Ординатура / Офтальмология / Английские материалы / Primary Care Ophthalmology_Palay, Krachmer_2005

FIGURE 13–4 Blocking of the red reflex by a cataract as viewed with the direct ophthalmoscope. Note the uniform orange glow around the edges of the cataract. The opacity blocks the red reflex in the center of the pupil.

FIGURE 13–5 Sunsetting. Intermittent downward deviation of the eyes occurs when lights are dimmed.

a whitish appearance of the pupil on penlight or room light examination, usually differs between the two eyes, and generally is associated with the absence of any light reflex when the direct ophthalmoscope is used to check the red reflex. The key to judging responses as normal is symmetry and uniformity across the entire reflex (Fig. 13–4).

Sunsetting, a tonic or intermittent downward deviation of the eyes (Fig. 13–5), may be benign in babies, especially those born prematurely, if it is intermittent and persists for only a few weeks. If the sunsetting is constant or associated with poor feeding, nausea, vomiting, lethargy, bulging fontanelle, or abnormal head circumferences on a growth chart, or if it develops suddenly in an infant who never exhibited it before, it may be a sign of increased intracranial pressure and mandates immediate referral to an ophthalmologist and/or neurologist to prevent permanent brain and optic nerve damage or even death.

If the child is growing well and the fontanelle is flat, but the sunsetting is persistent, it often is a sign of periventricular leukomalacia or other pathologic brain conditions. The risk of cerebral palsy is high in such children, and referral to a pediatric ophthalmologist is indicated.

A B

FIGURE 13–8 A, In this example of esotropia, the light reflex is off the center of the pupil in a temporal direction in the right eye. This child has congenital esotropia; both eyes are affected, but the fixating eye appears straight. B, Shortly after eye muscle surgery, the corneal light reflexes are centered on both pupils.

A B

FIGURE 13–9 Intermittent exotropia. A, The light reflex is off the center of the pupil in a nasal direction in the left eye when this child fixates in the distance. B, At near distance, control is better in exotropia, eyes are straight, and corneal light reflexes are centered.

FIGURE 13–10 Pseudoesotropia. The eyes appear crossed because of large epicanthal skin folds (1) covering the sclera

(2). This finding is normal before the nasal bridge develops fully. The corneal light reflexes are centered, proving the eyes are actually straight.

be difficult to elicit in the primary care office, so a suggestive history should prompt an ophthalmology referral.

The examination of the location of the pupillary light reflex to detect strabismus is the quickest and easiest method. Cover testing requires more practice and patience but is superior for detecting many types of strabismus (see Fig. 13–6). Fixation on a target is essential, and because children’s attention spans are short, many toys for distance and near testing are needed. This is a standard setup in the pediatric ophthalmology office, but it may not be available for most primary care practitioners. Although children view these toys as simply being entertaining, accurate testing is impossible without them.

For cover testing, the child sits in the parent’s lap. The clinician shows a toy at near distance and asks the child to touch or describe it to be sure fixation is occurring. One

FIGURE 13–12 Vision testing. Children often peek around standard occluders, especially if their better eye is covered.

FIGURE 13–13 An adhesive patch prevents peeking during vision testing.

years, but 20/20 to 20/30 for all ages at near distance. A vision measurement less than this or any difference in values between the eyes suggests a need for referral. In children older than 5 years, distance vision should be 20/20. For Allen cards, cards should be identified all the way to 20 feet; most Allen cards test to only 20/30, because children young enough to be illiterate generally read at only 20/30, not 20/20 at distance.

Once children know numbers, a standard number chart can be used. Letters give the greatest accuracy, and once a child is old enough to read letters, attention usually is sufficient to cooperate with testing using a chart at the end of the room. Sometimes having a parent point to each letter helps with attention and accuracy.

The importance of using an adhesive occlusive patch rather than an occluder or covering eye with a hand or other device cannot be overemphasized. If one eye sees poorly, children will peek with the other eye in order to give the right answers (Figs. 13–12 and 13–13). Only an adhesive occlusive patch prevents this.

Photoscreening is a more recent technology available to primary care offices. Flash photographs of children’s eyes are taken to detect opacities, refractive errors, and strabismus. Although extremely useful in many cases, especially refractive amblyopia, photoscreening should be used as a well-child screening test, not an examination

Conjunctivitis 239

FIGURE 13–14 Use of a lid speculum. An assistant holds the child snugly, especially the child’s arms. Keeping gentle pressure on both sides of the speculum with one hand to compress it, the clinician uses the other hand to elevate the upper lid and slide one lip under. Without allowing the speculum to spring open, the lower lid is pulled down and the other lip is slid under this lid. Next, pressure is removed from the speculum so that it will open the lids. A drop of proparacaine or tetracaine may be used in each eye before insertion. The procedure is not painful, but it is frightening to parents and child and reassurance is necessary.

•Eyelids may adhere when the child awakens.

•Eyelids may be erythematous or excoriated.

•Preauricular lymph node may be palpable.

