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Colored contact lenses make up a small percentage of your contact lens fits – perhaps 2-3% – and this has been declining slowly over the last 10-15 years. Why have we seen this trend? I think there are a few reasons. First, many practitioners I speak with despise fitting colored contact lenses; they find it inconvenient to fit into their workflow and problematic in terms of stocking yet more trials in limited space. A second potential reason for this trend has been a relative lack of new technology introduced in this market segment, at least in the last 10 years. All of this said, I am confident that there is indeed a demand for colored lenses – perhaps greater than we might think. |
Mimetogen Pharmaceuticals Inc., a privately-held biotechnology company, announced that the initial patients have been enrolled in the company's first pivotal Phase 3 clinical study of MIM-D3 ophthalmic solution for the treatment of dry eye syndrome.
MIM-D3 is the first in a class of molecules called TrkA agonists. MIM-D3 stimulates the production of mucin, which plays a critical role in the protection and overall health of the ocular surface. Mucins are essential for lubrication; the removal of allergen, pathogens, and debris; and corneal epithelial healing to reduce ocular surface damage. According to the company, MIM-D3 may have additional benefits than currently available dry eye therapies, including the potential to improve neural function, which may improve corneal sensitivity and integrity.
The pivotal trial will further evaluate the safety and efficacy of MIM-D3 in the treatment of dry eye syndrome. Approximately 400 patients will be randomized to receive 1% MIM-D3 ophthalmic solution or placebo twice daily over an 8 week period. The primary endpoints of the study are corneal fluorescein staining score in the CAE(SM) and ocular dryness. The safety and comfort of MIM-D3 compared to placebo will also be evaluated.
Bausch + Lomb (B+L) and Mimetogen Pharmaceuticals Inc. previously announced that B+L has acquired an option to license MIM-D3 for dry eye. Should B+L choose to pursue development based on the Phase 3 study results, the company will assume all development responsibilities and costs, and also will pay development milestones, sales milestones and royalty fees to Mimetogen.
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| On World Sight Day, an annual day to focus global attention on blindness and vision impairment, the Brien Holden Vision Institute (the Institute) released A Vision for All to See: A Report on Global Eye Health and Vision Care, aimed to raise awareness of the impending crisis of myopia and presbyopia and to create a call to action that prioritizes this growing issue.
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According to the Institute, in North America, more than 25 million people suffer from vision impairment due to uncorrected distance and near refractive error - the leading and most easily avoidable cause of vision loss. Two of the most rapidly increasing refractive error conditions are myopia and presbyopia. In the past 30 years, the number of people impacted by myopia in the U.S. among those aged 12 to 54 years has nearly doubled, growing from 25% in the early 1970s to 42% today (34 million people). As a result of the world's aging population and increased life expectancy, presbyopia is also on the rise. In 2010, the condition affected more than 143 million people in the U.S. and is estimated to grow to 1.5 billion worldwide by 2050.
According to Professor Brien Holden, founder of the Brien Holden Vision Institute, and the report, in addition to the human costs, global lost productivity resulting from vision impairment, specifically uncorrected refractive error, is estimated at U.S. $202 billion.
Even in the U.S., not everyone has access to eye care, and there are vast disparities by race, education and income. As reported by the Institute, studies show that from 1999 to 2008, people with less education and lower income were both less likely to visit an optometrist and less able to afford glasses when needed. The same study also found that more than 50% of Medicare beneficiaries had not visited an eye care provider or received an annual eye test.
The report may be viewed at http://www.brienholdenvision.org/vision_for_all_to_see/publication.html. |
 Plan now to attend the Optometric Management Symposium on Contemporary Eye Care, December 6-8, 2013 at Disney's Contemporary Resort in Lake Buena Vista, Florida. This popular annual symposium provides the perfect balance of timely, disease management courses and practice-building courses with plentiful networking and leisure time to enjoy all that Disney resorts and theme parks have to offer.
The educational program is presented by the Pennsylvania College of Optometry, Salus University. For agenda, more information and to register, visit www.OMConference.com.
–ADVERTISING |
Post-RK / Post-LASIK Cornea
By Edward Boshnick, OD, Miami, Florida |
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This image shows a 18mm scleral lens on a post-RK and post-LASIK cornea. Patient has 20/25 corrected vision with this lens.
We thank Dr. Boshnick for sending this image and welcome photo submissions from our 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
Loretta B. Szczotka-Flynn, OD, PhD, MS, FAAO |
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Corneal Ectasia and Regression after Hyperopic LASIK
Corneal ectasia after hyperopic LASIK is rare and only a few case reports can be found in the literature.1 In fact, topographic pseudokeratectasia is common after hyperopic LASIK, defined as one or more positive keratoconus screening findings in an eye with topographic central or inferior steepening detected by topography without corneal thinning or progressive changes.2 The incidence of topographic pseudokeratectasia after LASIK for primary hyperopia is between 28% to 56% and represents a relatively static condition.
