1. Polar. Opacity of the lens capsule and adjacent cortex on the anterior or posterior pole of the lens.
2. Zonular (lamellar). White opacities that surround the nucleus with alternating clear and white cortical lamella like an onion skin.
3. Nuclear. Opacity within the embryonic/fetal nucleus.
4. Posterior lenticonus. A posterior protrusion, usually opacified, in the posterior capsule (most common cause of nontraumatic acquired cataract).
Etiology
Idiopathic (most common).
Familial, autosomal dominant.
Galactosemia. (Cataract may be the sole manifestation when galactokinase deficiency is responsible. A deficiency of galactose-1-phosphate uridyl transferase may produce mental retardation and symptomatic cirrhosis along with cataracts. The typical oil-droplet opacity may or may not be seen.)
Persistent hyperplastic primary vitreous. (PHPV) (Unilateral. The involved eye is usually slightly smaller than the normal fellow eye. Examination after pupil dilatation may reveal a plaque of fibrovascular tissue behind the lens with elongated ciliary processes extending to it. Progression of the lens opacity often leads to angle-closure glaucoma.)
Rubella (Nuclear cataract, “salt-and-pepper” chorioretinitis, a smaller involved eye than the normal contralateral eye. Associated hearing defects and heart abnormalities are common.) Lowe’s syndrome (oculocerebrorenal syndrome) (Opaque lens, congenital glaucoma, renal disease, and mental retardation. X-linked recessive. Patients’ mothers may have small cataracts.) Others (Chromosomal disorders, systemic syndromes, other intrauterine infections, trauma, drugs, other metabolic abnormalities.)
Differential Diagnosis
See Leukocoria, Section 9.1.
Workup
1. History: Maternal illness or drug ingestion during pregnancy? Systemic or ocular disease in the infant or child? Radiation exposure or trauma? Family history of congenital cataracts?
2. Visual assessment of each eye alone, by using illiterate E’s, pictures, or by following small toys or a light.
3. Ocular examination: Attempt to determine the visual significance of the cataract. Evaluate the size and location of the cataract and whether the retina can be seen with a direct ophthalmoscope when looking through an undilated pupil. Cataracts 3 mm or more in diameter usually affect vision. A portable slit lamp is helpful when available, as is a retinoscope (a blunted retinoscopic reflex suggests the cataract is visually significant). Check for signs of associated glaucoma (e.g., large corneal diameter, corneal edema, breaks in Descemet’s membrane) and examine the retina for abnormalities, if possible.
4. Cycloplegic refraction.
5. B-scan ultrasonography may be helpful when the fundus view is obscured.
6. Medical examination by a pediatrician looking for associated abnormalities.
7. Red blood cell (RBC) galactokinase activity (galactokinase levels) with or without RBC galactose-1-phosphate-uridyltransferase activity to rule out galactosemia. This test is performed routinely on all infants in the United States.
8. Other tests as suggested by the systemic or ocular examination: (The chance that one of these conditions is present in a healthy child is remote.) 1. Blood: Calcium and phosphorus levels (hypocalcemia, hypoparathyroidism), glucose levels (hypoglycemia, diabetes mellitus).
2. Urine: Amino acid quantitation (Alport’s syndrome), amino acid content (Lowe’s syndrome).
3. Antibody titers for rubella.
Treatment
1. Referral to a pediatrician to treat any underlying disorder.
2. Treat associated ocular diseases (e.g., glaucoma, see Congenital Glaucoma, Section 9.10).
3. Cataract extraction, usually within days to weeks of discovery to prevent irreversible amblyopia, is performed in the following circumstances:
1. Vision is obstructed, and the eye’s visual development is at risk.
2. The lens is responsible for intraocular disease (e.g., lens-related glaucoma, uveitis).
3. Cataract progression threatens the health of the eye (e.g., in persistent hyperplastic primary vitreous).
4. After cataract extraction, treat amblyopia in children younger than 9 to 11 years.
5. A dilating agent (e.g., phenylephrine, 2.5%, t.i.d., homatropine, 2%, t.i.d., or scopolamine, 0.25%, qd) may be used as a temporizing measure, allowing peripheral light rays to pass around the lens opacity and reach the retina. This rarely is successful.
