Standard

Posted: 03/17/08

R State Standard £ Institutionally Developed College: N/A

OPD 108 – Contact Lens Instrumentation

Course Description

Introduces students to the contact lens field. Emphasis is placed on the development of contact lenses to correct visual defects, types of contact lenses, and consumer selection. Topics include: safety and environmental procedures; contact lens history; contact lens instruments;, contact lens terminology; corneal topography; lens types, prefitting evaluation, examination and patient/lens selection; and adverse effects of lens wear.

Competency Areas	Hours
Safety and Environmental Procedures	Class	5
Contact Lens History	D. Lab	0
Contact Lens Instruments	P. Lab/O.B.I.	3
Contact Lens Terminology	Credit	6
Corneal Topography
Lens Types
Prefitting Evaluation , Examination and Patient/Lens Selection
Adverse Effects of Lens Wear

Prerequisite:	OPD 102, Program admissions
Corequisite:

Course Guide

Competency	After completing this section, the student will be able to:	Hours
		Class	D.Lab	P.Lab/ O.B.I.
SAFETY AND ENVIRONMENTAL PROCEDURES		2	0	0
Safety	Describe safe practices to include environmental procedures.
	Practice safety measures to include environmental procedures.
CONTACT LENS HISTORY		8	0	0
Early concepts	Discuss the optical systems Leonardo Da Vinci described in the sixteenth century.
	Explain corneal neutralization as conceived by Rene Descartes in the seventeenth century.
	Describe the apparatus developed by Thomas Young in the early nineteenth century for the study of ocular structure.
	Describe the method proposed in the nineteenth century by Sir John F. W. Herschel for the compensation of an irregular cornea.
Contact lens invention	Compare and contrast the contact lens systems proposed by the late nineteenth century inventors Fick, Kalt, and Muller.
Glass contact lenses	Discuss the development of glass contact lenses and the reason they were discarded.
Plastic contact lenses	Discuss the development of plastic contact lenses and the limitation of the initial designs.
Corneal contact lenses	Discuss the work of Kevin Tuohy in perfecting corneal contact lenses.
Hydrogel soft lenses	Discuss the molding process for manufacturing soft lenses and the reason for high production losses.
	Discuss the development of the spin casting process used to manufacture soft lenses and the reason for high production losses.
	Discuss the development of the spin casting process used to manufacture hydrogel soft lenses.
Gas permeable contact lenses	Discuss the disadvantage of PMMA contact lenses which prompted development of a gas permeable material.
	Discuss the research efforts of Norman Gaylord in the development of gas permeable contact lens material.
Trends	Discuss the trend in new materials and processes for the manufacture of contact lenses.
CONTACT LENS INSTRUMENTS		10	0	10
Biomicroscope	Name the major parts of the biomicroscope used to examine the human eye.
	Describe the procedure used to operate a biomicroscope when examining the cornea.
	Use the biomicroscope to examine the cornea.
	Discuss what is observed when using the biomicroscope to perform an optic section.
	Use the biomicroscope to perform an optic section.
	Describe the biomicroscope procedure used when obtaining a parallelepiped examination.
	Use the biomicroscope for a parallelepiped examination.
	Discuss the use of the biomicroscope in retroillumination.
Keratometer	Explain the basic principles used in measuring corneal curvature with a keratometer.
	Name the major parts of a keratometer.
	Describe the calibration procedure used to standardize the keratometer.
	Calibrate a keratometer.
	Describe the procedure used to increase the accuracy of measurements obtained with a keratometer.
	Describe the procedure used to increase the range of a keratometer.
	Use a keratometer to measure corneal curvature.
Optical spherometer	Name the major parts of an optical spherometer.
	Describe the procedures used to measure the concave and convex curvatures of contact lenses with an optical spherometer.
	Use an optical spherometer to measure concave and convex curvatures of contact lenses.
	Describe the procedure used to measure toric base contact lenses with an optical spherometer.
	Use an optical spherometer to measure toric base contact lenses.
	Describe the procedure used to measure center thickness of a contact lens with an optical spherometer.
	Use an optical spherometer to measure center thickness of a contact lens.
	Describe the procedure used to measure the secondary (peripheral) curve of a contact lens with an optical spherometer.
	Use an optical spherometer to measure the secondary (peripheral) curve of a contact lens.
