presbyopia. presbyopia: program presbyopia: program definition the start and influential factors...
TRANSCRIPT
PRESBYOPIA
PRESBYOPIA: PROGRAM
Presbyopia: program
• Definition• The start and influential factors• Symptoms and signs• Determination of the addition• Prescription• Resolution of clinical cases
PRESBYOPIA: DEFINITION
Presbyopia: definition
– Difficulty focusing on objects because of an insufficient amplitude of accomodation for working comfortably in NV, supposing a well compensated refractive defect from far.
– It is a normal physiological state due to the loss of the accomodative capacity with the passage of time.
– The NPA moves away and the habitual work distance remains outside of the zone of comfortable and clear vision
PRESBYOPIA: THE START AND INFLUENCING FACTORS
Presbyopia: factors I
• The age at which the presbyopia appears depends on:– The accomodative capacity of the person– The habitual work distance (near)– The visual demand at near distances– The refractive error– Nutritional and geographical factors
Presbyopia: factors II
• Accomodative capacity of the person– A method used to determine the amplitude
of accomodation– Intersubject variability– Accomodation in comfortable vision
Presbyopia: factors III
• Habitual, near work distance:– Habit and anthropometric characteristics– At the beginning a slight distancing of the
material allows for comfortable vision
Presbyopia: factors IV
• The visual demand at near distances:– Does not diminish the accomodative capacity– Can make the symptoms more severe.
Presbyopia: factors V
• Refractive error in DV:– Myopia / Hypermetropia– Use of glasses / Contact lenses
Presbyopia: factors VI
• Nutritional and geographical factors
PRESBYOPIA: SYMPTOMS AND SIGNS
Presbyopia: symptoms and signs I
• Symptoms:– Blurry vision in NV– Distancing the reading material– Ocular fatigue– Headaches– In principle it can include blurry vision in
DV (after working in NV)
Presbyopia: symptoms and signs II
• Signs:– Reduced amplitude of accomodation in order to
work comfortably at the habitual reading distance.
– The amplitude of accomodation is determined with the necessary refraction in DV and through any of these methods:• Methods (already seen)
DondersSheardHofstetter’s formula:
Average amp acc = 18,5 – age x 0,3
Presbyopia: symptoms and signs III
Examples: Averageexpected amp acc = 18,5 – age x 0,3Amo Acc
Average
Ano AccComfortab
le
16,5cm
-2 sc
50
15cm-4 sc
55
+4 cc
60
25cm-1 cc
45
ObservationsAmp AccReal
NPARxAge
Presbyopia: symptoms and signs III
Examples: Averageexpected amp acc = 18,5 – age x 0,3
3,50D
2,00D
0,50D
5,00D
Amp accAverage
2,00
1,33D
0,00D
2,00D
Amp accComfortab
le
Amp acc normal for the age.NoC can see between 16,5 and 50cm approx.
4,00D
16,5cm
-2 sc
50
Amp acc normal for the age.NoC can see between 15 and 25cm approx.
2,66D
15cm-4 sc
55
Amp acc normal for the age. Has absolute presbyopia
0,00D
+4 cc
60
Amp acc is normal for the age. Will have presbyopia if the habitual work distance is <50cm approx.
