18.3 Vision Screening, Strabismus, Red Eye & Fluorescein
Key Takeaways
- An absent or white red reflex (leukocoria) is an emergency until retinoblastoma and other media opacities are excluded.
- Bright Futures: red reflex and inspection from infancy; instrument-based photoscreening when acuity cannot be done (about 12–36 months); visual acuity when the child can perform it (typically from age 3). Amblyopia has a critical period — refer strabismus rather than waiting for the child to outgrow a constant tropia.
- Nasolacrimal duct obstruction is a watery, non-infected eye that usually resolves with massage by 12 months; dacryocystitis is an infected sac.
- Sort conjunctivitis: viral versus bacterial versus allergic versus neonatal gonococcal or chlamydial disease (emergency). Fluorescein finds corneal abrasion, a herpes dendrite (do not give steroids), and ulcer.
- Hordeolum is painful; chalazion is a painless nodule. Orbital cellulitis (proptosis, painful extraocular motion) goes to the ED. Evert the lid for a foreign body.
Ophthalmology is clinical category #17. Domain I/II is Bright Futures vision screening. Domain III includes the named office procedure fluorescein staining, strabismus referral before the amblyopia window closes, and knowing which red eye is an emergency. Chapter 20.3 will list fluorescein among the ten procedures; this section is where you actually use it.
Quick Answer: A white or absent red reflex (leukocoria) is a retinoblastoma emergency. Screen with cover-uncover, photoscreening at Bright Futures instrument-based ages, and visual acuity when able. Amblyopia has a critical period — refer strabismus. NLDO is watery; dacryocystitis is infected. Conjunctivitis is viral, bacterial, allergic, or neonatal GC/CT (emergency). Fluorescein: abrasion, herpes dendrite (no steroids), ulcer. Hordeolum hurts; chalazion is a painless lump. Orbital cellulitis (proptosis, painful extraocular motion) is ED. Look for a foreign body.
Vision screening: red reflex, cover testing, photoscreening, acuity
Red reflex (Brückner) is part of the newborn and infant exam and remains indicated whenever vision or media opacity is in question. A symmetric orange-red reflex in both eyes is the goal. Leukocoria — a white, yellow, or absent reflex, including a new “white glow” on flash photographs — is retinoblastoma until proven otherwise, and also cataract, retinal detachment, Coats disease, or vitreous hemorrhage. Same-day ophthalmology/ED. Do not wait for the 6-month visit. An asymmetric reflex or a persistently dull reflex is also a referral, not a “family eye color” story.
Cover-uncover testing detects a manifest tropia (the uncovered eye moves to take up fixation when the other is covered). Alternate-cover testing can reveal a phoria. Constant strabismus after the first few months, or any unilateral visual-behavior concern, is not normal newborn dysconjugation, which may be intermittent until about 3–4 months. After that, refer rather than “wait to see if the eye straightens.”
Bright Futures / AAP vision screening ages to teach (use the current periodicity table in clinic; do not invent extra years):
| Age | What you do |
|---|---|
| Newborn through infancy | Red reflex, external inspection, fix-and-follow as development allows |
| About 12 and 24 months (and other toddler visits when acuity is impossible) | Instrument-based screening (photoscreening / autorefraction) is acceptable |
| Age 3 years and older, when the child can do it | Visual acuity with age-appropriate charts (LEA, HOTV, then Snellen); retry at 4 if the 3-year attempt fails |
| School-age well visits per periodicity (commonly 4, 5, 6, 8, 10, 12, 15 years) | Repeat acuity; refer failed lines |
Failed screening, a two-line difference between eyes, or caregiver concern despite a “passed” photoscreen still deserves pediatric ophthalmology, not another year of hope. Instrument-based screening does not replace red-reflex examination.
Amblyopia and strabismus: the critical period
Amblyopia is reduced best-corrected vision from abnormal visual experience (strabismus, anisometropia, deprivation by cataract or ptosis) during a critical period in early childhood. Treatment (glasses, patching or atropine of the better eye, surgery for some alignment problems) works far better early. Waiting until school-entry “when they can sit for a chart” can miss the window. That is why toddler photoscreening and infant red reflex exist.
Strabismus (esotropia, exotropia, hypertropia) is a leading amblyopia risk. Refer pediatric ophthalmology for a constant tropia, a tropia persisting after 4 months, an incomitant deviation, ptosis that covers the visual axis, or any leukocoria. Primary care does not prescribe patching without an ophthalmology plan. Pseudostrabismus from a wide nasal bridge and epicanthal folds has a normal corneal light reflex and cover test — confirm; do not refer every flat nasal bridge, and do not call a true esotropia “just the bridge.”
Nasolacrimal duct obstruction versus dacryocystitis
Congenital nasolacrimal duct obstruction (NLDO) presents with a watery eye, mattering, and a wet lower lid, usually without true conjunctival injection or photophobia. Onset is in the first months. Teach lacrimal sac massage (downward along the medial canthus) and eyelid hygiene. Most resolve by 12 months. Persistent obstruction after a year is an ophthalmology probing discussion, not another year of watchful mucus if the family is miserable — but it is still not an emergency if the sac is not infected.