6. Unilateral cataracts that are not large enough to obscure the visual axis requiring removal may still result in amblyopia. Treat amblyopia in children younger than 9 to 11 years (see Amblyopia, Section 9.6).
Follow-up
Young children that do not undergo surgery are monitored closely for cataract progression and amblyopia. Older children are less likely to develop amblyopia even if the cataract progresses; they are followed up on a 6- to 12-month basis.
Note Children with rubella must be isolated from pregnant women.
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9.8 OPHTHALMIA NEONATORUM
Purulent, mucopurulent, or mucoid discharge from one or both eyes in the first month of life, with diffuse conjunctival injection.
Other Signs
Eyelid edema, chemosis.
Etiology
Chemical [Seen within a few hours of instilling a prophylactic agent (e.g., silver nitrate), lasts no more than 24 to 36 hours. Rarely seen now that erythromycin is used routinely.]
Neisseria gonorrhoeae (May see gram-negative intracellular diplococci on Gram’s stain. Typically seen within the first few days.)
Chlamydia trachomatis (May see basophilic intracytoplasmic inclusion bodies in conjunctival epithelial cells, polymorphonuclear leukocytes, or lymphocytes on Giemsa stain. Presentation in the second week of life is common.)
Bacteria (Staphylococci, streptococci, and gram-negative species may be seen on Gram’s stain.)
Herpes simplex virus (May have typical herpetic vesicles on the eyelid margins, can see multinucleated giant cells on Giemsa stain.)
Differential Diagnosis
Dacryocystitis (Swelling and erythema of the inner canthus. Purulent discharge may be expressed from the punctum by rolling a finger from the lacrimal sac to the punctum. Nasal conjunctival injection may be present, but diffuse injection is typically not present. See Section 6.8, Dacryocystitis.)
Nasolacrimal duct obstruction (Tearing, may have a mild mucopurulent discharge from the punctum, minimal-to-no conjunctival injection or eyelid swelling. See Section 9.9, Congenital Nasolacrimal Duct Obstruction.)
Congenital glaucoma (Corneal enlargement >12.0 mm horizontally, photophobia, Haab’s stria, corneal edema, buphthalmos, tearing not discharge. See Section 9.10, Congenital Glaucoma.)
Workup
1. History: Previous or concurrent venereal disease in the mother? Were cervical cultures performed during pregnancy? If so, obtain the results.
2. Ocular examination with a penlight and then a blue light after fluorescein instillation; look for corneal involvement.
3. Conjunctival scrapings for two slides: Gram and Giemsa stain.
Technique: Irrigate the discharge out of the fornices, place a drop of topical anesthetic (e.g., proparacaine) in the eye, and scrape the palpebral conjunctiva of the lower eyelid with a flame-sterilized spatula after it cools off. Place the scrapings on the slides.
4. Conjunctival cultures for blood and chocolate agars. Chocolate agar should be placed in an atmosphere of 2% to 10% carbon dioxide immediately after being plated.
Technique: Reanesthetize the eye if necessary. Moisten a calcium alginate swab (a cotton-tipped applicator is a less-desirable alternative) with liquid broth media, and vigorously rub it along the inferior palpebral conjunctiva. Plate it directly on the culture dish. Repeat the procedure for additional cultures.
5. Scrape the conjunctiva for the chlamydial immunofluorescent antibody test.
6. Viral culture: Moisten another cotton-tipped applicator and roll it along the palpebral conjunctiva. Break off the end of the applicator and place it into the viral transport medium.
Treatment
Initial therapy is based on the results of the Gram’s and Giemsa stains, if they can be examined immediately. Therapy is then modified according to the culture results and the clinical response.
1. No information from stains, no particular organism suspected: Erythromycin ointment q.i.d. plus erythromycin elixir, * 50 mg/kg/day, for 2 to 3 weeks.
