Human herpesvirus 8 in corneal endotheliitis resulting in graft failure after penetrating keratoplasty refractory to allograft rejection therapy

Role of Recent PCR Tests for Infectious Ocular Diseases: From Laboratory-Based Studies to the Clinic

Infectious uveitis is a vision-threatening condition that requires prompt clinical diagnosis and proper treatment. However, rapid and proper diagnosis in infectious uveitis remains challenging. Several examination tests, including polymerase chain reaction (PCR) tests, are transitioning from laboratory-based basic research-level tests to bedside clinical tests, and recently tests have changed to where they can be performed right next to clinicians. In this review, we introduce an updated overview of recent studies that are representative of the current trends in clinical microbiological techniques including PCR tests for infectious uveitis.

Clinical Results and Utility of Herpesviruses Multiplex Polymerase Chain Reaction: Assessment of Aqueous Humor Samples From Patients With Corneal Endotheliitis and High Intraocular Pressure

PURPOSE

The main purpose of this study was to evaluate herpesvirus infection in patients with corneal endotheliitis and high intraocular pressure (IOP) using multiplex polymerase chain reaction (PCR) in aqueous humor samples.

MATERIALS AND METHODS

This was a retrospective, observational study of immunocompetent patients living in South Korea. Eligible subjects had typical corneal endotheliitis with an IOP≥21 mm Hg or required antiglaucoma medication. Multiplex PCR was performed using aqueous humor samples obtained at first visit to detect the DNA of 6 herpesviruses.

RESULTS

Forty-two eyes from 42 patients with >6 months' follow-up were analyzed. Of these, 16 were herpesvirus-positive: 3 herpes simplex virus 1, 3 varicella-zoster virus, 9 cytomegalovirus, and 1 Epstein-Barr virus. Eyes with coin-shaped or fine keratic precipitates (kps), high IOP, and a low baseline endothelial cell count were more likely to show a positive result on multiplex PCR. Univariate analysis showed that male sex (P=0.014), a previous history of uveitic glaucoma (P=0.048), and the presence of fine kps (P=0.031) were significantly associated with a positive PCR result. On multivariate analysis, male sex (P=0.010) and a previous history of uveitic glaucoma (P=0.031) showed a significant positive association.

CONCLUSIONS

Cytomegalovirus was the most commonly detected herpesvirus in patients with corneal endotheliitis and high IOP. A positive PCR result was seen more frequently in male individuals and patients with fine kps or a history of uveitic glaucoma.

Emerging Viral Infections Causing Anterior Uveitis

PURPOSE

To review the systemic and ocular manifestations of specific emergent viral infectious diseases relevant to the ophthalmologist with particular emphasis on anterior uveitis Methods: Review of literature.

RESULTS

Arboviral diseases are among the most important emergent and resurgent human infections, occurring mostly in tropical and subtropical zones, but appearing in virtually all regions of the world as a result of climate change, travel, and globalization. Arboviral infections are transmitted to humans by the bite of hematophagous arthropods, mainly mosquitoes. Systemic disease may range from asymptomatic to life-threatening. A wide variety of ocular manifestations, including uveitis, has been reported in association with these emerging viral diseases. Numerous viruses other than arboviruses also have been recently recognized as a potential cause of uveitis.

CONCLUSIONS

Proper clinical diagnosis of any emerging infectious disease is based on epidemiological data, history, systemic symptoms and signs, and the pattern of ocular involvement. The diagnosis is usually confirmed by detection of virus-specific DNA or antivirus antibodies in serum.

