Prescribing for Presbyopia
Presbyopia Posters at the GSLS
By Craig W. Norman, FCLSA
The 2012 Global Specialty Lens Symposium (GSLS) was a tremendous event this year with more than 600 contact lens specialists and industry personnel in attendance. One highlight was the 65 scientific and clinical posters. Of interest to me were those in the presbyopia category.
Presbyopia Poster Highlights
Matthew Lampa, OD, et al presented Assessing Multifocal Soft Contact Lens Centration with the Aid of Corneal Topography.
This poster highlighted the centration differences of common commercially available soft multifocal lenses evaluated using corneal topography over the lenses. Subjects had Medmont corneal topography performed without contact lenses as baseline and then later after wearing their multifocals, which were allowed to equilibrate on the eye and were verified by slit lamp examination. The authors used the tangential power difference display map to identify centration of the soft multifocals. As mentioned in this column previously (based on Lampa's work), the “line of sight” is critical for presbyopic success. This poster demonstrates the technique of utilizing a topographer to assess optical centration of a lens, which may help us better understand reasons for success or failure. By incorporating the angle lambda measurement, we have one more tool in identifying a successful multifocal patient.
Keith W. Harrison, FCLSA, presented the poster Modified Monovision for Presbyopic Correction of Keratoconus.
This case history detailed a previously failed bifocal GP contact lens wearer who had keratoconus. When the ectasia in his left eye advanced, the bifocal GPs neither fit well nor could provide adequate vision. Ultimately, the patient achieved success with a combination of a Duette Multifocal in the right eye and Clear-Kone (both SynergEyes) in the fellow eye. These results demonstrate that we should not assume that a single lens modality is the only contact lens alternative and that creatively “mixing and matching” lens designs can provide excellent vision and comfort results. It also makes the point that we shouldn't forget about presbyopic contact lens correction in keratoconus patients.
Catherine Peyre, MD, presented Evaluation of a Translating Progressive GP Lens: Bi-Expert Progress.
This French study looked at the merits and detriments of GP segmented bifocal or trifocal contact lenses. It described the ability to improve patient comfort in these prism-ballasted designs by achieving a uniform edge profile 360 degrees around the lens.
Peyre also described her pilot study of five presbyopes in a new progressive lens design. All patients were present bifocal lens wearers older than 55 years old who needed add power of 2.00D or greater and had visual complaints regarding their intermediate vision while working on a computer. This new design is composed of two spherical zones for distance and near vision, which are joined smoothly by an aspheric zone for intermediate vision. For all study patients, intermediate vision was restored by simply duplicating their previous lens parameters while including the new intermediate zone.
Alexis K.S. Vogt, et al presented Multifocals or Monovision? Clinical Results and Laboratory Measurements Provide Answers.
This clinical evaluation of PureVision2 HD Multi-Focal (Bausch + Lomb) lenses, utilizing Frisby Stereoacuity, confirmed that stereopsis was significantly better with multifocal correction than with monovision correction and not different from spectacle correction. Maintaining depth perception can provide an avenue to keep patients satisfied with presbyopic lens correction.
I will discuss two other posters that were also of interest in a future column. CLS
|Craig Norman is director of the Contact Lens Section at the South Bend Clinic in South Bend, Indiana. He is a fellow of the Contact Lens Society of America and is an advisor to the GP Lens Institute. He is also a consultant to B +L. You can reach him at email@example.com.|