2. Suspect chemical (e.g., silver nitrate) toxicity: No treatment. Reevaluate in 24 hours.
3. Suspect chlamydia: Erythromycin elixir, 50 mg/kg/day*, for 2 to 3 weeks, plus erythromycin ointment q.i.d. If confirmed by culture or immunofluorescent stain, treat the mother and her sexual partner or partners with one of the following:
Tetracycline, 250 to 500 mg p.o., q.i.d., or doxycycline, 100 mg p.o., b.i.d., for 7 days (for men and mothers who are neither breast-feeding nor pregnant) or
Erythromycin, 250 to 500 mg p.o., q.i.d., for 7 days (for breast-feeding or pregnant women).
Note Inadequately treated chlamydial conjunctivitis in a neonate can lead to chlamydial otitis or pneumonia.
4. Suspect Neisseria gonorrhoeae: Treatment is not well established. We favor the following:
1. Hospitalize and evaluate for disseminated gonococcal infection with careful physical examination (especially of joints). Blood and cerebrospinal fluid cultures are obtained if a culture-proven infection is present.
2. One dose of ceftriaxone, 125 mg i.m., or cefotaxime, 50 mg/kg i.v. or i.m., q 8 to 12 h for 7 days. In penicillin- or cephalosporin-allergic patients, an infectious disease consult is obtained.
3. Bacitracin ointment, q 2 to 4 h.
4. Topical saline lavage to remove any discharge, q.i.d.
5. All neonates with gonorrhea should also be treated for chlamydia with erythromycin elixir, 50 mg/kg/day* for 14 days.
Note If it is confirmed by culture, the mother and her sexual partner or partners should be treated in accordance with the sensitivity results for 7 days. If sensitivities not initially available, ceftriaxone is the first choice. Additionally, chlamydia should be treated as outlined earlier.
5. Gram-positive bacteria on Gram’s stain, with no suspicion of gonorrhea and no corneal involvement: Bacitracin ointment q.i.d. for 2 weeks.
6. Gram-negative bacteria on Gram’s stain, but no suspicion of gonorrhea, and no corneal involvement: Gentamicin or tobramycin ointment q.i.d. for 2 weeks.
7. Bacteria on Gram’s stain and corneal involvement: Hospitalize, workup, and treat as for Infectious Corneal Infiltrate/Ulcer, Section 4.12.
8. Suspect herpes simplex virus: Vidarabine, 3% ointment (e.g., Vira-A) 5 times per day, then cut dosage in half for 1 week. Systemic acyclovir for systemic disease after pediatric consultation.
Follow-up
Initially, examine daily as an inpatient or outpatient. If the condition worsens (e.g., corneal involvement develops), reculture and hospitalize. As mentioned, therapy is tailored according to the clinical response and the culture results. The frequency of follow-up visits may be reduced once improvement is clearly demonstrated.
* Erythromycin elixir is divided into four doses daily and placed into the baby’s formula.
References
Ullman S, Roussel TJ, Forster RK. Gonococcal keratoconjunctivitis. Surv Ophthalmol 1987;32:199.
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The Wills Eye Manual, 3rd Ed.
CHAPTER 9 PEDIATRICS
9.9 CONGENITAL NASOLACRIMAL DUCT OBSTRUCTION
Presentation Critical Signs Other Signs Etiology
Differential Diagnosis Workup
Treatment Follow-up
Presentation
Persistent tearing, chronic mucopurulent discharge, matting of the eyelids, may be unilateral or bilateral.
Critical Signs
Wet-looking eye or tears flowing over the eyelid; moist or dried mucopurulent material on the eyelashes (predominantly medially), and reflux of mucoid or mucopurulent material from the punctum when pressure is applied over the lacrimal sac, where the lower eyelid abuts the nose.
Other Signs
Erythema (irritation) of the surrounding skin; redness and swelling of the medial canthus. Preseptal cellulitis or dacryocystitis may rarely develop.
Note Nasolacrimal duct obstruction may be associated with an otitis or pharyngitis.