A greater problem after hyperopic LASIK is regression. To prevent regression (and the risk of rare ectasia) simultaneous corneal crosslinking has been considered at the time of LASIK. In a recent small cohort series of five hyperopic eyes in Greece,3 LASIK surgery was combined with immediate riboflavin application under the flap, followed by UV light irradiation. Postoperative assessments were performed at 1, 3, 6, and 12 months, with late follow up at 4 years, and results were compared with a matched cohort that received LASIK only. All eyes maintained refractive stability over the 4 years and there were no complications related to CXL, with topographic and clinical outcomes as expected for standard LASIK.
This limited series suggests that simultaneous LASIK and CXL for hyperopia is safe. Outcomes of the small cohort suggest that this technique may be promising for ameliorating hyperopic regression, presumed to be biomechanical in origin, and may also address ectasia risk.
1. Randleman JB, Banning CS, Stulting RD. Corneal ectasia after hyperopic LASIK. J Refract Surg. 2007 Jan;23(1):98-102.
2. Jin GJ, Lyle WA, Merkley KH. Laser in situ keratomileusis for primary hyperopia. J Cataract Refract Surg. 2005 Apr;31(4):776-84.
3. Aslanides IM, Mukherjee AN. Adjuvant corneal crosslinking to prevent hyperopic LASIK regression. Clin Ophthalmol. 2013;7:637-41. doi: 10.2147/OPTH.S39796. Epub 2013 Mar 31.
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A New Custom SiHy Material
Lagado Corporation (Menicon America) has introduced Lagado LSH, a new latheable silicone hydrogel material. Contamac's Definitive material was the first latheable SiHy which has allowed patients with high refractive errors, unusual corneal curvatures and diameters, and corneal irregularities to wear highly oxygen permeable soft contact lenses. With its high water content and low modulus, it has performed very well for numerous patients. The Lagado LSH material (mangofilcon A) differs from Definitive in a number of ways.
First, the water content of LSH is in the mid-range at 49% vs. 74% for Definitive. LSH has a Dk of 49 vs. 60 for Definitive, and modulus of 0.8 vs. 0.35 MPa for Definitive. LSH is plasma oxidized to create a highly wettable surface with a very low wetting angle. It is available in clear, blue, green, and aqua tints with UV absorber. With these material property differences, Lagado LSH and Definitive will likely have different fitting characteristics as well as varying performance on eyes. These differences will become apparent as we gain experience with the newer material. This will allow us to help even more patients benefit from a higher oxygen permeable material in specialty designs.
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Medical Applications and Outcomes of Bitangential Scleral Lenses.
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The purpose of this study was to evaluate the clinical results of a new scleral lens design with a bitangential (nonrotationally symmetrical) periphery.
All the necessary data were obtained during the 1-year study period. The bitangential scleral lenses were fitted and monitored according to a standardized fitting methodology. They were cut by precise submicron lathing from high-oxygen-permeable materials (including 10 scleral lenses from Menicon Z material). Subjective performance, visual acuity, and scleral lens-fitting characteristics were recorded after a median of 9.4 weeks (range, 3 weeks to 1 year).
Diagnoses in the 213 eyes (in 144 patients) were keratoconus (n = 121 eyes; 56.8%), ocular surface diseases (n = 31 eyes; 14.6%), penetrating keratoplasty (n = 29 eyes; 13.6%), and other forms of irregular astigmatism (n = 28 eyes; 13.1%). Many patients (164 lenses; 77.0%) gave high ratings for comfort. The most common diameter was 20.0 mm (162 lenses; 76.1%) (range, 18.5 to 21.5 mm). Median decimal best-corrected visual acuity with the bitangential scleral lenses was 0.8 (equivalent to Snellen 20/25) (range, 0 to 1.5). Most bitangential scleral lenses showed good fitting characteristics: optimal values were seen for lens movement (208 lenses; 97.7%) and lens position (208 lenses; 97.7%). Median central corneal clearance was 0.2 mm; clearances differed in the four peripheral directions. The median stabilization axis was 140 degrees (range, 0 to 180 degrees) in the right eyes and 60 degrees (range, 0 to 180 degrees) in the left eyes.
The authors concluded that the bitangential scleral lens-fitting and performance characteristics were clear and effective for the health professional and the patient. The high-oxygen-permeable material Menicon Z may, in theory, be of benefit to corneas with a high oxygen demand.
Visser ES, Van der Linden BJ, Otten HM, Van der Lelij A, Visser R. Medical Applications and Outcomes of Bitangential Scleral Lenses. Optom Vis Sci. 2013 Oct;90(10):1078-85.
Source: MSc ††MSc, PhD ‡BSc, FAAO §MD, PhD Visser Contact Lens Practice, Nijmegen, The Netherlands and the Department of Ophthalmology of the University Medical Center, Utrecht, The Netherlands (E-SV, HMO, RV); NKL Contactlenzen, Emmen, The Netherlands (BJJJVdL) and the Department of Ophthalmology of the University Medical Center Utrecht, The Netherlands (AVdL).
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