Corneal Refractive Surgery in Patients with a History of Herpes Simplex Keratitis: A Narrative Review

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.

In vivo CRISPR gene editing in patients with herpetic stromal keratitis

In vivo CRISPR gene therapy holds large clinical potential, but the safety and efficacy remain largely unknown. Here, we injected a single dose of herpes simplex virus 1 (HSV-1)-targeting CRISPR formulation in the cornea of three patients with severe refractory herpetic stromal keratitis (HSK) during corneal transplantation. Our study is an investigator-initiated, open-label, single-arm, non-randomized interventional trial at a single center (NCT04560790). We found neither detectable CRISPR-induced off-target cleavages by GUIDE-seq nor systemic adverse events for 18 months on average in all three patients. The HSV-1 remained undetectable during the study. Our preliminary clinical results suggest that in vivo gene editing targeting the HSV-1 genome holds acceptable safety as a potential therapy for HSK.

New-Onset of Herpes Simplex Keratitis After Blepharoplasty, Case Series and Review of the Literature

PURPOSE

To report 3 cases of new-onset herpes simplex keratitis (HSK) after uncomplicated extraocular plastic surgery and discuss potential risk factors.

METHODS

This case series includes 3 patients who underwent uncomplicated blepharoplastic surgery. Within 2 weeks postoperatively, all patients reported ocular discomfort, and their ophthalmic examinations revealed corneal lesions suspicious of HSK. One case was confirmed as an active herpes infection, and the other 2 cases were clinically diagnosed with HSK. The patients were treated with oral acyclovir and followed up for up to 6 weeks.

RESULTS

All patients demonstrated improvement without sequelae at follow-up visits from 5 days to 4 weeks after initiating acyclovir treatment.

CONCLUSIONS

Risk factors for new-onset HSK after uncomplicated extraocular surgeries may be related to an immunocompromised state, postoperative administration of topical or periocular corticosteroids, or environmental factors such as psychological stress. Ophthalmologists, particularly plastic surgeons, should be vigilant for ocular discomfort following eyelid surgeries and consider the possibility of herpes infection. This report highlights the importance of recognizing and managing HSK in the context of extraocular plastic surgery.

Post-laser refractive surgery keratitis: A concise narrative review

Laser refractive surgery (LRS) is a specialized surgical discipline within ophthalmology that focuses on vision correction via laser techniques. LRS requires a high rate of accuracy and exactitude to improve the visual outcome and minimize complications, which may lead to delayed visual recovery. Keratitis, either infectious or noninfectious, is a post-LRS complication that requires early diagnosis and proper interventional measures. In this narrative review, we summarize different aspects of keratitis following LRS. This literature review aims to provide a thorough understanding of the causes of post-LRS infectious keratitis and its appropriate management for successful outcomes.

Impact of Latent Virus Infection in the Cornea on Corneal Healing after Small Incision Lenticule Extraction

The aim of the present study is to analyze the impact of cornea virus latent infection on corneal healing after small incision lenticule extraction (SMILE) and predict the positive rate of virus latent infection in corneal stroma. A total of 279 patients who underwent SMILE were included in this study. Fluorescence quantitative PCR was used to detect virus infection in the lenticules, which were taken from the corneal stroma during SMILE. Herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2), Epstein-Barr virus (EBV), and cytomegalovirus (CMV) were detected. Postoperative visual acuity, spherical equivalent, intraocular pressure, corneal curvature (Kf and Ks), corneal transparency, and corneal staining were compared between the virus-positive group and the virus-negative group. The number of corneal stromal cells and inflammatory cells, corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), corneal nerve fiber length (CNFL), corneal total branch density (CTBD), and corneal nerve fiber width (CNFW) were evaluated using an in vivo confocal microscope. Out of 240 herpes simplex virus (HSV) tested samples, 11 (4.58%) were positive, among which 5 (2.08%) were HSV-1-positive and 6 (2.50%) were HSV-2-positive. None of the 91 CMV- and EBV-tested samples were positive. There was no statistical significance in the postoperative visual acuity, spherical equivalent, intraocular pressure, Kf and Ks, corneal transparency, corneal staining, the number of corneal stromal cells and inflammatory cells, CNFD, CNBD, CNFL, CTBD, and CNFW between the virus-positive and virus-negative groups (p > 0.05). In conclusion, there is a certain proportion of latent HSV infection in the myopia population. Femtosecond lasers are less likely to activate a latent infection of HSV in the cornea. The latent infection of HSV has no significant impact on corneal healing after SMILE.

Cell Biology of Spontaneous Persistent Epithelial Defects After Photorefractive Keratectomy in Rabbits

Purpose

To evaluate wound healing in rabbit corneas that developed a spontaneous persistent epithelial defect (PED) after photorefractive keratectomy (PRK).

Methods

Forty-eight 10- to 15-week-old female New Zealand White rabbits weighing 2.5 to 3.0 kg underwent either -3 diopter (D) or -9 D PRK to generate a series of corneas to study wound healing after injury. During that series, seven corneas developed a PED detected with 1% fluorescein staining at a slit lamp that either did not have epithelial closure by 1 week after surgery or subsequently had the closed epithelium break down to form a PED 2 to 3 weeks after surgery. The corneas had slit-lamp photography, with and without 1% fluorescein, and were removed from the normal PRK series. Each PED cornea was evaluated using immunohistochemistry for the myofibroblast marker α-smooth muscle actin (α-SMA), keratocyte marker keratocan, and mesenchymal cell marker vimentin, as well as basement membrane components perlecan and collagen type IV.

