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.
Case #4
Habitual Rx:
| Right | Left | |||||||||
| SPH | Cyl | AXIS | PRISM | BASE | SPH | Cyl | AXIS | PRISM | BASE | |
| +6.00 | -3.25 | 135 | Distance | +6.00 | -2.75 | 35 | ||||
| Inter | ||||||||||
| +2.00 | Near | +2.00 | ||||||||
Prescriber’s comments:
- First time bifocals.
Looking at the above prescription, consider the following discussion points with your dispensing team:
- What problems can you foresee with this prescription?
- How will this affect your lens selection?
- How would you manage the patient’s expectations?
Discussion
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- The high prescription will affect the weight and cosmesis of the lenses.
- The oblique cyls and the high Rx will cause problems when the patient looks down to read as they will experience base up and out.
Possible recommendations:
- Manage the patient’s expectations and pre-warn them of potential problems.
- Advise the patient that they may experience eye strain when reading in standard bifocals, however bifocals could still be considered as a convenient option for everyday use and minimal reading.
- For long-term reading, a separate pair of spectacles with lowered optical centres could be recommended to try and reduce the prismatic effect at near.
- The following lens options could also be considered to help reduce the prismatic effect at near caused by the oblique cyls:
- Round segs for a hyperopic prescription – possibly R30 for a larger reading area
- D-segs for a myopic prescription.
- Alternatively, putting prism into a prism-controlled bifocal segment could help counteract the prismatic effect.
- The lens size and centration of the frame should be accurate to help reduce the lens thickness with MSU. This could also reduce the cost for the patient.
- Contact lenses could be another potential option.
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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