Etiology
Usually the result of an imperforate membrane at the distal end of the nasolacrimal duct.
Differential Diagnosis
Conjunctivitis (Red eye, discharge. Usually acute. Follicles or papillae may or may not be present on the inferior tarsal conjunctiva. Tearing is not chronic.) Congenital anomalies of the upper lacrimal drainage system. (Atresia of the lacrimal puncta or canaliculus.)
Mucocele of the lacrimal sac (Bluish, cystic, nontender mass located just below the medial canthal angle. Caused by both a distal and a proximal obstruction of the nasolacrimal apparatus.) Other causes of tearing [e.g., entropion/trichiasis, corneal defects, foreign body under the upper eyelid, congenital glaucoma (See Section 9.10, Congenital Glaucoma).]
Workup
1. Exclude other causes of tearing with slit-lamp or penlight examination. Make sure the corneal diameter is not large, and ruptures in Descemet’s membrane are not present (congenital glaucoma).
2. Palpate over the lacrimal sac; reflux of mucoid or mucopurulent discharge from the punctum confirms the diagnosis.
Treatment
1. Digital pressure 2 to 4 times per day. The parent is taught to place his or her index finger over the child’s common canaliculus (inner corner of the eye) and to apply pressure several times a day.
2. Use erythromycin ointment b.i.d., prn, to control mucopurulent discharge if present.
3. In the presence of acute dacryocystitis, a systemic antibiotic is needed (See Section 6.8, Dacryocystitis).
The majority of cases will open spontaneously with this regimen by age 1 year. If this is not the case:
4. Nasolacrimal duct probing is usually performed after age 13 months, earlier if recurrent or persistent infections of the lacrimal system develop or at the request of the parents. The majority of obstructions will be corrected after the initial probing; others may require repeated probings. If patency is not established after two probings, place silicone tubing in the nasolacrimal duct and leave it in place for weeks to months.
Follow-up
Follow up by phone calls. The child returns if the situation becomes worse, acute dacryocystitis is present, or if the parents are unsure.
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9.10 CONGENITAL GLAUCOMA
Photophobia, tearing, enlarged cornea, hazy cornea, most commonly in an infant; red eye may be present.
Critical Signs
Enlarged globe and corneal diameter (horizontal corneal diameter >12 mm before age 1 year is suggestive), corneal edema, increased intraocular pressure (IOP), increased cup/disc ratio, commonly bilateral.
Other Signs
Linear tears in Descemet’s membrane of the cornea (Haab’s stria), usually running horizontally or concentric to the limbus; corneal stromal scarring; conjunctival injection; myopic shift in refractive error.
Etiology
Majority of cases:
Primary congenital glaucoma (Not associated with other ocular or systemic disorders.) Less common:
Sturge–Weber syndrome (Usually unilateral; may have a port-wine stain, cerebral calcifications, and seizures; not familial.) Rare:
Developmental anterior segment abnormality (e.g., Axenfeld’s syndrome, Rieger’s anomaly/syndrome, Peter’s anomaly, others) (Bilateral. Abnormalities of the cornea, iris, and anterior-chamber angle.)
Lowe’s syndrome (oculocerebrorenal syndrome) (Cataract, glaucoma, and renal disease; X-linked recessive.) Rubella (Glaucoma, cataracts, “salt-and-pepper” chorioretinopathy, hearing and cardiac defects.)
Aniridia (Iris hypoplasia, often with only a rudimentary iris stub visible on gonioscopy, cataracts, glaucoma, foveal hypoplasia, nystagmus.)
Others (e.g., neurofibromatosis, homocystinuria, persistent hyperplastic primary vitreous, secondary glaucoma from anteriorly displaced lens–iris diaphragm.)
Differential Diagnosis
Congenital megalocornea (Bilateral horizontal corneal diameter >13 mm with normal corneal thickness and endothelium. IOP and cup/disc ratio are normal.)
Trauma from forceps during delivery (May produce tears in Descemet’s membrane and localized corneal edema; however, the tears are typically vertical or oblique, and the corneal diameter is normal. Birth trauma is generally unilateral and may often be obtained from the history.)
