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Presbyopia/ Methods of Presbyopic Addition Determination (healthkura.com)

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Presbyopia and techniques of measurement
A fantastic presentation in the topic "Presbyopia and techniques of measurement"
A detailed information about presbyopia, techniques of presbyopic add determination and different correction methods.
Informative slide presentation on presbyopia for ophthalmology residents, ophthalmologists, optometrists, ophthalmic assistants, ophthalmic technicians, ophthalmic nurses, medical students, medical professors, teaching guides.

Presentation Contents:
--Introduction to presbyopia
-Types of presbyopia
-Risk factors
-Symptoms and signs
-Refractive error and presbyopia
-Methods of determining near add.
-Management of presbyopia

In a nutshell..
- The evaluation and management of presbyopia are important because significant functional deficits can occur when the condition is left untreated

- Undercorrected or uncorrected presbyopia can cause significant visual disability and have a negative impact on the pt.'s quality of life

- Finally, every tentative addition should be adjusted according to the particular needs of the patient

For Further Reading:
-Clinical Procedures in Optometry by J.D. Bartlett, J.B. Eskridge, J.F. Amos
-Primary Care Optometry by Theodere Grosvenor
-Borish’s Clinical Refraction by W.J. Benjamin
-Clinical Procedures for Ocular examination by Carlson et al
-American Academy of Ophthalmology
-Optometric Clinical Practice Guideline by American Optometric Association
-Internet

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Presbyopia/ Methods of Presbyopic Addition Determination (healthkura.com)

