Polymerase chain reaction in intraocular inflammation

Polymerase chain reaction in unilateral cases of presumed viral anterior uveitis

Background and objectives

Anterior uveitis is the most common form of intraocular inflammation. The main aim of this study was to determine the viral etiology in patients with unilateral cases of anterior uveitis.

Patients and methods

A total of 12 consecutive patients with the diagnosis of idiopathic unilateral anterior uveitis were included prospectively. Aqueous specimens were obtained from each patient by anterior chamber paracentesis and subjected to the detection of viral DNA/RNA genome by polymerase chain reaction assay for herpes simplex virus, varicella zoster virus, cytomegalovirus, Epstein–Barr virus, and rubella virus.

Results

There were six male and six female patients. The mean age was 43 years, with an age range of 11–82 years. All 12 cases presented with unilateral anterior uveitis. In four (33%) patients, polymerase chain reaction was positive for viral genome. Two patients were positive for herpes simplex virus type 1, one patient was positive for cytomegalovirus and one for Epstein–Barr virus.

Conclusion

Recent molecular diagnostic assays would help in the identification of the causative agent in patients with unilateral anterior uveitis.

Real-time and nested polymerase chain reaction in the diagnosis of multifocal serpiginoid choroiditis caused by Mycobacterium tuberculosis - a case report

Background

The term multifocal serpiginoid choroiditis (MSC) has been proposed for the infective variant of serpiginous choroiditis (SC) to distinguish it from typical SC believed to be autoimmune related. The role of Mycobacterium tuberculosis (MTb) in MSC has been studied by conventional polymerase chain reaction (PCR). However, the use of real-time PCR (RT-PCR) and nested PCR (N-PCR) in MSC has not been reported. This paper aims to highlight the usefulness of PCR in identifying MTb as a causative agent for MSC leading to its correct treatment with anti-tubercular therapy (ATT).

Findings

A young male with a family history of tuberculosis (TB) presented with a history of diminution of vision (DOV) since 3 months in his right eye (RE). He gave similar history in his left eye (LE) since 3 years. His fundus findings were suggestive of MSC. His high-resolution computed tomography (HRCT) chest and Quanti-FERON TB gold results were positive for MTb. These suggested TB to be the likely cause for MSC. This was confirmed by a positive N-PCR report of his aqueous specimen. Further RT-PCR was done to quantify the bacillary load before starting therapy. He was advised 9 months of ATT with 6 weeks of oral steroids. At last follow-up, the RE showed better healing than the LE with fewer chorioretinal scars and a better visual acuity.

Conclusions

RT and N-PCR for MTb are useful in establishing a tuberculous etiology in MSC. Coupled with a good response to ATT, these tests justify the use of ATT in MSC with a PCR-confirmed MTb report.

Electronic supplementary material

The online version of this article (doi:10.1186/s12348-014-0029-5) contains supplementary material, which is available to authorized users.

Vitreous analysis in the management of uveitis

A correct diagnosis of uveitis is often challenging, given the wide range of possible underlying conditions and the lack of typical phenotypes. Management decisions may be difficult in view of the risk of visual loss with either inappropriate or delayed therapy. Analysis of the vitreous may therefore be used to provide the clinician with valuable information. In this paper, we describe the main clinical situations in which vitreous sampling is indicated and provide some guidance to clinicians for tailoring their requests. These situations include suspected intraocular infection and suspected intraocular malignancy. We describe the principal tests carried out on vitreous samples, including cultures, polymerase chain reaction-based testing, and cytokine analysis. Limitations of the tests used are likely to become less as more advanced testing methods are introduced. The importance of selecting the appropriate investigations to support a clinical suspicion is emphasised, as is the interpretation of test results within a clinical context.

Clinical Features, Investigations, Management, and Prognosis of Serpiginous Choroiditis

Serpiginous choroiditis is an inflammatory form of posterior uveitis that affects the choroid, retinal pigment epithelium, and choriocapillaries. Known to be recurrent and progressive in nature, this bilateral disease can result in severe visual loss both during the active and healed stages. The age at onset is 40 to 50 years, but it can affect younger Indian population. It can be further classified into 3 types based on its clinical presentation, and they are, namely, peripapillary, macular, and ampiginous. Histological features further qualify the site of inflammation as evidenced by lymphocytic infiltration within the choroid and atrophy of choriocapillaries and retinal pigment epithelium. Despite a multitude of etiologies such as autoimmunity, infection, and degeneration, autoimmune causes remain the mainstay. Laboratory investigations can help rule out infections, whereas angiography can provide further insights into the progression of the disease. Newer investigations such as optical coherence tomography and fundus autofluorescence can help locate the lesion and identify the phase of the disease. Corticosteroids with immunosuppressives are the major management modality. Treatment of complications may require intravitreal injections, laser photocoagulation, or even vitreoretinal surgery.