Clinical Optics and Eye Accommodation

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.

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.