Congenital hereditary endothelial dystrophy (Bilateral corneal edema at birth with a normal corneal diameter and normal IOP.)
Mucopolysaccharidoses and cystinosis (Some inborn errors of metabolism produce cloudy corneas in infancy or early childhood, but usually not at birth; the corneal diameter and IOP are normal.) Nasolacrimal duct obstruction (Tearing, sometimes with a mild mucopurulent discharge from the punctum. The cornea is clear and not enlarged. The IOP is normal. See Section 9.9, Congenital Nasolacrimal Duct Obstruction.)
Workup
1. History: Other systemic abnormalities? Rubella infection during pregnancy? Birth trauma?
2. Ocular examination, including a visual-acuity assessment of each eye separately (can the child fixate and follow?), a penlight examination to detect corneal enlargement and haziness, and retinoscopy to estimate refractive error. IOP measurement by Tonopen or Schiötz tonometry is attempted. A dilated fundus examination is performed to evaluate the optic disc and retina.
Examination with a retinoscope or hand-held portable slit lamp is sometimes used in uncertain cases to look for tears in Descemet’s membrane and corneal edema.
3. Examination under anesthesia (EUA) is performed in suggestive cases and in those for whom surgical treatment is planned. The horizontal corneal diameter and IOP are measured; retinoscopy, gonioscopy, and ophthalmoscopy are performed. Ultrasound is often used to measure axial length. At 40 gestational weeks, the mean axial length is 17 mm. This increases to 20 mm on average by age 1 year. Axial-length progression also may be monitored by successive cycloplegic refractions.
Note IOP may be reduced substantially by general anesthesia, particularly halothane; an IOP of ³20 mm Hg under halothane anesthesia is suggestive of glaucoma. An exception is ketamine hydrochloride, which may increase IOP. In general, IOP is measured as soon as possible after general anesthesia is induced to achieve as accurate a measurement as possible.
Treatment
Definitive treatment is usually surgical. Medical therapy is temporary and is started initially, pending surgery.
Medical (any or all of the following may be used.)
1. Topical b-blocker (e.g., levobunolol or timolol, 0.25% to 0.5%, b.i.d.).
2. Carbonic anhydrase inhibitor (e.g., acetazolamide, 5 to 10 mg/kg p.o., q 6 h).
Note Miotics are rarely effective in controlling and may increase IOP, but they sometimes are used to constrict the pupil in preparation for a surgical goniotomy.
Surgical First choice, goniotomy (incising the trabecular meshwork with a blade under gonioscopic visualization) or trabeculotomy (opening Schlemm’s canal into the anterior chamber). These procedures are often repeated if they are unsuccessful at first attempt.
Other Trabeculectomy.
Note Amblyopia may be superimposed on glaucoma and should be treated by patching (see Section 9.6, Amblyopia).
Follow-up
Repeated examinations, under anesthesia when needed, are necessary to monitor corneal diameter, IOP, cup/disc ratio, and axial length. These patients must be followed up throughout life to monitor for progression.
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The Wills Eye Manual, 3rd Ed.
CHAPTER 9 PEDIATRICS
9.11 DEVELOPMENTAL ANTERIOR SEGMENT AND LENS ANOMALIES
Workup Treatment Follow-up
Unilateral or bilateral congenital abnormalities of the cornea, iris, anterior-chamber angle, and lens. Specific entities include the following:
Megalocornea (A nonprogressive corneal enlargement. The horizontal corneal diameter is >13 mm in the newborn. There are two types:
1. Simple megalocornea: Bilateral, clear corneas of normal thickness; sporadic or autosomal dominant.
2. Anterior megalophthalmos: Bilateral; associated with abnormalities of the iris, angle, and lens; may be associated with glaucoma; X-linked recessive.)
Microcornea [Horizontal corneal diameter <11 mm. May be isolated or associated with nanophthalmos (a small globe that is otherwise anatomically normal) and microphthalmos (a small globe with multiple anomalies).]
