The orbit and lacrimal system is bounded by the paranasal sinuses, eyelids, temporal region, and intracranial fossa ( Figs. 7.1 and 7.2 ). The orbit contains all of the supporting structures of the eye and produces unique signs and symptoms depending on the location and pathology of the underlying disease. Careful evaluation of these structures and their function allows for localization and identification of many processes, and represents a key step in determining the next steps of the workup. Processes that affect the orbit and lacrimal system include vascular, inflammatory, cystic, neural, muscular, lymphoid, fibrous, and osseous diseases. In addition, infections or diseases can extend from periorbital regions or metastasize to the orbit.
History
The location, quality, and timing of symptoms, as well as modifying factors, can aid in diagnosis and management of orbital and lacrimal disease. Review of old photographs helps to document a change in appearance.
Visual symptoms should be reviewed during the workup of both orbital and lacrimal diseases. Symptoms may include blurred vision, loss of vision, double vision, and light sensitivity. Diplopia must be clarified as either monocular or binocular. Monocular diplopia does not resolve with each eye closed; it is typically due to media opacities, such as cataract or tear film irregularities. Binocular diplopia resolves with either eye closed; it is due to misalignment of the eyes and may be due to orbital disease.
Inflammatory symptoms include the four classic symptoms of tenderness or pain (dolor), swelling (tumor), warmth (calor), and redness (rubor). Infections may present with similar findings and/or mucopurulent or purulent discharge. Because the orbit represents a compartment with vast sensory innervation passing through it, pain may occur in a variety of other orbital processes, including orbital hemorrhage and malignancy.
The timing and progression of symptoms may point to particular diagnoses. Infections (dacryocystitis, orbital cellulitis, mucormycosis) and hemorrhage (orbital hemorrhage, pituitary apoplexy) typically present acutely. Inflammations (nonspecific orbital inflammation, dacryoadenitis, myositis) and some tumors such as metastases may present subacutely. A more indolent presentation may occur with benign orbital tumors, such as cavernous malformations, lymphomas, dermoid cysts, mucoceles, or neurogenic tumors.
Tearing represents the most common symptom of lacrimal disease and may result from primary or secondary tear hypersecretion or from underdrainage of tears. Epiphora specifically relates to excess tears that overflow onto the cheek, which often implies underdrainage of tears owing to lacrimal outflow obstruction or tear pumping abnormality. Hypersecretion may occur from inflammation of the ocular surface. The most common cause of surface inflammation is keratoconjunctivitis sicca, or dry eye syndrome. Dry eye syndrome is often accompanied by burning, irritation, redness, ocular ache, foreign body sensation, blurred vision, photophobia, and mattering of eyelashes; however, tearing may be the sole symptom of dry eye. Other surface inflammations that may produce tearing include blepharitis, conjunctivitis, keratitis, allergies, Stevens-Johnson syndrome, and ocular cicatricial pemphigoid. Mechanical abrasion of the ocular surface may also result in tearing. This can occur with trichiasis, eyelid malpositions such as entropion, or tumors abutting the globe. Exacerbating factors for tearing could include wind, smoke, smog, or other environmental irritants. Lacrimal sac malignancies may present with blood-tinged tears (hemolacria), epistaxis, or a mass extending superior to the medial canthal tendon in addition to tearing. Infants with tearing should be evaluated by a pediatric ophthalmologist, as the differential diagnosis includes congenital glaucoma.
Medical History, Medications, and Allergies
The medical history should be reviewed for diseases that may affect the lacrimal system and orbit, including sinusitis or rhinitis, allergies and atopy, autoimmune disorders (in particular thyroid disease, Sjögren syndrome, sarcoidosis, granulomatosis with polyangiitis, rheumatoid arthritis, and systemic lupus erythematosus), Stevens-Johnson syndrome, ocular cicatricial pemphigoid, diabetes mellitus, history of local or systemic malignancies, and periocular trauma.
The ocular history should include previous eye surgeries or interventions. For patients with tearing, a history of punctal plug placement is particularly important. Certain ocular medications can exacerbate tearing or nasolacrimal duct obstruction (NLDO), such as topical glaucoma medications (timolol, dorzolamide, pilocarpine) and antivirals (idoxuridine, trifluridine).
Prior surgical history and interventions, including past nasal, sinus, dental, lacrimal, facial and cosmetic surgeries, history of radiation treatment, or a history of skin cancer and treatments, should be elicited.
Medication history pertinent to the orbital examination includes the use of corticosteroids or other immunosuppressants, thyroid medications, and blood thinners. For the lacrimal evaluation, pertinent medications include allergy medications, radioactive iodine 131, chemotherapy (paclitaxel, docetaxel, 5-fluorouracil, and others), and topical ocular lubricants. Dry eye syndrome can be exacerbated with antihistamines, antidepressants, antihypertensives, and oral contraceptives.
