44 Cavernous hemangioma. Fig. 2.25 The congenit al vascular anomaly occurs as a facial lesion most commonly occur in the eyelids. The le- sion regresses spontaneously in ap- proximately 70% of all cases. Symptoms: Hemangiomas include capillary or superficial, cavernous, and deep forms. Diagnostic considerations: Hemangiomas can be compressed, and the skin will then appear white. Differential diagnosis: Nevus flammeus: This is characterized by a sharply demarcated bluish red mark (“port-wine” stain) resulting from vascular expansion under the epidermis (not a growth or tumor). Treatment: A watch-and-wait approach is justified in light of the high rate of spontaneous remission (approximately 70%). Where there is increased risk of amblyopia due to the size of the lesion, cr yotherapy, intralesional steroid injections, or radiation therapy can accelerate regression of the hemangioma. Prognosis: Generally good. 2.7.1.7 Neurofibromatosis (Recklinghausen’s Disease) Definition A congenital developmental defect of the neuroectoderm gives rise to neural tumors and pigment spots (café au lait spots). Neurofibromatosis is regarded as a phacomatosis (a developmental disorder involving the simultaneous presence of changes in the skin, central nervous system, and ectodermal portions of the eye). 2 The Eyelids Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 45 Symptoms and diagnostic considerations: The numerous tumors are soft, broad-based, or pediculate, and occur either in the skin or in subcutaneous tissue, usually in the vicinity of the upper eyelid. They can reach monstrous proportions and present as elephantiasis of the eyelids (Fig. 2. 26). Treatment: Smaller fibromas can be easily removed by surgery. Larger tumors always entail a risk of postoperative blee ding and recurrence. On the whole, treatment is diff icult. 2.7.2 Malignant Tumors 2.7.2.1 Basal Cell Carcinoma Definition Basal cell carcinoma is a frequent, moderately malignant, fibroepithelial tumor that can cause severe local tissue destruction but very rarely metastasizes. Neurofibroma. Fig. 2.26 Larger fibromas can lead to elephantiasis of the eyelids. 2.7 Tumors Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 46 Epidemiology: Approximately 90% of all malignant eyelid tumors are basal cell carcinomas. Their incidence increases with age. In approximately 60% of all cases they are localized on the lower eyelid. Morbidity in sunny countries is 110 cases per 100000 persons (in central Europe approximately 20 per 100 000 persons). Dark-skinned people are affected significantly less often. Gender is not a predisposing factor. Etiology: Causes of basal cell carcinoma may include a genetic disposition. Increased exposure to the sun’s ultraviolet radiation, carcinogenic substances (such as arsenic), and chronic skin damage can also lead to an increased inci- dence. Basal cell carcinomas arise from the basal cell layers of the epidermis and the sebaceous gland hair follicles, where their growth locally destroys tissue. Symptoms: Typical characteristics include a firm, slightly raised margin (a halo resembling a string of beads) with a central crater and superficial vascular- ization with an increased tendency to bleed (Fig. 2. 27). Ulceration with “gnawing” peripheral proliferation is occasionally referred to as an ulcus rodens; an ulcus terebans refers to deep infiltration with invasion of cartilage and bone. Diagnostic considerations: The diagnosis can very often be made on the basis of clinical evidence. A biopsy is indicated if there is any doubt. Loss of the eyelashes in the vicinity of the tumor always suggests malig- nancy. Treatment: The lesion is treated by surgical excision within a margin of healthy tissue. This is the safest method. If a radical procedure is not feasible, Basal cell carcinoma. Fig. 2.27 A halo resembling a string of beads, superficial vascu- larization, and a central crater with a tendency to bleed are characteristic signs of this mod- erately malignant tumor. 2 The Eyelids Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 47 the only remaining options are radiation therapy or cryotherapy with liquid nitrogen. Prognosis: The changes of successful treatment by surgical excision are very good. Frequent follow-up examinations are indicated. The earlier a basal cell carcinoma is detected, the easier it is to remove. 2.7.2.2 Squamous Cell Carcinoma This is the second most frequently encountered malignant eyelid tumor. The carcinoma arises from the epidermis, grows rapidly and destroys tissue. It can metastasize into the regional lymph nodes. Remote metastases are rarer. The treatment of choice is complete surgical removal. 