We are seeing a lot of new technology emerge on the market to help us fit our contact lens patients. Some of this technology may relate to improving ocular surface conditions (e.g., pre-existing or concurrent dry eye), while other technology is directly aimed at improved measures of the ocular surface itself (e.g., ocular surface shape). We have and are covering these technologies extensively in the hopes that we keep you up-to-date on potential technologies to include in your practice.
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The International Keratoconus Academy of Eye Care Professionals (IKA) was recently established to promote ongoing professional education and scientific
development in the area of keratoconus and other forms of corneal ectasia. Its mission is to promote and develop the knowledge base and awareness of the
state of the art pertaining to the diagnosis and management of keratoconus and other forms of corneal ectasia. And further, IKA will promote the awareness
and understanding of the most appropriate and effective treatment strategies for the management of these diseases.
IKA will accomplish its mission by providing an array of educational initiatives which will include live events, web-based education, social media
activities and publications in the professional literature. The organization will also be dedicated to supporting ongoing clinical research. IKA will
function as a complementary entity to other organizations that support patients with these diseases such as the National Keratoconus Foundation (NKCF) and
will work cooperatively to establish a comprehensive effort to advance knowledge, awareness and quality of care.
The founding executive board of IKA includes: S. Barry Eiden, OD, FAAO; Andrew Morgenstern, OD, FAAO; Timothy McMahon, OD, FAAO; Joseph Barr, OD, FAAO;
William Tullo, OD, FAAO; Clark Chang, OD, FAAO; Eric Donnenfeld, MD; and Yaron Rabinowitz, MD. An international physician’s advisory board comprised of
expert optometrists and ophthalmologists is being formed. Professionals interested in membership in IKA may e-mail info@keratoconusacademy.com.
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Bausch + Lomb announced availability of the PureVision2 Multi-Focal Fit Guide mobile application (app) in the U.S., which is designed to help eyecare
practitioners successfully fit patients into PureVision2 for Presbyopia contact lenses. On average, fitting a multi-focal contact lens on a patient takes
2.6 attempts.1 The new app was developed to help streamline the multi-focal fitting process for doctors by delivering a guide that is not only
convenient and accessible, but also helps reduce patient chair time and the need for follow-up visits.2
The interactive app enables ECPs to calculate the initial lens selection by directly entering the patient’s sphere and cylinder information, including ADD,
based on the patient’s most recent refraction. Following evaluation of the performance of initial lens selection on the eye, the ECP will determine if
further refinement is needed to improve distance or reading vision. A simple selection in the app will provide instantaneous feedback and an updated lens
recommendation.
The app is free to download in the App Store and is compatible with all iPhone, iPad and iPod touch devices running iOS 6 or higher. The app will also be
extended later this year to include Biotrue ONE day contact lenses for Presbyopia.
1. Kadence International PureVision2 Multi-Focal contact lenses for Presbyopia Quantitative Testing. July 2012.
2. Thirty-nine ECP's from 10 countries refitted 422 existing soft contact lens wearing presbyopes into PureVision 2 for Presbyopia contact lenses. Patients
returned for a follow up visit after 1-2 weeks. ECP assessment of lens performance including ease of fit, and patient satisfaction with lenses in real
world conditions, were measured using a 6-point agreement survey.
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Accu-Lens released its new translating bifocal for the advanced presbyopic patient with high add powers of +2.25 and greater. According to the company,
Accent’s design incorporates a proprietary constant sector transition zone that eliminates the typical “glare” in bifocal transitions so patients have
crisp and sharp vision at both distance and near. In addition, Accent’s One-Cut positioning chamfer provides exceptional comfort and clarity.
Accent is available in a variety of materials, and fitting sets are available upon request. For more information call 800-525-2470.
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The American Optometric Association (AOA) unveiled the name of its optometric registry —AOA's MORE (Measures and Outcomes Registry for Eyecare), powered by
Prometheus Research. The registry is an AOA member benefit, but will be available to non-members for a fee. AOA's MORE will launch at
Optometry's Meeting 2015 in Seattle, Washington, June 24-28.
With more data, more access and more quality measurement solutions, AOA's MORE represents a technological milestone in optometry for helping doctors keep
up with advances in the ever-changing world of value-driven health care. (Click here for an optometric registry FAQ.)
