Clinical Optics and Eye Accommodation
43 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is one requirement for attending the clinical lab session?

  • Wearing casual attire
  • Arriving without a name badge
  • Partnering up with fellow students
  • Being on time (correct)
  • What aspect of eye accommodation is expected to decline with age?

  • The capacity for near vision adjustment (correct)
  • The speed of light entering the eye
  • The overall size of the eye
  • The ability to see far distances clearly
  • Which reference material is recommended for understanding theoretical and practical principles of clinical optics?

  • Jones (2010) Modern Visual Science
  • Elliott’s Primary Eye Care
  • Kim's Optometry Handbook
  • Keirl (2007) Clinical Optics and Refraction (correct)
  • Before participating in the presbyopic lab session, what preparatory step is required?

    <p>Read chapter 4, pages 95-100 of Elliott’s Primary Eye Care</p> Signup and view all the answers

    What does understanding normative values for accommodation help to inform when working with patients?

    <p>Choosing an appropriate near addition for various situations</p> Signup and view all the answers

    What is the main reason for prescribing a near ADD?

    <p>To assist with tasks requiring near vision.</p> Signup and view all the answers

    In the given case scenarios, how is the Near ADD calculated?

    <p>By determining the difference between near and distance prescriptions.</p> Signup and view all the answers

    Which method is considered the most reliable for determining the final ADD?

    <p>Age – expected method.</p> Signup and view all the answers

    What factors are considered when analyzing the need for an ADD?

    <p>Tasks performed and symptoms revealed.</p> Signup and view all the answers

    In Case Scenario 1, what is the final value of Near ADD for both eyes?

    <p>+1.25.</p> Signup and view all the answers

    Which technique involves assessing the patient's ability to focus at various distances?

    <p>Amplitude of accommodation.</p> Signup and view all the answers

    What does the ADD value indicate in the context of presbyopia?

    <p>The additional power needed for near tasks.</p> Signup and view all the answers

    Which of the following is NOT a method for determining ADD?

    <p>Ocular alignment assessment.</p> Signup and view all the answers

    What is the tentative addition for a 50-year-old patient reading at 40cm given their accommodation requirement is 2.50D?

    <p>+1.25D</p> Signup and view all the answers

    At what age does presbyopia typically begin when the amplitude of accommodation (AoA) is less than 5D?

    <p>45</p> Signup and view all the answers

    According to the sources, what proportion of the available amplitude of accommodation should an individual ideally be able to exert comfortably when determining the tentative add?

    <p>50</p> Signup and view all the answers

    For a 70-year-old patient, what is the expected tentative add when reading at 40cm?

    <p>+2.50D</p> Signup and view all the answers

    How much accommodation should a 60-year-old person with an expected AoA of 1.00D conservatively retain as a reserve based on Lawrence and Maxwell's recommendation?

    <p>0.5</p> Signup and view all the answers

    For which age group is the expected minimum amplitude of accommodation (min.AoA) exactly equal to 2.50D?

    <p>50</p> Signup and view all the answers

    What tentative addition is suggested for a 55-year-old patient who requires +2.00D at 40cm?

    <p>+2.00D</p> Signup and view all the answers

    Which of the following methods of calculating the tentative add involves using the formula 'Add = WD (D) - 1/2Amp (D)'?

    <p>40</p> Signup and view all the answers

    What happens to the crystalline lens as a person ages?

    <p>It grows heavier and denser.</p> Signup and view all the answers

    At what age does the decline in accommodation begin to significantly affect near vision?

    <p>40 years old.</p> Signup and view all the answers

    Which of the following is a consequence of presbyopia?

    <p>Blurred near vision despite clear distance vision.</p> Signup and view all the answers

    What is the primary role of the ADD provision in presbyopes?

    <p>To shift the blur circle for near vision.</p> Signup and view all the answers

    What optical property of the lens increases with aging, contributing to vision changes?

    <p>Positive spherical aberration increases.</p> Signup and view all the answers

    How does the near point change for a presbyope compared to a younger individual?

    <p>The near point moves further away.</p> Signup and view all the answers

    What is the primary challenge faced by non-spectacle wearers in their 40s when developing presbyopia?

    <p>They must begin using reading glasses.</p> Signup and view all the answers

    Which aspect of accommodation is assessed in pre-presbyopic patients?

    <p>The range of clear vision with a given ADD.</p> Signup and view all the answers

    What is the primary reason individuals experience difficulty focusing on close objects as they age?

    <p>The lens loses its ability to change shape, making it difficult to focus on near objects.</p> Signup and view all the answers

    Which symptom is least likely associated with presbyopia?

    <p>Sudden, bright flashes of light in peripheral vision</p> Signup and view all the answers

    What common misconception about glasses for presbyopia is mentioned?

    <p>Wearing glasses will weaken the muscles in the eyes.</p> Signup and view all the answers

    What happens to the lens when an individual tries to read after prolonged near work?

