What should be included in a “baseline” eye examination? 

• Visual acuity (“center vision”) 
• Visual field (“peripheral or side vision”) 
• Pupil exam (“the black part of the eye”) 
• Slit Lamp exam (exam of the structures of the “front part of the eye”) 
• Motility exam (“how the eye moves”) 
• Dilated fundus exam (“looking at the back of the eye including the optic nerve”) 

 

What symptoms will the patient have? 

• Unexplained usually painless decreased visual acuity or visual field-common 
• Double vision (diplopia)-less common 
• Droopy eyelid (ptosis)-less common 

 

Why should every patient with a pituitary adenoma have an eye exam?

• Visual loss may be the presenting and only sign of pituitary tumor
• Visual improvement may indicate treatment response of pituitary tumor
• Progressive visual loss may indicate recurrence of tumor
• Baseline ophthalmologic exam

 

What is the eye doctor looking for?

• Decreased visual acuity or visual field
• Abnormalities in the response of the pupil
• Abnormal eye movements
• Optic atrophy (visible damage to the optic nerve)

 

How does a pituitary adenoma decrease vision?

• Pituitary tumors (and other types of brain tumors) can cause visual loss by pressure (compression) of the visual pathway
• Depending on where the tumor is located the vision loss may be in one or both eyes and may affect central vision or side vision

 

How does a pituitary tumor cause double vision?

• Compression of the nerves that control eye movement (ocular motor nerves or cranial nerves III, IV, and VI)
• Loss of vision can cause loss of the ability to keep the eyes aligned (fusion)

 

How does pressure on the anterior visual pathway cause visual loss?

• Pressure on the optic nerve causes loss of vision in the ipsilateral (“same side”) eye
• Pressure on the optic chiasm causes a bitemporal hemianopsia (“loss of temporal side vision in each eye”)
• Pressure on the optic tract causes a homonymous hemianopsia (Homo: same, Hemi: half, Opsia: loss of vision)

 

What factors make it more or less likely that the patient with visual loss due to a pituitary tumor will recover vision?

• Age (younger patients do better)
• Vasculopathic risk factors: patients without hypertension, diabetes or other medical problems do better
• Duration of visual loss (the longer the symptoms have been present, the less likely the vision will return
• Presence of optic atrophy (optic atrophy implies some component of irreversible visual loss)

 

What is the anatomy of the visual pathway?

• Visual information passes through the cornea (the clear part of the eye), the lens, to the retina (like film in a camera) and to the optic nerve, optic chiasm (a crossing point), then to the optic radiations and the occipital cortex
• Pituitary adenomas affect the anterior (or front part of the brain) visual pathway

 

Is the visual loss reversible after treatment?

• If the pressure on the visual pathway can be relieved most patients experience improvement in vision after treatment

 

How often should I see the eye doctor?

• Preoperative baseline
• Postoperative baseline
• Postoperative 3 months
• Postoperative 9-12 months
• Yearly if stable

 

When should I call my eye doctor?

• Blurry central or side vision
• Double vision
• Droopy eyelid

 

One additional note

• Persons with Cushing’s should also be checked for cataracts since long term exposure to cortisol increases your chances of cataracts.

 

Author: Dr. Andrew Lee, MD (Spring, ’98)

Editor’s Note: Dr. Andrew G. Lee, MD, Baylor College of Medicine, Division of Neurosurgery, MD Anderson Cancer Center, University of Texas, Neuro-ophthalmology Unit, Department of Ophthalmology, Neurology and Neurosurgery, Baylor College of Medicine, Division of Neurosurgery, MD Anderson Cancer Center, University of Texas