Posterior embryotoxon (A prominent, anteriorly displaced Schwalbe’s ring. A normal variant.)
Axenfeld’s anomaly (Posterior embryotoxon associated with iris strands that span the angle to insert into the prominent Schwalbe’s ring. Fifty to sixty percent of patients develop glaucoma.
Autosomal dominant or sporadic.)
Rieger’s anomaly (Axenfeld’s anomaly plus iris thinning and abnormally shaped and displaced pupils. Fifty to sixty percent of patients develop glaucoma. Autosomal dominant or sporadic.) Rieger’s syndrome (Rieger’s anomaly associated with dental, craniofacial, and skeletal abnormalities. May be associated with short stature caused by growth hormone deficiency, cardiac defects, deafness, and mental retardation. Autosomal dominant or sporadic.)
Peter’s anomaly [Central corneal opacity, usually with iris strands that extend from the iris collarette to the margin of the corneal defect. The lens may be clear and normally positioned, cataractous and displaced anteriorly (making the anterior chamber shallow), or adherent to the corneal defect.]
Microspherophakia (The lens is small and spherical in configuration. The lens can subluxate into the anterior chamber, causing a secondary glaucoma.)
Anterior and posterior lenticonus (An anterior or posterior ectasia of the lens surface. Posterior occurring more commonly than anterior. Often associated with cataract. Usually unilateral.) Ectopia lentis (May be associated with Marfan’s syndrome, homocystinuria, Weill–Marchesani syndrome, aniridia, and trauma. Simple ectopia lentis is either a sporadic or autosomal dominantly inherited condition with bilateral, usually superior, lens displacement. Glaucoma may occur because of displacement of the lens–iris diaphragm.)
Ectopia lentis et pupillae (Lens displacement associated with pupillary displacement in the opposite direction. Glaucoma may occur. Autosomal recessive.)
Aniridia (Bilateral, near-total absence of the iris. The pupil appears to occupy the entire area of the cornea. Glaucoma, foveal hypoplasia with poor vision, nystagmus, and corneal pannus can occur. At least two inheritance patterns are known to exist:
1. Autosomal dominant in two thirds of patients. This type is not associated with Wilms’ tumor.
2. Sporadic in one third of patients. Twenty-five percent of children with sporadic aniridia will develop Wilms’ tumor.)
Workup
1. History: Family history of ocular disease? Associated systemic abnormalities?
2. Complete ophthalmic examination, including gonioscopy of the anterior-chamber angle and intraocular pressure (IOP) determination (may require examination under anesthesia [EUA]).
3. Complete physical examination by a primary care doctor with blood pressure determination (may be elevated with renal abnormalities).
4. Chromosomal karyotype in patients with sporadic cases of aniridia. (There is an increased incidence of Wilms’ tumor in patients with a deletion of the short arm of chromosome 11.) 5. Renal ultrasound and possibly intravenous pyelography in patients with sporadic aniridia to monitor for Wilms’ tumor. The frequency and duration of monitoring should be determined by a
pediatrician and/or pediatric oncologist. One suggested schedule is to evaluate every 3 months up to age 5, and then every 6 months up to age 10, and then once per year up to age 16.
Treatment
1. Correct refractive errors and treat amblyopia if present (see Section 9.6, Amblyopia). Children with unilateral structural abnormalities often have improved visual acuity after amblyopia therapy.
2. Treat glaucoma if present. b-Blockers and carbonic anhydrase inhibitors may be used. Pilocarpine and epinephrine compounds are not as effective and are not used in primary therapy (see Primary Open-Angle Glaucoma, Section 10.1). Surgery is often used initially (see Congenital Glaucoma, Section 9.10).
3. Consider cataract extraction if a significant cataract exists and a corneal transplant if a dense corneal opacity exists.