2.7.2.3 Adenocarcinoma The rare adenocarcinoma arises from the meibomian glands or the glands of Zeis. The firm, painless swelling is usually located in the upper eyelid and is mobile with respect to the skin but not with respect to the underlying tissue. In its early stages it can be mistaken easily for a chalazion (see p. 39). The lesion can metastasize into local lymph nodes. An apparent chalazion that cannot be removed by the usual surgical procedure always suggests a suspected adenocarcinoma. The treatment of choice is complete surgical removal. 2.7 Tumors Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 49 3 Lacrimal System Peter Wagner and Gerhard K. Lang 3.1 Basic Knowledge The lacrimal system (Fig. 3.1) consists of two sections: ❖ Structures that secrete tear fluid. ❖ Structures that facilitate tear drainage. Anatomy of the lacrimal system. Orbital part of the lacrimal gland Plica semilunaris Superior punctum lacrimale Lacrimal sac Nasolacrimal duct Superior lacrimal canaliculus Inferior concha Fundus of the lacrimal sac Inferior punctum lacrimale Fig. 3.1 The lacrimal system consists of tear secretion structures and tear drainage structures. Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 50 Structure of the tear film. Oily layer (approx. 0.1 µm) – cholesteryl esters – cholesterol – triglyceride – phospholipids Water layer (approx. 8 µ m) – 98–99% water – approx. 1% inorganic salts – approx. 0.2–0.6% proteins, globulins, and albumin – approx. 0.02–0.06% lysozyme – Rest: glucose, urea, neutral mucopolysaccharides (mucin), and acidic mucopolysaccharides Mucin layer (approx. 0.8 µm) Epithelium with microvilli and folds Oily layer, 0.1 µ m Meibomian glands Lacrimal gland Water layer, 8 µ m Conjunctival goblet cells Mucin layer, 0.8 µ m Fig. 3.2 The tear film is composed of three layers: ❖ An oily layer (prevents rapid desiccation). ❖ A watery layer (ensures that the cornea remains clean and smooth for optimal transparency). ❖ A mucin layer (like the oily outer layer, it stabilizes the tear film). Position, structure, and nerve supply of the lacrimal gland: The lacrimal gland is about the size of a walnut; it lies beneath the superior temporal mar- gin of the orbital bone in the lacrimal fossa of the frontal bone and is neither visible nor palpable. A palpable lacrimal gland is usually a sign of a pathologic change such as dacryoadenitis. The tendon of the levator palpebrae muscle divides the lacrimal gland into a larger orbital part (two-thirds) and a smaller palpebral part (one-third). Several tiny accessory lacrimal glands (glands of Krause and Wolfring) located in the superior fornix secrete additional serous tear fluid. The lacrimal gland receives its sensory supply from the lacrimal nerve. Its parasympathetic secretomotor nerve supply comes from the nervus interme- dius. The sympathetic fibers arise from the superior cervical sympathetic ganglion and follow the course of the blood vessels to the gland. Tear film: The tear film (Fig. 3.2) that moistens the conjunctiva and cornea is composed of three layers: 1. The outer oily layer (approximately 0.1 µm thick) is a product of the mei- bomian glands and the sebaceous glands and sweat glands of the margin of 3 Lacrimal System Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 51 the eyelid. The primary function of this layer is to stabilize the tear film. With its hydrophobic properties, it prevents rapid evaporation like a layer of wax. 2. The middle watery layer (approximately 8 µm thick) is produced by the lacrimal gland and the accessory lacrimal glands (glands of Krause and Wolfring). Its task is to clean the surface of the cornea and ensure mobility of the palpebral conjunctiva over the cornea and a smooth corneal surface for high-quality optical images. 3. The inner mucin layer (approximately 0.8 µm thick) is secreted by the goblet cells of the conjunctiva and the lacrimal gland. It is hydrophilic with respect to the microvilli of the corneal epithelium, which also helps to sta- bilize the tear film. This layer prevents the watery layer from forming beads on the cornea and ensures that the watery layer moistens the entire surface of the cornea and conjunctiva. Lysozyme, beta-lysin, lactoferrin, and gamma globulin (IgA) are tear-specific proteins that give the tear fluid antimicrobial characteristics. Tear drainage: The shingle-like arrangement of the fibers of the orbicularis oculi muscle (supplied by the facial nerve) causes the eye to close progress- ively from lateral to medial instead of the eyelids simultaneously closing along their entire length. This windshield wiper motion moves the tear fluid medially across the eye toward the medial canthus (Figs. 3. 