Portland Community College | Portland, Oregon

Course Number:
OMT 206
Course Title:
Diagnostic Procedures I
Credit Hours:
4
Lecture Hours:
30
Lecture/Lab Hours:
0
Lab Hours:
30
Special Fee:
$12.00

Course Description

Introduces fundamentals of diagnostic testing and techniques including: applanation tonometry, slit lamp biomicroscopy, Goldmann and automated perimetry, ocular motility and advanced keratometry. Emphases building clinical skills.

Addendum to Course Description

Updating CCOG's so that teaching material does not overlap other courses in the program.

Intended Outcomes for the course

Upon successful completion students should be able to:

1. Skillfully complete patient workup in a clinical setting.
2. Accurately perform and document the biomicroscopy and visual field examination, retinoscopy and refractometry in the clinical setting.
3. Efficiently and accurately perform applanation tonometry under supervision in a clinical setting.

Outcome Assessment Strategies


At the beginning of the course, the instructor will detail the methods used to evaluate student progress and the criteria for assigning a course grade. The methods may include one or more of the following tools: examinations, quizzes, homework assignments, research papers, laboratory modules, student participation and demonstration of competency.

Course Content (Themes, Concepts, Issues and Skills)

LENSOMETRY

  • Demonstrate proficiency in reading glasses: single vision torics, bifocals, trifocals, progressives, and its proper recording in a medical record.

  • Demonstrate proficiency in marking the optical center and measuring the PD of glasses.

  • Demonstrate measuring glasses with prism using the PCD, and calculating compound prism.  

  • Discuss the significance of vertex distance.

INTERMEDIATE VISUAL FIELDS

  • Review and demonstrate Amsler grid, confrontational fields, tangent screen and automated visual field testing.

  • List and describe manual techniques for testing the visual field including tangent screen, and Goldmann perimetry.

  • Describe the use of an arc shaped perimeter for DMV fields.

  • List automated methods for testing the visual field.

  • Define: false positive, false negative, fixation losses and acceptable percentage for a quality field.

  • Identify the indication for the following tests with the Humphrey Field Analyzer: Full Threshold vs. SITA Standard vs. SITA Fast. 30-2, 24-2, 10-2, 60-4, Superior 36, Superior 64, Esterman monocular/binocular test.

  • Describe the process of the HFA for calculating the trial lens power for the test, and the proper position of trial lenses in the lens holder.

  • Demonstrate calibration of the Goldmann perimeter, including both stimulus and background.

  • Describe when corrective lenses are required and for which portion of the Goldmann perimetry procedure.

  • Demonstrate plotting a peripheral and a central isopter, blind spot, and static check with a Goldmann perimeter.

  • Distinguish the difference between static and kinetic field testing.

  • Differentiate testing strategies for glaucoma and neurological examinations.     

  • Describe the procedure for confirming steps with respect for the horizontal or vertical meridian.

  • Describe screening of possible malingering patient with tangent screen and expected results.

SLIT LAMP BIOMICROSCOPY

  • Describe the history and evolution of the slit lamp biomicroscope.

  • Describe two major styles of slit lamps.

  • Define coaxial as it relates to the slit lamp.

  • Differentiate magnification vs. illumination in isolating pathology with the slit lamp.

  • Describe the procedure for properly setting each eyepiece of the slit lamp microscope.

  • List 6 direct and 6 indirect forms of illumination with the slit lamp.

  • Describe the use and technique for each of the following forms of illumination: diffuse, parallel piped, optical sectioning, tangential, conical beam, specular reflection, proximal illumination, sclerotic scatter, direct retro-illumination from the iris, indirect retro-illumination from the iris, retro-illumination from the fundus and iris transillumination.

  • List the different filters available on the slit lamp and their usage.

  • Describe the vital dyes and their usage when used with the slit lamp including: Fluorescein, Rose Bengal and Lissamine green.

  • Describe when the Seidel test is used and how it is performed, and how it is documented.

  • Describe when the Tear Break up Time test is performed and how it is documented.

  • Describe accessory lenses available to use with the slit lamp microscope; why and how they should be used.

  • Differentiate between direct and indirect gonioscopic lenses.

  • Describe basic set-up and of the slit-lamp and basic procedure when scanning the eye.

  • Utilize biomicroscopy to perform and document an anterior segment and ocular adnexa examination.

  • Identify and document normal slit lamp findings.

  • Describe the grading system to document abnormal slit lamp findings.

  • Identify common terminology used to describe abnormal slit lamp findings.

  • Demonstrate proficiency of estimating the anterior chamber using the Van Herick€™s technique.

  INTERMEDIATE TONOMETRY

  • Describe the differences in tonometers.

  • Outline the advantages and disadvantages of each kind of tonometer.

  • Explain how to use each tonometer.

  • Decide which instrument to use to accomplish the measurement with greatest accuracy, efficiency, and least amount of discomfort to the patient.

  • Discuss proper methods of cleaning and list 3 acceptable methods for disinfecting tonometers.

  • Discuss technique for each method of tonometry: non-contact, Tono-Pen, Schiotz, pneumotonometer, hand-held tonometers, MacKay-Marg, I-Care tonometer and Goldmann applanation.

