105 Epibulbar dermoid in oculoauriculovertebral dysplasia (Goldenhar’s syndrome). Fig. 4.19 a Epibulbar der- moid on the limbus of the cornea. b Additional preauricular appendages. 4.5.3 Epithelial Conjunctival Tumors 4.5.3.1 Conjunctival Cysts Conjunctival cysts are harmless and benign. Occurrence is most often post- operative (for example after surgery to correct strabismus), post-traumatic, or spontaneous. They usually take the form of small clear fluid-filled inclu- sions 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). 4.5 Tumors Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 106 Conjunctival hemangioma. Fig. 4.20 Small cavernous pro- liferations of blood vessels on the conjunctiva. Conjunctival cyst. Fig. 4.21 Small, clear, fluid-filled inclusions of con- junctival epithelium. 4.5.3.2 Conjunctival Papilloma Papillomas are of viral origin (human papillomavirus) and may develop from the bulbar or palpebral conjunctiva. They are benign and do not turn malig- nant. 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. 4 Conjunctiva Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 107 Conjunctival papilloma. Fig. 4.22 Broad- based papilloma originating from the surface of the palpebral con- junctiva. 4.5.3.3 Conjunctival Carcinoma Conjunctival carcinomas are usually whitish, raised, thickened areas of epithelial tissue whose surface forms a plateau. These lesions are usually ker- atinizing squamous cell carcinomas that develop from epithelial dysplasia (precancer) and progress to a carcinoma in situ (Fig. 4. 23). Conjunctival carci- nomas 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 Typi- cal features in- clude the whitish, raised, thickened area of epithelial tissue. 4.5 Tumors Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 108 4.5.4 Melanocytic Conjunctival Tumors 4.5.4.1 Conjunctival 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 cys- tic 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. Increas- ing pigmentation of the nevus as a result of hormonal changes during preg- nancy 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. 4.5.4.2 Conjunctival Melanosis Definition Conjunctival melanosis is a pigmented thickening of the conjunctival epi- thelium (Fig. 4.24 c). 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 con- genital 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 conjunctiva. 4 Conjunctiva Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 109 Differential diagnosis of pigmented conjunctival changes. Figs. 4.24a –j a Pigmented con- junctival nevus. b Unpigmented conjunctival nevus. c Primary acquired melano- sis. Continued Ǟ 4.5 Tumors Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 110 Differential diagnosis of pigmented conjunctival changes. Fig. 4.24d Con- genital melanosis. e Malignant con- junctival melanoma. f Malignant melanoma of the ciliary body pene- trating beneath the conjunctiva. 4 Conjunctiva Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 111 Differential diagnosis of pigmented conjunctival changes. Fig. 4.24g Metallic foreign body that has healed within the conjunctiva. h Adrenochrome deposits (from eyedrops contain- ing epinephrine). i Iron deposits from make-up (mascara) Continued Ǟ 4.5 Tumors Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 112 Differential diagnosis of pigmented conjunctival changes. Fig. 4.24j Ochronosis (alkaptonuria). Treatment: Because the disorder occurs diffusely over a broad area, treat- ment is often difficult. Usually it combines excision of the prominent deeply pigmented portions (for histologic confirmation of the diagnosis) with cryo- coagulation 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 conjunc- tival nevus; see above). Conjunctival melanomas are not usually as aggres- sively 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 eye- lid 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. 4.5.4.3 Congenital Ocular Melanosis Benign congenital melanosis (Fig. 4.24d) is subepithelial in the episclera. The conjunctival epithelium is not involved. Pigmentation is bluish gray. In con- trast to acquired melanosis, congenital melanosis remains stable and station- ary throughout the patient’s lifetime. In contrast to nevi and acquired mela- nosis, 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 4 Conjunctiva Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 113 that malignant melanomas in the choroid occur more frequently in patients with congenital melanosis. 4.5.5 Conjunctival Lymphoma Prominent areas of salmon-colored conjunctival thickening frequently occur- ring in the inferior fornix (Fig. 4. 25) are often the first sign of lymphatic dis- ease. Identifying the specific forms and degree of malignancy requires biopsy and histologic examination. Lesions may range from benign lymphoid hyper- plasia to malignant lymphomas that are moderately to highly malignant. Because lymphomas respond to radiation, a combination of radiation therapy and chemotherapy is usually prescribed according to the specific histologic findings. 4.5.6 Kaposi’s sarcoma This is a prominent, light to dark red tumor in the conjunctival fornix or pro- ceeding from the palpebral conjunctiva. It consists of malignant spindle cells and nests of atypical endothelial cells. Today Kaposi’s sarcomas are seen most frequently as opportunistic disease in patients with AIDS ( Acquired Immune Deficiency Syndrome). The ophthalmologist can make a tentative diagnosis of AIDS on the basis of typical clinical signs on the conjunctiva and order further diagnostic studies (Fig. 4. 26). Recently there has been evidence that herpes virus (HHV-8) is involved in the development of Kaposi’s sarcoma. Conjunctival lymphoma. Fig. 4.25 Typi- cal salmon- colored conjunc- tival tumor in the inferior fornix. 4.5 Tumors Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 114 4.6 Conj unctival Deposits These can occur in both the conjunctiva and cornea. Some, like some tumors, lead to pigmented changes in the conjunctiva. However, their typical appear- ance usually readily distinguishes them from tumors (Fig. 4. 