Ординатура / Офтальмология / Английские материалы / Ophthalmology A Short Textbook_Lang_2000

104 4 Conjunctiva

Conjunctival irritation symptoms can occur with Graves’ orbitopathy, gout, rosacea, neurodermatitis, erythema multiforme, Sjögren’s syndrome, and

Reiter’s syndrome (triad: conjunctivitis or iridocyclitis, urethritis, and polyarthritis). Parinaud’s oculoglandular syndrome describes a clinical syndrome of widely varied etiology. Granulomatous conjunctivitis always occurs unilaterally and in conjunction with swollen preauricular and submandibular lymph nodes in the presence of tuberculosis, syphilis, viruses, bacteria, fungi, and parasites. The excisional biopsy of the conjunctival granuloma is itself part of the treatment of granulomatous conjunctivitis. The specific medications will depend on the underlying disorder.

4.5Tumors

Primary benign conjunctival tumors (nevi, dermoids, lymphangiomas, hemangiomas, lipomas, and fibromas) occur frequently, as do tumor-like inflammatory changes (viral papillomas, granulomas such as suture granulomas after surgery to correct strabismus, cysts, and lymphoid hyperplasia). Malignant conjunctival tumors (carcinomas in situ, carcinomas, Kaposi’s sarcomas, lymphomas, and primary acquired melanosis) are rare.

Benign lesions may become malignant; for example, a nevus or acquired melanosis may develop into a malignant melanoma. This section presents only the most important tumors.

4.5.1Epibulbar Dermoid

Epibulbar dermoid is a round dome-shaped grayish yellow or whitish congenital tumor. It is generally located on the limbus of the cornea, extending into the corneal stroma to a varying depth. Epibulbar dermoids can occur as isolated lesions or as a symptom of oculoauriculovertebral dysplasia (Goldenhar’s syndrome). Additional symptoms of that disorder include outer ear deformities and preauricular appendages (Figs. 4.19a and b). Dermoids can contain hair and minor skin appendages. Ophthalmologists are often asked to remove them for cosmetic reasons. Surgical excision should remain strictly superficial; complete excision may risk perforating the globe as dermoids often extend through the entire wall of the eyeball.

4.5.2Conjunctival Hemangioma

Conjunctival hemangiomas are small, cavernous proliferations of blood vessels. They are congenital anomalies and usually resolve spontaneously by the age of seven. Where this is not the case, they can be surgically removed (Fig. 4.20).

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Epibulbar dermoid in oculoauriculovertebral dysplasia (Goldenhar’s syndrome).

Fig. 4.19

a Epibulbar dermoid on the limbus of the cornea.

b Additional preauricular appendages.

4.5.3Epithelial Conjunctival Tumors

4.5.3.1Conjunctival Cysts

Conjunctival cysts are harmless and benign. Occurrence is most often postoperative (for example after surgery to correct strabismus), post-traumatic, or spontaneous. They usually take the form of small clear fluid-filled inclusions of conjunctival epithelium whose goblet cells secrete into the cyst and not on to the surface (Fig. 4.21). Cysts can lead to a foreign-body sensation and are removed surgically by marsupialization (removal of the upper half of the cyst).

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Conjunctival hemangioma.

Fig. 4.20 Small cavernous proliferations of blood vessels on the conjunctiva.

Conjunctival cyst.

Fig. 4.21 Small, clear, fluid-filled inclusions of conjunctival epithelium.

4.5.3.2Conjunctival Papilloma

Papillomas are of viral origin (human papillomavirus) and may develop from the bulbar or palpebral conjunctiva. They are benign and do not turn malignant. As in the skin, conjunctival papillomas can occur as branching pediculate tumors or as broad-based lesions on the surface of the conjunctiva (Fig. 4.22). Papillomas produce a permanent foreign-body sensation that is annoying to the patient, and the entire lesion should be surgically removed.

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Conjunctival papilloma.

Fig. 4.22 Broadbased papilloma originating from the surface of the palpebral conjunctiva.

4.5.3.3Conjunctival Carcinoma

Conjunctival carcinomas are usually whitish, raised, thickened areas of epithelial tissue whose surface forms a plateau. These lesions are usually keratinizing squamous cell carcinomas that develop from epithelial dysplasia (precancer) and progress to a carcinoma in situ (Fig. 4.23). Conjunctival carcinomas must be excised and a cytologic diagnosis obtained, and the patient must undergo postoperative radiation therapy to prevent growth deep into the orbit.