    <p>The lens muscles become fatigued, making it harder to accommodate.</p> Signup and view all the answers

    Which of the following statements about presbyopia progression is true?

    <p>The lens loses flexibility at a predictable rate with age.</p> Signup and view all the answers

    Which of the following best describes asthenopic symptoms?

    <p>Visual discomfort associated with prolonged near work.</p> Signup and view all the answers

    What does the term 'Add working distance' refer to?

    <p>The distance at which an individual can comfortably read small text.</p> Signup and view all the answers

    Which is a critical factor to consider when determining the final ADD?

    <p>The range specified in previous prescriptions.</p> Signup and view all the answers

    What mathematical formula is used to calculate the near point for a patient aged 70 years?

    <p>Near point = 1 / (WD(D) + 1/2 AOA(D))</p> Signup and view all the answers

    What is the farthest point of the range of clear vision calculated given an AOA of 1.00D and a near add of 2.50D?

    <p>50cm</p> Signup and view all the answers

    In which scenario would bifocals be most suitable?

    <p>For an existing wearer with presbyopia.</p> Signup and view all the answers

    Which type of lens is indicated for first-time varifocal wearers?

    <p>Non-tolerant varifocal lenses.</p> Signup and view all the answers

    What is the primary consideration for determining the range of clear vision?

    <p>Current prescription and working distances.</p> Signup and view all the answers

    What does 'over-plus' caution entail in the context of optical prescriptions?

    <p>Avoiding an excess of plus lenses which could lead to discomfort.</p> Signup and view all the answers

    Study Notes

    Attendance Code

    • Attendance code is displayed on various slides.

    Nut-Free Zone

    • A graphic displays a red octagon with the words "STOP NUT-FREE ZONE".
    • Images of food items, including packaged snacks and nuts are included.
    • Images of beauty products are also part of the graphic.

    Lecture Recording Information

    • This lecture is being recorded.
    • The recording will be available via the Panopto block on the module DLE pages.
    • Students can ask questions or make comments.
    • If a student asks a question, it may appear on the recording.
    • Students can ask the lecturer to pause the recording if they do not want their questions to be recorded.

    OPT505 Lecture 12

    • The topic of the lecture is Presbyopia and the Near Add.
    • The lecture is taught by Ellie Livings.

    Intended Learning Outcomes

    • Understand the purpose, role, and mechanism of accommodation.
    • Clinically assess accommodation in pre-presbyopic patients.
    • Determine the near ADD in presbyopes.
    • Ascertain the range of clear vision with a given ADD.

    Presbyopia

    • Loss of accommodation ability starts from birth.
    • The ability to accommodate declines to affect near objects by the 40's.
    • Near object distance is 33cm to 40cm.
    • This can be frustrating for those who didn't wear glasses before.

    Pre-Presbyopia

    • Correcting lens positions blur circle on the retina.
    • Clear distance vision.
    • Accommodation for near requires effort.

    Presbyopia Information

    • Correcting lenses place a blur circle on the retina.
    • Distance vision remains clear.
    • Near vision is blurred because accommodation isn't adequate.

    Crystalline Lens and Ageing

    • The lens continues to grow throughout a person's life and becomes heavier and denser as well as stiffer.
    • Axial thickness increases, but the equatorial diameter remains constant.
    • Refractive index changes.
    • Increase in positive spherical aberration.
    • Reduced light transmission.
    • Protein degeneration can lead to cataract.
    • The images of lenses at different ages are provided

    Presbyopia: Loss of Accommodation

    • Images of a monkey lens at different ages.
    • Graph illustrating a decline in accommodation amplitude with age.

    Age and Monocular Amplitude of Accommodation

    • Table presenting minimum, average, and maximum monocular accommodation amplitudes for different ages based on Hoffstetter formula (1944).
    • The table shows normative accommodation data.

    Preliminary Diagnosis Case Study

    • The case study describes a patient, 47 years old, without glasses, experiencing difficulty reading.
    • The preliminary diagnosis is likely presbyopia accompanied with an adjustment in distance correction.
    • The patient may need glasses for distance or special glasses for reading.

    Presbyopia Symptoms

    • Difficulty maintaining and changing focus.
    • Vision worsens in the evening/poor light.
    • Frontal headaches, especially associated with near work.
    • Asthenopic symptoms.
    • Feeling current glasses aren't strong enough.

    Explaining Presbyopia

    • Young eyes have clear, flexible lenses.
    • Aging eyes' lenses lose flexibility, thus requiring more effort to focus.
    • Glasses don't weaken the eyes; they're tools for vision improvement.
    • Early morning vision or good light may make it easier to focus.

    Managing Presbyopia Refractively

    • Table presenting SPH, CYL, and AXIS for both right and left eyes along with the addition.
    • Explanation of distance corrections and near task accommodation.

