Acquired immune deficiency syndrome (AIDS)

Description

Ocular manifestations of HIV infection Although the incidence of opportunistic ocular infections in HIVinfected patients has fallen substantially since the introduction of highly active antiretroviral therapy (HMRT) in 1996, the ocular manifestations of H IV infection are diverse and require specialized, intensive and often prolonged management. Overall, ocular complications of HIV (Table 1.1) and its treatment occur in approximately 75 per cent of patients during the course of the disease. Several of these conditions receive specific attention elsewhere in this book. Importantly, ocular infections in HIVinfected individuals (particularly those with a low CD4+ lymphocyte count) are often atypical and progress rapidly.

HIV retinopathy This is the most common ocular manifestation of HIV infection, affecting 40-60 per cent of HIV-positive individuals. It is a non-infectious and usually asymptomatic microangiopathy characterized by multiple cotton-wool spots with or without associated hemorrhages and microaneurysms. Possible causes include immune complex deposition, infection of the retinal vascular endothelium and altered blood flow. Histopathological findings are similar to those of diabetic retinopathy (pericyte dropout, microaneurysms and
microvascular occlusion).

Symptoms HIV retinopathy is asymptomatic in the vast majority of patients. In contrast, for example, patients with cytomegalovirus retinitis usually experience visual symptoms such as floaters, variable loss of vision or altered visual fields.

Signs The typical sign of HIV retinopathy is 2 multiple cotton-wool spots. Retinal hemorrhages and microaneurysms are less common. Other retinal changes or vitreous inflammation usualiy reflect opportunistic infections, such as cytomegalovirus retinitis, toxoplasmosis, syphilis and necrotizing herpetic
retinopathy.

Prevalence

The prevalence of HIV retinopathy increases with progression of HIV/AIDS and falling CD4+ lymphocyte count. Most patients with advanced AIDS have some degree of hllV retinopathy. CMV retinitis is the most common ocular opportunistic infection, occurring in approximately 30 per cent of patients.

Significance

Ocular complications may be the presenting feature of HIV infection. The immunosuppressed state of these patients often allows rapid progression of ocular infections.

Differential diagnosis

Cytomegalovirus retinitis; diabetic retinopathy – non-proliferative; hypertensive retinopathy; central retinal vein occlusion; retinal vasculitis; ophthalmic artery hypoperfusion syndrome.

See also

Cotton-wool spots; Lymphoma; Necrotizing herpetic retinopathies; Toxoplasmosis.

Management

Blood tests HIV infection is confirmed by screening and confirmatory antibody tests. In developed countries, CD4+ count and viral load assays are performed at regular intervals to monitor disease progression and response to treatment, under the supervision of a specialized physician. HIV retinopathy is a clinical diagnosis. Other causes of non-infectious microvasculopathy, such as diabetes