Accomodative insufficiency s


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  • often have accommodative dysfunction, because accommodation compensates for hyperopia
    should be advised for patient with excess accommodative response
  • Push – up method
    With the best visual acuity subjective lens ,reduced snellen chart is placed at a distance of 40 cm& patient’s attention is drawn to 20/20 row of letters.
    For monocular determination of NPA ,the left eye is occluded & patient keeps focus onthe 20/20 row of letters on the reduced snellen chart as the chart is moved closer.
    Patient is asked to report the blur point .At this point NPA is recorded as distance in (cm) from test card to spectacle plane of eye as indicated on reading rod.
  • Accomodative insufficiency s

    1. 1. GauriSh Shrestha, M.Optom, FIACLE Program Co-ordinator Institute of Medicine Sadhana Sharma, B.Optom II year
    2. 2.  Accommodation  Unit of measurement  Accommodative insufficiency  Signs & symptoms  Care process  Management  Conclusion  References
    3. 3.  It is the dioptric adjustment of the crystalline lens of the eye to obtain clear vision for a given target of regard.  It is the process by which the refractive power of eye is altered to ensure a clear retinal image.
    4. 4.  Ciliary muscle contracts (ciliary ring shortens & zonules are relaxed)  Tension in capsule is relieved (equator of lens move forward & lens becomes spherical)  Dioptric power of lens increases (near object focuses clearly on retina)
    5. 5.  The lens fibers & lens capsule lose their elasticity  Size & shape of the lens increases  Decrease accommodative amplitude  The difference between the dioptric power need to focus for near(P) and distance (R) is called amplitude of accommodationamplitude of accommodation  A= P-RA= P-R
    6. 6. Time from birth Amp Acco Birth 18.5D 8 years 14D 40 years 4D 70 years 0.0D We lose 1D every 4 years
    7. 7. 10 15 20 25 30 35 40 45 50 55 14 12 10 8.5 7 5.5 4.5 3.5 2.5 1.75 0 10 20 30 40 50 60 1 2 3 4 5 6 7 8 9 10 Age(yrs) Amp(D)
    8. 8.  Max= 25-0.4 (Age)  Average= 18.5- 0.3 (age)  Min= 15.5-0.25 (Age)
    9. 9.  Accommodative insufficiency is an anomaly that is characterized by an inability to focus or sustain focus at near  An insufficient amplitude of accommodation based on age-expected norms
    10. 10.  Headache: “Do you get a headache when you read or study?”  Asthenopia: “Do you feel tiredness or tearing in the eyes when you read or study?”  Floating text: “Do you see the words appear to float on the page, swim, jump or wiggle when you read or study?”  Facility problems: “Do you have difficulties in quickly changing focus from the board, to your textbook, and back to the board again?”
    11. 11.  Some children with accommodative insufficiency do not present complaint? Why
    12. 12.  Relationship between AC/A ratio  Relationship between CA/C
    13. 13. 1. Ophthalmic :  Disease of accommodating components  Hypermetropia  Uncorrected myopia (noticed by the patient after correction of refractive error) 2. Medical :  Poor general health, malnutrition, general weakness
    14. 14. 3. Trauma :  Trauma to eye resulting in loss of acommodation 4. Drugs :  Certain drugs adversely affect accommodation such as antidepressants, cycloplegics, antihistamines, Marijuana etc
    15. 15.  Blurred vision for near  Headaches  Eyestrains  Reading problems  Fatigue & sleepiness  Loss of comprehensio n over time
    16. 16.  Pulling sensation around eye  Movement of print
    17. 17. Visual acuity Variability between near & distance VA may indicate accommodative anomaly.
    18. 18. Refraction - uncorrected hyperopia (Latent hyperopia)
    19. 19.  Esotropia Reduced convergence demand causing accommodative dysfunction  Exotropia Vergence dysfunction causing accommodative dysfunction
    20. 20.  CI notices clear vision  AI notices blur vision
    21. 21.  RAF rule Method (Push up method) moving a test object closer to eyes  Positive relative accommodation (PRA) Method placing a minus lens in front of eyes  Lag of Accommodation Dynamic retinoscopy
    22. 22.  Near point card is placed at a distance of 40 cm.  Patient is instructed to watch 20/20 line of letter each eye separately  Asked to report when letter begins to blur as minus power is gradually added to patient’s subjective correction.
    23. 23.  To arrive at amplitude of accommodation, Add 2.50 D (for 40 cm WD) to minus lens power used to blur the letters.  For e.g. if add of -4.00D to subjective refraction blurs the letters, the amplitude of accommodation is +4.00 + 2.50 D = 6.50D  If positive lenses is necessary to add to clear up the letter at 40 cm, the amount of plus power necessary to clear up the letter is subtracted from 2.50D to determine amplitude of accommodation.
    24. 24. Basis for treatment - General Principles are :  To assist the patient to function efficiently in near vision tasks  To relieve ocular, physical & psychological symptoms associated with disorders.
    25. 25. Cause should be eradicated ( medical problems, drugs, ophthalmic etc…) if present
    26. 26. Optical correction Appropriate refractive correction first Estimate amount of amplitude of accommodation for given age if it is disabling for near visual task, Prescribe glass to relieve symptoms
    27. 27.  Prescribing reading glasses decrease the demand on accommodative system. However, accommodation becomes passive (it is problem we are discussing)
    28. 28.  Solution: Amp of Accommodation =6.0D Functional amplitude of accommodation=3.0D Max near working distance = 33.3cm Normal Amp of accommodation for the age= 13D
    29. 29. Deficit is 7 D for the age= not practicable to prescribe Maintain least distance of distinct vision= 25cm= 4.0D Glasses should be prescribed at least 1.0D Range of accommodation for near work= 25cm to 50cm
    30. 30.  The purpose of accommodative therapy is to increase the amplitude, speed, accuracy & ease of accommodative response.  At the end of therapy patient should be able to make the rapid accommodative responses without evidence of fatigue.  A vision therapy for accommodative insufficiency usually requires 12 to 24 office visits
    31. 31. In office 1.Flippers 2.Brock-string exercise 3.Hart-chart rock exercise 4.minus lens procedure In home 1. Push up paddle 2. Hart chart rock exercise 3. Flippers 4. Brock-string exercises
    32. 32.  It is a holder with two minus & two plus lenses of equal magnitude  Subject focuses through one pair of lenses at an object at near distance (40 cm)  When object is clearly focused, a flick is quickly performed to the other lens pair & subject focuses through this.  Process is then again repeated.
    33. 33.  Through changing the fixation distance it is done with large & small hart charts, consisting of ten rows, each with ten letters  Letters of large chart have a visual subtense of 20/20 at a distance of 20 feet.  Small chart is a small version of large hart chart  Children using these charts practice keeping their places when switching from far to near.
    34. 34.  Consists of a white string of approximately 10 feet in length with 3-5 small wooden beads of different colors.  During therapy one end of string is held at tip of nose whereas the other end is tied to a fixed point.
    35. 35. Explain the procedure
    36. 36.  Monocular versus binocular  Person reads a letter in a push up paddle while moving the target closer until sustained blur is noticed  Can be combined with distance Hart chart rock
    37. 37.  Principle similar to flipper lens.  Minus lens of increased strength is gradually introduced in front of each eye while the subject reads 20/20 equivalent letters at near until s/he notices blur. S/he must be encouraged to make letters read clear
    38. 38.  Treatment is best addressed by use of therapeutic spectacle lenses. The usually prescribed ones are multifocal form to allow improved near vision while not disturbing distance vision.