Clinical efficacy of oral and topical acyclovir in herpes simplex virus stromal necrotizing keratitis

Infectious Keratitis: An Update on Role of Epigenetics

Epigenetic mechanisms modulate gene expression and function without altering the base sequence of DNA. These reversible, heritable, and environment-influenced mechanisms generate various cell types during development and orchestrate the cellular responses to external stimuli by regulating the expression of genome. Also, the epigenetic modifications influence common pathological and physiological responses including inflammation, ischemia, neoplasia, aging and neurodegeneration etc. In recent past, the field of epigenetics has gained momentum and become an increasingly important area of biomedical research As far as eye is concerned, epigenetic mechanisms may play an important role in many complex diseases such as corneal dystrophy, cataract, glaucoma, diabetic retinopathy, ocular neoplasia, uveitis, and age-related macular degeneration. Focusing on the epigenetic mechanisms in ocular diseases may provide new understanding and insights into the pathogenesis of complex eye diseases and thus can aid in the development of novel treatments for these diseases. In the present review, we summarize the clinical perspective of infectious keratitis, role of epigenetics in infectious keratitis, therapeutic potential of epigenetic modifiers and the future perspective.

Role of Intravenous Acyclovir in Treatment of Herpes Simplex Virus Stromal Keratitis with Ulceration: A Review of 2 Cases

BACKGROUND Herpes simplex virus (HSV) stromal keratitis with ulceration is one of the most serious forms of herpes corneal infection and is one of the most difficult conditions in terms of clinical management. We assessed the efficacy of intravenous acyclovir in the treatment of this condition. CASE REPORT Two cases of HSV stromal keratitis with ulceration were reported in terms of clinical presentation, investigation, treatment, and outcome.Diagnosis was confirmed by polymerase chain reaction (PCR) analysis. PCR testing of corneal scraping samples identified HSV-1 in the first patient and HSV-2 in the second patient. The first patient initially presented with herpes geographic epithelial keratitis and progressed to HSV stromal keratitis with ulceration during treatment with a prophylactic dose of oral acyclovir. Despite oral acyclovir therapy, the cornea lesion continued to worsen. The treatment was switched to intravenous acyclovir. The stromal infiltration gradually improved, and the epithelial defect closed. The second patient, who had undergone penetrating keratoplasty for 13 years, presented with extensive corneal infiltration and corneal melting. The laboratory work-up was positive for HSV-2, and intravenous acyclovir was prescribed. The patient's corneal infiltration improved, but a persistent epithelial defect was present. Then, 100% autologous serum was used until the epithelial defect closed. Prophylactic treatment with oral acyclovir was prescribed to both patients to prevent disease recurrence. CONCLUSIONS Intravenous acyclovir might be considered as an alternative treatment for patients with HSV stromal keratitis with ulceration who do not respond to oral acyclovir or those with an extensive infection on a corneal graft.

Noninvasive Diagnosis of Viral Keratouveitis with Retro-corneal Endothelial Plaques: A Case Series

Purpose: The aim of this study was to evaluate the noninvasive diagnostic methods in managing the herpetic keratouveitis with retro-corneal endothelial plaques.Methods: 12 patients suspected to have unilateral herpetic keratouveitis with retro-corneal endothelial plaques were included. Slit lamp photos, AS-OCT, IVCM and corneal scraping culture were taken in all cases to help diagnosing and managing the disease. All patients received systemic and topical anti-viral treatment immediately and combined with topical steroids three days later.Results: Corneal scraping culture ruled out bacterial and fungal infection. AS-OCT showed that the boundaries between the corneal endothelial surface were clear in all patients. Corneal endothelial density and subbasal nerve plexus significantly decreased in all patients. Endothelial plaques reduced or disappeared in all patients with the treatment.Conclusions: Retro-corneal endothelial plaques and hypopyon are associated clinical manifestations of viral keratouveitis. AS-OCT and IVCM enhanced early detection and assessment during the follow-ups of the disease.

Clinical Pattern And Visual Impairment Associated With Herpes Simplex Keratitis

Purpose

Herpes simplex keratitis (HSK) has varied presenting patterns, and is one of the leading causes of corneal scarring and subsequent visual disability. This study was carried out to determine the incidence and patterns of HSK presenting at a tertiary eye center in eastern Nepal and to assess the associated visual impairment.

