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

than the original injury. The pH may be tested with a standard pH strip on the conjunctiva to gauge the effectiveness of irrigation.

Follow-up

•Prevention is the best treatment, so children should be advised to wear polycarbonate safety goggles for sports and other high-risk activities. BB guns and paintball weapons are major causes of severe eye injuries in children. Bungee cords, golf clubs, and small sports balls such as racquet balls are other common causes of severe injuries.

Preseptal and Orbital Cellulitis

Symptoms

•Preseptal cellulitis: Erythema, warmth, and swelling of the eyelids are noted.

•Orbital cellulitis: Irritability, lethargy, decreased vision, high fever, and a more toxic appearance are present.

Signs

Preseptal Cellulitis

•The skin of the eyelids is red and swollen, with sharply circumscribed or diffuse areas of involvement.

•Conjunctival injection may be present.

•Mucopurulent discharge from the nasolacrimal system may occur if this is the source of infection.

Orbital Cellulitis

•All of the signs as described for preseptal cellulitis are present.

•Small or diffuse areas of infection may be associated with marked motility disturbance.

•Proptosis (a pushing of the eyeball forward because of a mass of infection behind the globe) may develop, depending on the location of the infection

•A large focus of pus accumulates near the optic nerve, causing the nerve to begin to lose function, a decrease in vision, a sluggishly reactive pupil, and a possible afferent pupillary defect.

Etiology

Cellulitis can result from the following:

•Ethmoid or maxillary sinus disease

•Lacerating trauma around the eye

•Bacterial infection with nasolacrimal duct obstruction

•Buccal mucosa infection

•Stye or chalazion

•Note: Because the orbital septum in children is extremely thin and does not provide a good barrier against infection from the anterior skin surface, preseptal cellulitis

Headache 265

Symptoms

•Headaches occur.

•Vision may be blurred or decreased.

Signs

• Usually, no signs are present.

Differential Diagnosis

•Migraine: Severe unilateral or bilateral headache, especially if associated with nausea or vomiting and relieved only by sleep, often is a migraine. The onset in most cases is in early childhood. The classic scintillating scotoma or wavy lines across the field of vision occur in only a minority of patients. A history of this phenomenon, however, is almost diagnostic for migraine. Often, a family history of migraine headaches is reported. Before the age of puberty, boys and girls experience migraines with equal frequency. After puberty, the incidence of migraines decreases in boys but increases in girls. Thus, a hormonal etiology is suspected.

•Tension or stress headaches: Often present in children, tension or stress headaches are generally not as prolonged as a migraine. They often occur toward the end of the day at school and are relieved by acetaminophen or aspirin. Children may associate them with reading, but questioning will often reveal that only one specific subject in school precipitates the headache.

•Increased intracranial pressure: If a headache is chronic and unremitting, does not subside with sleep or any medication, and is worse in the morning or associated with decreased vision, nausea or vomiting, double vision, or crossing of the eyes, increased intracranial pressure must be suspected. If the child is young enough, head circumference plots should be reviewed. In older children, a careful history is needed and physical examination performed for precocious puberty, ataxia, weight loss, and altered mental status and signs of craniopharyngioma and posterior fossa tumors. A funduscopic examination to detect papilledema (an elevation of the optic nerve, often with hemorrhage on the nerve [Fig. 13–28]) should be performed. If these signs or symptoms are present, the case should be referred to an ophthalmologist and/or neurologist or neurosurgeon as an emergency.

Treatment

•In cases of apparent migraine, triggers should be identified. These often include certain foods such as chocolate, uncorrected refractive error, skipping of meals, lack of sleep, and menstruation. If the headaches still persist once all triggers have been addressed, many appropriate medications are available. They must be used with care in children, and consultation with a pediatric neurologist may be indicated.

•In cases of milder, possibly tension-related headaches, stress-reducing activities are emphasized. Parents and children often perceive that the child’s eyes are the source of the problem in tension headaches. The only ocular problems that cause headaches are uncorrected astigmatism of high degree, severe hyperopia in older children, iritis, and convergence insufficiency. If vision complaints accompany the headaches, examination by a pediatric ophthalmologist is warranted.

266 CHAPTER 13 • Pediatric Ophthalmology

FIGURE 13–28 Elevated optic nerve head (papilledema) in a child who had a headache for 1 week, otitis media, and transverse sinus thrombosis from mastoiditis. Symptoms and signs resolved with serial lumbar puncture, antibiotic administration, and heparin therapy.

