Blurred vision is the most common visual complaint vision is the loss of sharpness of vision and the inability to see small details
Etiology
The causes of blurred vision range from mild to potentially catastrophic. Most causes involve the orbit (anterior and posterior segments); although a number of extraocular causes must be considered (medication, cerebrovascular event, sarcoidosis, herpes simplex).
The causes of blurred vision range from mild to potentially catastrophic. Most causes involve the orbit (anterior and posterior segments); although a number of extraocular causes must be considered (medication, cerebrovascular event, sarcoidosis, herpes simplex).
Epidemiology
Certain age-related eye disorders such as macular degeneration, cataracts, and temporal arteritis may cause blurred vision. In younger patients, blurred vision is often acquired through trauma, occupational exposures, and infections.
Certain age-related eye disorders such as macular degeneration, cataracts, and temporal arteritis may cause blurred vision. In younger patients, blurred vision is often acquired through trauma, occupational exposures, and infections.
History
Careful attention should be paid to the rapidity of the onset, associated eye pain, and whether the blurring is unilateral or bilateral. Blurred vision that worsens at night may indicate a cataract (2). Intermittently blurred vision may be caused by excess tearing, allergies, uncontrolled diabetes, acute glaucoma, transient ischemic attacks, cerebrovascular insufficiency, and multiple sclerosis (3). Other important factors include a family history of eye disorders (macular degeneration, glaucoma), any work exposures (chemicals), medications (such as corticosteroids, antibiotics), and past medical history (diabetes, hypertension).
Careful attention should be paid to the rapidity of the onset, associated eye pain, and whether the blurring is unilateral or bilateral. Blurred vision that worsens at night may indicate a cataract (2). Intermittently blurred vision may be caused by excess tearing, allergies, uncontrolled diabetes, acute glaucoma, transient ischemic attacks, cerebrovascular insufficiency, and multiple sclerosis (3). Other important factors include a family history of eye disorders (macular degeneration, glaucoma), any work exposures (chemicals), medications (such as corticosteroids, antibiotics), and past medical history (diabetes, hypertension).
Physical examination
The physical examination should include the following elements:
Careful documentation of visual acuity (corrected and uncorrected) is important to monitor the progression of the disease. If the patient is unable to discern letters on the Snellen eye chart, the examiner should determine the extent of acuity impairment by testing the distance from the patient's eyes at which the patient can first see the examiner's fingers.
Visual field testing may indicate an underlying stroke (homonymous field defect) or retinal detachment (quadrant or hemispheric loss of vision).
Ocular muscle involvement may be detected by testing the cardinal positions of the orbit through range of motion.
Conjunctival erythema and discharge should be noted. The corneal light reflex should be symmetric and sharp; fluorescein staining should be performed to evaluate for the evidence of trauma, ulcers, or herpetic lesions. The anterior chamber (space between the cornea and the iris) should be evaluated with a penlight for blood (hyphema) and pus (hypopyon).
In up to 20% of the cases, pupillary examination may be the only clue to serious underlying pathology. Using a penlight, the abnormalities of pupillary size or shape (the pupils should be symmetric; a unilateral miotic pupil may indicate iritis) or color (black is normal) may be detected. Other findings may include cataracts, ruptured globes (with eccentric pupils), and optic nerve disease (afferent papillary defect—paradoxical papillary dilatation in response to light).
Direct ophthalmoscopy may reveal an abnormal red reflex that suggests a hemorrhage, cataract, or retinal detachment. Papilledema warrants further evaluation.
The physical examination should include the following elements:
Careful documentation of visual acuity (corrected and uncorrected) is important to monitor the progression of the disease. If the patient is unable to discern letters on the Snellen eye chart, the examiner should determine the extent of acuity impairment by testing the distance from the patient's eyes at which the patient can first see the examiner's fingers.
Visual field testing may indicate an underlying stroke (homonymous field defect) or retinal detachment (quadrant or hemispheric loss of vision).
Ocular muscle involvement may be detected by testing the cardinal positions of the orbit through range of motion.
Conjunctival erythema and discharge should be noted. The corneal light reflex should be symmetric and sharp; fluorescein staining should be performed to evaluate for the evidence of trauma, ulcers, or herpetic lesions. The anterior chamber (space between the cornea and the iris) should be evaluated with a penlight for blood (hyphema) and pus (hypopyon).
In up to 20% of the cases, pupillary examination may be the only clue to serious underlying pathology. Using a penlight, the abnormalities of pupillary size or shape (the pupils should be symmetric; a unilateral miotic pupil may indicate iritis) or color (black is normal) may be detected. Other findings may include cataracts, ruptured globes (with eccentric pupils), and optic nerve disease (afferent papillary defect—paradoxical papillary dilatation in response to light).
Direct ophthalmoscopy may reveal an abnormal red reflex that suggests a hemorrhage, cataract, or retinal detachment. Papilledema warrants further evaluation.
Testing
An elevated sedimentation rate may suggest a diagnosis of temporal arteritis. Computed tomography is appropriate to evaluate blurred vision following trauma, or when there is concern for mass effect
An elevated sedimentation rate may suggest a diagnosis of temporal arteritis. Computed tomography is appropriate to evaluate blurred vision following trauma, or when there is concern for mass effect
Causes of Blurred Vision
Painless conditins
Sudden onset Unilateral- Vitreous hemorrhage, macular degeneration, retinal detachment, retinal-vein occlusion, amaurosis fugax, cataracts
Sudden onset Bilateral- Poorly controlled diabetes, medications (anticholinergics, cholinergics, corticosteroids), migraines, psychological trauma.
Gradual onset Unilateral -Cataracts,macular degeneration, tumor
Gradual onset Bilateral - Cataracts, macular degeneration, medications (hydrochloroquine, ethambutol, digoxin toxicity), optic chiasm mass, fatigue, refractive errors (myopia, hyperopia, astigmatism, presbyopia); incorrect eyewear
Painful conditions
Sudden onset Unilateral - Corneal abrasion, infection or edema, uveitis, traumatic hyphema, acute glaucoma, temporal arteritis, optic neuritis, orbital cellulitis
Sudden onset Bilateral- Trauma, chemical spill, welder's exposure
Gradual onset Unilateral- Rare
Gradual onset Bilateral - Rare (sarcoidosis, collagen vascular disease)
Genetics
Macular degeneration, glaucoma, collagen vascular diseases, diabetes, and multiple sclerosis (optic neuritis) are potentially heritable conditions.
Macular degeneration, glaucoma, collagen vascular diseases, diabetes, and multiple sclerosis (optic neuritis) are potentially heritable conditions.
Clinical manifestations
A careful history and physical examination often limit the differential diagnosis. Conditions that require immediate ophthalmologic referral include acute glaucoma, retinal detachment, vitreous hemorrhage, retinal-vein occlusion, herpes simplex infection, and orbital cellulitis.
A careful history and physical examination often limit the differential diagnosis. Conditions that require immediate ophthalmologic referral include acute glaucoma, retinal detachment, vitreous hemorrhage, retinal-vein occlusion, herpes simplex infection, and orbital cellulitis.
