Hospital for Sick Children's, The: Atlas of Pediatric Ophthalmology & Strabismus, 1st Edition

4

Conjunctiva

Alex V. Levin

Thomas W. Wilson

David Rootman

Jerome Kazdan

The conjunctiva is derived from surface ectoderm and has an important role in maintaining ocular surface integrity. Goblet cells within the conjunctiva provide the inner layer of the trilaminar tear film for lubrication and surface wetting. Tumors of the conjunctiva are often benign but must be observed for possible malignant transformation. Conjunctival findings may assist in the diagnosis of systemic diseases, and conjunctival biopsy can be a useful diagnostic tool. As the conjunctival epithelium is contiguous with the corneal epithelium and vascular supply to the limbus is brought in part by the conjunctiva, it is not uncommon for conjunctival disease to coexist with corneal disease or anterior segment inflammation (iritis).

The conjunctiva also extends upward and downward to form the superior and inferior fornices where it reflects out onto the inner surface of the lids. Bulbar conjunctiva, which overlies the globe, may or may not be affected in some disorders. The same is true for palpebral conjunctiva. The fornices may serve as repositories for chemical or particular matter, and therefore, lid eversion is an essential part of complete conjunctival examination. Defects or foreign bodies in the conjunctiva can be detected by topical fluorescein staining, whereas rose bengal can be used to detect devitalized conjunctival epithelial cells.

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Figure 4.1 Amelanotic Nevus

In childhood, most conjunctival nevi initially appear amelanotic and show little or no active melanin production until the pubertal years. Microcysts within the lesion are common. Prominent vessels leading to the lesion with telangiectasia within the nevus may also be seen. Conjunctival nevi are most commonly located in the perilimbal area in the interpalpebral fissure. Even though conjunctival nevi have a low chance of malignant transformation, nevi that are increasing in size or become more inflamed should be excised with cryotherapy at the base of the lesion.

 

Figure 4.2 Melanotic Nevus

Conjunctival nevi consist of melanocytic nevus cells classified based upon location within the epithelium. The nevus cells can be located in the epithelium (junctional nevus), subepithelium, or both layers (compound nevus). Most of the lesions are located near the limbus, are slightly raised, and can contain a variable amount of pigment. Lesions should be followed by serial photography. Although rare, malignant transformation can occur, especially in the teenage years. Signs of transformation include growth, formation of an elevated mass, increased feed vasculature, and extension into contiguous structures.

 

Figure 4.3 Caruncle Nevus

A nevus located within the caruncle typically presents during puberty, contains small cysts, and does significantly change in size. The caruncle is an extension of the conjunctival tissue and serves little purpose in terms of ocular health. Surgical excision is recommended for pigmented lesions that are changing in size, gaining pigmentation, or associated with inflammation.

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Figure 4.4 Axenfeld Loops

Axenfeld loops are areas of pigmentation surrounding an intrascleral nerve or blood vessel. They are typically located a few millimeters posterior to the limbus and appear as variably sized, slate gray, pigmented patches circumferentially equidistant from the limbus. Under high magnification, the pigment appears as rectangular deposits at the level of the episclera. These lesions are a normal variant, benign, and of no ophthalmic concern.

 

Figure 4.5 Ocular Melanosis

Ocular melanosis is a form of episcleral pigmentation, usually slate gray, that tends to occur as broad patches with no anatomic correlate, unlike Axenfeld loops (see Fig. 4.4). This form of episcleral pigmentation is seen in darkly pigmented individuals and is not associated with malignant transformation. The lesions may be uni- or bilateral. Pigmentation does not move with the conjunctiva.

 

Figure 4.6 Oculodermal Melanocytosis

The combination of ocular melanosis (see Fig. 4.5) and similar skin pigmentation, known as nevus of Ota, is called oculodermal melanocytosis. The skin has a bluish gray appearance. Other uveal structures, including the iris and retinal pigment epithelium, can have increased pigmentation (Fig. 4.7). Nevus of Ota is more common in darkly pigmented individuals and is typically unilateral. It is more common in certain ethnic groups, particularly in far eastern Asia. When found in the Caucasian population it has a higher incidence of associated malignancy, including choroidal melanoma.

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Figure 4.7 Iris Melanosis

Iris melanosis is often associated with oculodermal melanocytosis (see Figs. 4.5 and 4.6). The usual iris crypts are missing, particularly in the peripheral two thirds of the iris. Instead, the iris appears flat with or without a large number of tiny bumps following no particular pattern. The iris tends to be chocolate brown, particularly when compared to the other eye. Gonioscopy is normal and there is no increased association with glaucoma. However, eyes with iris melanosis in the presence of oculodermal melanocytosis may have a higher risk of ocular melanoma. Malignant transformation is very rare in childhood.

