OPT505 Lecture 14: Routine Refraction Basics

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Questions and Answers

What is the primary objective of binocular balancing in routine refraction?

To ensure each eye has a different prescription.

To prevent any interaction between the two eyes during testing.

To achieve an even distribution of accommodation between the eyes. (correct)

To maintain equal visual acuity between both eyes.

Which statement is true regarding latent hyperopia?

It only occurs in one eye and does not affect binocular vision.

It is completely invisible and cannot be detected in a routine examination.

It results solely from age-related changes in the eye.

It can lead to unbalanced accommodation if not addressed appropriately. (correct)

What is a common consequence of unbalanced accommodation between the eyes during refraction?

Asthenopia, or eye strain, may occur. (correct)

A complete failure of the visual system.

Increased visual acuity in one eye.

Enhanced depth perception in the affected eye.

Why is the procedure for monocular refraction significant in routine eye examinations?

It allows for individual assessment of each eye’s refractive needs. Signup and view all the answers

Which element is NOT part of the basic mini routine of BR-TY-RN for eye examination?

Measurement of both eyes simultaneously. Signup and view all the answers

What is the significance of a retinoscopy result of R+1.25/-1.00 x 180 for Mr. Abdul Khan?

Indicates he has a hyperopic refractive error with some astigmatism Signup and view all the answers

How does age affect the ability to accommodate in hyperopes?

Accommodative ability decreases with age Signup and view all the answers

What is one characteristic of hyperopia in children mentioned in the content?

It is considered amblyogenic if anisometropic greater than 1.5 diopters Signup and view all the answers

What condition is Ms. Sara Kalique likely experiencing based on her provided details?

Binocular vision dysfunction with significant exophoria Signup and view all the answers

What is one reason for low tolerance or understanding of hyperopia in early presbyopes?

Previous latency is often no longer sufficient Signup and view all the answers

What is the purpose of occluding one eye during retinoscopy?

To evaluate monocular refraction Signup and view all the answers

Which technique is typically used when fusional vergence is present during monocular subjective refraction?

Modified Humphriss Signup and view all the answers

What should be added to the right eye after occluding the left eye for retinoscopy for 1-2 seconds?

+0.25DS Signup and view all the answers

When performing binocular balance, which method utilizes a polarized chart?

Humphriss Immediate Contrast Signup and view all the answers

Which of the following combinations effectively refines the spherical component during refraction?

Binocular Add and Binocular Balance Signup and view all the answers

What characteristic is unique to the Turville Infinity Balance method?

It offers a virtual target at infinity Signup and view all the answers

What occurs to the central vision of the left eye during the occlusion process?

It becomes suppressed Signup and view all the answers

During binocular fogging, which technique is employed to create visual blur?

Blur LE back about 3 lines Signup and view all the answers

What is the purpose of binocular addition in retinoscopy?

To offer maximum plus to patients during near work Signup and view all the answers

Which of the following steps is performed after binocular balancing?

Un-occlude the right eye Signup and view all the answers

What is the initial fogging prescribed for the left eye during binocular refraction?

+0.75DS to +1.00DS Signup and view all the answers

What is the final requirement after performing the refraction stage in retinoscopy?

To document findings accurately and clearly Signup and view all the answers

How does monocular fogging contribute to accommodation relaxation?

It reduces the accommodative demand on one eye Signup and view all the answers

What is the role of the binocular vision status (BVS) during the procedure?

To determine the quality of binocular balance Signup and view all the answers

In the context of binocular addition, why might it be unnecessary to perform this step?

Because monocular fogging already provides necessary accommodation relief Signup and view all the answers

What should be done after fogging the left eye during the binocular refraction procedure?

Check the end visual acuity using a standard chart Signup and view all the answers

What characterizes latent hyperopia?

Clear distance vision due to ciliary muscle tonus Signup and view all the answers

Which type of hyperopia is uncorrectable by the ciliary muscle's effort?

Absolute hyperopia Signup and view all the answers

What is a common management strategy for latent hyperopia?

Control accommodation during retinoscopy Signup and view all the answers

What is the first action to take after checking the end visual acuity (VA)?

Remove fogging lenses Signup and view all the answers

At what point should cycloplegia be considered in evaluating hyperopia?

When binocular issues like esotropia are suspected Signup and view all the answers

What might indicate the need for gradual increase in prescriptions for latent hyperopia?

Significant differences in binocular vision results Signup and view all the answers

When might occluding the left eye be necessary during binocular refraction?

When the patient experiences double vision or discomfort Signup and view all the answers

Which drop percentage is used for cycloplegia in hyperopia assessment?

1.0% cyclopentolate hydrochloride Signup and view all the answers

What should be considered if a patient's pupil size is small during refraction?

Changes in prescription should be minimized due to minimal blur difference Signup and view all the answers

What should be done if there is uncertainty about giving the plus prescription?

Target the middle of the clarity range or reduce the extreme plus Signup and view all the answers

Which of the following defines facultative hyperopia?

Amount of hyperopia correctable with maximum accommodation Signup and view all the answers

In the case of Miss Jenny Peters, what should be checked after retinoscopy with +1.00 blur?

The clarity of her visual acuity Signup and view all the answers

What is an essential component when dealing with manifest hyperopia?

Determining the residual hyperopia after ciliary muscle adjustment Signup and view all the answers

What is a clinical consideration when a change in prescription exceeds +0.50 DS?

It could suggest over-plussing or a genuine need for correction Signup and view all the answers

During binocular refraction, what is the goal when selecting the lens power?

To achieve the most plus power with the best VA Signup and view all the answers

What could increase the difficulty in detecting a 0.25 change during refraction?

Excessive media opacification Signup and view all the answers

Study Notes

NUT-FREE ZONE

Images show various foods and personal care products.
A sign warns of a nut-free zone.

