Definitions: Enucleation: surgical removal of the entire globe. Evisceration: surgical removal of the entire contents of the globe, leaving a scleral shell. Exenteration: removal of the entire orbit, including the globe, eyelid, and orbital contents—usually performed for malignant tumors. Key…
Definition The orbit is the bony cavity that contains the eye, eye muscles, lacrimal gland, and other structures that serve eye functions. Numerous diseases affect the orbit and can involve any of these tissues, including neural, muscular, vascular, lymphatic, and…
Definition Injuries varying from simple skin abrasions to more complex cases with extensive tissue loss and underlying fractures of the facial skeleton caused by blunt or penetrating facial trauma. Key Features Partial-thickness eyelid injury. Eyelid margin lacerations. Eyelid injuries with…
Definition: Cutaneous cancers that arise from the epidermis, dermis, or adnexal structures of the eyelid. Rarely, they may be metastatic from distant sites. They include a number of histologically distinct tumors from diverse skin cell types. Key Features Flat, eroded,…
Definition: Benign eyelid lesions can arise from epithelial or dermal adnexal elements. These include epithelium, hair follicles, apocrine and eccrine glands, blood vessels, and nerves. Some may appear aggressive and must be differentiated from malignancies. Key Features Three to six…
Definition Ectropion is an outward rotation of the eyelid margin from the eye. Key Features Ectropion may result from progressive age-related eyelid laxity, vertical skin shortening, orbicularis muscle weakness from facial nerve palsy, or mechanical force on the eyelid from…
Definition Entropion: a commonly encountered inward rotation of the tarsus and eyelid margin ( Fig. 12.5.1 ). Key Features Symptoms and signs include ocular foreign body sensation, secondary blepharospasm, ocular discharge, tearing, superficial keratopathy, and corneal scarring. The natural course…
Definition Ptosis is defined as the upper eyelid resting in a droopy, abnormally low position while the eye is in primary gaze. Key Features Blepharoptosis (ptosis) is caused by a weakness in one or both of the eyelid retractors, the…
Definitions Computed tomography: An imaging technique where contrast differences are based on tissue density based on the passage of X-rays through tissues. Magnetic resonance imaging: An imaging technique where density differences are based on tissue proton density and their resonance…
Definition The orbit is the anatomical space bounded by seven orbital bones and enclosed within the multilamellar periorbita. It is separated above from the intracranial compartment and medially and inferiorly from the paranasal sinuses. The orbit contains the eye and…