    Case Scenarios

    • Tables presenting distance and near rx values for different scenarios.
    • Calculation of near addition.

    Determining Tentative Add Amount

    • The analysis begins with a review of symptoms and visual needs using historical or current data
    • A determination is made to establish a tentative add amount based on a patient's needs for near vision.

    Tentative Add Methods

    • Techniques for determining the approximate add for presbyopia.
    • The age-related accommodation method is highlighted as reliable when compared to other methods.

    Average WD and Accommodation

    • A table relates age in years to expected accommodation at 40cm, and the deficit in accommodation.
    • Tentative Add values.

    Determining Tentative Add

    • A calculation using the patient's working distance (WD) and amplitude of accommodation (AOA) to determine a tentative add amount.
    • The individual can exert 50% of the AOA or 2/3 of AOA.
    • Example of a person aged 50, who requires 2.50D for a 40cm WD, and has 2.50D as a minimum AOA.

    Age and Tentative Add Amounts

    • A table displays the correlation between a patient's age, expected accommodation, and tentative add for near work.

    Determining the Final ADD

    • Selecting a tentative add, ensuring a clear range for near and intermediate distances.
    • Recording working distance with range.
    • Important factors such as comfort, prescription history, pupil size, and patient age should influence selection.
    • Acuity (sharpness of vision) of the prescription should be confirmed.

    Determining the Final ADD

    • Refining the estimated ADD using ±0.25DS flippers presented binocularly.
    • Emphasis on providing the most minus/least plus.
    • Recording the N-number of smallest letters read for RE and LE at the preferred working distance.

    Calculating Range of Clear Vision

    • Calculation formulas for determining near and far points.
    • Example for a patient aged 70 and near add at 2.50D for 40cm.
    • Range of clear vision presented as numerical values.

    Other Considerations

    • High Add in low vision circumstances
    • IOL in one eye
    • Special tasks with regard to close/far working distances

    Glasses Options

    • Bifocal, varifocal, occupational, single pairs, and sep pairs glasses discussed.
    • Most manufacturers have a non-tolerance policy for first time varifocal wearers.

    Where am I Looking?

    • Visual aid showing where a person looks when wearing different types of glasses (single vision, bifocals, trifocals, and progressive).
    • Shows differences in how different lens solutions support different types of vision.

    Good, Better, Best?

    • A grading system for glasses, with descriptions for Standard, Advanced, Superior, and Elite quality levels.

    Lens Quality (PX View)

    • Image showing a section of a lens.

    Occupational/Enhanced Readers

    • Available for differing graduations.
    • Wider near and intermediate range than standard varifocals.
    • Provides a smoother transition between near vision tasks and tasks where distance will be required.
    • Not suitable for driving.

    Avoiding Non-Tols

    • Tips on comparing the new Add to previous prescriptions.
    • Checking the patient's comfort level in the consulting room.
    • Providing information regarding work or task requirements.
    • Checking for a significant change in the distance prescription.
    • For new pseudophakic patients, consider prior rx, lens type, and spec mag.

    H&S in Presbyopia

    • Factors to consider during a patient health and lifestyle study in those experiencing issues with presbyopia.
    • Issues with regards to correction barriers, and patient preferences.
    • Options to consider including contact lenses or surgery.

    Additional Considerations

    • Risk of pathology
    • Need for baselines (IOP, fields, OCT)
    • Driving: DVLA standards, Estermann, comfort

    Advice and Management

    • Considering distance vision changes alongside near vision changes.
    • Evaluating patient circumstances when using the patient's binocular vision.
    • Understanding how practical concerns and prognoses influence recommendation.
    • Determining suitable glasses for an individual patient.

    Patient One

    • Patient age, visual acuity data, prescription details, and add information.

    Patient Two

    • Age, visual acuity data, prescription details, and add information.

    Patient Three

    • Age, visual acuity data, prescription details, and add information.

    Patient Four

    • Patient age, visual acuity data, prescription details, and add information.

    Practical on Thursday

    • Instructions for the practical including time, attire, and preparation requirements.

    Background Learning

    • Learning objectives for prior or prerequisite knowledge or understanding
    • Reading assignments.
    • Important for students already having prior learning.

    Further Reading

    • List of suggested books or articles related to the subject.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Description

    This quiz focuses on clinical optics, specifically regarding the requirements for attending lab sessions and understanding the principles of eye accommodation. It covers important aspects such as preparatory steps and normative values critical for patient interactions. Test your knowledge on these essential topics in clinical practice.

    More Like This

    201 Clinical Localization in Neurology
    30 questions
    Clinical Judgement Nursing Process Flashcards
    17 questions
    Clinical Micro Chapter 8 Flashcards
    17 questions
    Aniseikonia in Clinical Optics
    40 questions
    Use Quizgecko on...
    Browser
    Browser