Lecture Notes 15 Special Senses: Eyes Classroom Activity to Accompany Medical Terminology Systems, Sixth Edition Barbara A. Gylys ∙ Mary Ellen Wedding

2 Structure Globe-shaped, 2.5 cm in diameter Three layers Fibrous outer tunic Vascular middle tunic Sensory inner tunic Spaces within the eye are filled with fluids to support internal structures 15 SPECIAL SENSES: EYES

3 Function Eyes and accessory structures Receptor organs provide vision. Refraction system focuses light rays on receptors in the retina. 15 SPECIAL SENSES: EYES

4 Structure and Function Exercise Q: What is the composition of the outer layer of the eyeball? A: Sclera, white of eye, is the outer layer and is made of fibrous connective tissue. Q: What does the middle layer of the eyeball consist of? A: The middle layer is the vascular layer. It includes choroid, ciliary body, and iris. Q: What does the inner layer consist of? A: The inner tunic consists of the retina, which contains the visual receptor cells (photoreceptors). 15 SPECIAL SENSES: EYES

5 Cataract Signs and Symptoms Opacity or cloudiness of lens or its surrounding membrane. Develops slowly, most frequently due to aging and can be familial. May occur after eye injury or surgery, or with diabetes. Gradual loss or blurring of vision, but painless. As cataract matures, pupil of the eye may appear white. SPECIAL SENSES: EYES 15

6 Cataract Treatment Depends on degree of visual impairment. Depends on age, general health, and occupation of the individual. Glasses for mild cases. Surgery when vision is impaired. Surgical extraction of defective lens. SPECIAL SENSES: EYES 15

7 Cataract Treatment (continued) Lens extraction followed by use of eyeglasses, contact lenses, or surgically implanted lenses called intraocular lenses (IOLs). Two most common surgical methods to remove cataracts: phacoemulsification and intracapsular and extracapsular extraction. SPECIAL SENSES: EYES 15

8 Clinically Related Exercise Q: An 80-year-old woman presents for an annual check up and asks the ophthalmologist what causes cataracts. A: The doctor explains it is a change in chemical composition of the lens with loss of lens transparency. Also, it is attributed to aging (senile cataracts), eye injuries (traumatic cataracts), certain diseases (secondary cataracts), and heredity or birth defects (congenital cataracts). Q: Mary presents to OP surgery for cataract repair. The surgeon will use ultrasonic vibrations to break the lens into tiny particles and then suction it out of the eye. This surgical procedure is called (keratectomy, laser iridectomy, phacoemulsification). A: phacoemulsification Q: Fred is having cataract surgery followed by a surgically implanted lens. The abbreviation for intraocular lenses is _________________. A: IOL SPECIAL SENSES: EYES 15

9 Strabismus Signs and Symptoms Eyes cannot be directed to focus on the same object. Esotropia, also called cross-eye Exotropia, also called wall-eye 15 SPECIAL SENSES: EYES

10 Strabismus Treatment Depends on the cause. Often consists of covering the normal eye, forcing the child to use the deviating one. Exercises and corrective lenses may be ordered. Surgical correction may be necessary. 15 SPECIAL SENSES: EYES

11 Clinically Related Exercise Q: When eyes deviate from the normal position toward various directions, the diagnosis is _____________________. A: strabismus Q: A 5-year-old girl is diagnosed with strabismus. She has a deviation of one eye toward the other eye. This is often referred to as cross- eye. The medical term for this type of strabismus is __________________. A: esotropia Q: A 7-year-old boy displays deviation of the visual axis of one eye toward the other and complains of double vision. The MA charts the symptom of double vision as _________________. A: diplopia Q: Tom’s right eye intermittently deviates away from the other eye. The medical term for this type of strabismus is __________________. A: exotropia SPECIAL SENSES: EYES 15

12 Glaucoma Signs and Symptoms Accumulated fluid pressure within the eye damages the retina and optic nerve, often causing blindness. 15 SPECIAL SENSES: EYES

13 Glaucoma Signs and Symptoms (continued) Common forms develop asymptomatically. Often not detected until irreparable damage occurs to the retinas or optic nerves. When symptoms appear late, they may include aching eyes and visual disturbances such as seeing halos around lights or a noticeable loss of peripheral vision. 15 SPECIAL SENSES: EYES