Results

All seven corneas that had PRK with a PED, even the two evaluated at only 1 week after PRK, had α-SMA-positive myofibroblasts populating the anterior stroma within the PED, along with comingled α-SMA-negative cells that were likely corneal fibroblasts and possibly bone marrow-derived fibrocytes. Both perlecan and collagen type IV accumulated in the anterior stroma of the epithelial defects without an epithelial basement membrane, likely produced by corneal fibroblasts to modulate transforming growth factor-β entering the stroma from the tears and peripheral epithelium.

Conclusions

Corneas with a PED that occurred following PRK (a procedure that produces a transient neurotropic state in the cornea) had myofibroblasts populating the superficial stroma within the epithelial defect as early as 1 week after the surgery.

Translational Relevance

Pharmacologic treatments that trigger myofibroblast apoptosis, including topical losartan, could facilitate decreased scarring fibrosis in corneas with a PED.

Post photorefractive keratectomy (PRK) infectious keratitis; six-year experience of a tertiary eye hospital

BACKGROUND/OBJECTIVES

As an essential development in the new century, surface ablation procedures have attracted increasing attention. There exists a concern regarding the risk of infectious keratitis. Hence, we aimed to investigate the rate and predisposing factors of infectious keratitis after photorefractive keratectomy (PRK).

SUBJECTS/METHODS

This retrospective study was designed in two phases. First, the rate of post-PRK keratitis of Farabi Eye Hospital was investigated. In other words, the targeted population was the patients who developed keratitis after performing procedure at Farabi Eye Hospital. In the second phase, all the patients with the diagnosis of post-PRK keratitis were studied regardless of the centre where surgery was performed. Patients with the diagnosis of infectious keratitis between 2014 and 2020 were enrolled and following information was analyzed: demographics, presentation time after surgery, perioperative medications, culture results, risk factors, medical treatment, complications, and final visual acuity.

RESULTS

The total number of PRK procedures in our centre was 24,986 (13,253 patients), in which 6 eyes of 5 patients developed keratitis. Beside these 5 patients, 24 referred patients (24 eyes) from the other centres were enrolled. Finally, a total number of 29 patients (30 eyes) were included. Our analysis revealed that manipulation of contact lens, dry eye, and blepharitis were the essential predisposing factors for keratitis development.

CONCLUSION

The overall post-PRK keratitis occurrence rate of our study was 0.02%. Our observation highlighted the importance of preoperative examination and treatment of the lids and dry eye disease.

The Impact of Antiviral Resistance on Herpetic Keratitis

ABSTRACT

Herpes simplex keratitis resistance to antiviral treatment presents a growing concern. The herpes simplex virus has many different mechanisms of resistance to antiviral treatment, which have been well described. Resistance to acyclovir occurs because of mutations in the viral thymidylate kinase and DNA polymerase that decrease this enzyme's affinity for its substrate. This article discusses factors that explain the prevalence of this resistance, the ability for recurrences in immunocompromised populations, current treatments for acyclovir-resistant herpes simplex keratitis, and novel therapies for this growing concern.

Update on contraindications in laser corneal refractive surgery

More than 25 years of experience with refractive surgery techniques (since the FDA [Food and Drug Administration] of the United States approved the use of the excimer laser in the remodeling of the cornea in 1995), added to the technological advances in ophthalmology (femtosecond laser, topography-guided ablation, anterior segment imaging systems) and increased understanding of refractive errors, higher order aberrations, and corneal biomechanics make corneal laser refractive surgery a safe method and effective for the correction of these defects. However, to date, there are still certain circumstances that represent a contraindication for its application, in addition to others that could be associated with complications, and that must be carefully analyzed. This review analyzes the current contraindications for laser corneal refractive surgery listed in the Preferred Practice Protocols (PPPs) of the American Academy of Ophthalmology and the Spanish Ophthalmology Society. These protocols are based on the best scientific evidence currently available and allow clear recommendations to be drawn, improving the safety profile of these techniques. Contraindications can be differentiated into relative or absolute; among the latter are: age less than 18 years, the absence of refractive stability and the existence of certain ocular pathologies (including certain corneal dystrophies, keratoconus, poorly controlled dry eye) or systemic pathologies (active autoimmune processes or poorly controlled diabetes mellitus). Other circumstances such as the use of certain drugs (amiodarone, isotretinoin), extreme values of mean central keratometry and pachymetry, history of previous uveitis or glaucoma, pregnancy and lactation, are considered relative contraindications according to the PPPs. However, there are studies that demonstrate the safety of refractive surgery in some of these cases.

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.

Dermatology and Skin Conditions for Hand Surgeons

The hand surgeon must be familiar with all aspects of hand pathology, and while faced with dermatological pathology in daily practice, a comprehensive understanding of skin pathology is often lacking. Dermatological pathology may have an impact on the hand surgeon in multiple ways-before surgery (requiring optimization), after surgery, or by mimicking surgical pathology (whereby surgical management may be contraindicated). Adequate knowledge of the basics of dermatology allows for optimal patient care. This review article highlights the common (and the not so common) skin conditions that hand surgeons may encounter in their practice.

Postrefractive infectious keratitis: prevention, diagnosis, management, and prognosis

PURPOSE OF REVIEW

Improve outcomes from an elective procedure by preventing a rare but sight-threatening complication.

RECENT FINDINGS

Advancement in anti-infective prophylaxis, and therefore shift in the causative organism permits better diagnostic and empiric management.

SUMMARY

Infectious keratitis presents in different patterns depending on the refractive procedure. Atypical causative organisms may respond poorly to empiric therapy and impair vision. Therefore, microbial identification is of utmost importance and therapy is adjusted accordingly.