Differential Diagnosis for a 17-year-old boy with vision 20/25
Single most likely diagnosis
- Refractive error: The most common cause of decreased vision in a 17-year-old boy is a refractive error, such as myopia (nearsightedness), hyperopia (farsightedness), or astigmatism. A refractive error can easily be corrected with glasses or contact lenses.
Other Likely diagnoses
- Amblyopia: Also known as lazy eye, amblyopia is a condition where the brain favors one eye over the other, causing decreased vision in the less-used eye. It is often diagnosed in childhood, but mild cases may not be noticed until later.
- Dry eye or blepharitis: These conditions can cause eye irritation, discomfort, and blurred vision, especially if the boy spends a lot of time staring at screens or has allergies.
- Conjunctivitis or other infectious conjunctivitis: Pink eye, whether viral or bacterial, can cause temporary blurred vision, redness, and discharge.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Retinal detachment: Although rare, retinal detachment is a medical emergency that can cause permanent vision loss if not treated promptly. Symptoms may include sudden flashes of light, floaters, or a curtain descending over the field of vision.
- Diabetic retinopathy: If the boy has diabetes, high blood sugar levels can damage the blood vessels in the retina, leading to vision problems.
- Optic neuritis: Inflammation of the optic nerve can cause pain, blurred vision, and loss of color vision, and may be associated with multiple sclerosis or other conditions.
Rare diagnoses
- Uveitis: Inflammation of the uvea, the middle layer of the eye, can cause blurred vision, eye pain, and sensitivity to light.
- Keratoconus: A progressive thinning of the cornea that can cause distorted vision, double vision, and sensitivity to light.
- Retinitis pigmentosa: A genetic disorder that causes progressive vision loss, often starting with night blindness and peripheral vision loss.