prescribing for astigmatism
Let Your Astigmatic Patients Try Soft Toric Lenses
BY TIMOTHY B. EDRINGTON, OD, MS, FAAO
Arecent survey conducted by Decision Analyst and sponsored by Bausch & Lomb found that more than 40 percent of astigmatic patients felt that their astigmatism was the reason why they could not wear contact lenses. Survey results indicated that "two-thirds of astigmats who have never worn contact lenses and nearly half of those who have worn contact lenses in the past would be highly motivated to wear lenses if they were available to correct astigmatism." It appears that there are longstanding misconceptions concerning the current widespread availability and success of contact lenses to correct astigmatism.
Holden (1975) reported that only 3.4 percent of prospective contact lens patients required a refractive cylinder correction of 3.00D or more. A large number of "stock" toric hydrogel and silicone hydrogel lenses are available in cylinder corrections of at least 2.75D. Therefore, eyecare practitioners are not always offering soft toric lenses as a vision correction option for their astigmatic patients. This may be due to a perception that soft toric contact lenses are difficult to fit and prescribe, to unsuccessful past experiences in fitting these lenses, or to a feeling that soft toric lenses are no longer profitable, especially if additional chair time is necessary to fit a toric lens design.
Worth Another Look
The old school of thought was that soft torics were not reproducible and were difficult to fit. Lens reproducibility is basically a non-issue with current toric lens manufacturing techniques.
Another benefit of most of today's soft torics is that they are prescribed to be replaced on a more frequent schedule than in the past. This more frequent replacement with a clean, fresh lens leads to improved lens comfort and reduced risk of giant papillary conjunctivitis (GPC).
The increased availability and prescribing of silicone hydrogel toric lenses have minimized past concerns over decreased oxygen transmissibility from thicker profile toric lens designs. Also, the available range of sphere, cylinder, and axis parameters is expanding readily in the silicone hydrogel toric lens segment. Manufacturers' consultation services and easy-to-access online resultant cross-cylinder calculators, along with better lens reproducibility, have reduced the difficulty in prescribing the optimal soft toric contact lens.
With the increased availability of disposable soft toric diagnostic lens fitting sets, you can often dispense patients a pair of lenses that correct their refractive error, thereby providing instant gratification. All of these factors contribute to fewer and more efficient office visits to achieve visual success and patient happiness.
I feel that if you give toric soft lenses another opportunity to succeed in your office, you and your patients will be pleasantly surprised. Patients tend to follow your prescription recommendations. Make contact lenses, and specifically soft torics, one of your prescribing options more frequently. Remember, your patients look to you for new and improved vision correction modalities. CLS
For references, please visit www.clspectrum.com/references.asp and click on document #163.
Dr. Edrington is a professor at the Southern California College of Optometry. He has also worked as an advisor to B&L. E-mail him at firstname.lastname@example.org.