed the medical history of 543 patients who underwent cross-linking surgery. Results: In the analyzed group, there were nine cases of herpetic keratitis (six men and three women), aged from 16 to 40 years (mean 26.2 years). The mean follow-up period was 49.3 months (16–82 months). The average time from surgery to the manifestation of the first symptoms of keratitis was 4.3 days (2–6 days). In two cases, iritis was observed, and in one of them, iritis was the first symptom. After systemic and topical administration of acyclovir, ulceration healed in all patients. Corneal healing time ranged from 10 days to 3 weeks (average 13.7 days). In one patient, a recurrence of the inflammation was observed after 8 months. Conclusion: Patients should be carefully observed in the early post-CXL period. Herpetic keratitis could be induced by CXL even in patients with no history of herpetic disease.