Dispensing: Prescription analysis – Case #1

This case was among a series presented by Miranda Richardson FBDO, Assistant Director of Professional Examinations for the Association of British Dispensing Opticians, for peer discussion at the second Specsavers Dispensing Conference (SDC2) in August 2018.

Introduction

An essential part of our ongoing development as dispensing professionals is to take the opportunity to reflect upon what we do in practice and consider alternative approaches we could adopt in future to generate even better outcomes for our patients. This process is magnified in effectivity when conducted with fellow dispensers in a group session, and will benefit the knowledge and capability of the team overall. It is also very effective at identifying possible training needs.

In her SDC2 presentation, Miranda introduced a four-step process for prescription analysis. This kind of structured approach is vital, as often it can be too easy to default to finding solutions without adequately exploring the factors that may be contributing to the concern.

The four-step process involves consideration and discussion of the following:

  1. What is the prescription for?
  2. Are there any errors or any information missing?
  3. What could be a potential problem?
  4. How could you solve the problem?

Below is an example case for discussion within your team. Over the coming months, different cases will be presented, with the conclusions and some possible solutions hidden at the bottom of the article to facilitate peer discussion and allow you to compare your findings.

Finally, you will encounter other instances in practice that will warrant further analysis. As well as discussing them in practice, please submit any of these cases to ProFile so that other practices can benefit from the experience.

Richard Couch
Head of Dispensing Advancement

 

Case #1

Habitual Rx:

Right Left
SPH Cyl AXIS PRISM BASE SPH Cyl AXIS PRISM BASE
+12.50 +2.00 180 Distance +13.50 DS
Inter
+3.00 Near


Prescriber’s comments:

  • Patient would like PPLs (progressive power lenses / multifocals)
  • Tested vertex distance is 15mm


Looking at the above prescription, consider the following discussion points with your dispensing team:

  • How would you describe this patient?
  • What does the prescription in the left eye indicate?
  • How will this affect your lens selection in the left eye?
  • What would you dispense in the right eye?
  • Would you recommend any tints or coatings?
  • What is the relevance of the vertex distance?
  • What would you consider when selecting the frame?

Discussion

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  • This is an aphakic patient. Aphakia is the removal of the crystalline lens, but an implant has not been replaced, leaving the high hypermetropic prescription.
  • It could be assumed that the left eye is a balance as is indicated by the prescription, which is sphere plus half the cyl of the right eye. Therefore, the patient is potentially awaiting cataract removal in their left eye.
  • The left eye as a balance does not really require a progressive lens and could therefore be a single vision balance, which would reduce the expense for the patient.
  • As the right eye is the only functioning eye, consider progressive lens design. Without the expense of two progressive lenses, a top-end individualised progressive lens could be an option. With mono-vision the patient will converge less when looking at near. Therefore, an individualised progressive lens with no inset or reduced inset can be specified to minimise the patient’s near vision entering the distortion zone.
  • As the crystalline lens has been removed and not replaced in the right eye, there should be consideration of UV protection.
  • Indices and material should also be considered, as with only vision in one eye, safety would have to be taken into account and high index glass lenses perhaps avoided. Higher index lenses may affect the quality of vision when taking into account the v-value of the material.
  • Due to the Px having quite a large vertex, it would be expected they would sit closer, so there may be a need to calculate effectivity:

Possible recommendations:

  • Right eye individualised progressive with no inset specified, as well as a UV and MAR coating, and a low or mid-index plastics material.
  • Left eye single vision balance lens of the same material and index as the right eye, with a UV and MAR coating to match the right lens.
  • With lower index lenses, the shape of the frame would need to be rounded or oval and preferably a plastics frame to help disguise some of the lens thickness. This would need to be fitted close to the patient to aid the field of view and to prevent effectivity problems resulting from the frame slipping.

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More in the Prescription Analysis series
Case #1 and series introduction
Case #2
Case #3
Case #4
Case #5
Case #6
Case #7
Case #8

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