Corneal lipidosis in patients with the acquired immunodeficiency syndrome

Corneal Involvement in HIV-infected Individuals

Corneal involvement in HIV-infected individuals may be broadly classified into two categories, namely, infectious and noninfectious with the vast majority of manifestations occurring in the former. In this article, we shall focus on these two categories and strive to highlight those presentations that should alert the clinician to suspect underlying HIV infection. Infectious group mainly consists of Herpitic group of viral infections. Bacterial causes may be due to Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeroginosa, alpha hemolytic Streptococcus, Micrococcus and Bacillus. Fungalf keratitis in HIV-infected individuals depends on the geographic locations from which patient comes. Microsporidia and Acanthamoeba are common Protozoal causes. Non-infective inflammatory causes include peripheral ulcerative keratitis, keratoconjunctivitis sicca, and squamous cell carcinoma of the conjunctiva. Severity which is abnormally severe or very minimally reactive makes the clinician suspect of immunosuppression.

HIF-1α is essential for effective PMN bacterial killing, antimicrobial peptide production and apoptosis in Pseudomonas aeruginosa keratitis

Hypoxia-inducible factor (HIF)-1α, is a transcription factor that controls energy metabolism and angiogenesis under hypoxic conditions, and a potent regulator of innate immunity. The studies described herein examined the role of HIF-1α in disease resolution in BALB/c (resistant, cornea heals) mice after ocular infection with Pseudomonas (P.) aeruginosa. Furthermore, the current studies focused on the neutrophil (PMN), the predominant cell infiltrate in keratitis. Using both siRNA and an antagonist (17-DMAG), the role of HIF-1α was assessed in P. aeruginosa-infected BALB/c mice. Clinical score and slit lamp photography indicated HIF-1α inhibition exacerbated disease and corneal destruction. Real time RT-PCR, immunohistochemistry, ELISA, Greiss and MPO assays, bacterial load, intracellular killing, phagocytosis and apoptosis assays further tested the regulatory role of HIF-1α. Despite increased pro-inflammatory cytokine expression and increased MPO levels after knocking down HIF-1α expression, in vivo studies revealed a decrease in NO production and higher bacterial load. In vitro studies using PMN provided evidence that although inhibition of HIF-1α did not affect phagocytosis, both bacterial killing and apoptosis were significantly affected, as was production of antimicrobial peptides. Overall, data provide evidence that inhibition of HIF-1α converts a normally resistant disease response to susceptible (corneal thinning and perforation) after induction of bacterial keratitis. Although this inhibition does not appear to affect PMN transmigration or phagocytosis, both in vivo and in vitro approaches indicate that the transcriptional factor is essential for effective bacterial killing, apoptosis and antimicrobial peptide production.

Anterior Segment and External Ocular Disorders Associated with Human Immunodeficiency Virus Disease

The eye is a common site for complications of human immunodeficiency virus (HIV) infection. Although cytomegalovirus retinitis remains the most prevalent of the blinding ocular disorders that can occur in individuals with the acquired immunodeficiency syndrome (AIDS), several important HIV-associated disorders may involve the anterior segment, ocular surface, and adnexae. Some of these entities, such as Kaposi sarcoma, were well described, but uncommon, before the HIV epidemic. Others, like microsporidial keratoconjunctivitis, have presentations that differ between affected individuals with HIV disease and those from the general population who are immunocompetent. The treatment of many of these diseases is challenging because of host immunodeficiency. Survival after the diagnosis of AIDS has increased among individuals with HIV disease because of more effective antiretroviral therapies and improved prophylaxis against, and treatment of, opportunistic infections. This longer survival may lead to an increased prevalence of anterior segment and external ocular disorders. In addition, the evaluation and management of disorders such as blepharitis and dry eye, which were previously overshadowed by more severe, blinding disorders, may demand increased attention, as the general health of this population improves. Not all individuals infected with HIV receive potent antiretroviral therapy, however, because of socioeconomic or other factors, and others will be intolerant of these drugs or experience drug failure. Ophthalmologists must, therefore, still be aware of the ocular findings that develop in the setting of severe immunosuppression. This article reviews the spectrum of HIV-associated anterior segment and external ocular disorders, with recommendations for their evaluation and management.

Ultrastructural features and prevalence of tubuloreticular structures in the ocular vasculature of patients with AIDS: a study of 23 cases

BACKGROUND

Tubuloreticular structures (TRS) are subcellular inclusions that are most commonly found in endothelial cells and lymphocytes of patients with autoimmune or collagen vascular disorders. In AIDS, TRS have been described in various tissues throughout the body including the lung, kidney, liver, muscle, and skin.

METHODS

Ocular tissues from 23 patients with AIDS were examined by electron microscopy. These included 17 postmortem eyes in addition to three chorioretinal and three conjunctival biopsy specimens.

RESULTS

The overall prevalence of TRS in the ocular and conjunctival endothelial cells was found to be 83% (19/23).

CONCLUSIONS

This is the first documented study of the prevalence of these structures in the ocular structures of patients with AIDS. Given the high frequency of their occurrence in AIDS, it is recommended that the presence of TRS in ocular or conjunctival tissues be an indication for obtaining an HIV antibody titre. Additionally, a rheumatological examination for HIV seronegative patients is suggested.