Methods

This was a descriptive, cross-sectional study at a tertiary eye-care center that included 302 cases of clinically diagnosed HSK over a period of 1 year. Detailed ocular examination was done in all patients. Clinical manifestations and visual acuity at presentation and on subsequent visits in cases that followed up were recorded. Findings were noted in structured format and later assessed.

Results

Of 302 cases of HSK, 53 presented with epithelial keratitis, 156 with stromal keratitis without ulceration, 22 with stromal keratitis with ulceration, 66 with endothelitis, and five with neurotrophic ulcers. Presenting visual acuity in 108 patients (35.7%) was <3/60. Of 175 patients who followed up, 36 patients continued to have vision <3/60.

Conclusion

This study shows that HSK has diverse presentation and can cause significant vision impairment. Stromal keratitis without ulceration was the most common presentation in our study. In developing nations, due to higher incidence of fungal and bacterial keratitis, HSK is not studied much. Few epidemiological data are available on the subject, and since the disease is notorious for recurrence, long-term study is paramount to estimate the burden of visual morbidity caused by the disease.

Pearls and paradigms in Infective Keratitis

Infective Keratitis is a commonly encountered sight-threatening ocular emergency. In developing countries, it is a major cause of corneal blindness. Empirical treatment without microbiological work up often leads to treatment failure. Indiscriminate use of steroid antibiotic combination worsens the situation and makes further management challenging. The correct line of management can be potentially sight saving for both the ophthalmologist and the patient. This article on Infective keratitis has been written keeping best practices and protocols in mind. In a very simple and concise form, it focuses on the salient features of clinical presentation of infective keratitis and the stepwise approach to subsequent management in a patient. It explains in detail the way to perform corneal scraping, the importance of the same and further management based on microbiologically proven result. The management part includes indications and methods for medical as well as surgical intervention. We aimed to share our experience in the management of patients presenting with infective keratitis in the clinic.

A case of blurred vision and viral keratitis postcataract surgery

An 84-year-old woman underwent cataract surgery. In 3 weeks, the right eye presented with blurred vision, corneal irritation and photophobia. After 5 weeks, symptoms in the right eye worsened and ganciclovir was prescribed. Based on clinical findings, viral keratitis was suspected; real-time PCR (RT-PCR) assay of tear samples from the right eye was performed. Thereafter 1 week, the left eye also exhibited similar symptoms. The RT-PCR was performed using a sample from the left eye; the results suggested the presence of Epstein–Barr virus and cytomegalovirus. A combination of confocal microscopy and RT-PCR assay of tear samples can supplement slit-lamp observation and help diagnose atypical and refractory postcataract surgery viral keratitis.

Active Pedicle Epithelial Flap Transposition Combined with Amniotic Membrane Transplantation for Treatment of Nonhealing Corneal Ulcers

Introduction. The objective was to evaluate the efficacy of active pedicle epithelial flap transposition combined with amniotic membrane transplantation (AMT) in treating nonhealing corneal ulcers. Material and Methods. Eleven patients (11 eyes) with nonhealing corneal ulcer who underwent the combined surgery were included. Postoperatively, ulcer healing time was detected by corneal fluorescein staining. Visual acuity, intraocular pressure, surgical complications, and recurrence were recorded. Corneal status was inspected by the laser scanning confocal microscopy and anterior segment optical coherence tomography (AS-OCT). Results. The primary diseases were herpes simplex keratitis (8 eyes), corneal graft ulcer (2 eyes), and Stevens-Johnson syndrome (1 eye). All epithelial flaps were intact following surgery, without shedding or displacement. Mean ulcer healing time was 10.8 ± 3.1 days, with a healing rate of 91%. Vision significantly improved from 1.70 to 0.82 log MAR (P = 0.001). A significant decrease in inflammatory cell infiltration and corneal stromal edema was revealed 2 months postoperatively by confocal microscopy and AS-OCT. Corneal ulcer recurred in 1 eye. None of the patients developed major complications. Conclusion. Active pedicle epithelial flap transposition combined with AMT is a simple and effective treatment for nonhealing corneal ulcers.