A new era of uveitis: impact of polymerase chain reaction in intraocular inflammatory diseases

Uveitis is a sight-threatening intraocular inflammatory disorder which may occur from both infectious and non-infectious or autoimmune causes. The frequency of infectious uveitis and autoimmune uveitis varies depending on countries and regions. According to a nationwide survey conducted by the Japanese Ocular Inflammation Society, infectious and non-infectious uveitis accounted for 16.4 and 50.1% of new patients, respectively while the remaining 33.5% of new uveitis cases were not classified or were idiopathic uveitis. Infectious uveitis is particularly important because it causes tissue damage to the eye and may result in blindness unless treated. However, it can be treated if the pathogenic microorganisms are identified promptly and accurately. Remarkable advancements in molecular and immunological technologies have been made in the last decade, and the diagnosis of infectious uveitis has been greatly improved by the application of molecular and immunological investigations, particularly polymerase chain reaction (PCR). PCR performed on a small amount of ocular samples provides a prompt, sensitive, and specific molecular diagnosis of pathogenic microorganisms in the eye. This technology has opened a new era in the diagnosis and treatment of uveitis, enabling physicians to establish new clinical entities of uveitis caused by infectious microorganisms, identify pathogens in the eyes of many patients with uveitis, and determine prompt diagnosis and appropriate therapy. Here we review the PCR process, new PCR tests specialized for ocular diseases, microorganisms detected by the PCR tests, diseases in the eye caused by these microorganisms, and the clinical characteristics, diagnosis, and therapy of uveitis.

In Vivo Confocal Microscopy Use in Endotheliitis

PURPOSE

The use of in vivo confocal microscopy has been valuable in detecting and managing corneal pathology. This case study documents endotheliitis using in vivo confocal microscopy where apparent resolution of endothelial edema on clinical examination resulted in the discovery of subclinical findings with confocal scanning. The purpose of this case study was to discuss a rare corneal pathology and the clinical value of confocal scanning.

CASE REPORT

A 30-year-old Asian Indian woman presented with unilateral endotheliitis and trabeculitis of presumed varicella zoster virus etiology. She was treated successfully with oral antiviral and topical corticosteroid therapy. Subclinical endotheliitis was detected using in vivo confocal microscopy, prompting the continuation of prophylactic, low-dose, topical corticosteroid therapy and topical hyperosmotics.

CONCLUSIONS

Further research is warranted to better understand the role of confocal microscopy in endotheliitis therapeutic management, endothelial cell count and morphology, and keratic precipitate characterization. To date, prophylactic oral antivirals and/or topical corticosteroids may play a role in immune suppression of the herpes virus, although prospective, randomized, controlled clinical trials have not focused specifically on endotheliitis cases.

Necrotizing keratitis caused by acyclovir-resistant herpes simplex virus

Background

We report a case of necrotizing keratitis caused by acyclovir (ACV)-resistant herpes simplex virus (HSV) with a clinical appearance similar to a previous fungal keratitis infection.

Methods

Observational case report.

Results

Penetrating keratoplasty was performed in the left eye with a history of herpetic keratitis that resolved with periodic treatment with ACV ointment and a topical steroid. The left eye was painful and red with an abscess and corneal erosion in the peripheral donor cornea. Examination of the scraped corneal epithelium by light microscopy and culturing identified Candida albicans; polymerase chain reaction (PCR) was negative for human herpes viruses. After antifungal treatment, the ocular pain gradually decreased and the lesions slowly improved but recurred with a similar clinical appearance. A second light microscopy examination and cultures were negative for pathogens including C. albicans. PCR was positive for HSV-1 DNA; treatment with 3% topical ACV ointment was unsuccessful. A third examination showed only HSV-1 DNA. Despite antiviral ACV ointment, no clinical improvement occurred based on the HSV DNA copy numbers, which were the same before and after treatment, indicating a possible ACV-resistant strain. When topical trifluorothymidine was substituted for ACV, clinical improvement occurred and the HSV DNA copy numbers decreased.

Conclusion

Necrotizing keratitis induced by ACV-resistant HSV occurred independently after fungal keratitis, with a similar clinical appearance in this case, making diagnosis and treatment difficult. Monitoring the HSV DNA load by real-time PCR could be useful for refractory cases even with atypical clinical appearances.

