HIV-associated eye disorders are common among people living with HIV, with between 70 and 80% experiencing some form of eye problem during the course of their disease. While many of these disorders are associated with later-stage infection—when a person’s CD4 count drops below 250 cells/mL (and even more so below 100 cells/mL)—they can, in fact, occur at stage of infection.
Among the eye-related disorders associated with HIV:
- Below 500 cells: herpes zoster (shingles); Kaposi sarcoma (KS), lymphoma, tuberculosis (TB)
- Below 200 cells: herpes simplex virus (HSV), pneumocystosis, toxoplasmosis
- Below 100 cells: aspergillosis, cytomegalovirus (CMV), cryptococcosis, HIV encephalopathy, microsporidiosis, molluscum contagiosum (MC), mycobacterium avium complex (MAC), progressive multifocal encephalopathy (PML), varicella-zoster virus (VZV)
While HIV-associated eye disorders are more often caused by these and other opportunistic infections (OIs), they may also be a direct result of the HIV infection itself, manifesting with changes—sometimes minor, sometimes profound—to the nerve and vascular structure of the eye itself.
Since the advent of combination antiretroviral therapy (ART), the incidence of many of these infections has dropped dramatically, although they remain high in regions where access to therapy remains sparse and/or control of disease is poor.
Identifying the cause of an HIV-associated eye disorder typically begins by determining where the infection is presenting.
Infections of the Eyelid, Tear Ducts, and Conjunctiva
Known as the ocular adnexa, this section of the ocular anatomy provides protection and lubrication to the eye itself and includes the eyelid, tear ducts, and conjunctiva (white of the eyes). The most common infections to present within these areas are herpes zoster virus (HSV), Kaposi sarcoma (KS), and molluscum contagiosum (also known as “water warts”). Microvascular changes—dilation of veins and arteries, micro-aneurisms—are also known to occur in about 70 to 80% of people with HIV, and may be directly related to the HIV infection itself
Infections of the ocular adnexa may present with painful shingles running along the ophthalmic nerve to the eye; dark purplish tumors on and around the eyelid; or pox-like bumps affecting one or both the eyelids.
Infections on the Front of the Eye (Cornea, Iris, and Lens)
The anterior (front) segment of the eye functions primarily by refracting light and adjusting focus needed for vision, and includes the cornea, iris, lens, and anterior chamber (the fluid-filled space between the cornea and iris). Some of the more common infections of the anterior segment are varicella-zoster virus (the virus associated with chickenpox and shingles); microsporidiosis (a protozoan infection); herpes simplex (the virus associated with cold sores and genital herpes); and other opportunistic fungal or bacterial infections.
Many of these infections tend occur in later-stage disease when an HIV-positive person’s immune system is effectively compromised. Keratitis, a sometimes painful and itchy inflammation of the cornea, is one of the frequent symptoms note in anterior segment infections, whether caused by varicella-zoster virus, herpes simplex, or fungal infection like Candida or Aspergillus.
Infections to the Back of the Eye (Retina and Optic Nerve)
The posterior (back) segment of the eye functions by maintaining the shape of the eyeball, holding the lens in place, and triggering nerve impulses to the brain from photoreceptor cells on the back of the eyes. The retina, choroid (the vascular layer of the eye), and optic nerve comprise much of the posterior segment, with a number of HIV-associated disorders presenting within these ocular layers, more often in later stage HIV disease.
Disorders of the posterior segment—primarily presenting with vascular changes to the retina—are seen in as many as 50% to 70% of people with HIV, and may sometime result in persistent or acute damage to the retina (called retinopathy).
Other HIV-associated infections of the posterior segment are cytomegalovirus (one of the most common ocular infections among people with HIV); tuberculosis (TB); toxoplasmosis (a common and easily transmitted parasitic infection); and cryptococcosis (another common HIV-related fungal infection).
Infections of the Eye Socket
While there are few HIV-associated infections of the orbital segment of the eye (also known as the eye socket), aspergillosis—a fungal infection that typically occurs in persons with advanced HIV disease—is known to cause the inflammation of the orbital eye tissue (cellulitis) in some. Similarly, lymphomas (blood cell tumors) may present within this segment, again usually when the individual’s CD4 has dropped below 100 cells/mL.