LECTURE RECORDING

The lecture is being recorded.
The recording will be available on the module DLE pages.
Students can comment or ask questions.
Questions may appear on the recording.
Participants can ask to pause recording if they do not want their questions to be included.

OPT505 LECTURE 14: BUILDING A ROUTINE REFRACTION

The lecture is about building a routine refraction.
The lecturer is Ellie Livings.

INTENDED LEARNING OUTCOMES

Understand 'basic routine'.
Monocular v binocular refraction.
Binocular balancing.
Latent hyperopia.

PRINCIPLES OF EYE EXAMINATION OR SIGHT TEST

Internal and external examinations are required.
Additional tests are necessary to detect injury or disease.
The same optometrist should conduct the entire episode of care, unless transferred.
Responsible optometrist interprets findings.
Automated instruments, such as visual field analyzers, are part of examination.

KEY POINTS

There is a suggested equipment list (Annex 1).
All clinical findings must be recorded.
Sufficient time must be allowed for the examination.
The format and content of the examination are based on professional judgement and legal requirements.
An 'episode of care' in the context of eye exam encompasses the entire care journey from initial testing to final prescription.

BASIC MINIMUM ROUTINE

Introduction (Intro), health & safety (H&S), prelims.
Objective refraction.
Subjective refraction.
Supplementary tests.
Health assessment.
Record management.
Time estimate per section in minutes.

PROCEDURE FOR MONOCULAR REFRACTION

Follow red arrows.
Retinoscopy using occlusion of one eye, followed by un-occlusion.
Refraction of each eye, including best vision spherical (BVS) and cylinder (x-cyl) measurements.
Refine spherical values.
Obtain VA values for each eye.
Plus 1 blur.
Un-occlude and Balance both eyes.
Binocular Add (+0.25DS).

BINOCULAR CONSIDERATIONS

Most people have binocular vision.
Accommodation balance between eyes is needed.
Accommodation is not independent, eyes need to accommodate together.
Unbalanced accommodation can lead to asthenopia.

WHAT'S THE PROBLEM WITH OCCLUSION?

Occlusion can dilate the pupil and result in refractive changes from spherical aberration.
Occlusion can mask latent nystagmus and make subjective refraction difficult.
Incorrect assessment of astigmatism could result from occlusion.
Occlusion stimulates accommodation.

ACCOUNTING FOR ACCOMODATION AND BINOCULARITY

Refraction can be completed separately monocularly, or as a combined binocular process.
Blurry vision of one eye when refactoring leads to suppression of central vision but peripheral fusion is maintained for binocularity.

PLUS 1 BLUR

Shows visual acuity (VA) when one eye is blurred by 1 diopter (plus 1).
Diagram shows visual acuity for each eye on a scale.

ACCOMMODATIVE BALANCE

Diagram with measurement scales indicating accommodation for each eye.

MONOCULAR V BINOCULAR REFRACTION

Separated monocular refraction process for each eye.
Combined binocular refraction process encompassing both eyes.
Monocular subjective approach required when binocular accommodation is not a concern.

SUBJECTIVE REFRACTION

Monocular subjective testing method for people with poor binocular vision.
Binocular subjective method for people with normal binocular vision.
Pros and cons of each type of subjective testing.

WHO GETS BINOCULAR BALANCING/REFRACTION?

People with monocular vision.
People with deep amblyopia.
People with strabismus.
People with very poor VA in one eye.

TECHNIQUE 1: MONOCULAR SUBJECTIVE + BINOCULAR BALANCE

Monocular refraction (RE/LE).
Binocular balancing.
Binocular add.
Record final Rx with final VA values.
Retinoscopy steps for each eye.

MONOCULAR SUBJECTIVE + BINOCULAR BALANCE: OPTIONS

Multiple refracting techniques to measure binocular balance.
Techniques for cases with or without fusional vergence present.

RELAXING ACCOMMODATION EQUALLY IN BOTH EYES

Methods such as Modified Humphriss, Humphriss Immediate Contrast, and Prism Dissociated Balance for better binocular accomodation.

MODIFIED HUMPHRISS

Steps to accurately determine appropriate lens power for patient.
Instructions on what to ask the patient.

CASE SCENARIOS

Case studies providing specifics such as patient age, eye condition, and retinoscopy results to indicate the need for monocular or binocular refraction.

CYCLOPLEGIC COMPARISON

Table comparing different cycloplegic drugs based on dose, maximum cycloplegia time, duration of action, tonus allowance, and residual accommodation.

DEALING WITH LATENT HYPEROPIA

Strategies to manage latent hyperopia focusing on subjective and binocular refraction, prescribing adjustments, monitoring cover tests, and patient communication.

CYCLO

Issues to consider with unstable ret reflex testing.
When binocular issues are suspected.
History of amblyopia/high plus.
Unequal vision/VA without refractive causes.

WHAT DROPS?

Cycloplegic eye drops are available to temporarily paralyze the ciliary muscles.
Description of different drops, including effects, duration and recovery time.

PRESCRIBING POST-CYCLO

Instructions for referring patients appropriately and measuring visual acuity pre and post procedure, reducing prescription as required, and communicating with parents.

BACKGROUND LEARNING

Suggested activities for review prior to attending the session on these topics. (Reading specific lab book sections, reviewing Moodle resources, studying and preparing for the full routine procedure, reviewing health, safety, prelims, and management).

Studying That Suits You

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Description

This quiz covers the essential principles of routine refraction as discussed in OPT505 Lecture 14 by Ellie Livings. You'll explore fundamental concepts such as monocular and binocular refraction, balancing techniques, and the importance of thorough eye examinations. Test your knowledge on key learning outcomes and critical practices in optometry.