Utility of real-time PCR analysis for appropriate diagnosis for keratitis

Real-time polymerase chain reaction (PCR) is a quantitative method to measure the amount of amplified PCR product in real time with high sensitivity. We have applied this method to detect pathogens in cases of keratitis with an unknown cause. The scraped corneal epithelium for epithelial keratitis or aqueous humor for stromal or endothelial keratitis was obtained and DNA was extracted. The DNA from specific pathogens was amplified using specific primers and TaqMan probe, and assessed quantitatively. Here, we review previously reported noteworthy examples of keratitis diagnosed by our real-time PCR system as follows: cases with Acanthamoeba keratitis whose causative pathogen was only detected by real-time PCR despite not being detected by histological examination and culture; zoster sine herpete with atypical pseudodendrite; acyclovir-resistant herpetic keratitis estimated by changes in viral DNA copy numbers before and after treatment; and corneal endotheliitis positive for cytomegalovirus, human herpes virus-7, or human herpes virus-8. Real-time PCR helps ophthalmologists to make an early diagnosis and provide appropriate treatment for keratitis with complex clinical appearances.

Coincidence of Varicella-Zoster Virus Anterior Uveitis in a Patient with Chandler's Syndrome

Purpose

We report a patient who, based on the clinical manifestations, was originally diagnosed as having Chandler's syndrome and later developed varicella-zoster virus (VZV) DNA-positive anterior uveitis.

Methods

The patient with Chandler's syndrome who manifested anterior uveitis underwent a complete ophthalmologic examination. Polymerase chain reaction (PCR) was used to amplify the viral DNA in the aqueous humor to determine the cause of the intraocular inflammation.

Results

Slit-lamp biomicroscopy showed focal iris atrophy and peripheral anterior synechiae (PAS); specular microscopy of the corneal endothelium disclosed the hammered-silver appearance. Based on these clinical findings, we diagnosed this patient as having Chandler's syndrome. During the follow-up period, however, the inflammatory cells suddenly appeared in the anterior chamber with formation of keratic precipitates and an increased intraocular pressure (IOP). VZV DNA was displayed in the aqueous humor by PCR. Based upon the diagnosis of VZV anterior uveitis, corticosteroids and acyclovir were given topically and systemically. The inflammation subsided with these medications; however, trabeculectomy was finally needed to control the IOP due to PAS progression.

Conclusion

The coincidence of VZV anterior uveitis with Chandler's syndrome may constitute an implication for the possible viral etiology of iridocorneal endothelial syndrome.

Identification of cytomegalovirus and human herpesvirus-6 DNA in a patient with corneal endotheliitis

PURPOSE

To report the case of a patient with unilateral corneal endotheliitis in which both cytomegalovirus (CMV) and human herpesvirus-6 (HHV6) DNA was identified in the aqueous humor.

CASE

A 67-year-old man with corneal endotheliitis OD was referred to us for decreased visual acuity. Local corneal stromal edema, pigmented keratic precipitates, a coin-shaped lesion and minimal anterior chamber reaction were observed by slit-lamp biomicroscopy. Cells with owl's eye appearance in the endothelial cell layer were observed by in vivo laser confocal microscopy. The patient had rheumatoid arthritis, which was treated by oral prednisolone and intravenous abatacept. Polymerase chain reaction analysis of aqueous humor samples detected both CMV and HHV6 DNA, but not other HHVs. Treatment with topical ganciclovir and systemic valganciclovir resulted in a clear cornea.

CONCLUSIONS

A patient with corneal endotheliitis had both CMV and HHV6 DNA identified in the aqueous humor. Although both viruses were identified in this case, clinical manifestations resembled CMV corneal endotheliitis, and it was unclear whether HHV6 could affect the clinical course. Systemic abatacept and corticosteroid therapy might play a positive role in cases with both CMV and HHV6 DNA in this corneal endotheliitis.