Styes and Chalazia

Symptoms

•Usually no symptoms are noted, but evidence of mild pain or discomfort may be present.

•In rare cases, vision is blurred as a result of induced astigmatism.

Signs

•An elevated, slightly tender, bright red nodule is present on the outer lid surface, or a very erythematous circumscribed area on the conjunctival lining of the inner eyelid is evident in the early stages (see Fig. 4–16).

•In later stages, the lesion becomes nontender but remains round and very firm, loses its reddish color, but does not disappear (see Fig. 4–17).

Differential Diagnosis

•In children, lesions of this type almost always are hordeola (styes), which is the acute phase, or chalazia, which is the chronic phase.

•In rare cases, basal cell or other types of cancer are present.

•In children with neurofibromatosis, a neuroma of the eyelid can develop.

•The lesions of molluscum contagiosum usually are much smaller than styes and have an umbilicated center.

•The lesions of tuberous sclerosis usually are not confined to the lids and can thus be differentiated.

Treatment

•For styes (hordeola), rapid institution of very warm compresses used for 15 to 20 minutes several times a day with or without topical erythromycin ointment in the

Strabismus 267

eye often brings about resolution. Children who are predisposed to styes and chalazia get them repeatedly unless lid hygiene is practiced. This involves using commercially available eye scrub pads or baby shampoo on a warm, wet washcloth to scrub along the base of the eyelashes daily. The meibomian glands, which open near the base of the eyelashes, become plugged in persons who have thick secretions, causing the stye. In older children and adolescents in whom tetracycline may be used safely without damaging the teeth, a regimen of oral tetracycline or doxycycline usually is very effective when recurrent hordeola are resistant to daily lid scrubs.

•For chalazia, warm soaks, antibiotics, and scrubs usually are not effective. Chalazia must be removed by an ophthalmologist. In older, cooperative children, this procedure can be performed in the office setting with use of local anesthesia. For very young children, removal requires anesthesia in the operating room. Large chalazia can cause refractive errors, specifically astigmatism. Thus in young children, these lesions should be treated aggressively, and if vision is decreased, an ophthalmologic consultation is needed.

Strabismus

The peak occurrences of benign esotropia are before 6 months of age (congenital) and between 2 and 4 years (accommodative). Congenital exotropia is rare; intermittent exotropia is quite common. It often is seen fleetingly in the first year of life; in one third of affected children, the episodes of exotropia increase in frequency during early childhood and adolescence.

Symptoms

•Double vision and loss of depth perception are initial symptoms. Very young children usually are not aware of either symptom. Blindness (amblyopia) evolves slowly in many cases if strabismus is not treated.

Signs

•The pupils of the eye are misaligned.

•In esotropia, one or both eyes are deviated inward.

•In exotropia, one or both eyes are deviated outward.

•In hypertropia, one eye is deviated upward.

•In some types of strabismus, one or both eyes cannot move fully in one or more directions.

Differential Diagnosis

Considerations in the differential diagnosis depend on the form of strabismus.

With Acute Acquired Esotropia

•Increased intracranial pressure causing sixth nerve palsy or paresis

•Acute viral sixth nerve palsy

•Accommodative esotropia

•Undetected congenital esotropia

268 CHAPTER 13 • Pediatric Ophthalmology

With Acute Acquired Exotropia

•Acute third nerve palsy

•Intermittent exotropia with a breakdown of fusion

•Undetected congenital exotropia

With Vertical Misalignment of Eyes

•Acute fourth nerve palsy

•Decompensated congenital fourth nerve palsy

•Partial third nerve palsy

•Dissociated vertical deviation in a child who had a congenital horizontal misalignment

•Other congenital eye muscle syndromes

Treatment

•All patients with strabismus should be immediately referred to an ophthalmologist.

•Treatment varies with the form of strabismus.

Esotropia

If the cause is sixth nerve paresis from increased intracranial pressure, normalization of intracranial pressure, either medically or accomplished with neurosurgery, generally results in resolution of the sixth nerve palsy within 6 months. Amblyopia therapy is needed during this time. Any sixth nerve palsy that does not resolve within 6 months after the insult requires eye muscle surgery.

Viral sixth nerve palsies usually disappear spontaneously once the underlying illness resolves; however, amblyopia therapy during and after the paresis often is necessary in young children.