14 Glaucoma Treatment Standard course of treatment is drug therapy. Certain types of drugs may be applied to the surface of the eye to decrease intraocular pressure. Other drugs may be prescribed that decrease production of aqueous humor. Severe cases employ laser surgery to promote drainage of aqueous humor. 15 SPECIAL SENSES: EYES

15 Clinically Related Exercise Q: The ophthalmologist diagnoses Mrs. J with increased intraocular pressure. The abbreviation for this diagnosis is _____________. A: IOP Q: A 67-year-old is diagnosed with glaucoma. The physician prescribes eye drops to decrease aqueous humor production in the eyes. This type of medication is known as an _____________________ agent. A: antiglaucoma Q: Mary presents with complaints of aching eyes and seeing halos around lights. The ophthalmologist finds an increase in intraocular pressure and charts the diagnosis as ________________________. A: glaucoma Q: The patient asks the ophthalmologist about complications of not treating her glaucoma. A: He tells her that accumulated fluid produces pressure within the eye which damages the retina and optic nerve, and leads to total loss of vision. SPECIAL SENSES: EYES 15

16 Medical Vocabulary achromatopsia apnea astigmatism blepharospasm conjunctivitis dacryorrhea diabetic retinopathy diplopia 15 SPECIAL SENSES: EYES

17 Medical Vocabulary (continued) hordoleum Purulent inlammatory infection of a sebaceous gland of the eyelid; also called sty. 15 SPECIAL SENSES: EYES

18 Medical Vocabulary (continued) iridotomy macular degeneration 15 SPECIAL SENSES: EYES

19 Diagnostic Procedures Tonometry Detects glaucoma by measuring increased intraocular pressure Visual acuity test 15 SPECIAL SENSES: EYES

20 Word Building Exercise Q: Instrument to measure hearing: A: audiometer Q: Examination of the pupil: A: pupilloscopy Q: Act of measuring tension: A: tonometry Q: Inflammation of the retina: A: retinitis Q: Fear of light: A: photophobia Q: Paralysis of the eye: A: ophthalmoplegia 15 SPECIAL SENSES: EYES

21 Medical and Surgical Procedures Cataract surgery Phacoemulsificati on Iridectomy SPECIAL SENSES: EYES 15

22 Medical and Surgical Procedures Laser photocoagulation Seals leaking or hemorrhaging retinal blood vessels associated with diabetic retinopathy. Light from laser creates heat that coagulates the tissues. SPECIAL SENSES: EYES 15

23 Clinically Related Exercise Q: During eye surgery the ophthalmologist asks for the surgical instrument to incise the cornea. This instrument is called a ____________. A: keratotome Q: After undergoing cataract surgery, a patient is unable to see. The ophthalmologist suggests a surgical procedure that requires an incision into the colored muscular layer that surrounds the pupil. This portion of the eye is known as the ____________________. A: iris Q: A 62-year-old patient with drooping eyelids that impair her sight requires surgery. The procedure for a surgical repair of the eyelids is referred to as ___________________________. A: blepharoplasty Q: Zia is diagnosed with glaucoma and is scheduled for an excision of a portion of the iris to relieve intraocular pressure. This excision of the iris is documented in the medical record as an __________________. A: iridectomy 15 SPECIAL SENSES: EYES

24 Pharmacology Antiglaucoma drugs Miotics Mydriatics 15 SPECIAL SENSES: EYES

25 Clinically Related Exercise Q: Prior to an eye examination, the technician administers an agent to dilate the pupils, which is known as a(n) (antiglaucoma drug, miotic, mydriatic). A: mydriatic Q: The nurse administers drops to constrict the pupils. This medication is known as a(n) (antiglaucoma drug, miotic, mydriatic). A: miotic Q: To reduce intraocular pressure by lowering the amount of aqueous humor in the eyeball and increase aqueous humor outflow, a(n) (antiglaucoma drug, miotic, mydriatic) is prescribed. A: antiglaucoma drug 15 SPECIAL SENSES: EYES