4,00D
25cm-1 cc
45
ObservationsAmp accReal
NPARxAge
PRESBYOPIA: DETERMINATION OF THE ADDITION
Presbyopia: determination of the addition I
• Trial method• Amplitude of accomodation method• Cross-cylinder (near) method• Bichromatic test method• Age method
Presbyopia: determination of the addition II
• Trial method– Patient with Rx in DV, test to 40 cm (or
habitual distance of NV) well lit– Mono and/or binocularly
• Cover LE and go on adding +0.25D in the RE until the patient sees clearly
• The same for LE• Refine the result adding 0.25D binocularly
Presbyopia: determination of the addition III
• Amplitude of Accomodation method– Takes into account that 1/2 the amplitude of
accomodation (amp acc) remains in reserve– With the adequate Rx for DV, determine the amp acc
through the push-up method – Apply the formula:
• Addition = 1/dt (m) - amp acc/2dt = work distance
– Example:• Amp acc=2D; dt= 33 cm• Ad=1/0,33 - 2/2= 2 D
Presbyopia: determination of the addition IV
• Cross-cylinder method from near:– Patient with Rx for DV– Dim lighting– Grid optotype at habitual distance in NV– Cross-cylinder with negative axis at 90°. Ask
which lines he/she sees more clearly:• We hope they are the horizontal lines• Add positive lenses until verticle and
horizontal lines are seen equally clearly
– Can be done monocularly or binocularly
Presbyopia: determination of the addition V
• Bichromatic method:– Patient with Rx for DV– Bichrome test at the habitual distance in NV– Ask on which background the patient sees the
letters more clearly• We hope it is the green background• Add positive spheres until he/she says “better on
the red background”• Reduce positives until he/she sees equally in both
eyes
– In case of doubt allow slightly better vision in the red background
Presbyopia: determination of the addition VI
• The age method:– Empirical method based on clinical
experience– Patient with Rx for DV– Reading test at a habitual distance in NV– There are approximated addition tables
depending on age– Refine the result adding 0.25D binocularly
Presbyopia: determination of the addition VI
• The age method:– The tables can vary according to geographical zone
AGE (years)
Addition at 40cm
Addition at 33cm
40 +0.25 D +1.00 D
45 +0.75 D +1.50 D
50 +1.25 D +2.00 D
55 +1.75 D +2.50 D
60 +2.00 D +3.00 D
65 +2.25 D
70 +2.50 D
Table proposed by Borish (1970)) Empirical table in Spain
AGE (years)
Addition at 40cm (approx)
40 - 45 +0,75 a +1,00 45 - 50 +1,00 a +1,75 50 - 55 +1,75 a +2,25
55 - 65 +2,50 > 65 +2.50 a +2,75
Presbyopia: determination of the addition VII
• All of the previous methods are approximate• It is essential to make necessary
adjustments with trial frames in a situation as similar to real life as possible
• Demonstrate the steps of the accomodation check
• Explain to the patient:– The need for distinct compensation in DV and NV– The expected evolution
PRESBYOPIA: PRESCRIPTION
Presbyopia: prescription I
• It is important to determine the best form of compensation for the person’s visual needs:– Monofocal in NV– Bifocal– Progressives– Occupational lenses
Presbyopia: prescription criteria I
• Monofocal lenses– Useful for static, long-term tasks– The glasses should be taken off to see from
distances
• Bifocal lenses– For NV and DV – Inform about image jump and displacement
• Progressive lenses– For DV, NV and intermediate distances– There are peripheral areas with optical aberrations– Very precise adaptation
PRESBYOPIA: CASES
Presbyopia: case 1-I
• JAR, 46-year-old woman. High school teacher.
• MC: Difficulty focusing on text in NV. Best vision when she distances the text. In DV she says she sees well with her glasses.
• PH: Has worn glasses since the age of 9. No significant changes in the last 20 years. No illnesses or ingestion of medication.
• FH: Unimportant.
Presbyopia: case 1-II
• Habitual Rx and AV in DV and NV:– RE: -4,50; 20/20; NV: 20/30– LE: -5,00; 20/20; NV: 20/30-2
• Binocularity in habitual conditions:– Cover test:
• DV: Ortho• NV: Low exophoria
– Proximal convergence: 5/10cm
Presbyopia: case 1-III
• Retinoscopy:– RE: -4,50– LE: -5,00
• Subjective DV and AV:– RE: -4,50; AV: 20/20– LE: -5,00; AV: 20/20
• Addition in NV: +1,00; AV 20/20 in both eyes. Good comfort.– Vision check: from 20 to 60cm approximately
• Ocular health exams: within normal limits
Presbyopia: case 1-IV
• Complete diagnosis of the case• Proposed treatment and plan of
revisions• Possible evolution of the condition
Presbyopia: case 1-V
• Complete diagnosis of the case– Simple myopia in both eyes– Presbyopia– Binocularity: within normal limits– Other tests are within normal limits
Presbyopia: case 1-VI
• Proposed treatment:– A change to the prescription in DV is not justified.– An addition in NV of +1,00D is necessary.– After discussing the possible options, a monofocal for
NV is decided upon:• RE: -3,50• LE: -4,00
– Use for tasks in NV. – Show the patient that with them the vision in DV is
inadequate.– Revision in 1½-2 or before if there are symptoms.– Explain the condition to the patient.
