Cancer-Associated Visual Syndromes (Paraneoplastic)

Cancer-associated visual syndromes, also called paraneoplastic visual syndromes, occur when the immune system's response to cancer mistakenly attacks parts of the visual system. The cancer itself doesn't directly invade the eyes—instead, antibodies meant to fight the cancer cross-react with eye or brain tissues.

Types of Paraneoplastic Visual Syndromes

Cancer-Associated Retinopathy (CAR)

• Most common paraneoplastic visual syndrome
• Affects photoreceptors (rods and cones)
• Causes progressive vision loss, often bilateral
• Associated with small cell lung cancer, gynecologic cancers
• Anti-recoverin antibodies most common

Symptoms:

• Progressive vision loss
• Photophobia
• Prolonged glare after bright lights
• Night vision problems
• Visual field deficits

Melanoma-Associated Retinopathy (MAR)

• Associated with cutaneous melanoma
• Typically affects bipolar cells
• Shimmering or flickering vision
• Night blindness prominent
• May occur years after melanoma diagnosis

Paraneoplastic Optic Neuropathy

• Affects the optic nerve
• May resemble optic neuritis
• Associated with various cancers
• Anti-CRMP-5 (CV2) antibodies common

Paraneoplastic Cerebellar Degeneration with Visual Symptoms

• Affects cerebellum and brainstem
• Nystagmus
• Oscillopsia
• Double vision
• Associated with breast, ovarian, lung cancers

Diagnosis

Clinical Evaluation

• Detailed history (smoking, cancer history)
• Complete eye examination
• Visual field testing
• Electroretinogram (ERG)—often markedly abnormal

Antibody Testing

Common paraneoplastic antibodies:

• Anti-recoverin
• Anti-enolase
• Anti-CRMP-5 (CV2)
• Anti-Hu
• Anti-Yo

Cancer Workup

If paraneoplastic syndrome suspected:

• CT chest/abdomen/pelvis
• PET scan
• Mammogram (women)
• Testicular ultrasound (men)
• May need repeated surveillance if initial workup negative

Treatment

Cancer Treatment

• Treating the underlying cancer is primary goal
• May stabilize or improve visual symptoms
• Surgery, chemotherapy, radiation as appropriate

Immunomodulatory Therapy

• IV steroids
• IVIG
• Plasma exchange
• Rituximab
• Other immunosuppressants

Supportive Care

• Low vision rehabilitation
• Visual aids
• Orientation and mobility training

Prognosis

• Variable depending on:
  • Type of syndrome
  • Specific cancer type
  • Response to cancer treatment
  • How early treatment started
• Some patients stabilize
• Others progress despite treatment
• Early cancer detection may improve outcomes

When to Suspect

Consider paraneoplastic syndrome when:

• Rapid, unexplained bilateral vision loss
• Abnormal ERG without clear cause
• History of smoking or known cancer
• Visual symptoms with systemic symptoms
• Vision loss resistant to standard treatments