AOA’s MORE is a secure and easy-to-use data portal that will report to Centers for Medicare and Medicaid Services (CMS) for
increased reimbursements. It will help doctors with clinical improvement solutions and collect data (outcomes and population information). It will be
optometry’s collective database of clinical information to support increased access for patients and eventually support scope of care. Only non-identifying
information recorded, such as diagnosis or visual acuity, will be shown to AOA. The AOA will only see collective data and will not be able to see or obtain
any information about specific doctors or patients.
It will help doctors:
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Report clinical quality data to the Physician Quality Reporting System
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Satisfy meaningful use Stage 2 objectives
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Benchmark performance with peers
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Contribute to the profession
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This eye underwent Radial Keratotomy in 1985 followed by LASIK in 2005. These two surgeries created a severely irregular cornea and distorted vision which
could not be corrected with conventional lenses. This eye was fit with a 16.8mm reverse geometry scleral lens which allowed the patient to see 20/20
without distortions.
We thank Dr. Boshnick for this image and we welcome photo submissions from our other readers! It is easy to submit a photo for consideration for publishing
in Contact Lenses Today. Simply visit http://www.cltoday.com/upload/upload.aspx to upload
your image. Please include an explanation of the photo and your full name, degree or title and city/state/country.
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RESEARCH REVIEW
S. Barry Eiden, OD, FAAO
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What’s the Deal with Base Curves? Is There More to It?
A study was conducted to evaluate the sagittal height differences among a selection of commercially available monthly or two week replacement silicone
hydrogel soft contact lenses.1 The sagittal height (CL-SAG) of four frequent replacement silicone hydrogel lenses (lotrafilcon B, balafilcon A,
comfilcon A and senofilcon A) was measured for all base curve radius manufactured in spherical (-3.00D and +3.00D) and toric (=C-0.75×180°) designs. Two
different lenses of each lens type were evaluated in order to evaluate the “intra” CL-SAG. Measurements of contact lens sagittal height were determined by
using the SHSOphthalmic omniSpect by Optocraft.
The intra CL-SAG difference (the difference between two identical lenses from the same batch) was 11 μm ±SD 2μm. The CL-SAG of all minus lenses ranged from
3454 to 3765μm (an inter CL-SAG difference of 311μm), while the plus spherical lenses ranged from 3493 to 3757μm (inter CL-SAG difference 264μm). In the
toric lens group, the range in toric minus lenses was 3495-3953μm (inter CL-SAG difference 458μm) and 3493-3980μm in the plus group (inter CL-SAG
difference 487μm). The inter CL-SAG difference between the spherical and the toric lenses was statistically significant (p=0.03).
The authors concluded that notable differences in sagittal height among different commercially available frequent replacement silicone hydrogel lenses
exist. Different lenses with the same package base curve value had marked differences in CL-SAG, with potential clinical significance on-eye in terms of
lens behavior. The inter CL-SAG variance in the spherical lens group was smaller than in the toric lens group.
Various elements go into how a contact lens will behave on the ocular surface in terms of physical fit (centration, movement and corneal draping). Base
curve, although typically considered to be the most important in the minds of most clinicians, is only one of many. Material modulus, thickness profiles
also can significantly influence fit. Of greatest importance however is the sagittal height of the contact lens and how that relates to the sag of the
cornea being fit. Lenses with steeper base curves, larger diameters, and to some degree lower posterior aspheric eccentricity (if a posterior aspheric
design CL), will result in a contact lens design with a greater sagittal height. Understanding the principles of sagittal height in contact lens design
is critical in order to achieve successful fitting outcomes. Realizing that variations in CL sagittal height exist between various designs of commercially
available SiHy frequent replacement lenses along with sag variations within what should be the same CL should be understood by the contact lens
practitioner.
1. van der Worp E, Mertz C. Sagittal height differences of frequent replacement silicone hydrogel contact lenses. Cont Lens Anterior Eye. 2015 Feb
18 [Epub ahead of print]
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Benefits of Omega Fatty Acid Supplementation
As a general rule, I recommend oral omega fatty acid supplementation to almost all my patients (dry eye or not) so it was nice to find a recent study, with
corneal impression cytology, to support my rationale for doing so. The aim of this study was to evaluate the effect of dietary omega-3 fatty acid (O3FA)
supplementation on dry eye symptoms, tear film tests, and conjunctival impression cytology in patients with contact lens wear-associated dry eye.1
In this randomized, double-blind, multicenter trial, contact lens wearers (n = 496) were randomized to receive either O3FAs or placebo capsules (corn oil)
twice daily for 6 months. Subjects underwent examinations at baseline, 3 months, and 6 months. At each visit, a questionnaire of dry eye symptoms and lens
wear comfort was administered. Subjects further underwent measurement of tear film break-up time and a Schirmer test. Conjunctival impression cytology was
performed by the transfer method. Improvement in symptoms and lens wear comfort were primary outcome measures. Changes from baseline in TBUT, Schirmer, and
Nelson grade (scoring system in impression cytology measuring goblet cell density) at 6 months were secondary outcome measures.
