presbyopic cl
TRANSCRIPT
CONTACT LENS FOR PRESBYOPES
OPTOM FASLU MUHAMMED
A large % of population needs correction for Presbyopia
100 million presbyopes in india & 10 million adding every year
PRESBYOPIA
It’s a part of normal ageing process,where the eye loses its ability to easily focus on near objects
So, need near correction.
Single Vision Reading Glasses,Bifocals,Trifocals OR Multifocal With Contact Lenses On The Eye There Are 2 Options to Correct Near Vision With Spectacle Over Contact lens
CORRECTING OPTIONS
OPTION 1: Fit CL For Distance; Don’t Overcorrect
* Determine Near Addition Over CL On Trial Frame
*Prescribe Reading Glass Over CL
OPTION 2 : Ideal For Pt’s Who Do Near/Intermediate Work All Day
*Give near add on CL*Give Minus Power For Distance In The Form
Of Spectacles For Driving And Other Distance Task
Highly motivated Those who have adequate tear film & no lid
disease/ abnormality Whose jobs don’t require fine va Affordability
PATIENT SELECTION
MONOVISION CORRECTION
ALTERNATING/TRANSLATING VISION LENSES
SIMULTANEOUS VISION LENSES
CL PRESBYOPIA CORRECTION
Eye Dominance Test
Equipment required: your arms and hands, and an object about 10 feet (3 meters) away
Procedure: Extend both arms in front of your body and place the hands together so as to make a small triangle between your thumbs and the first knuckle (see image). With both of your eyes open, look through the triangle and focus on a specific small object. Close your left eye. If the object remains in view, you are right eye dominant. If your hands appear to move off the object and move to the left, then you are left eye dominant.
ONE EYE IS CORRECTED FOR DISTANCE VISION OTHER EYE FOR NEAR VISION
IT’S THE EASIEST & AN EFFECTIVE MEANS OF CORRECTING PRESBYOPIA
SUCCESS RATE IS AS HIGH AS 70%
MONOVISION
The visual system can suppress the central focus image thus enable the object of interest to be seen clearly .
PRINCIPLE
Determine the distance & near corescription Determine the dominant and non-dominant
eye Fit The Dominant With The Distance POWER
Prescrptn And Non Dominant Eye For Near Power Prescrptn
FITTING PROCEDURE
EG:-4.00 DSPH (OU) ADD +1.50 DSPH (OU) Dominant Eye With -4.00 DSPH(DISTANCE) &
Non Dominant With -2.50 DSPH (NEAR )
Use disposable lens and give an office trial. Record BVA for distance and near
Don’t attempt uniocular VA now The eye with near power’ll read less for
distance and eye with distance power’ll read less for near
Explain fitting technique now Some pt’s may need sum adaptatn time &
may be dissatisfied with reduction of stereopsis
Follow up,and fit the final lens
Adaptation time-atleast 2 wks Advise-continue normal activities if possible No night driving Don’t compare eyes Set pt’s expectations Educate visual improvement overtime
TIPS-MONOCULAR VN FITTING
Translating Vision typesLike executive type bifocal spectacle lensPt when look down gaze lower lid lifts the
near segments up, towards the pupil /the visual axis thus the pt see clear for near
Popular in RGP Near and far can’t be seen clearly same
time
BIFOCAL/MULTIFOCAL CL
Sharp near/far vision When it works well,it’s very successful Works Better In Rgp & Less
Successful/Common In Scl
ADVANTAGES
Takes longer in adaptation Comfort is less due to thick design Dependence on eye -lens relationship
DISADVANTAGES
Distance & near images focused on retina simultaneously
Brain’ll be select/concentrate on one /other will be ignored
Like looking via net across the window @ distance object
SIMULTANEOUS VN
Sharp near and far vision
DISADVNTGESCompromised intermediate vision
Ghosting(doubling) is sometimes a problem
ADVNTGES
1.CONCENTRIC DESIGNConcentric segment show sharp demarcation
b/w distance and near powers
2 TYPES
Center nearCenter distance
3 TYPES
2.Diffractive bifocal Made up of concentric rings, Something like
a fresnel prism Higher the addition more no; of rings
3.Aspheric DesignsProg.Addition type of lens formed with
alteration in ant. & Post. Curvature of lens Power is uniformly increase/decreases in
periphery due to asphericity
One eye is fitted with distance correction and other eye is bifocal lens
Improves binocularity & stereo acuity which may be reduced in mono Vn
Tried in pt’s who are sensitive to distance vn
MODIFIED MONO VISION
High myopes Pts with busy schedules Dry eyes Flat corneas Laxity of lower lid High astigmatism External ocular disease / abnormality
UNSUCCESSFUL CL FITTING -PRESBYOPES
THANK YOUUUU