Accommodative esotropia is the most common cause of eye crossing in children 2 to 4 years of age and usually is caused by uncorrected hyperopia (Fig. 13–29). These children require cycloplegic refraction by a pediatric ophthalmologist and must wear their spectacles all the time. As the eye grows, the hyperopia often decreases. In some children, the prescription strength can be decreased over time with monitoring by serial examinations, and glasses may not be required for straight eyes by approximately 9 years of age. If the glasses are not worn, permanent esotropia requiring surgical correction and amblyopia causing blindness of one eye usually result. Some children also require a bifocal to correct crossing at near distance. Contact lenses, rather than spectacles, may be used in some cases but are difficult to manage in young children. Refractive surgery in young children with this condition is controversial and is currently under study.

Exotropia

Intermittent exotropia may be treated with eye exercises, glasses, or surgical correction, depending on the patient’s age, frequency of deviation, magnitude of deviation, refractive error, and other considerations.

Third nerve palsy exotropia is extremely difficult to treat. Surgery often can improve cosmetic alignment, and intensive patching therapy for amblyopia is required, but normal movement of the eyes and use of the eyes together usually cannot be achieved.

Amblyopia 269

A B

FIGURE 13–29 A, Accommodative esotropia. In this child, fixation with the right eye is preferred; the pupillary light reflex is temporal to the center of the pupil in the left eye because it is crossing in. Vision was not normal even in the right eye because of severe hyperopia. B, After the child started wearing spectacles with full hyperopic correction, the eyes are straight (i.e., pupillary light reflexes are centered), corrected vision is 20/20 in each eye, and stereopsis (depth perception) returned to normal. Such good outcome is possible only if glasses are quickly prescribed once crossing begins.

Hypertropia

Acute fourth nerve palsy may be a viral entity or a disorder secondary to an intracranial pathologic disease. Prompt referral to an ophthalmologist is recommended.

Decompensated congenital fourth nerve palsy should be treated if the child demonstrates a significant head tilt. The treatment of choice is surgery. Exercises do not help this condition, although concomitant exercises for the foreshortened neck muscles may be necessary. Rarely, surgical correction of the torticollis is necessary if the neck does not straighten after the eye muscle surgery has been performed. In other vertical muscle palsies and abnormalities, correction is more complex and beyond the scope of this chapter.

Amblyopia

Symptoms

•Vision is decreased in one eye, typically to the range of legal blindness (20/200).

•The amblyopia is bilateral in some cases.

•When the disorder is unilateral, children rarely complain or notice the visual deficit.

270 CHAPTER 13 • Pediatric Ophthalmology

Signs

•In some cases, no signs occur. The eyes appear normal. Visual acuity is found to be decreased on standardized testing, provided that the fellow eye is completely occluded to prevent peeking.

•Strabismus is possible, with the poorly seeing eye turning inward in very young children and outward in older children. Decreased stereopsis can be detected on standard testing for the condition.

•In rare cases, an afferent pupillary defect is present in the affected eye.

Differential Diagnosis

The diagnostic possibilities depend on whether vision is decreased in one or both eyes.

With Severely Decreased Vision in One Eye

•Amblyopia

•Refractive error

•Abnormality of the retina or optic nerve

•Cataract

•Malingering

With Bilateral Decreased Vision

When the deficit is bilateral, the visual acuity often is reduced in both eyes to the 20/200 range; nystagmus is present if the deficit occurred within the first 3 months of life and absent if the deficit occurred later.

•Bilateral refractive errors

•Bilateral amblyopia

•Bilateral optic nerve or retinal dysfunction

Treatment

•The mainstay of treatment is early correction of the underlying cause, followed by patching of the better eye under a strictly prescribed regimen appropriate for the child’s age.

•Deprivation amblyopia is seen in patients with congenital cataracts, hemangiomas of the eyelid, severe congenital ptosis, and corneal leukomas. If this condition is present at birth, it must be completely corrected, including optical correction, before 3 to 4 months of age for the child to have any potential for normal vision. This type of amblyogenic factor generally must be picked up by the pediatrician on the baby’s nursery exit examination or at a well-baby checkup.