Dacryocystitis is infection of the sac: erythema, swelling, tenderness below the medial canthus, sometimes fever. That is systemic antibiotics and often urgent ophthalmology, not massage alone. A spreading cellulitis around the sac is not NLDO.
Conjunctivitis: viral, bacterial, allergic, neonatal GC/CT
| Pattern | Clues | Primary-care move |
|---|---|---|
| Viral | Watery, often sequential eyes, URI, preauricular node | Supportive; hygiene; no steroids |
| Bacterial | Purulent discharge, lids glued | Topical antibiotic in a well child; reccheck |
| Allergic | Itch, bilateral, cobblestoning, seasonal or perennial atopy | Allergen avoidance, oral antihistamine or mast-cell/antihistamine drops; no routine antibiotic |
| Neonatal gonococcal | First few days of life, hyperpurulent, risk of perforation | Emergency: systemic therapy, ophthalmology, evaluate disseminated disease |
| Neonatal chlamydial | Often 1–2 weeks, watery-to-purulent | Systemic macrolide (treats pneumonia risk); not drops alone |
Neonatal GC/CT conjunctivitis is an emergency pathway, not “erythromycin ointment and see you at 2 weeks” if the infant already has disease. Chemical conjunctivitis from silver nitrate is largely historical; prophylaxis questions still appear. Any red eye in the first month with copious pus is same-day care.
Fluorescein staining: abrasion, dendrite, ulcer
Fluorescein staining is the named CPNP-PC procedure for the painful, photophobic, or traumatized eye after you inspect and, when needed, evert the lid.
- Numb with a drop of topical anesthetic if you use it for the exam (do not send a bottle home).
- Moisten a fluorescein strip, touch the conjunctiva, ask the child to blink.
- View with cobalt-blue light.
- Irrigate extra dye. Document the pattern. Dispose of the strip; do not contaminate the bottle if you use liquid dye.
| Pattern | Diagnosis | Do / do not |
|---|---|---|
| Linear or geographic uptake after trauma or a fingernail | Corneal abrasion | Pain control, often a brief topical antibiotic in children, follow-up; no patching as routine; no topical anesthetic for home |
| Branching, dendritic uptake | Herpes simplex keratitis | Ophthalmology now. Do NOT prescribe topical steroids. Steroids worsen herpetic keratitis |
| Dense round defect, infiltrate, hypopyon, contact-lens wearer | Corneal ulcer | Same-day ophthalmology; not a primary-care steroid-antibiotic combination drop |
Contact-lens red eye is ulcer until proven otherwise. Recheck abrasions; a worsening or nonhealing stain is not “still just a scratch.”
Hordeolum, chalazion, periorbital versus orbital cellulitis, foreign body
A hordeolum (stye) is an infected eyelid gland: painful, red, localized. Warm compresses are first-line; consider topical or oral antibiotics if surrounding cellulitis is present. A chalazion is a painless lipogranuloma from a blocked meibomian gland — a firm nodule, little acute infection. Compresses; refer if it persists or distorts vision. Do not I&D an eyelid in the well-child room as casual primary care.
Preseptal (periorbital) cellulitis is lid swelling and redness without orbital signs; the child may have a bug bite or sinus history and still move the eye comfortably with no proptosis. Treat selected well, older children with oral antibiotics and close follow-up after you have excluded orbital disease.
Orbital cellulitis is an ED / hospital disease: proptosis, painful extraocular motion, ophthalmoplegia, vision change, chemosis, or toxicity, often from ethmoid sinus disease. Do not send that child home on cephalexin. Imaging and IV antibiotics happen in the hospital with ophthalmology and ENT.
Foreign body: history of dust, sand, or metal, tearing, a scratchy sensation. Evert the upper lid, inspect the fornices, irrigate, then fluorescein for a secondary abrasion. A visible, loose conjunctival FB can come out with irrigation or a moist swab. A metallic corneal FB, a rust ring, a penetrating injury (irregular pupil, leaking, hyphema), or a high-velocity metal history is ophthalmology, not a cotton-tip adventure. Do not pressure-patch a globe you think is open.
Exam traps
- Calling leukocoria “camera artifact” for a month.
- Waiting until kindergarten to refer a constant esotropia.
- Treating NLDO as bacterial conjunctivitis for 8 weeks of drops.
- Topical steroids for a red eye you have not stained — especially a dendrite.
- Drop-only therapy for neonatal GC/CT.
- Sending orbital cellulitis home as a stye.
- Skipping lid eversion for a “corneal abrasion” that is a subtarsal FB.
Screen the reflex, catch amblyopia while the brain will still rewire, stain the painful eye, withhold steroids from dendrites, and move leukocoria, neonatal hyperpurulent conjunctivitis, and orbital cellulitis out of clinic the same day.
A 4-month-old’s flash photograph shows a white glow in one pupil, and the office red reflex is dull and white on that side. The infant otherwise feeds well. What is the correct action?
A 7-year-old has a swollen, red eyelid, fever, proptosis, and pain with extraocular movement after a week of sinus symptoms. Which disposition matches orbital versus preseptal teaching?
A school-age child has a painful, photophobic red eye. Fluorescein under cobalt-blue light shows a branching dendritic pattern. What is the CPNP-PC procedure-based plan?