Differential Diagnosis

Before 1 Week of Age

In infants younger than 1 week of age, diagnostic possibilities include the following:

•Toxic conjunctivitis from perinatal prophylaxis: The infant usually is initially seen with red lids and watery discharge.

•Infectious disorders (usually acquired in the birth canal): Most often staphylococci, Chlamydia, herpesviruses, and Neisseria gonorrhoeae are the infectious agents. The infant initially is seen with quiet lids and mucopurulent discharge, but symptoms can appear identical to those of toxic conjunctivitis. If discharge is purulent and excessive (so-called hyperacute), gonorrhea is possible. Emergency referral to an ophthalmologist is required, because blindness can result within 24 to 48 hours if the infection is not treated (Fig. 13–15). Systemic antibiotic treatment is also required.

•Children born at home may not receive appropriate prophylaxis and are at particular risk for infectious conjunctivitis.

After 1 Week of Age or with Community Exposure

In infants older than 1 week or those with community exposure, considerations in the differential diagnosis include the following:

•Viral infections: Especially with adenovirus or respiratory syncytial virus infections, massive lid swelling may be present in infants, simulating cellulitis. An enlarged preauricular node or upper respiratory infection often is present.

•Nasolacrimal duct obstruction: If the conjunctivitis is chronic and in particular unilateral, duct obstruction should be considered.

240 CHAPTER 13 • Pediatric Ophthalmology

FIGURE 13–15 Hyperacute gonorrheal conjunctivitis.

Immediate institution of topical and systemic antibiotic therapy is needed to prevent blindness.

•Congenital glaucoma: If manifestations include photophobia, an enlarged cornea, and, in particular, watery and chronic discharge, this disorder must be ruled out or confirmed. Congenital glaucoma necessitates immediate ophthalmologic referral and treatment.

Treatment

•In infants younger than 1 week of age with red lids and a watery discharge, toxic etiology is likely. All eye medications are ceased, conjunctival culture is obtained, and the infant is observed for 24 to 48 hours. If no improvement is seen after 48 hours or discharge is mucopurulent, antibiotic drops (e.g., polymyxin B/trimethoprim [Polytrim], 1 drop 3 to 4 times a day or erythromycin ointment 4 times a day) are administered. If one of these agents was used for prophylaxis, it should not be readministered, because it may have been a causative factor. If the infant’s condition does not improve in 48 hours, routine bacterial cultures, as well as Chlamydia culture, should be performed. An ophthalmologist is consulted for these studies and further workup. Systemic antibiotics are required for Chlamydia infection due to the risk of pneumonia.

•If the discharge is hyperacute, Gram stain and culture (including chocolate agar) are indicated to look for gonorrhea; the infant receives presumptive treatment for gonorrhea with intravenous cefotaxime (Claforan) 50 mg/kg/dose every 12 hours for 7 days. The eyes should be irrigated with saline every 10 to 30 minutes, gradually decreasing to every 2 hours until the purulent discharge clears. Hospital admission and an ophthalmologic consultation should be done immediately. Gonorrhea can penetrate an intact cornea rapidly, causing blindness. The mother also is tested.

•If cultures, PCR assay, or stains reveal Chlamydia organisms, systemic as well as topical treatment is indicated because of the risk of pneumonia. The mother should also be tested.

•If Haemophilus influenzae is recovered, systemic treatment is given. Infection with this organism often proves refractory to topical treatment and is associated with a high risk for development of cellulitis and meningitis.

Nasolacrimal Duct Obstruction

Symptoms

•Usually no symptoms result from the obstruction, but patients may have irritation of the eyelids and conjunctiva if the condition is longstanding or bacterial superinfection is present (Fig. 13–16).

•Nasal stuffiness or respiratory distress if mucocele with nasal cyst is present.

Signs

•The obstruction usually is bilateral but asymmetrical.

•The tear lake usually is elevated, and the lashes look wet.

•With bacterial superinfection, a chronic mucopurulent discharge occurs, and the eyelids adhere in the morning. Later in the course, the periorbital skin becomes thickened and excoriated, and the conjunctiva becomes injected.

•A bluish mass beneath the medial canthal tendon on the side of the nose may be present with mucocele.

Etiology

•Most cases result from failure of the valve of Hasner to open; however, absence of the puncta or other anomalies of the system also may be factors preventing drainage (Fig. 13–17).

•The origin usually is idiopathic, and the disorder is very common.

Associated Factors and Diseases

•Infants with syndromes involving midface hypoplasia, clefting, craniosynostosis, trisomy 21, and mass lesions such as dermoids of the canthal area are at increased risk.

Workup

•To differentiate between conjunctivitis and nasolacrimal duct obstruction, the examiner presses a cotton-tipped swab firmly over the lacrimal sac while observing the puncta (Fig. 13–18). If a reflux of mucopurulent material is seen, the diagnosis is nasolacrimal duct obstruction, not solely conjunctivitis.

FIGURE 13–16 Chronic nasolacrimal duct obstruction with bacterial superinfection. This child has been treated with topical and systemic antibiotics without resolution. If nasolacrimal duct obstruction is present, infection will not clear without probing. Note skin changes. All signs resolved 24 hours after probing.