Vision Loss

Definition

(Show Disclaimer) Note: I copy the "definition" of something straight from the book. I find it's best to have an all-encompassing definition in order to better orient myself when I am studying.

Also I could not find one source for this topic but felt it was necessary to cover. Merged sources from multiple topics...so it may be a little incomplete.

Show Definition Acute Vision Loss (from UptoDate): Acute persistent visual loss is defined as lasting at least 24 hours and is typically not caused by transient ischemia. Acute transient visual loss is defined as a sudden deficit in visual function in one or both eyes lasting less than 24 hours. It is caused by a temporary vascular occlusion in the circulation to the eye or visual cortex, or by neuronal depression after a seizure or migraine.

Note: Otherwise all else is chronic, this note attempts to cover at least superficially chronic vs. acute vision loss.

Incidence/Prevalance

Likely not important for the NAC OSCE Exam:

(If you're a keener click here)

1 in 28 U.S adults over age 40 have vision impairment
Adults > age 70 compromise 8% of U.S population but ~70% of cases of visual impairment.

Predisposing factors

Age
Diabetes
Medications: Sulfa drugs, diuretics, cholinergics.

Pathogenesis

The cornea and the lens account for the refraction of light coming into the eye onto the retina. The cornea accounts for more (~2/3) of the total load, but pathogenesis may involve either structure.

Common Findings

Vision loss, peripheral or central.
Diplopia
May have limitations of ADLs

Other Signs and Symptoms

Need to rule out temporal arteritis: Headache, double vision, jaw pain, fatigue, weight loss, night sweats, fever.
Need to rule out central retinal artery occlusion (CRAO): Acute onset, loss is limited to one area of the visual field, thrombosis risk (e.g. Afib, CAD, prev. hx of stroke, carotid artery occulsion), almost always uniocular.
Need to rule out retinal detachment: Acute onset, floaters/sparks, flashes of light, recent trauma, previous hx of retinal disease
If Diabetic retinopathy, other complications of diabetes: peripheral neuropathy, CKD, ACS/CAD, skin changes.

History

HPI: onset and severity of symptoms, Is night time vision impaired? Are there flashes of light? Is there floaters or sparks in the vision?
ROS:
ALL/MEDS/HIITS: (What are HIITS? - Click to expand), Rx history
PMH/FAMHx/OBGYN: especially peripheral vascular disease, diabetes.
SOCHx:

Physical Exam

Coming soon.

Diagnostic Tests

Fundoscopy
CBC w/ ESR, CRP if suspecting temporal arteritis.
Hemoglobin A1c, OGTT if suspecting diabetic retinopathy.
Vascular studies (CTA neck, CT head w/o contrast, Doppler US) if suspecting vascular.

DDx

Physiological:
- Presbyopia
- Cataract
- Macular degeneration
Vascular:
- Temporal Arteritis
- Retinal artery, retinal vein occlusion
- Diabetic Retinopathy
Structural:
- Traumatic
- Retinal detachment