4. Genetic counseling.
5. Systemic abnormalities (e.g., Wilms’ tumor) are managed by pediatric specialists.
Follow-up
1. Ophthalmic examination every 6 to 12 months throughout life, checking for increased IOP and other signs of glaucoma.
2. If amblyopia exists, then follow-up may need to be more frequent (see Section 9.6, Amblyopia)
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9.12 THE BLIND INFANT
Workup Treatment
An infant whose visual skills are far below those expected (e.g., an inability to fix on and follow objects after several months of age) may have an obvious or inconspicuous ocular or neuro-ophthalmic disorder. Obvious causes include bilateral central corneal opacities, congenital cataracts, or infectious retinal problems with macular scarring. The following are conditions that may not be obvious on clinical examination.
1. Conditions that usually produce a searching nystagmus:
1. Pupils react poorly to light:
Any severe ocular disease or malformation [e.g., retinopathy of prematurity (ROP), cataracts, aniridia, optic nerve atrophy, optic nerve hypoplasia] diagnosed by examination.
Leber’s congenital amaurosis [May have a normal-appearing fundus initially, but by age 1 to 3 years, may develop narrowing of retinal blood vessels, optic disc pallor, and pigmentary retinal changes. The electroretinogram (ERG) is markedly abnormal or flat. Autosomal recessive.]
Optic nerve hypoplasia [A small optic disc that can be difficult to detect when bilateral (compare disc to vessels). If unilateral, may be seen with strabismus, a relative afferent pupillary defect, and unilateral poor fixation instead of searching nystagmus. When present, a “double ring” sign (a pigmented ring at the inner and outer edge of peripapillary atrophy) is diagnostic. Usually idiopathic, but can be a result of maternal diabetes or quinine, phenytoin, alcohol, or lysergic acid diethylamide (LSD) use.]
Note Optic nerve hypoplasia is rarely associated with septo-optic dysplasia (de Morsier syndrome), which includes midline abnormalities of the brain and growth, thyroid, and other tropic hormone deficiencies. Growth retardation, seizures as a result of hypoglycemia, and diabetes insipidus may develop.
Congenital optic atrophy (Rare. Pale, normal-sized optic disc, often associated with mental retardation or cerebral palsy. Normal ERG. Autosomal recessive or sporadic.)
Congenital stationary night blindness (Visual acuity may even be normal, nystagmus less common, associated with myopia. ERG is abnormal. Autosomal dominant, recessive, and X-linked forms exist.)
2. Pupils react briskly to light:
Infantile nystagmus (Some patients with this condition have a severe visual deficit. The iris is normal. It may be accompanied by face turn, head nodding, or both.) Albinism with delayed maturation (Iris transillumination defects and foveal hypoplasia are seen.)
2. No nystagmus present and pupils react normally to light:
Diffuse cerebral dysfunction (Infants do not respond to sound or touch and are neurologically abnormal. Vision may slowly improve with time.)
Delayed maturation of the visual system (Normal response to sound and touch, and neurologically normal. The ERG is normal, and vision usually develops between age 4 and 12 months.) Extreme refractive error (Diagnosed on cycloplegic refraction.)
Achromatopsia (Rod monochromatism) (Pupils react normally to light but have paradoxical pupils. Normal fundus, but photopic ERG is markedly attenuated or nonrecordable. Scotopic ERG is normal.)
Workup
1. History: Premature? Normal development and growth? Maternal infection, diabetes, or drug use during pregnancy? Family history of eye disease?
2. Evaluate the infant’s ability to fixate on an object and follow it with each eye individually (cover one eye and then the other).
3. Pupillary examination, noting both equality and briskness.
4. Look carefully for nystagmus.
5. Penlight examination of the anterior segment; check especially for iris transillumination defects with a slit lamp.
6. Dilated retinal and optic nerve evaluation.
7. Cycloplegic refraction.
8. ERG, especially if Leber’s congenital amaurosis is suspected.
9. Consider a CT scan and/or MRI of the brain in cases with other focal neurologic signs, seizures, failure to thrive, developmental delay, optic nerve hypoplasia, optic atrophy, or neurologically
9. Consider a CT scan and/or MRI of the brain in cases with other focal neurologic signs, seizures, failure to thrive, developmental delay, optic nerve hypoplasia, optic atrophy, or neurologically