Presbyopia: case 1-VIII
• Possible evolution of the condition:– Stability of the refractive defect in DV– Need for a new graduation for NV in about 2
years due to increase in the presbyopia.
Presbyopia: case 2-I
• MPA, 52-year-old male. Taxi driver.• MC: When he wants to read for a while
he notices blurry vision in NV even with his glasses. Greater difficulty in low lighting.
• PH: Wears bifocals when working and for NV since he was 6 or 7. No illnesses or ingestion of medication.
• FH: Irrelevant.
Presbyopia: case 2-II
• Habitual Rx and AV in DV and NV:– RE: +0,50; AV:20/25; NV: +1,75; AV: 20/30-2
– LE: +0,50; AV:20/25; NV: +1,75; AV: 20/40
• Binocularity in habitual conditions:– Cover test:
• DV: Ortho• NV: Ortho
– Proximal convergence: 10/15cm
Presbyopia: case 2-III
• Retinoscopy:– RE: +1,50-0,50x180º– LE: +1,75-0,25x180º
• Subjective DV and AV:– RE: +1,50-0,50x180º; AV: 20/20– LE: +1,75-0,25x180º; AV: 20/20
• Addition in NV: +1,75; AV 20/20 in both eyes. Habitual work distance: 45cm– Vision check: from 30 to 55cm approximately
• Ocular health exams: within normal limits
Presbyopia: case 2-IV
• Complete diagnosis of the case• Proposed treatment and plan of
revisions• Possible evolution of the condition
Presbyopia: case 2-V
• Complete diagnosis of the case– Low hypermetropis manifested in both eyes– Low, direct astigmatism in both eyes– Presbyopia– Binocularity: within normal limits– Other tests within normal limits
Presbyopia: case 2-VI
• Proposed treatment:– After discussing the possible options,
progressives have been decided upon:• RE: +1,50-0,50x180º; Ad: +1,75• LE: +1,75-0,25x180º; Ad: +1,75
– Habitual use. – Revision within 1½-2 years or before if
symptoms reappear.– Explain the condition to the patient.
Presbyopia: case 2-VIII
• Possible evolution of the condition:– Stability of the refractive defect in VA– Need for a new graduation for NV in a few
years due to slight increase in the presbyopia.
PRESBYOPIA: BIBLIOGRAPHY
Presbyopia: Bibliography
• Amos JF. Diagnosis and management in vision care. Butterworth-Heinemann, 1987
• Milder B, Rubin ML. The fine art of prescribing glasses (2nd edition). Triad Publishing company, 1991
• Brookman KE. Refractive management of ametropia. Butterworth-Heinemann, 1996
• Werner DL, Press LJ. Clinical pearls in refractive care. Butterworth-Heinemann, 2002
• Eskridge JB, Amos JF, Barlett JD. Clinical procedures in optometry. Lippincott Co, 1991.
Presbyopia: web pages
• http://www.emedicine.com/oph/topic724.htm• http://www.emedicine.com/oph/topic699.htm• http://www.tarso.com/Presbyopia.html• http://www.nlm.nih.gov/medlineplus/spanish/
ency/article/001026.htm• http://www.agingeye.net/otheragingeye/
presbyopia.php• http://en.wikipedia.org/wiki/Presbyopia• http://www.eyetopics.com/articles/48/1/
Presbyopia