The Multifocal is designed to mimic the tear profile of a single vision lens with the exception of the variable central aspheric back surface. This alters the tear layer thickness and generates the reading addition. The design is based on the fitting of a single vision lens, so the best fit for a standard diagnostic lens is required. The diagnostic lens should centre well with displaced or high-riding lenses being avoided. With this information, we will then incorporate the required degree of asphericity to generate the reading addition.

The lens ordered will have required altered fluorescein pattern and the patient will notice an increased depth of focus, improving their ability to read and perform close work. For some this improvement is instant, but for others, a longer adaptation period is required. Assuming satisfactory acuity for distance and near, the patient should trial the lens for up to two weeks before making any change to the lens power from resultant over-refractions.

If the fit of the lens is poor then check the fitting using the original single vision diagnostic set. When ordering a change in prescription we will need to know the original lens order so that the required alterations can be incorporated.

If you originally ordered:
7.80 9.60 -4.50 Add +2.00
and you find an over-refraction of -0.50 distance and no extra add is required (i.e. plano over-refraction in front of patient for near vision) then you will need 7.80 9.60 -5.00 Add +2.50, inform the laboratory you need an extra -0.50 in the distance and no extra power for near.

If you originally ordered:
7.80 9.60 -4.50 Add +1.50
and you find an over-refraction of -0.50 distance and an extra add of +0.50 is required (i.e. +0.50 over-refraction in front of patient for near vision) then you will need 7.80 9.60 -5.00 Add +2.50, inform the laboratory you will need an extra -0.50 in the distance and an extra +0.50 for near. Remember: This lens needs at least 15 to 20 minutes to settle for the tear film to stabilise and provide the reading addition.

Contra Indications

As with all lenses, not every patient is suitable for all designs. To maintain confidence and a high success rate, avoid prescribing this lens to patients who present the following:

• Poor centration with the single vision diagnostic lens. The Quasar Plus Multifocal lens will work best when centration is good. A high-riding lens or displaced lens will not allow the optics of the lens design to provide any reading addition.
• Astigmatism greater than 2.00D. A stable freely moving lens design is needed; high degrees of corneal astigmatism will result in a compromised fit and will disrupt the visual performance. Using single vision lens designs to correct high degrees of astigmatism creates variable fluctuating tear film. Such fluctuations interrupt the back surface optics of the Multifocal; therefore these situations should be avoided.
• Cannot establish a satisfactory single vision diagnostic fit. If a patient cannot wear or use single vision rigid lenses, they are unlikely to be successful with the Multifocal design. The design has been developed to help you with the presbyopic lens population.
• Any corneal pathology present, i.e. keratoconus. A diseased cornea will not provide a stable platform, as a result the patient will complain of variable vision or an unreliable reading add.

Quick Fitting Guide

• Establish the best fit using the Quasar diagnostic set. This is best achieved by starting with a lens with a B.O.Z.R on flattest K
• Confirm good centration
• Perform an over-refraction with the best-fit lens
• Determine the required reading addition
• Confirm the over-refraction for distance

Then order the lens providing the following information:

• B.O.Z.R. (from the single vision lens used in the trial)
• Total Diameter (from the single vision lens used in the trial)
• B.V.P. (power of the diagnostic lens plus over-refraction)
• Required reading addition.

Contra Indications

• Poor centration with the diagnostic lens
• Astigmatism greater than 2.00D
• You could not establish a satisfactory single vision diagnostic lens fit
• Any corneal pathology present, i.e. keratoconus

• Clear distance vision
• Clear near vision
• Easy to fit
• High success rate
• True binocular vision
• Long term patient satisfaction
• Simulated fitting and ordering software available

Parameters