•Amblyopia resulting from uncorrected refractive error is a very common type of amblyopia that often is undiagnosed until the child is too old for the most effec-

tive treatment. This condition is missed because the refractive error occurs in only one eye or because the refractive error is much greater in one eye than in the other. The brain favors the better-seeing eye unless spectacles or contact lenses are prescribed. Usually the eyes stay straight and appear normal. Only careful testing for a difference in brightness on the red reflex test, with photoscreening, or reading of an eye chart in verbal children with complete occlusion of the better eye can detect

this type of amblyopia. Spectacle or contact lens correction is sufficient if the condition is detected early and the amblyopia is mild. If the amblyopia is detected later, patching of the fellow eye also must be instituted. If both eyes have equal, high refractive errors and glasses are not worn before the age of 8 or 9 years, vision will never be perfect because of bilateral refractive amblyopia.

•Strabismic amblyopia is caused by the underlying esotropia, exotropia, or vertical deviation. Because the brain cannot process two images at once, it ignores one image, and one eye loses the ability to see. Again, timing of diagnosis and treatment is critical. If strabismus is present from birth and amblyopia begins very early, complete correction is not possible unless treatment is started within the first months or years of life. If the strabismus begins between 2 and 4 years of age and is rapidly corrected, no amblyopia may result. The longer the amblyopia is untreated, the more severe and harder to reverse it becomes. Generally, refractive and strabismic amblyopia can be effectively treated up to the age of 9 years, whereas deprivation amblyopia does not have a good outcome after a child is 4 months to a year old in most cases. Strabismus must be treated before children reach 2 years of age for them to have the best chance of regaining stereopsis. Despite these guidelines, some children have better outcomes than expected, even at advanced ages. Therefore, if parents and child are interested in treatment, it may be attempted even after the age for optimal outcome.

•Organic amblyopia results from an anatomic abnormality of the eye, such as dragging of the retina in retinopathy of prematurity, coloboma, and optic nerve hypoplasia. The potential for vision in the eye is not 20/20; however, amblyopia therapy must be instituted shortly after birth for the patient to attain the best possible vision.

Refractive Errors

Symptoms

•Vision is decreased.

•Eye strain sometimes occurs.

•Diplopia may be present.

Signs

•Squinting is observed.

•Blinking of the eyes is excessive.

•The child rubs the eyes.

•The child performs poorly on tasks requiring good distance vision at school.

•The child has poor tolerance for extended periods of reading.

Differential Diagnosis

Although refractive errors are the cause of decreased vision in a majority of cases, other diagnostic possibilities include the following:

•Midline brain tumors that compress the optic chiasm

•Tumors of the optic nerves

272CHAPTER 13 • Pediatric Ophthalmology

•Optic neuritis

•Iritis

•Retinal degenerations

•Corneal dystrophies

•Developmental cataracts

Workup

•Any child who fails a vision screening test or whose parents have noted evidence of decreased vision should be referred for a complete ophthalmologic examination and cycloplegic refraction. This test objectively measures refractive errors and does not rely on a child’s answers to a vision test. It also allows for close examination of the optic nerve and retina. Because many progressive disorders result in few signs initially, all children who have decreased vision that is not immediately improved to normal with spectacles should be monitored closely for the development of neurologic and other signs.

•An ophthalmologist should determine the need for glasses in infants using the retinoscope and dilation with cyloplegic drops.

Treatment

•Not all refractive errors in children need to be treated. Unless associated with esotropia, small amounts of hyperopia do not mandate treatment. Minimal myopic correction or correction for small amounts of astigmatism need not be instituted until children begin school.

•High refractive errors are associated with bilateral amblyopia and developmental delays, particularly delayed walking. In these children, spectacle correction should be immediate.

•Because the natural developmental desire is to see clearly, glasses are readily accepted and worn by infants if the refractive error significantly interferes with vision. Even small infants keep them on and search for them if the glasses markedly improve vision and fit comfortably. Often an infant who has been wearing glasses appropriately will become less tolerant of wear, which usually indicates that the prescription should be changed and mandates another referral to the pediatric ophthalmologist. The eye grows very rapidly during infancy, and lenses may need to be changed every 3 to 6 months for the first 2 years of life. Slightly less frequent changes in lenses are needed over the next couple of years. After a child is 4 years of age, yearly examinations are usually acceptable.

•Refractive errors have a genetic basis, although they usually do not follow simple mendelian inheritance patterns. Thus if parents have high refractive errors, children should be seen at an early age to rule out or confirm refractive errors. All children who wear glasses should be questioned about sports participation and should have a separate pair of prescription wrap-around safety goggles for sports.

•Topical medications that may slow the progression of myopia have shown efficacy in animal models and are in clinical trials, but such agents are not yet available commercially.