Pachometer	Name the major parts of the pachometer.
	Discuss the use of the pachometer in fitting contact lenses.
	Describe the procedure used when making measurements with the pachometer. Calibrate the pachometer. Use the pachometer for peripheral corneal measurements.
CONTACT LENS TERMINOLOGY		5	0	0
Terminology	Define the term anterior optic zone diameter.
	Define the term anterior peripheral curve.
	Define the term diameter as it relates to contact lenses.
	Define the term posterior central curve radius.
	Define the term posterior optic zone diameter.
	Define the term posterior peripheral curve.
	Define the term posterior peripheral curve width.
	Define the term posterior secondary.
	Define the term posterior secondary curve.
	Define the term radius as it relates to a contact lens.
	Define the term transition zone as it relates to a contact lens.
	Name the organization that standardizes terminology associated with the manufacturing of contact lenses.
CORNEAL TOPOGRAPHY		5	0	0
Classical concept	Define the corneal cap.
	Name the zones of the cornea according to the classical concept.
	Compare the cap diameter and peripheral zone width with the chord diameter.
Contour measurements	Name the zone of the cornea which is measured by a keratometer.
	Discuss the relationship of the K reading to corneal contour.
	Discuss the problems of obtaining an accurate measurement of the cornea using a keratometer.
	Contrast and compare the keratometer, small-mire keratometer, photo keratometer, and template methods of measuring corneal contour.
LENS TYPES		5	0	5
Monocurve	Describe the construction of monocurve contact lenses.
	Discuss the limitation of monocurve contact lenses.
Bicurve	Describe the construction of bicurve contact lenses.
	Explain the difference between band width and chord width measurements of the peripheral curve of bicurve contact lenses.
Tricurve	Describe the construction of tricurve contact lenses.
Multicurve	Describe the construction of multicurve contact lenses.
	Compare and contrast monocurve, bicurve, tricurve, and multicurve contact lenses.
Front bevel	Describe the location of a front bevel on a contact lens.
	Discuss the purpose for adding a front bevel to a contact lens.
Posterior bevel	Describe the location of a posterior bevel on a contact lens.
	Discuss the purpose for adding a posterior bevel to a contact lens.
PREFITTING EVALUATION, Examination and Patient/Lens Selection		10	0	10
Consultation	State the purpose of a consultation between the contact lens practitioner and the potential wearer.
Contact lens wear	Discuss the criteria for successfully wearing contact lenses.
Vision	Discuss reports of improved visual acuity by contact lens wearers when compared with acuity from spectacles.
Adaptability	Discuss expected adaptation period among soft and hard contact lens wearers.
Appearance	Describe changes in appearance resulting from contact lens wear.
Loss within eye	Explain why movement of a lens to a point behind the eye is not possible.
Occupations	Discuss cases in which contact lens wear has prevented serious eye injury.
Fees	State the reasons for use of a written fitting agreement.
Fitting agreement	Describe the minimum amount of information contained in a completed fitting agreement.
Lens loss	Discuss procedure available to offset the financial cost of replacing lost lenses.
Legal considerations	Define the term informed consent.
	Explain the purpose of a contact lens prescription release.
Record keeping	Discuss the contents of a contact lens examination form.
Prognosis	Describe the conditions which indicate acceptance of contact lens wear.
ADVERSE EFFECTS OF LENS WEAR		5	0	5
Rejection	State the percentage of rejection among customers fitted with trial lenses.
	Explain the conditions which may lead to rejection on the part of a potential contact lens wearer.
Vision	Discuss reports of decreased visual acuity by contact lens wearers when compared with acuity from spectacles.
Safety	Describe possible injury which may arise from contact lens wear.
Occupations	Describe occupational conditions under which contact lens wear should be avoided.
	Discuss possible problems of contact lens wear while viewing computer display monitor.
Prognosis	Describe the conditions which indicate rejection of contact lens wear.

Suggested Resources

Mandell, R. B. (1988). Contact Lens Practice (4^th ed.). Springfield, IL: Charles C. Thomas.

Soper, J. W., et al. (1984). Adverse Effects of Contact Lenswear: An Atlas for Ophthalmic Practitioners. Thorofare, NJ: Slack.

Stein & Slatt. (1990). Fitting Guide for Rigid and Soft Contact Lenses (3^rd ed.). St. Louis: Mosby.