  • Describe the proper end point image in Goldmann applanation tonometry.

  • Identify the position of the mires (overlapping, separate, uneven, too thick, too thin€¦) and how it relates to pressure reading.

  • Describe interpretation of the measuring dial of a Goldmann applanation tonometer in recording intra-ocular pressure.

  • Describe and give the proper abbreviation of the units measured in tonometry.

  • Describe the intra-ocular changes during the systole and diastole of the heartbeat.

  • Describe the proper rotation of the tonometer prism head for patients with corneal cylinder of more than 3 diopters.

  • Demonstrate the process of checking calibration of a Goldmann applanation tonometer in all three measurement ranges.

  • Demonstrate checking calibration of TonoPen and proper measurement technique including replacement of OcuFilm tip covers.

  • Demonstrate disinfecting each instrument.

  • Perform and document applanation tonometry with a tono-pen and Goldmann.  

  • Describe the procedure for non-contact tonometry.

  • Describe the procedure for indentation tonometry.

  • Describe Schiotz tonometry including checking of calibration, cleaning and assembly.

  • Describe when additional weights are required in measurement with Schiotz tonometers.

  • Describe how central corneal thickness relates to measurement of intra-ocular pressure readings.

  • Describe how intra-ocular pressure readings are converted for thick or thin corneas.

  • List 3 types of patients contraindicated for tonometry.  

  • Review common glaucoma drops and possible side effects.

RETINOSCOPY

  • Describe the history and evolution of the retinoscope.

  • State and explain the principles of and indications for retinoscopy.

  • Describe the mechanism and functioning of the streak retinoscope.

  • Describe the various types of behavior of the retinoscopic streak.

  • Explain the recording of retinoscopic results and transpose those results into sphero-cylinderical form.

  • Perform retinoscopy on the human eye.

  • Demonstrate appropriate maintenance of various retinoscopes.

  • List at least 3 types of patients for whom retinoscopy is critical because refractometry cannot be performed.

  • Describe the proper setup, with both phoropter and trial frames, for performing retinoscopy.

  • Describe the reasons for both fogging the fellow eye and having the fellow eye un-occluded during retinoscopy.

  • Describe proper sleeve position for both the Copeland type and Welch Allyn types of retinoscopes.

  • Describe the purpose of using a working lens or subtracting working distance from the patients retinoscopic findings.

  • Review the calculation of the working distance.

  • List the steps performed when retinoscoping in plus cylinder.

  • Determine the cylinder axis using various phenomena: Thickness, Intensity, Break/Skew phenomenon.

  • Confirm the axis using the €œstraddling the axis€ technique.

  • Explain the use of the double spheremethod in retinoscopy, and demonstrate.

  • Practice scoping with a sciascopy lens rack and describe its indications.

  • List the types of motion observed in patients with emmetropia, myopia, hyperopia and astigmatism.

  • List the types of lenses used to neutralize motion in myopes, hyperopes and astigmats.

  • Describe a method of confirming that neutrality has been achieved in retinoscopy.

  • Describe techniques to avoid reflection/artifacts when scoping.

  • Give estimated spherical refractive errors for patients with visual acuities of: 20/80, 20/200, 20/400, and worse than 20/400.

  • Explain how keratometry findings can help in finding proper correction of axis in retinoscopy.

  • Describe a retinoscopic reflex in patients with high refractive error.

REFRACTOMETRY

  • Differentiate between refraction and refractometry.

  • Define emmetropia, ametropia, hyperopia, myopia and astigmatism.

  • Describe symptoms of myopes, hyperopes and astigmats.

  • Identify all knobs, dials and parts of the phoropter.

  • List the five main steps in refractometry.

  • List at least 5 rulesto use during refractometry.

  • Describe the proper use of the Jackson Cross Cylinder in testing both cylinder axis and power (in plus cylinder).

  • Describe the 4-Step Test when looking for cylinder power when spheres alone do not correct vision adequately.

  • Describe the astigmatic clock and its usage.

  • Describe the duochrome test and its usage in preventing over-minusing.

  • Describe the principle of binocular balancing and how it is performed.

  • Describe the principle of the fogging technique and how it is performed.

  • Describe prism dissociation method and how it is performed to balance a refraction.

  • Define aphakiaand pseudophakia.

  • Describe techniques to use with aphakic patients.

  • Describe trial frames and loose lenses distinguish how refractometry with these is different than that with a phoropter.

  • Define vertex distance and explain when/how it is measured in performing refractometry.

  • Define Halberg Clipsand explain when/how they are used when over-refracting.

  • Define presbyopia and list common symptoms.

  • List estimated adds for each agefor each group of presbyopes.

  • List the process for checking the patients near rangewith adds in place.

  • List three methods of measuring amplitude of accommodation.

  • Describe subjective and objective methods of measuring refractive error.

  • Explain the refinement technique using a cross cylinder lens.

  • Describe the difference between manifest and cycloplegic refractometry and indications.

  • List and review mydriatic and cycloplegic drops.

ADVANCED KERATOMETRY

  • Describe the history of the keratometer.
  • Demonstrate proficiency in reading K€™s.

  • Identify the benefits of keratometry in contact lens fittings, retinoscopy and refractometry.

  • Demonstrate extending the range of the keratometer