 

Figure 4.8 Conjunctival Hemangioma

Conjunctival hemangioma is a benign tumor presenting with bright red vascularized lesion of the conjunctiva, usually in the inferior fornix. This patient has a diffuse conjunctival hemangioma associated with deeper orbital involvement (see Chapter 11: Orbit, Fig. 11.4), always a consideration with conjunctival hemangioma. Treatment is indicated only for reconstructing appearance, as this tumor is rarely visually significant. The hemangioma may be sessile or polypoid. In the latter case it should be distinguished from pyogenic granuloma (Fig. 4.9). Although topical steroids may be tried, definitive treatment requires surgery or thermocautery. Surgical intervention should be restricted to the anterior portion of the tumor only.

 

Figure 4.9 Pyogenic Granuloma

Pyogenic granuloma is a fibrovascular proliferation following inflammation (hordeolum), surgery (strabismus, chalazion removal, or scleral buckle), trauma, or foreign body. The typical lesion is bright red, pedunculated, and highly vascular. It may be so friable that it bleeds when touched. Treatment includes a trial of topical steroids. If that fails, surgical removal with cauterization or cryotherapy of the lesion base after excision is usually effective. Recurrence following surgical removal is not uncommon. Malignant transformation does not occur.

 

Figure 4.10 Viral Conjunctivitis

Adenoviral conjunctivitis is the most common viral conjunctivitis. The epidemic keratoconjunctivitis type is highly contagious. Patients will commonly have upper respiratory illness and a history of contact with another infected individual. The conjunctiva is significantly hyperemic with a watery mucoid discharge. Follicles of the conjunctiva are common. A tender preauricular node (note right temporal swelling) supports the diagnosis but is not pathognomonic of viral conjunctivitis. Dramatic lid swelling can occur. Treatment is confined to lubrication, cool compresses, and comfort measures.

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Figure 4.11 Pseudomembrane

Pseudomembranes are white or gray-white collections of leukocytes and inflammatory debris on the palpebral conjunctiva that are not attached to the underlying tissues and therefore do not bleed when removed. They are particularly common in epidemic keratoconjunctivitis (see Fig. 4.10), but may also be seen in conjunctivitis caused by a number of viral and bacterial organisms. They must be differentiated from true membranes as seen in Stevens Johnson syndrome (see Chapter 15: Dermatology, Fig. 15.11).

 

Figure 4.12 Subepithelial Infiltrates

Subepithelial corneal infiltrates are not uncommon sequelae of epidemic keratoconjunctivitis but may also result from other infectious causes. They appear as gray amorphous small infiltrates below the corneal epithelium with no particular pattern of distribution. Pain and photophobia are characteristic. Although they are responsive to topical steroids, it may be difficult to stop the steroids once begun. Symptomatic relief is preferred. The lesions usually appear toward the end of the active viral illness and persist after all other signs of viral conjunctivitis have resolved. The infiltrates shown here are somewhat larger and fewer in number than those seen with adenovirus. This should lead to investigation for possible Epstein-Barr virus conjunctivitis/keratitis.

 

Figure 4.13 Neonatal Gonorrhea Conjunctivitis

Gonococcal conjunctivitis of the newborn commonly presents with severe injection, chemosis, lid swelling, and large amounts of purulent discharge. Neisseria gonorrhoeae is one of few known pathogens that can penetrate an intact cornea epithelium. Therefore, suspected ocular gonorrhea is considered an ophthalmic emergency. Even if conjunctival swab Gram stain is inconclusive, the presence of purulent conjunctivitis in a neonate should result in the initiation of systemic treatment with antibiotics, preferably cephalosporins, immediately after appropriate cultures are taken. Treatment should include topical antibiotics, frequent saline lavage, a search for other sexually transmitted diseases that may have been acquired pre- or perinatally, and similar testing of the mother and her partner(s). Gonorrhea conjunctivitis in older children should raise concerns about possible covert sexual abuse.

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Figure 4.14 Chlamydia Conjunctivitis

Chlamydia trachomatis is a common cause of infectious ophthalmia neonatorum. The conjunctiva is very erythematous, with the palpebral conjunctiva being affected more severely than the bulbar conjunctiva. Unlike adult or childhood trachomatis conjunctivitis, there are no follicles or limbal infiltrates present. Systemic involvement includes a pneumonitis, which can occur weeks or months after the ocular infection. Therefore, systemic treatment with erythromycin is necessary to eradicate the Chlamydia trachomatis from the nasopharynx. This conjunctival scraping taken from a patient with Chlamydia trachomatis shows intracytoplasmic inclusion bodies on Giemsa stain.