Pertinent substance history includes cocaine use (nasal septum defects) and tobacco smoking history (thyroid eye disease and other inflammatory disorders, malignancy).
The family history may play a role in some orbital and lacrimal diseases, such as thyroid eye disease, nasolacrimal duct obstruction, and certain malignancies.
Ophthalmic Examination
The ophthalmic examination must evaluate the function of myriad structures within the orbit and lacrimal system, including the visual sensory system, the oculomotor system, the globe, the somatic sensory system, the periocular structures, and the lacrimal system. The examination can localize a disease process and point to the proper imaging or other evaluation techniques.
Visual Sensory System
Although it is obviously critical to determine the exact cause of vision loss, the most important aspect of vision regarding the orbit is whether vision loss is due to a problem of the eye itself, or due to compression of the optic nerve from an orbital process. Optic nerve function can affect visual acuity, but so can many other disorders that are not orbital in origin.
Optic nerve function can be further characterized by assessing visual acuity, pupillary response, visual fields, and color vision. Visual acuity should be performed one eye at a time either at near or distance, with the patient wearing glasses or contact lenses, or with a pinhole. The swinging flashlight test detects a relative afferent pupillary defect, and this test is critical to master for any surgeon operating on the orbit. In general, the pupil of each eye should constrict in a similar fashion when the light is brought in front of the eye. If the affected eye dilates when the light is brought over from the unaffected eye, this signifies optic nerve dysfunction. The dilation may be very subtle. Other tests for optic nerve function include confrontational visual field testing, which can be done with the examiner’s fingers placed in peripheral quadrants while the patient gazes straight ahead. Static perimetry (e.g., Humphrey visual field analyzer [Carl Zeiss Meditec Inc., Dublin, CA]) using special devices provides a much more detailed assessment to detect smaller degrees of nerve damage and is recommended in most cases other than at the bedside and in urgent situations.
Color vision is another test of optic nerve function. Color vision is more likely to be reduced in vision loss due to optic neuropathy compared with other types of vision loss, such as media opacities, macular disease, or amblyopia. This is particularly important for orbital disease. Compressive diseases may affect color vision before affecting other optic nerve function parameters. It is best tested using books with standardized Ishihara color plates (Kanehara Shuppan Co., LTD, Tokyo, Japan), but if these are unavailable, color vision can be tested by subjectively asking the patient to compare the saturation of a red object presented to each eye.
To complete the visual sensory examination, a slit-lamp examination should be performed. This biomicroscopic examination evaluates both the surface and the contents of the eye. It can detect an elevated tear meniscus in lacrimal disease, or signs of exposure keratopathy in orbital disease. Vision loss from an ocular surface issue such as exposure of the cornea must be distinguished from that caused by an optic neuropathy to guide proper treatment. Similarly, a slit-lamp examination can tease out other causes of vision loss, such as cataract, media opacities such as vitreous hemorrhage, or retinal disease. Evaluation of the optic nerve using the slit lamp and a handheld lens, or direct ophthalmoscope, can detect swelling of the optic nerve in more acute and anterior orbital cases of optic neuropathy or pallor of the optic nerve in chronic cases.
Oculomotor System
The oculomotor system should evaluate the function of the extraocular muscles. The position of the eyes can be determined by asking the patient to look at the examiner’s nose while covering one eye and looking for movement of the other. Eyes that are aligned (orthophoria) will not move with this test. If, for example, the eye moves laterally to find the examiner’s nose while the fellow eye is being occluded, this signifies the eye is deviated inward (esotropia). This could be due to restriction of the medial rectus muscle or to weakness of the lateral rectus muscle. Next, ductions, or examination of extraocular motility, are performed by asking the patient to move the eyes in all cardinal directions of gaze. The degree of movement in the four cardinal directions should be compared to the fellow eye. Some processes in the orbit can restrict eye movement. These include fractures entrapping a muscle or inflammatory diseases affecting extraocular muscle(s). In the example provided, a medial restriction would cause limited lateral (abduction) movement of the eye. However, limited eye movement may be due to causes other than restriction, such as cranial nerve (CN) III, IV, and VI palsy. Each nerve palsy presents with unique extraocular movement (EOM) patterns. Neuromuscular diseases, such as myasthenia gravis, may also limit eye movement. To determine whether a limited eye movement is due to a restrictive cause or other cause, forced ductions may be performed ( Fig. 7.3 ). Classically, after numbing the ocular surface, forceps can be used to grasp the muscle insertion and move the eye in the opposite direction to determine if the muscle is mechanically restricted. In the case of medial rectus muscle restriction, if the medial rectus insertion is grasped, the eye cannot be pushed laterally to its full extent. In the case of palsy, the eye can be moved to its full extent. Caution is recommended, however, as forced ductions can be uncomfortable and can result in oculocardiac reflex and bradycardia if there is restriction. Some examiners use a cotton-tipped applicator instead of forceps.