3 a – c). The superior and inferior puncta lacrimales collect the tears, which then drain through the superior and inferior lacrimal canaliculi into the lacrimal sac . From there they pass through the nasolacrimal duct into the inferior concha (see Fig. 3.1). Combined function of the orbicularis oculi muscle and the lower lacrimal system. Opening the eye Levator palpebrae superioris muscle (oculomotor nerve) Closing the eye Orbicularis oculi muscle (facial nerve) Figs. 3.3 a –c As the eyelids close, they act like a windshield wiper to move the tear fluid medially across the eye toward the puncta and lacrimal canaliculi. a b c 3.1 Basic Knowledge Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 52 Measuring tear secretion with Schirmer tear testing. Fig. 3.4 A strip of litmus paper is folded over and inserted into the conjunctival sac of the temporal third of the lower eyelid. Normally, at least 15 mm of the paper should turn blue within five minutes. 3.2 Examination Methods 3.2.1 Evaluation of Tear Formation Schirmer tear testing: This test (Fig. 3.4) provides information on the quan- tity of watery component in tear secretion. ❖ Test: A strip of litmus paper is inserted into the conjunctival sac of the tem- poral third of the lower eyelid. ❖ Normal: After about five minutes, at least 15 mm of the paper should turn blue due to the alkaline tear fluid. ❖ Abnormal: Values less than 5 mm are abnormal (although they will not necessarily be associated with clinical symptoms). The same method is used after application of a topical anesthetic to evaluate normal secretion without irritating the conjunctiva . Tear break-up time (TBUT): This test evaluates the stability of the tear film. ❖ Test: Fluorescein dye (10 µl of a 0.125% fluorescein solution) is added to the precorneal tear film. The examiner observes the eye under 10 – 20 power magnification with slit lamp and cobalt blue filter and notes when the first signs of drying occur (i) without the patient closing the eye and (ii) with the patient keeping the eye open as he or she would normally. ❖ Normal: TBUT of at least 10 seconds is normal. Rose bengal test: Rose bengal dyes dead epithelial cells and mucin. This test has proven particularly useful in evaluating dry eyes (keratoconjunctivitis sicca) as it reveals conjunctival and corneal symptoms of desiccation. 3 Lacrimal System Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 53 Impression cytology: A Millipore filter is fastened to a tonometer and pressed against the superior conjunctiva with 20 –30 mm Hg of pressure for two seconds. The density of goblet cells is estimated under a microscope (normal density is 20 –45 goblet cells per square millimeter of epithelial sur- face). The number of mucus-producing goblet cells is reduced in various dis- orders such as keratoconjunctivitis sicca, ocular pemphigoid, and xeroph- thalmia. 3.2.2 Evaluation of Tear Drainage Conjunctival fluorescein dye test : Normal tear drainage can be demon- strated by having the patient blow his or her nose into a facial tissue following application of a 2% fluorescein sodium solution to the inferior fornix. Probing and irrigation: These examination methods are used to locate ste- noses. After application of a topical anesthetic, a conical probe is used to dilate the punctum. Then the lower lacrimal system is flushed with a physio- logic saline solution introduced through a blunt cannula (Figs. 3. 5 a and b). If the passage is unobstructed, the solution will drain freely into the nose. Canalicular stenosis will result in reflux through the irrigated punctum. If the stenosis is deeper, reflux will occur through the opposite punctum (Fig. 3.6). A probe can be used to determine the site of the stricture, and possibly to eliminate obstructions (Fig. 3. 7). Radiographic contrast studies: Radiographic contrast medium is instilled in the same manner as the saline solution. These studies demonstrate the shape, position, and size of the passage and possible obstructions to drainage. Digital substraction dacryocystography: These studies demonstrate only the contrast medium and image the lower lacrimal system without superim- posed bony structures. They are particularly useful as preoperative diagnos- tic studies (Fig. 3.8). Lacrimal endoscopy: Fine endoscopes now permit direct visualization of the mucous membrane of the lower lacrimal system. Until recently, endo- scopic examination of the lower lacrimal system was not a routine procedure. 3.2 Examination Methods Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. [...]