Lens wear comfort levels improved significantly from baseline in the O3FA group. There was a significant increase in TBUT and Nelson grade in the O3FA
group as compared with the placebo group. The magnitude of increase in Schirmer score was relatively small. The results of this study point toward benefits
of orally administered O3FAs in alleviating dry eye symptoms, improving lens wear comfort, and cytological changes in contact lens wearers. Certainly there
are numerous commercially available oral omega fatty acid preparations—I encourage you to prescribe them to your patients.
1. Bhargava R, Kumar P. Oral omega-3 Fatty Acid treatment for dry eye in contact lens wearers. Cornea. 2015 Apr;34(4):413-20. doi:
10.1097/ICO.0000000000000386.
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Medical Interventions for Acanthamoeba Keratitis
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Acanthamoeba
are microscopic, free-living, single-celled organisms which can infect the eye and lead to Acanthamoeba keratitis (AK). AK can result in loss of
vision in the infected eye or loss of eye itself; however, there are no formal guidelines or standards of care for the treatment of AK.
The objective of this study was to evaluate the relative effectiveness and safety of medical therapy for the treatment of AK.
The authors searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2015, Issue 1), Ovid MEDLINE, Ovid MEDLINE In-Process and
Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to January 2015), EMBASE (January 1980 to January 2015), PubMed (1948 to
January 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (1982 to January 2015), the metaRegister of Controlled Trials
(mRCT) (www.controlled-trials.com), ClinicalTrials.gov ( www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform
(ICTRP) (www.who.int/ictrp/search/en). They did not use any date or language restrictions in the
electronic search for trials. We last searched the electronic databases on January 9, 2015.
The authors included randomized controlled trials (RCTs) of medical therapy for AK, regardless of the participants' age, sex, or etiology of disease. They
also included studies that compared either anti-amoeba therapy (drugs used alone or in combination with other medical therapies) with no anti-amoeba
therapy or one anti-amoeba therapy with another anti-amoeba therapy.
Two authors independently screened search results and full-text reports, assessed risk of bias, and abstracted data. They used standard methodological
procedures as set forth by the Cochrane Collaboration.
The authors included one RCT (56 eyes of 55 participants) in this review. The study compared two types of topical biguanides for the treatment of AK:
chlorhexidine 0.02% and polyhexamethylene biguanide (PHMB) 0.02%. All participants were contact lens wearers with a median age of 31 years. Treatment
duration ranged from 51 to 145 days. The study, conducted in the UK, was well-designed and had low risk of bias overall. Outcome data were available for 51
(91%) of 56 eyes. Follow-up times for outcome measurements in the study were not reported. Resolution of infection, defined as control of ocular
inflammation, relief of pain and photosensitivity, and recovery of vision, was 86% in the chlorhexidine group compared with 78% in the PHMB group (relative
risk (RR) 1.10, 95% confidence intervals (CI) 0.84 to 1.42). In the chlorhexidine group, 20 of 28 eyes (71%) had better visual acuity compared with 13 of
23 eyes (57%) in the PHMB group at final follow-up (RR 1.26, 95% CI 0.82 to 1.94). Five participants required therapeutic keratoplasty: 2 in the
chlorhexidine group compared with 3 in the PHMB group (RR 0.55, 95% CI 0.10 to 3.00). No serious adverse event related to drug toxicity was observed in the
study.
The authors concluded that there is insufficient evidence to evaluate the relative effectiveness and safety of medical therapy for the treatment of AK.
Results from the one included study yielded no difference with respect to outcomes reported between chlorhexidine and PHMB. However, the sample size was
inadequate to detect clinically meaningful differences between the two groups as indicated by the wide confidence intervals of effect estimates.
Alkharashi M, Lindsley K, Law HA, Sikder S. Medical interventions for acanthamoeba keratitis. Cochrane Database Syst Rev. 2015
Feb 24;2:CD010792. doi: 10.1002/14651858.CD010792.pub2
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