  1. 1. Presbyopia and Techniques of Measurement Bikash Sapkota B. Optometry 3rd year Maharajgunj Medical Campus, Nepal
  2. 2. LAYOUT o Introduction o Types of presbyopia o Risk factors o Symptoms and signs o Refractive error and presbyopia o Methods of determining near add. o Management of presbyopia
  3. 3. o Presbyopia (from Greek presbys = old man + ops = see like, sight) o Gradual, irreversible decrease in amplitude of accommodation as expected with age o Normal physiological state Definition
  4. 4. o Eye exhibits a progressively diminished ability to focus on near objects o The onset is usually anticipated by age 40 or AA tends to drop below 5.00D o Eye crystalline lens loses elasticity (the ageing of a lens) o Old aged eye (आँखा बुढो भयो) Definition
  5. 5. Amplitude of Accommodation and Age The amplitude of accommodation declines throughout life until at about 50 or 60 years of age when it becomes zero
  6. 6. Recession of near point with age
  7. 7. Accommodation Insufficiency & Presbyopia AI PRESBYOPIA Accommodative power is significantly less than the normal physiological limit for the patient’s age Physiological insufficiency of accommodation is normal for age Asthenopic symptoms are more prominent Symptoms of decreased near VA is more prominent
  8. 8. Epidemiology oWorldwide in 2005 over 1.04 billion oBy the year 2020 the worldwide prevalence is expected to rise to 1.37 billion oThe average age of onset-betn 42 and 44 years of age oEarly loss of accommodative ability can be induced by certain systemic disease, medications, and trauma -Holden BA, Fricke TR, Ho SM, Wong R, Schlenther G, Cronjé S, Burnett A, Papas E, Naidoo KS, Frick KD. Global vision impairment due to uncorrected presbyopia. Arch Ophthalmol. 2008 Dec;126(12):1731-9.
  9. 9. Pathophysiology Lenticular and extra-lenticular theories • Lenticular  sclerosis of the nuclear lens tissue  decreased distance between ciliary muscle and lens equator  lens capsule with age becomes thicker, less extensible and brittle
  10. 10. • Extra-lenticular  age related hyalinization of ciliary processes and ciliary muscles  loss of elasticity in the zonules  decreasing resistance of the vitreous humor against the accommodating lens capsule
  11. 11. Some of the Theories Theories Helmholtz Schachar Catenary
  12. 12. In Presbyopia Ciliary muscle contraction ceases Posterior zonular fibres pull the ciliary muscle backward Increases tension on the zonular fibres Increase in lens diameter, decrease in lens thickness and a flattening of the anterior and posterior lens surface curvatures Decrease in optical power Helmholtz theory
  13. 13. Schachar’s Theory Ciliary muscle contracts Equatorial zonular tension is increased Anterior and posterior zonules are simultaneously relaxed Central surfaces of the lens steepen Peripheral surfaces of the lens flatten
  14. 14. oPresbyopia results from growth of equatorial diameter of the lens oWith age, the perilenticular space is reduced and ciliary muscle contraction no longer tense the zonules and expand coronally oBased on this theory introduced new sx for presbyopia scleral expansion bands
  15. 15. Catenary Theory oProposed by Coleman oThe zonular fibers function like the support pylons of a suspension bridge and determine the natural curvature of the lens
  16. 16. Ciliary muscle contracts Initiates a pressure gradient between the vitreous and aqueous compartments Anterior capsule and the zonule form a trampoline shape or hammock shaped surface Steep radius of curvature in the center of the lens with slight flattening of the peripheral anterior lens Presbyopia occurs d/t - increase lens volume with age - results in a reduced response of anterior radius of curvature to the vitreous pressure gradient created by ciliary body contarction
  17. 17. Optics of Presbyopia
  18. 18. Types of Presbyopia PresbyopiaFunctional Incipient Premature Nocturnal Manifest Absolute
  19. 19. oBorderline, beginning, early or pre-presbyopia oEarliest stage when symptoms or difficulty are first encountered in near vision oMore difficulty in dim illumination while can do well in bright illumination Incipient Presbyopia
  20. 20. oPt.’s history suggests a need for a reading add., but pt. performs well visually on testing and, given the choice, may prefer to remain uncorrected Incipient Presbyopia
  21. 21. o When faced with gradually declining AA and continued near task demands, adult pts. eventually report visual difficulties o The interaction between the pt.'s AA and the patient's near vision demands is critical Functional Presbyopia
  22. 22. o The age at which presbyopia becomes symptomatic varies o Due to variations in distance vision status, environment, task requirements, nutrition, or disease state Functional Presbyopia
  23. 23. oPresbyopia occuring at an earlier age than expected for normal population oUsually associated with ocular diseases, nutritional deficiencies or ingestion of certain drugs oUncorrected hyperopia oPremature sclerosis of crystalline lens Premature Presbyopia
