Michael Baertschi, MSc Mmed Education FAAO
Michael Wyss, MSc FAAO
Simon Bolli, Eidg dipl Augenoptiker
Marc Fankhauser, Eidg dipl Augenoptiker
The accelerated orthokeratology procedure has been on the market in our country for more than 10 years, and it is used in our practice and worldwide to the satisfaction of many of our patients. However, previously it could correct presbyopia only by monovision or by providing additional reading glasses. In many cases, patients were informed that because of presbyopia they were not able to benefit from orthokeratology. But bifocal orthokeratology lenses have been available since 2009; this case report will show the benefits of such a simultaneous bifocal orthokeratology design.
A Caucasian male, 52 years of age, had been wearing contact lenses since he was in his 20s. Over the last 7 years, symptoms of presbyopia have been bothering him. He tried several different contact lens options, including monovision, (R)GP translating and simultaneous lens designs as well as hydrogel translating and simultaneous designs, but none of these solved his problems entirely; either discomfort (dry eye) or vision related problems still occurred.
Orthokeratology eliminates the dry eye issue, and with the new bifocal design, simultaneous bifocal images are presented to the eye in a manner similar to other (R)GP or hydrogel lens systems on the market. The design we used (Falco, Switzerland) includes an additional curve between the central treatment zone and the reverse zone (Figure 1).
Figure 1: Bifocal orthokeratology design (Falco Switzerland)
The fluorescein pattern of the ordered contact lenses illustrated the assumed zones of the lens design nicely. The Reverse Zone appears much wider than in regular orthokeratology lenses. A closer look shows a fine classical reverse curve in the area in which a bubble is present (Figure 2), and a faint addition zone toward the center treatment zone.
Figure 2: Fluorescein pattern of the bifocal orthokeratology design
The optical outcome was superb after 1 month of wear. Compared to traditional orthokeratology, the adaptation time took about 1 week longer for distance vision to become solid. The patient reported a massive increase in overall quality of life. Visual acuity OU was 1.0 for distance (20/20), and reading at 40cm achieved 1.0 as well. Corneal topography showed a well-centered and regular treatment zone. The distance zone appeared somewhat smaller, and the bull’s-eye formation presented with a somewhat softer transition than in normal orthokeratology (Figure 3).
Figure 3: Differential Mapping of Pre/Post - Treatment
The importance of topographical differential mapping during orthokeratology should not be underestimated. Sagittal and tangential maps reflect different aspects of the fitting, but differential mapping pre- and post-treatment are the most powerful tools in orthokeratology management. The true corneal changes between pre- and post-lens fit are thus displayed. Lens centration is especially key for successful orthokeratology, but the apex is not always in the theoretical center of the cornea. Additionally, the precise amount of corrected myopia can be seen directly from the differential mapping, which provides a good indication of the subjective visual outcome.
Orthokeratology gives our patients a lot of freedom and can improve their quality of life. Presbyopia should no longer be considered impossible for this modality. The presented bifocal design works well, and patients love to be relieved from the use of any visual aids. Presbyopic patients with dry eye problems during multifocal soft or (R)GP contact lens wear could particularly benefit from this kind of lens design.
Michael Baertschi was the senior optometrist at the University Eyehospital Basel from 2000 to 2007. He is the owner of Kontaktlinsenstudio Baertschi in Bern, Switzerland and the CEO of Eyeness AG in Bern. Michael graduated from Pennsylvania College of Optometry as M.Sc. Optom. and from the University of Bern as M.med. Educ. Michael Baertschi is a fellow of the American Academy of Optometry and president of the Swiss Interlens group.
Michael graduated from Olten SHFA in Switzerland and did his MSc at the Hochschule Aalen Germany (in cooperation with New England College of Optometry and Pacific University, USA). Since 1999 he has worked in a private practice (kontaktlinsenstudio Baertschi in Bern, Switzerland) as Optometrist for specialty contact lens fitting. Additionally, he is an adjunct Faculty Member at the New England College of Optometry USA, Hochschule Aalen Germany, TVCI in Prague (Czech Republic) and FHNW Optometry in Olten Switzerland. Michael is a clinical investigator for several Industry Partners and has published or lectured on several topics in the contact lens field throughout the world. Michael is a Fellow of the American Academy of Optometry and serves as a the vice chairman of the Admittance Committee for new Fellows outside the USA.