Published online by Cambridge University Press: 19 May 2010
OCULAR DISORDERS OF AGING
Approximately 80 million Americans experience visual impairment and more than 3 million Americans 40 years and older are legally blind. The rate of visual impairment and blindness is highest in the geriatric population. In a population-based study, the rate of visual impairment in individuals 80 years and older was 15–30 times greater than individuals 40–50 years old. In addition, because many are unaware of their eye disease, otherwise healthy patients 65 years and older should have a comprehensive eye examination every 1–2 years.
Ophthalmologists are in the unique position of being able to provide not only primary eye care, but also comprehensive medical and surgical eye care for the elderly. Preventing blindness is an important factor in assisting an elderly person to function autonomously and to lead a productive life. Blinding disorders can cause significant personal, familial, and societal burdens. A thorough ophthalmological evaluation allows for diagnosis and potential treatment of common and uncommon eye diseases.
EYELIDS AND LACRIMAL SYSTEM
The function of the eyelids is to protect the surface of the globe. The eyelids are composed of an anterior lamella consisting of the cilia, dermis, orbicularis oculi muscle, and lid retractors (Figure 37.1A). The tarsal plate, which is composed of dense connective tissue, and the palpebral conjunctiva constitute the posterior lamella (Figure 37.1B).
The function of tear film is to provide the cornea with 1) lubrication and protection; 2) a smooth optical surface; 3) antimicrobial properties; and 4) necessary nutrients. The tear film is composed of three layers: lipid, aqueous, and mucinous layers.