  24. 24. oNear vision difficulties result from an apparent decrease in the AA in dim light oIncreased pupil size and decreased depth of field are usually responsible for this reduction in the range of clear near vision in dim light Nocturnal Presbyopia
  25. 25. Manifest presbyopia oPresbyopia with some amplitude of accommodation present Absolute presbyopia oPresbyopia with amplitude of accommodation completely absent
  26. 26. Risk Factors o Age Typically affects function at or after age 40 o Hyperopia Additional accommodative demand (if uncorrected) o Occupation Near vision demands o Gender Earlier onset in females (short stature, menopause)
  27. 27. Risk Factors o Ocular disease or trauma Removal or damage to lens, zonules, or ciliary muscle o Systemic disease Diabetes mellitus; multiple sclerosis; cardiovascular accidents; vascular insufficiency; myasthenia gravis; anemia; influenza; measles o Drugs e.g., alcohol, chlorpromazine, hydrochlorothiazide, antianxiety agents, antidepressants, antipsychotics, antispasmodics, antihistamines, diuretics
  28. 28. o Iatrogenic factors Scatter (panretinal) laser photocoagulation; intraocular surgery o Geographic factors Proximity to the equator (higher average annual temperatures, greater exposure to ultraviolet radiation) o Other Poor nutrition; decompression sickness; ambient temperature Risk Factors
  29. 29. “My arms are not long enough to see up close anymore” "I have to hold my book further away" “Newspaper print is not what it used to be" Symptoms and Signs
  30. 30. o Blurred vision and the inability to see fine details at the customary near working distance o Other common symptoms are delays in focusing at near or distance, ocular discomfort, headache, aesthenopia, neck & back ache, redness & watering, fatigue or drowsiness from near work, increased working distance, need for brighter light for reading, squinting & diplopia SIGNS Reduced amplitude of accommodation Symptoms and Signs
  31. 31. Distance Intermediate Near The vision with Presbyopia
  32. 32. Basic Principles oFind refractive error for distance and correct it first oFind presbyopic correction needed in each eye separately and add it to distance correction oNear point should be taken consideration according to profession of pt.
  33. 33. Basic Principles oOver correction should be avoided oAdditional correction for intermediate distance may be required oPresbyopic add should leave certain percentage of AA in reserve
  34. 34. AA in Reserve oAmount of a new addition should permit a certain percentage of the AA to remain in reserve oRule-of-thumb - Leaving one-half of the AA in reserve (Lawrence and Maxwell) - Leaving one-third of the AA in reserve (Sheard and Giles)
  35. 35. Presbyopia correction and the accommodation in reserve o A small decline in the AA up to the age of 52 o After the age of 52 the results are based on the depth-of-focus of the eye o Females have slightly greater accommodation than males of the same age o The power of the add. correlates to the age of the subject o Common figures of AA in reserve adopted have been one-half and one-third (no strict rule) - by Michel Millodot and Susan Millodot, 2007: Ophthalmic and Physiological Optics, Volume 9, Issue 2
  36. 36. Methods of Determining Near Add o Addition based on amplitude of accommodation o Tentative addition based on age o Plus build-up method o Bichrome method o Cross-cylinder method o Relative accommodation method o Dynamic Retinoscopy
  37. 37. Tentative add based on Amplitude of Accommodation oAmplitude of accommodation decreases with age - Presbyopia is reported when NPA exceeds 8 inches (22cm) i.e, AA = 4.50D (Donders) oPresbyopia exists when amplitude of accommodation is less than 5D (Morgan)
  38. 38. Tentative add based on Amplitude of Accommodation oMeasured by the push-up method or the minus lens to blur method oFor older persons, AA can be measured with the pt.’s addition oThe amount of the add is then subtracted from the result of the test
  39. 39. Tentative add based on Amplitude of Accommodation oAmount of a new add. should permit a certain percentage of the AA to remain in reserve
  40. 40. oWorking distance (WD)= 40cm RAF (AA) = 2.00D What should be the near addition Accommodation required for WD = 2.50 D Accommodation in Reserve = 1.00D Amount of accommodation left = 1.00D Amount of Near addition = (2.50 –1.00) = +1.50D Example 1
  41. 41. Example 2 oWorking distance (WD)= 25cm RAF (AA) = 1.50D What should be the near addition Accommodation required for WD = 4.00 D Accommodation in Reserve = 0.50D Amount of accommodation left = 1.00D Amount of Near addition = (4.00 –1.00) = +3.00D
  42. 42. Tentative Addition based on Age o Amplitude of accommodation to age (Hofstetter) • Maximum = 25.0 – 0.4 (age) • Probable = 18.5 – 0.3 (age) • Minimum = 15.0 – 0.25 (age) • Amount of near add calculated by holding certain amount of accommodation in reserve Rule of 4’s Amplitude= 4x4-(Age/4)
  43. 43. Hofstetter’s Table of Age and Amplitude Age of Range (Years) Minimum Expected Amplitude (Diopter) Range of Near Add in Diopter for 40 cm. 40 to 44 5.00 to 4.00 +0.75 to +1.00 45 to 49 3.75 to 2.75 +1.00 to +1.50 50 to 54 2.50 to 1.50 +1.50 to +2.00 55 to 59 1.25 to 0.25 +2.00 to +2.25 60 and over 0 +2.25 to +2.50
