OCULOPLASTICS

ORBIT DISORDERS

Lisa A. Mansueto, M.D.


I. Thyroid Disease


A. Type I Disease - no restrictive myopathy; thought to be caused by a circulating factor that stimulates orbital fibroblasts to produce hyluronic acid; hyluronic acid then induces fatty hyperplasia and tissue edema
        1. Usually young women (ratio 9 female: 1 male)
        2. Average age 36 years
        3. Normal extraocular motility, except at far extremes of gaze, may have minimal diplopia
        4. Lack of inflammation
        5. Proptosis usually symmetric - varies from mild to severe
        6. CT scan shows - increased fatty tissue and possibly enlarged extraocular muscles
        7. Eyelid retraction can be asymmetric
        8. Compressive optic neuropathy does not occur in these patients, despite at times relatively severe proptosis
        9. Clinical symptoms with Type I
              a. Exposure keratitis
              b. Superior limbic keratitis
              c. All due to lid retraction and proptosis to cause exposure

B. Type II Disease - restrictive myopathy with diplopia within 20 degrees of primary position
        1. More equal gender distribution (1.5 female: 1.0 male)
        2. Average age of 52 years
        3. Characteristically asymmetric proptosis
        4. 36% of Type II patients develop compressive optic neuropathy 
        5. CT scan shows extraocular muscle enlargement ( preferentially inferior and medial recti muscles) with sparing of tendon insertion site and asymmetry
        6. Clinical symptoms with Type II
               a. Exposure keratitis
               b. Superior limbic keratitis
               c. Diplopia
               d. Compressive optic neuropathy
               e. Orbital inflammation

C. Environmental Factors
        1. Some antibodies directed towards certain bacteria have been shown to cross-react with thyroid stimulating hormone receptors on the thyroid gland
        2. Smoking - most important environmental factor in pathogenesis of diseases. One study found: 83% of patients with Graves' ophthalmopathy were smokers, as compared to 31% of normal and 40% of hyperthyroid patients (Haag and Asplund, 1987)
            b. Nunery et al. (1993) found Type I patients smoke at a rate of 63% and Type II patients smoke at a rate of 83%, compared to control group of 26%


II. Idiopathic Inflammatory Orbital Pseudotumor


A. Unknown Etiology - unrelated to specific local or systemic disorders

B. Clinical Presentation - severe orbit pain, restricted eye movements, and exophthalmos are most common

C. Radiographic Findings - may show thickened extraocular muscles with muscle tendon enlarged, diffuse inflammation of orbital soft tissue, enlargement of lacrimal gland, a ring of tissue around the globe that enhances with contrast, focal masses

D. Diagnosis -  made by excluding other causes of orbital mass lesions, such as neoplasm, Wegener's granulomatosis, Graves' disease, and definitive diagnosis of a localized mass

E. Treatment - high dose steroids treatment usually provides relief; if with Cytoxan or Methotrexate beneficial; if this fails, then radiation therapy

F. Prognosis - may be a one time event or chronic; often if chronic, scarring can produce fibrosis of orbital soft tissues, including retrobulbar fat or extraocular muscles


III. Spastic Disorders


A. Benign Essential Blepharospasm
        1. Bilateral disease - only eyelids and eyebrows close/spasm
        2. No known etiology
        3. Dry eye syndrome usually associated
        4. Work-Up: No MRI needed, as this is a clinical diagnosis
        5. Treatments
               a. BOTOX Injections
               b. No oral medications helpful
               c. Debulk orbicularis oculi muscle
               d. Interrupt path of facial nerve branch to ocular muscles

B. Hemifacial Spasm
        1. Localized to only half of the face
        2. Pathology may cause spasms to occur - tumor, stroke, redundant arterial loop irritating facial nerve
        3. Work-Up: Requires MRI of brain and brainstem to evaluate for intracranial pathology
        4. Treatments
               a. Neurology consultation - some oral medications helpful to control spasms
               b. BOTOX injections
               c. If tumor and/or arterial loop causing spasms, neurosurgical consultation required


IV. Anophthalmic Sockets


A. Ptosis

B. Ectropion

C. Shrunken Orbital Tissue, Volume Loss
        1. Superior Sulcus Deformity - Decreased overall orbital volume; expand with dermal fat graft and/or buccal mucous membrane graft


V. Trauma - Orbit and Ocular


A. Lid Lacerations

B. Canalicular Lacerations

C. Penetrating Ocular Injuries

D. Orbital Fractures

E. Orbital Foreign Body