Clinical Eye Examinations: Study Notes

Lids and Lacrimal Apparatus

• Ptosis is classified as congenital myogenic simple, congenital with superior rectus weakness, neurogenic (congenital III N palsy, Horner's syndrome, Marcus Gunn syndrome), or acquired (EOM mechanical, eyelid mass, aponeurotic involutional trauma, blepharochalasis, pregnancy, Graves' disease, myogenic chronic progressive external ophthalmoplegia, oculopharyngeal dystrophy, myotonic dystrophy, myasthenia gravis, neurogenic acquired IIIN palsy, acquired Horner's syndrome, levator muscle botox injection, or mechanical).
• Congenital myogenic ptosis involves isolated dysfunction of the levator muscle; ptosis is present at primary gaze, with reduced movement of the upper lid in upgaze and impaired closure on downgaze.
• Marginal reflex distance 1 (MRD1) measures 4-4.5 mm; MRG2 measures 5.0-5.5 mm.
• Congenital neurogenic ptosis is associated with oculomotor nerve palsy.
• Horner's syndrome presents with mild ptosis, decreased iris pigmentation, miosis, and anhidrosis.
• Marcus Gunn syndrome involves aberrant innervation of the levator muscle by motor fibers of the trigeminal nerve.
• Acquired aponeurotic ptosis involves involutional disinsertion of the aponeurosis from the tarsal plate; ptosis is present at primary gaze, with full excursion with upgaze.
• Acquired myogenic ptosis is related to Myasthenia Gravis.
• Myasthenia Gravis is an autoimmune disease characterized by skeletal muscle weakness where autoantibodies impair acetylcholine binding at the post-synaptic neuromuscular junction.
• Diagnosis of myasthenia involves observing increased ptosis with repeated elevation and depression of the eye.
• In myasthenia, ask the patient to look down for 15 seconds and then look up at an elevated target; the lid overshoots and then falls slightly (Cogan's twitch test).
• Applying ice to the eyelid for 2 minutes significantly reduces myasthenic ptosis.
• Eyelid tumors are benign (neoplasms, hamartomas, or choristomas) or malignant.
• Benign neoplasms are acquired cellular tumors of cells that are atypical but not sufficient to be classified as malignant.
• Benign neoplasms enlarge slowly and never give metastasis.
• Hamartomas are congenital tumors composed of normal or near-normal cells and tissues for the anatomic site but in excessive amounts.
• Choristomas are congenital tumors consisting of normal cells.
• Sebaceous cysts are opaque and asymptomatic.
• Cysts of Moll are small, translucent cysts on the lid margin caused by obstruction of a sweat gland.
• Cysts of Zeis are opaque cysts on the eyelid margin caused by blockage of an accessory sebaceous gland.
• Xanthelasma are lipid-containing bilateral lesions which may be associated with hypercholesterolemia in youth.
• Squamous papilloma of the skin is focal hyperplasia of stratified squamous epithelium of the epidermis.
• Keratoacanthoma is a rapidly growing squamo-proliferative lesion with a central keratin.
• Diagnosis of keratoacanthoma- is squamous cell carcinoma.
• The acquired nevus usually appears between the ages of five and 15 years.
• Capillary hemangioma is a hamartoma.
• Malignant eyelid tumors include basal cell carcinoma, squamous cell carcinoma, and sebaceous gland carcinoma.
• Basal cell carcinoma is the most common malignant tumor, arising from pluripotent stem cells within the basal layers of the epidermis.
• It is slow-growing, locally invasive, and non-metastasizing.
• Clinical presentation of basal cell carcinoma includes a firm, painless, indurated nodule, with pearly rolled border and small telangiectatic surface vessels.
• Treatment of basal cell carcinoma is excision.
• Prognosis for basal cell carcinoma is usually very good, but deep invasion of the tumor can be difficult to treat.
• Squamous cell carcinoma arises from stratified squamous epithelium.
• It is less common but more malignant than basal cell carcinoma.
• Risk factors for squamous cell carcinoma include UV irradiation, chronic exposure to arsenic, hydrocarbons, immunosuppressive drugs, albinism, and chronic skin lesions.
• Clinical sign of squamous cell carcinoma is a hard nodule or a scaly patch.
• Squamous cell carcinoma can metastasize to lymph nodes.
• Treatment for squamous cell carcinoma is excision with healthy tissue around.
• Sebaceous gland carcinoma of the eyelid is a rare but potentially fatal neoplasm that represents approximately 5% of malignant eyelid tumors.
• This tumor arises from sebaceous glands of the soft periocular region, including Meibomian glands and Zeis glands, and presents in the caruncle and conjunctiva.
• The tumor is most common as a solitary eyelid nodule, often misdiagnosed as a persistent or recurring chalazion or blepharitis, and should be considered in middle-aged people with unilateral blepharitis.
• Diagnosis requires biopsy, and treatment includes surgical excision, exenteration, or chemotherapy.
• Alcrimia, lacrimal hypersecretion, and paradoxical lacrimation (crocodile tears) are disorders of the lacrimal secretory system.
• Dacryoadenitis is an acute inflammation of the lacrimal apparatus, mostly in children as a complication of mumps; in adults, it is associated with N. gonorrhea.
• Symptoms include pain, redness, and edema, presenting as an S-shaped curve.
• Chronic dacryoadenitis (longer than one month) is associated with sarcoidosis, Grave's disease, Sjogren syndrome, lymphoma, syphilis, and leprosy.
• Lacrimal drainage system disorders include nasolacrimal duct obstruction and dacryocystitis.
• Infantile dacryocystitis is due to failure of canalization of the nasolacrimal duct.
• A persistent membrane at the Hasner valve may be the culprit.
• Dacryocystitis can occur if untreated (microorganisms involved in infantile dacryocystitis are Haemophilus influenzae, Streptococcus pneumoniae, staphylococcus species).
• Adult dacryocystitis occurs in postmenopausal women due to fibrosis of the duct.
• Microorganisms involved in adult dacryocystitis are S. aureus, S. epidermidis, P. aeruginosa, and propionibacterium species.
• Clinical findings of dacryocystitis include tearing, discharge, pain, and swelling.
• Treatment for infantile dacryocystitis involves forceful compression of the lacrimal sac.
• If stenosis persists more than 6 months, probing or temporary silicone tent intubation is used.
• In adults, surgical treatment by dacryocystorhinostomy (forming a permanent fistula between the lacrimal sac and the nose) is indicated.