Ocular examination procedure &Office Instrumentation : Ocular examination procedure &Office Instrumentation
Section Objectives : Section Objectives Recognize and describe the purpose of ophthalmic instruments commonly found in the office of an eye care practitioner
Describes the clinical procedure of contact lens fitting
Contact Lens Fitting &Office Instrumentation : Contact Lens Fitting &Office Instrumentation The eye care professional utilize a variety of instruments to assess visual acuity and ocular health
The goal of fitting contact lens is to satisfy patient’s needs on visual, cosmetic & health requirement.
In-Office Instrumentation : In-Office Instrumentation Discussion of instruments are grouped in four categories:
Basic eye exam
Contact lens exam
Evaluating spectacles and contact lenses
Ophthalmic research
Eye examination & CL Fitting Procedure : Basic Eye Exam
History taking
Refraction
Slit Lamp Examination
Ophthalmoscopy Contact Lens Exam
Keratometry
Trial Fitting
Over-refraction
Lens Delivery
Education on contact
lens wear
Aftercare visit Eye examination & CL Fitting Procedure
Basic Eye Exam : Basic Eye Exam History taking
Visual acuity measurement with Snellen Chart
Objective refraction with Autorefractor / Retinoscope
Subjective refraction with Phoropter or Trial Frame
External eye examination with Slit Lamp
Internal eye examination with Opthalmoscope
History Taking : Reason for contact lens
Understands patient expectation & motivation
Contact lens history
General health condition
Ocular health condition
Any medication taken
Occupational, recreational, environmental factors History Taking
Clinician’s Abbreviations : Clinician’s Abbreviations In US:
O.D. (ocular dextrus): viewing with right eye only
O.S. (oculus sinister): viewing with left eye only
O.U. (oculus uterque): viewing with both eyes
In UK:
it is just known as plain
R.E. (Right Eye): viewing with right eye only
L.E. (Left Eye): viewing with left eye only
BVA (Binocular): viewing with both eyes
Visual Acuity: Snellen Chart : Visual Acuity: Snellen Chart Measure of the eye’s ability to detect or resolve detail
Measured with Snellen chart by reading letters at specific distance
Visual acuity is expressed as a fraction 20/20 (US) or 6/6 (UK)
20/20 means patient can read the 20/20 line on chart at a distance of 20 feet
6/6 means patient can read the 6/6 line at a distance of 6 meters 60
36
24
18
12
9
6
5
4.5
4
3
Objective Refraction: Retinoscope : Objective Refraction: Retinoscope Objective refraction – measures refractive status of the eye independent of patient responses
Observes reflection of light from retina using retinoscope
Objective Refraction: Autorefractor : Objective Refraction: Autorefractor Evaluates patient’s refractive error by electronically assessing reflection of light from retina
Results are estimates and require refinement with phoropter
Subjective Refraction: Trial Frame : Subjective Refraction: Trial Frame A variety of trial lenses and other optical devices can be put into trial frame for assessing patient’s vision
Provides subjective assessment of patient’s refractive status
Subjective Refraction: Phoropter : Subjective Refraction: Phoropter Phoropter contains a variety of lenses and other optical devices for assessing patient’s vision
Provides subjective assessment of patient’s refractive status
External Eye Examination: Slit Lamp : External Eye Examination: Slit Lamp Slit lamp is a biomicroscope with special lighting system for the observation of structures of the anterior eye
Also evaluates fitting of contact lenses on the eye
External Eye Examination: Slit Lamp : External Eye Examination: Slit Lamp
Internal Eye Examnination: Ophthalmoscope : Internal Eye Examnination: Ophthalmoscope Ophthalmoscope is a special optical device with lighting system for the observation of inside of the eye
Evaluates internal structures of the eye
Ophthalmoscope : Direct Ophthalmoscopy Ophthalmoscope
Examination of the retina : Examination of the retina Direct ophthalmoscopy
No pupil dilation
Magnified view
Cannot examine the periphery of the retina
More useful in examination of the macular & Optic nerve head Indirect Ophthalmoscopy
Pupil dilation required
No / low magnification
Give a wider view of the retina (up to Ora Serrata)
Provide a stereoscopic (3D) image
Use in thorough exam of the retina (retinal degeneration or detachment)
Instruments in a CL Exam : Instruments in a CL Exam Central corneal curvature measured with Keratometer
Central/ peripheral corneal curvature measured with Autokeratometer
Whole corneal curvature measured with Corneal Topography
Corneal Curvature: Keratometry : Corneal Curvature: Keratometry An optical device that measures corneal curvature by measuring the image size from reflection of cornea
Measures radius of curvature over central three millimeters of cornea
Corneal Curvature: Autokeratometer : Corneal Curvature: Autokeratometer Provides option to measure central & peripheral corneal curvature
Provides corneal measurement automatically
Corneal Topography : Provides information about corneal shape over most corneal surface
Orbscan also provides topographic data on corneal thickness
Most useful for:
refractive surgery
corneal problems, e.g. Keratoconus
RGP fitting, e.g. Ortho-K Corneal Topography
Trial Fit : Discussion on the choices of CL
Initial selection for trial fit
Hydrogel
Disposable
PRP Lens
RGP
Determines on-eye lens performance and allows patients to experience contact lens wear Trial Fit
Trial Fit : Select lens parameters according to manufacturer’s recommendation
Check lens fitting after 5-15 minutes of initial adaptation
Good fitting for soft contact lens:
Comfortable
Central position & full corneal coverage
Adequate movement
Accurate & stable orientation for torics Trial Fit
Over-refraction : Fine adjustment on final prescription
Patient experiences the visual quality of contact lenses Over-refraction
Lens Delivery : Education on lens care & lens handling
Reassures normal adaptation symptoms
e.g. mild redness, dryness, lens awareness
Recommend wearing time, build up
gradually from 4 hours
Recommend replacement schedule, 1 year
for traditional SCL, 1 year for RGP,
manufacturer’s recommendation for PRD Lens Delivery
Slide 27: Patient daily self test:
see good
look good
feel good
Whenever experience warning signs, patient should remove lenses and seek for professional opinion Patient Education
Aftercare Visit : Critical for continued success of contact lens wear
1st week, 1st month, 3rd month, every 6-month
Follow up on
Wearing condition
Visual acuity
Lens fitting
Lens condition
Lens care condition
Eye health condition Aftercare Visit
Thank You : Thank You