Intraocular inflammation: its causes and investigations

Relevance of erythrocyte sedimentation rate and C-reactive protein in patients with active uveitis

PURPOSE

To relate erythrocyte sedimentation rates (ESR) and C-reactive protein (CRP) values to different uveitis entisties.

METHODS

A retrospective study of patients with a first episode of active uveitis visiting the Erasmus University Medical Center, uveitis clinic, Rotterdam, the Netherlands, was performed. Levels of ESR and CRP were determined within 2 weeks and 1 week after onset of uveitis, respectively. Uveitis had to be of unknown origin at that moment. The specific etiologic groups were related to ESR and CRP values.

RESULTS

The majority of patients with uveitis had ESR and/or CRP values within the normal limits and no association of ESR and/or CRP with the specific cause of uveitis was observed. However, elevation of ESR ≥ 60 mm/h and/or CRP ≥ 60 mg/L was mostly seen in patients with systemic immune-mediated diseases (8/59, 14% of all with immune-mediated diseases) or systemic infectious causes (7/38, 18% of all infectious uveitis). Patients with ocular toxoplasmosis typically exhibited normal ESR and CRP (9/11, 82%) while patients with endogenous endophthalmitis had elevated ESR and/or CRP in 6/7, 86%. Sarcoidosis-associated uveitis showed predominantly elevated ESR (13/24, 54%; range 20-59 mm/h in 11/13, 85%). Human immunodeficiency virus-positive patients had more often elevated ESR values when compared to the remainder of patients (9/11, 82% vs. 64/163, 39%, 18%, P = 0.009). The cause of uveitis was established in 19/20 (95%) of patients with ESR ≥ 60 mm/h and/or CRP ≥ 60 mg/L.

CONCLUSIONS

The majority of patients with first attack of uveitis had ESR and CRP within the normal limits. Elevated levels of ESR and CRP reflected systemic involvement and high levels of both values were associated with established uveitis cause.

Analysis of interaction between the apicomplexan protozoan Toxoplasma gondii and host cells using label-free Raman spectroscopy

Label-free imaging using Raman micro-spectroscopy (RMS) was used to characterize the spatio-temporal molecular changes of T. gondii tachyzoites and their host cell microenvironment. Raman spectral maps were recorded from isolated T. gondii tachyzoites and T. gondii-infected human retinal cells at 6 h, 24 h and 48 h post-infection. Principal component analysis (PCA) of the Raman spectra of paraformaldehyde-fixed infected cells indicated a significant increase in the amount of lipids and proteins in the T. gondii tachyzoites as the infection progresses within host cells. These results were confirmed by experiments carried out on live T. gondii-infected cells and were correlated with an increase in the concentration of proteins and lipids required for the replication of this intracellular pathogen. These findings demonstrate the potential of RMS to characterize time- and spatially-dependent molecular interactions between intracellular pathogens and the host cells. Such information may be useful for discovery of pharmacological targets or screening compounds with potential neuro-protective activity for eminent effects of changes in brain infection control practices.

Ocular infections in sub-Saharan Africa in the context of high HIV prevalence

Healthy eyes and good vision are important determinants of populations' health across the globe. Sub-Saharan Africa is affected by simultaneous epidemics of ocular infections and human immunodeficiency virus (HIV). Ocular infection and its complications, along with cataract and ocular trauma, are common conditions in this region with great impact on daily life. In this review, we discuss the epidemiology, clinical manifestations and microbial aetiology of the most important infectious ocular conditions in sub-Saharan Africa: conjunctivitis, keratitis and uveitis. We focus specifically on the potential association of these infections with HIV infection, including immune recovery uveitis. Finally, challenges and opportunities for clinical management are discussed, and recommendations made to improve care in this neglected but very important clinical field.

Bilateral macular thickening in mild unilateral anterior uveitis: is HLA-B27 involved?

BACKGROUND

Macular thickening (MT) without clinically recognized macular edema has been described in anterior uveitis (AU). Although fellow-eyes of patients have been used as controls in several studies, little is known about macular thickness in these eyes. We studied the rate and extent of MT in both AU-affected and quiescent fellow-eyes of phakic AU patients with good visual acuity (VA). We also assessed macular thickness related to HLA-B27 presence and to recurrence, since these issues have been almost unexplored by previous optical coherence tomography (OCT) studies.

METHODS

Patients with AU were prospectively included and macular thickness was measured with OCT initially and on follow up. Macular thickness in patients' affected eyes (n = 30) as well as in their quiet fellow-eyes (n = 28) was compared with eyes of age- and gender matched controls. Inter-ocular differences in macular thickness between AU affected eyes and their fellow-eyes were assessed in patients (n = 28), also in a subgroup with visual acuity ≥ 0.8 (n = 23) by one-sample Student's t-tests. Inter-ocular differences were also assessed related to HLA-B27 presence and related to the status of current AU episode (initial or relapse).

RESULTS

Subclinical MT is present in both quiet fellow-eyes and AU-affected eyes of patients. MT was found in most cases of AU, even in phakic eyes with good VA. There was a larger increase in macular thickness in HLA-B27-positive than in HLA-B27-negative patients. No differences in macular thickness were found between patients with their first AU episode and patients with recurrent episodes.

CONCLUSIONS

MT probably reflects systemic immune-mediated response to the inflammatory disorder in AU, and it is possible that HLA-B27-related factors are involved in the pathogenesis of AU. These observations are in line with and extend the current understanding of the mechanisms behind MT in AU.

CXCL10 is required to maintain T-cell populations and to control parasite replication during chronic ocular toxoplasmosis

PURPOSE

Toxoplasma gondii is a major cause of ocular disease, which can lead to permanent vision loss in humans. T cells are critically involved in parasite control, but little is known about the molecules that promote T-cell trafficking and migration in the retina. Thus, the aim of this study was to image and dissect the T-cell response during chronic toxoplasmic retinochoroiditis.

METHODS

C57BL/6 mice were infected with the Me49 strain of T. gondii, and T cells that infiltrated the eye were analyzed by flow cytometry and imaged using multiphoton microscopy. IFN-γ, CXCL9, CXCL10, and CXCR3 mRNA levels were measured by real-time PCR. To investigate the role of CXCL10, mice were treated with anti-CXCL10 antibodies, and histopathology and immunohistochemistry were performed to monitor changes in pathology, cellular infiltration, and parasite burden in the eye.

RESULTS

Infection with T. gondii leads to the infiltration of highly activated motile T cells into the eye. These cells express CXCR3 and are capable of producing IFN-γ and TNF-α, and CD8+ T cells express granzyme B. The expression of CXCL9 and CXCL10 in the retina was significantly upregulated during chronic infection. Treatment of chronically infected mice with anti-CXCL10 antibodies led to decreases in the numbers of CD3+, CD4+, and CD8+ T cells and the amount of IFN-γ mRNA expression in the retina and an increase in replicating parasites and ocular pathology.

CONCLUSIONS

The maintenance of the T-cell response and the control of T. gondii in the eye during chronic infection is dependent on CXCL10.

Headache attributable to disorders of the eye

Sensory innervation to the eye and periocular area arises from the ophthalmic branch of the trigeminal nerve. Thus, ocular, orbital, and systemic disorders may produce head pain with ocular signs and symptoms. Whereas some of these entities have characteristic diagnostic features, others mimic primary headache disorders such as migraine and cluster headache. This article reviews common ocular and neuro-ophthalmic conditions that are accompanied by pain in or near the eye.