  44. 44. Plus build-up Method oWorks best when the corrected VA is normal at distance oCan be done binocularly or monocularly  Plus lenses are increased in steps of 0.25D to the amount necessary to first read the desired letters at a customary working distance  The power of add is then increased in 0.25D steps to the amount preferred by the pt.
  45. 45. o Monocular build-up usually lands in more amount of near addition Since less accommodation is available because of a lack of convergence accommodation Plus build-up Method
  46. 46. Bichrome Method oBased on natural chromatic aberration of eye oWidely used for determining spherical component of distant correction oWhen an ametropic eye is out of focus for distance, - red target is clearer in myopia - green target in hyperopia oThe same principles apply at near distance
  47. 47. o For presbyopic pts. red & green are focused behind the retina with red farther away o For Uncorrected or undercorrected presbyopic pt. - letters on green background clearer o An overcorrection for a near target - the letters on red background clearer Bichrome Method
  48. 48. Appropriate correction Over corrected Uncorrected or under corrected Bichrome Method
  49. 49. o Pt.’s distance correction is placed on a trial frame o Bichrome target is placed at habitual near distance (40cm) o Tell the pt. to look at letters on both Green and red background carefully o Ask the pt. which side has the sharper and clearer letters - Green clear : add plus in 0.25 step - red clear : remove plus - until pt. sees letters equally clear in both background Bichrome Method
  50. 50. o With the older patients, - the crystalline lens becomes markedly yellow - blue green light being partially absorbed and scattered - gives a red bias to the test o Difficult in protanopic patient; since the red background will appear much dimmer than the green o Precaution : the subject is instructed to emphasize on clarity of letters and not the background Demerits of Bichrome test Bichrome Method
  51. 51. The Cross Cylinder Method o Used to establish the point of accommodation for a customary near WD (40 cm), adding plus lenses until the horizontal and vertical lines on the cross cylinder grid subjectively appeared equally clear o The target consists of 4 to 5 vertical and horizontal lines presented to pt. at 40 cm o Illumination is diffuse and subdue, sufficient to allow pt. to see target satisfactorily
  52. 52. The Cross Cylinder Method +0.50DC -0.50DC +0.50DS/-1.00DCꭓ180
  53. 53. The Cross Cylinder Method
  54. 54. o Place the pt.’s best distance correction on the phoropter (trial frame) o Put the cross cylinder grid at pt.’s customary near working distance (40cm) o Place the Jackson Cross Cylinder in front of both of the pt.’s eyes, with the minus cylinder axis at 900 (Red marks vertical) (+0.50DS/-1.00DC ꭓ 090) (be cautious not to change the axis of the correcting cylinder) The Cross Cylinder Method
  55. 55. o Cross cylinder creates artificial astigmatism with an interval of Sturm of 1.00D o If pt. accommodates exactly for the target, both sets of lines are equally clear o If pt. under-accommodates, the horizontal lines appear clear o Can be done monocularly or binocularly The Cross Cylinder Method
  56. 56. Two variations of technique With Myopisation Without Myopisation The Cross Cylinder Method
  57. 57. The Cross Cylinder Method o A +3.00 D lens is added binocularly to the distance correction of pt. such that the individual can see the vertical lines more sharply o The add is then decreased binocularly in 0.25 D steps until both the vertical and horizontal lines appeared equally clear With Myopisation
  58. 58. The Cross Cylinder Method o With the distance correction placed in the phoropter, pt. is asked which lines appear clearer, sharper or blacker o If the horizontal lines are clearer, plus lenses are added binocularly in 0.25 D steps until equality is reached o Power of the plus lenses added is the tentative add o In pt. initially appreciate the vertical lines or both more clearly, the addition is recorded as zero Without Myopisation
  59. 59. Relative Accommodation Method o NRA - measure of maximum ability to relax accommodation while maintaining clear, single binocular vision of a test object at a specified distance o PRA - measure of the maximum ability to accommodate while maintaining clear, single binocular vision of a target at a specified distance o The difference between the NRA and the PRA is called the relative accommodative amplitude
  60. 60. Relative Accommodation Method o Based on the concept of placing the accommodative demand in the middle of the range of relative accommodation o To measure NRA and PRA, - pt.'s distance refraction and a tentative add is placed in the phoropter (Trial frame) - the near point test card (N6 target) is placed at the reading distance (usually 40 cm)
  61. 61. Relative Accommodation Method o NRA is determined by adding plus power lenses binocularly until the pt. is no longer able to read the fine print on the test card o PRA is determined by adding minus power lenses until the pt. is no longer able to read the fine print o Near add = (NRA+PRA)/2