Conjunctival squamous cell carcinoma.

Fig. 4.23 Typical features include the whitish, raised, thickened area of epithelial tissue.

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4.5.4Melanocytic Conjunctival Tumors

4.5.4.1Conjunctival Nevus

Birthmarks can occur on the conjunctiva as on the skin. They are usually located near the limbus in the temporal portion of the palpebral fissure, less frequently on the lacrimal caruncle. These benign, slightly raised epithelial or subepithelial tumors are congenital. Fifty percent of nevi contain hollow cystic spaces (pseudocysts) consisting of conjunctival epithelium and goblet cells. Conjunctival nevi may be pigmented (Fig. 4.24a) or unpigmented (Fig. 4.24b), and they may increase in size as the patient grows older. Increasing pigmentation of the nevus as a result of hormonal changes during pregnancy or puberty or from exposure to sunlight can simulate an increase in the size of the nevus, as can proliferation of the pseudocysts. Conjunctival nevi can degenerate into conjunctival melanomas (50% of conjunctival melanomas develop from a nevus). Therefore, complete excision and histologic diagnostic studies are indicated if the nevus significantly increases in size or shows signs of inflammation.

Photographs should always be taken during follow-up examinations of conjunctival nevi. Small clear watery inclusion cysts are always a sign of a conjunctival nevus.

4.5.4.2Conjunctival Melanosis

Definition

Conjunctival melanosis is a pigmented thickening of the conjunctival epithelium (Fig. 4.24c).

Epidemiology: Conjunctival melanosis is rare like all potentially malignant or malignant tumors of the conjunctiva.

Etiology: Unclear.

Symptoms: Acquired conjunctival melanosis usually occurs after the age of 40. Typical symptoms include irregular diffuse pigmentation and thickening of the epithelium that may “come and go.”

Diagnostic considerations: Acquired conjunctival melanosis is mobile with the conjunctiva (an important characteristic that distinguishes it from congenital melanosis). It requires close observation with follow-up examinations every six months as it can develop into a malignant melanoma.

Differential diagnosis: This disorder should be distinguished from benign congenital melanosis (see below), which remains stable throughout the patient’s lifetime and appears more bluish gray than brownish. In contrast to acquired melanosis, it is not mobile with the conjuncti

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Differential diagnosis of pigmented conjunctival changes.

Figs. 4.24a–j

a Pigmented conjunctival nevus.

b Unpigmented conjunctival nevus.

c Primary acquired melanosis.

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Differential diagnosis of pigmented conjunctival changes.

Fig. 4.24d Congenital melanosis.

e Malignant conjunctival melanoma.

f Malignant melanoma of the ciliary body penetrating beneath the conjunctiva.

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Differential diagnosis of pigmented conjunctival changes.

Fig. 4.24g Metallic foreign body that has healed within the conjunctiva.

h Adrenochrome deposits (from eyedrops containing epinephrine).

i Iron deposits from make-up (mascara)

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Differential diagnosis of pigmented conjunctival changes.

Fig. 4.24j

Ochronosis (alkaptonuria).

Treatment: Because the disorder occurs diffusely over a broad area, treatment is often difficult. Usually it combines excision of the prominent deeply pigmented portions (for histologic confirmation of the diagnosis) with cryocoagulation of the adjacent melanosis and in some cases with postoperative radiation therapy.

Clinical course and prognosis: About 50% of conjunctival melanomas develop from conjunctival melanosis (the other 50% develop from a conjunctival nevus; see above). Conjunctival melanomas are not usually as aggressively malignant as skin melanomas. The radical resection required to remove the tumor can be a problem. Multiple recurrences will produce significant conjunctival scarring that can result in symblepharon with fusion of the eyelid skin and conjunctiva. Where the tumor has invaded the eyelids or the deeper portions of the orbit, orbital exenteration will be unavoidable to completely remove the tumor.

4.5.4.3Congenital Ocular Melanosis

Benign congenital melanosis (Fig. 4.24d) is subepithelial in the episclera. The conjunctival epithelium is not involved. Pigmentation is bluish gray. In contrast to acquired melanosis, congenital melanosis remains stable and stationary throughout the patient’s lifetime. In contrast to nevi and acquired melanosis, congenital melanosis remains stationary when the conjunctiva above it is moved with forceps. Congenital ocular melanosis can occur as an isolated anomaly of the eye or in association with skin pigmentations (oculodermal melanosis or Ota’s nevus). Although the tumor is benign, evidence suggests