... orbital rim is exposed Then a window is opened to expose the nasal mucosa The nasal mucosa and the lacrimal sac are both incised in an H-shape and door-like flaps are raised The anterior and posterior mucosal flaps are then sutured together This creates a new drainage route for the tear fluid that bypasses the nasolacrimal duct a Orbital rim b c Lang, Ophthalmology © 20 00 Thieme All rights reserved Usage... may be accompanied by malaise, fever, and involvement of the regional lymph nodes The pain may be referred as far as the forehead and teeth An abscess in the lacrimal sac may form in advanced disorders; it can spontaneously rupture the skin and form a draining fistula Lang, Ophthalmology © 20 00 Thieme All rights reserved Usage subject to terms and conditions of license 58 3 Lacrimal System Acute dacryocystitis... Illacrimation should be distinguished from exudation Illacrimation is usually reflex lacrimation in reaction to a conjunctival or corneal foreign body or toxic irritation Follicle Lymphocytes in the palpebral and bulbar conjunctiva accumulate in punctate masses of lymph tissue cells that have a granular appearance Follicles occur typically in viral and chlamydial infections (Fig 4.9) Papillae Papillae... which will appear partially closed (pseudoptosis) Foreign-body sensation, a sensation of pressure, and a burning sensation are usually present, although these symptoms may vary between individual patients Intense itching always suggests an allergic reaction Photophobia and lacrimation (epiphora) may also be present but can vary considerably Simultaneous presence of blepharospasm suggests corneal involvement... Bulbar conjunctiva Conjunctival fornix Palpebral conjunctiva Surface of the cornea (functions as a part of the conjunctival sac) Meibomian gland Fig 4.1 The conjunctiva consists of the bulbar conjunctiva, the conjunctival fornices, and the palpebral conjunctiva The surface of the cornea functions as the floor of the conjunctival sac 4 .2 Examination Methods Inspection: The bulbar conjunctiva can be evaluated...54 3 Lacrimal System Irrigation of the lower lacrimal system under topical anesthesia Figs 3.5 a and b First the punctum is dilated by rotating a conical probe Then the lacrimal passage is flushed with a physiologic saline solution The examiner should be particularly alert to good drainage or possible reflux a b Lang, Ophthalmology © 20 00 Thieme All rights reserved Usage subject to terms and conditions... removal is indicated in such cases The head and body of the pterygium are largely removed, and the sclera is left open at the site The cornea is then smoothed with a diamond reamer or an excimer laser (a special laser that operates in the ultraviolet range at a wavelength of 193 nm) Clinical course and prognosis: Pterygia tend to recur Keratoplasty is indicated in such cases to replace the diseased... inflamed lacrimal sac causes large quantities of transparent mucoid pus to regurgitate through the punctum Chronic inflammation of the lacrimal sac can lead to a serpiginous corneal ulcer Treatment: Surgical intervention is the only effective treatment in the vast majority of cases This involves either a dacryocystorhinostomy (creation of a direct connection between the lacrimal sac and the nasal mucosa;... bulbar conjunctiva A half-moonshaped fold of mucous membrane, the plica semilunaris, is located in the medial corner of the palpebral fissure This borders on the lacrimal caruncle, which contains hairs and sebaceous glands Function of the conjunctival sac: The conjunctival sac has three main tasks: 1 Motility of the eyeball The loose connection between the bulbar conjunctiva and the sclera and the “spare”... Orbital cellulitis (usually associated with reduced motility of the eyeball) Treatment: This will depend on the underlying disorder Moist heat, disinfectant compresses (Rivanol), and local antibiotics are helpful Clinical course and prognosis: Acute inflammation of the lacrimal gland is characterized by a rapid clinical course and spontaneous healing within eight Lang, Ophthalmology © 20 00 Thieme All . the safest method. If a radical procedure is not feasible, Basal cell carcinoma. Fig. 2. 27 A halo resembling a string of beads, superficial vascu- larization, and a central crater with a tendency to. that secrete tear fluid. ❖ Structures that facilitate tear drainage. Anatomy of the lacrimal system. Orbital part of the lacrimal gland Plica semilunaris Superior punctum lacrimale Lacrimal sac Nasolacrimal duct Superior. sun’s ultraviolet radiation, carcinogenic substances (such as arsenic), and chronic skin damage can also lead to an increased inci- dence. Basal cell carcinomas arise from the basal cell layers of