24). The follow- ing conjunctival and corneal deposits and discolorations may occur: Adrenochrome deposit (Fig. 4.24 h). Prolonged use of epinephrine eyedrops (as in glaucoma therapy) produces brownish pigmented changes in the infe- rior conjunctival fornix and on the cornea as a result of epinephrine oxidation products (adrenochrome). This can simulate a melanocytic conjunctival tumor. Therefore, the physician should always ascertain whether the patient has a history of prolonged use of epinephrine eyedrops. No therapy is indi- cated. Iron deposits (Fig. 4.24i). In women, iron deposits from eye make-up and mascara are frequently seen to accumulate in the conjunctival sac. No therapy is indicated. Argyrosis. Prolonged used of silver-containing eyedrops can produce brownish black silver deposits in the conjunctiva. Ochronosis (alkaptonuria: an inherited autosomal recessive deficiency of the enzyme homogentisate 1,2-dioxygenase). Approximately 70% of all patients with ochronosis exhibit brownish pigmented deposits in the skin of the eye- lids, conjunctiva, sclera, and limbus of the cornea (Fig. 4. 24j). The deposits increase with time. The disorder cannot be treated in the eye. Kaposi’s sarcoma. Fig. 4.26 Promi- nent dark red tumor in the con- junctival fornix in a patient with AIDS. 4 Conjunctiva Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. [...]... hemispherical protrusion (Fig 5.6) that tends to produce myopia, and flattening of the cornea (cornea plana) that tends to produce hyperopia 5 .3. 2 Corneal Size Anomalies (Microcornea and Megalocornea) Corneal size anomalies are usually congenital and on the whole are rare An abnormally small cornea (microcornea) has a diameter less than 10.0 mm) It usually causes severe hyperopia that in advanced age often... endothelium are closed by cell enlargement and cell migration Diameter: The normal average diameter of the adult cornea is 11.5 mm (10 – 13 mm) A congenitally small cornea (microcornea, diameter less than 10.0 mm) or a congenitally large cornea (megalocornea, diameter from 13 to 15 mm) is always an abnormal finding (see Corneal Size Anomalies) Lang, Ophthalmology © 2000 Thieme All rights reserved Usage subject... 5.4.7 Acanthamoeba Keratitis Epidemiology: This is a rare type of keratitis and one which may have been diagnosed too rarely in the past Etiology: Acanthamoeba is a saprophytic protozoon Infections usually occur in wearers of contact lenses, particularly in conjunction with trauma and moist environments such as saunas Symptoms: Patients complain of intense pain, photophobia, and lacrimation Diagnostic... sent in for laboratory examination Treatment: Conservative treatment Topical agents currently include propamidine (only available through international pharmacies as Prolene) and pentamidine, which must be prepared by a pharmacist Usually broad-spectrum antibiotic eyedrops are also administered Cycloplegia (immobilization of the pupil and ciliary body) is usually required as well Surgical treatment Emergency... predisposes the patient to angle closure glaucoma (see Table 10.2, p 236 ) An abnormally large cornea (megalocornea) may be as large as 13 – 15 mm Corneal enlargement in the newborn and infants may be acquired due to increased intraocular pressure (buphthalmos) Combinations of microcornea and megalocornea together with other ocular deformities may also occur 5.4 Infectious Keratitis 5.4.1 Protective Mechanisms... (below 30 0 – 400 cells per mm2), cataract surgery is combined with a corneal transplant This is done to ensure that the patient will be able to see even after cataract surgery, which sacrifices additional endothelial cells 5.2.6 Measuring the Diameter of the Cornea An abnormally large or small cornea (megalocornea or microcornea) will be apparent from simple visual inspection A suspected size anomaly can... eye O A thin basement membrane anchors the basal cells of the stratified squamous epithelium to Bowman’s layer This layer is highly resistant but cannot regenerate As a result, injuries to Bowman’s layer usually produce corneal scarring O Beneath Bowman’s layer, many lamellae of collagen fibrils form the corneal stroma The stroma is a highly bradytrophic tissue As avascular tissue, it only regenerates... viral keratitis 5.4.4 Bacterial Keratitis Epidemiology: Over 90% of all corneal inflammations are caused by bacteria Etiology: The pathogens listed in Table 5.1 are among the most frequent causes of bacterial keratitis in the urban population in temperate climates Table 5.1 The most common bacterial pathogens that cause keratitis Bacterium Typical characteristics of infection Staphylococcus aureus Infection... contact with possible causative agents) However, this clinical syndrome has become far more prevalent today as a result of the increased and often unwarranted use of antibiotics and steroids Etiology: The most frequently encountered pathogens are Aspergillus and Candida albicans The most frequent causative mechanism is an injury with fungus-infested organic materials such as a tree branch Symptoms: Patients... nerves, amebas, and hyphae Although not yet routinely used in clinical practice, confocal corneal microscopy appears to be a promising examination method for the future 5 .3 Developmental Anomalies 5 .3. 1 Protrusion Anomalies 5 .3. 1.1 Keratoconus Definition Conical, usually bilateral central deformation of the cornea with parenchymal opacification and thinning of the cornea Epidemiology: Keratoconus is . Conjunctival Carcinoma Conjunctival carcinomas are usually whitish, raised, thickened areas of epithelial tissue whose surface forms a plateau. These lesions are usually ker- atinizing squamous cell carcinomas. congenital melanosis remains stable and station- ary throughout the patient’s lifetime. In contrast to nevi and acquired mela- nosis, congenital melanosis remains stationary when the conjunctiva above. Bowman’s layer usually produce corneal scarring. ❖ Beneath Bowman’s layer, many lamellae of collagen fibrils form the cor- neal stroma . The stroma is a highly bradytrophic tissue. As avascular tissue,