 

Figure 4.15 Phlyctenule

Conjunctival phlyctenule is a discreet raised area of inflammation of the bulbar conjunctiva in the intrapalpebral fissure. The lesions are typically a yellowish white nodule that is surrounded by conjunctival hyperemia. Phlyctenules are frequently located at or a few millimeters posterior to the limbus. Rarely, the lesion may be on the cornea with blood vessels extending from the limbus to the lesion. The most common cause is staphylococcal hypersensitivity in the setting of blepharitis (see Chapter 2: Lids and Adnexa, Fig. 2.23). Tuberculosis should also be considered. Treatment should be directed toward the underlying blepharitis. Lid hygiene and topical antibiotics should be started with or without a short course of topical steroids.

 

Figure 4.16 Parinaud Oculoglandular Syndrome

Parinaud oculoglandular syndrome is a granulomatous conjunctivitis that typically is unilateral and has associated neck lymphadenopathy. Patients will often present with conjunctivitis and associated fever and rash. Note the typical yellow conjunctival lesions. Possible causes include cat scratch disease, tularemia, and sporotrichosis. Diagnosis is confirmed with a conjunctival biopsy, and the treatment is to target the underlying infection.

 

Figure 4.17 Allergic Chemosis

Allergic chemosis can be caused by environmental allergens or topical medications. The conjunctiva is thickened and has a clear, “boggy” appearance. The area of swelling can occur rapidly and dramatically. Treatment includes topical lubrication, topical vasoconstrictor/antihistamines, and steroids if necessary. The inciting agent is rarely found. The chemosis may be uni- or bilateral. Other causes of chemosis include infection, paralysis (e.g., in ventilated intensive care unit patients), trauma, cranial vault surgery (especially craniofacial procedures involving a bicoronal flap), and hypoalbuminemia.

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Figure 4.18 Vernal Papillary Conjunctivitis

Vernal conjunctivitis is a seasonal inflammation of the conjunctiva most commonly found in young boys. It is typically bilateral and presents with severe itching, photophobia with significant injection of the conjunctiva, and a thick, white mucous discharge. Giant papillae are commonly found on the upper tarsus and resemble “cobblestones.” Small white dots (Trantas dots) may be seen in the limbal area. Treatment of vernal conjunctivitis includes topical steroids and mast cell stabilizers. Topical antihistamines and cold compresses also can be helpful in relieving the symptoms.

 

Figure 4.19 Shield Ulcer

Shield ulcers typically occur in the superior half of the cornea and have an oval shape. A combination of mechanical irritation and the toxic effects of the inflammatory mediators from the vernal conjunctivitis causes the ulcers. Treatment should be aimed at reducing the vernal response with topical mast cell stabilizers and steroids. Bandage contact lenses with or without antibiotic coverage may be indicated.

 

Figure 4.20 Limbal Vernal

Limbal vernal occurs more commonly in the African and Asian population and clinically is seen as small gelatinous elevations circumferentially at the limbus. Like vernal conjunctivitis (see Fig. 4.18), it is seasonal and may be associated with tearing, itching, and red eye, and small white dots (Trantas dots) may be seen in the limbal area. The elevated areas may have some pigmentation, as shown here. Topical steroids and mast cell stabilizers are the treatment of choice.

 

Figure 4.21 Conjunctival Lymphoid Hyperplasia

Children will often have an increased number and size of follicles in the lower fornix and on the lower palpebral conjunctiva without significant erythema or symptoms. This reaction is similar to other areas of lymphoid hyperplasia (tonsils or lymph nodes) that occurs in particular from approximately 2 to 10 years of age. This benign asymptomatic condition requires no intervention. Care must be taken not to confuse this with the follicular reaction of other disorders, such as viral conjunctivitis (see Fig. 4.10).

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Figure 4.22 Ligneous Conjunctivitis

Ligneous conjunctivitis is a chronic membranous conjunctivitis mainly affecting the pediatric population. It will often coincide with a systemic illness including otitis media, respiratory infection, and sinusitis. The palpebral conjunctiva is severely injected and white, woodlike structures extend from the conjunctival surfaces. Treatment is very difficult and a wide variety of agents have been used. Autologous plasminogen drops may have particular benefit. However, some cases will spontaneously resolve. Removal of the lesions results in conjunctival bleeding and recurrences are common. The lesion may cause severe corneal damage.