  62. 62. Example oSuppose pt. can read fine print with +1.00D add oBlurring occurs when add increased to +2.00D and reduced to +0.50D oRange of clear vision is 1.50D (from +2.00D to +0.50D add) oFinal add is (+0.50+2.0)/2= +1.25D
  63. 63. Dynamic Retinoscopy o Determine lag of accommodation o Reduce amount of lag by +0.50 to +0.75D o Prescribe remaining as addition for near
  64. 64. Comparing methods of determining addition in presbyopes o All the techniques display similar behavior and provide a tentative addition close to the final addition o Among the methods used, the age-expected procedure is recommended, as this technique produce results that correlate best with the final add o Likelihood of error is high and supports the idea that any tentative add has to be adjusted according to the particular needs of each pt. - CLINICAL AND EXPERIMENTAL OPTOMETRY 2008; B. Antona, F. Barra, A. Barrio, A. Gutierrez, E. Piedrahita, Y. Martin Department of Optics II, Universidad Complutense, Madrid, Spain
  65. 65. An evaluation of estimation methods for determining addition in presbyopes o All the methods used display similar behavior and provide a tentative addition close to the final addition o Every tentative addition should be adjusted according to the particular needs of the patient - Arq Bras Oftalmol. 2013;76(4):218-20 by L.C. Bittencourt, M.R. Alves, D.O. Dantas, P.F. Rodrigues, E.D. Santos-Neto
  66. 66. Determination of Final Addition o Customary near working distance o Nature of the near work o Physical nature of the patient o Illumination level o Status of the accommodation-convergence relationship o Change in the amount of the addition
  67. 67. Refractive Error and Presbyopia HYPEROPES EMMETROPES MYOPES
  68. 68. Hypermetrope - presbyope oHyperopes have their near point considerably further away than emmetropes (exhibit apparent relatively reduced accommodative amplitudes) oThus effectively become presbyopic a few years earlier than either myopes or emmetropes oStronger converging lenses
  69. 69. Myope - presbyope oIn the myopes develop presbyopia later in life oBetter to take off distance prescription glasses for reading (near task) oWeaker converging lenses
  70. 70. Anisometropic distance correction - Presbyopia o Unequal adds may also be prescribed o Measure the ranges monocularly o Bifocals may produce reading discomfort because of an induced vertical prismatic effect in the reading position o Specially designed slab-off lenses or single vision reading glasses may be required (Ophthalmology by Myron Yanoff and Jay s. Duker)
  71. 71. Contact Lenses Spectacles Surgery Management of Presbyopia
  72. 72. o A variety of options are available o Recommendations are made on the basis of the pt.'s specific vocational and avocational needs o Success of treatment depends on - the lens power - the specific visual tasks and characteristics of the individual pt. - the appropriate pt. education given by the practitioner Management of Presbyopia
  73. 73. Optical Correction with Spectacle Lenses o Single vision lenses o Bifocal lenses o Trifocal lenses o Progressive addition lenses o Occupational lenses Management of Presbyopia
  74. 74. Optical Correction with Contact Lenses o Single vision contact lenses o Bifocal and multifocal contact lenses - Alternating vision bifocal contact lenses - Simultaneous vision contact lenses o Monovision contact lenses o Modified monovision contact lenses Management of Presbyopia
  75. 75. Combination of Contact and Spectacle Lenses o Many contact lens wearers gain some advantage by combining the use of spectacles with their contact lenses o Early presbyope who is already a contact lens wearer continues to use their contact lenses for distance vision and acquires a pair of reading spectacles for near, an approach that has been shown to cause the least visual confusion at near (Sidock et al., 2000) Management of Presbyopia
  76. 76. Surgical Treatment oLaser in-situ keratomileusis (LASIK) oMultifocal intraocular lens (IOL) oAccommodating intraocular lens implants oConductive keratoplasty (monovision) oScleral expansion Management of Presbyopia
  77. 77. Management of Presbyopia
  78. 78. In a nutshell.. o The evaluation and management of presbyopia are important because significant functional deficits can occur when the condition is left untreated o Undercorrected or uncorrected presbyopia can cause significant visual disability and have a negative impact on the pt.'s quality of life o Finally, every tentative addition should be adjusted according to the particular needs of the patient
  79. 79. For Further Reading o Clinical Procedures in Optometry by J.D. Bartlett, J.B. Eskridge, J.F. Amos o Primary Care Optometry by Theodere Grosvenor o Borish’s Clinical Refraction by W.J. Benjamin o Clinical Procedures for Ocular examination by Carlson et al o American Academy of Ophthalmology o Optometric Clinical Practice Guideline by American Optometric Association o Internet

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