Before you know it, kids and teens will be headed back to school, and we will be moving full steam ahead into the fall season in the Northern Hemisphere. Before the school year starts is a great time to promote “back to school” eye care. In the hustle and bustle of this time of year, don’t let parents lose sight of the importance of eye care in this special population. Also, use these encounters as an opportunity to initiate important discussions about contact lenses and how they might benefit kids and teens, whether in school, sports, or otherwise.
Jason J. Nichols, OD, MPH, PhD
CooperVision Acquires Procornea
CooperVision, Inc. acquired Procornea Nederland BV, a manufacturer of special contact lenses based in Eerbeek, the Netherlands. The acquisition adds Procornea’s Dreamlite orthokeratology contact lenses to CooperVision’s offerings; these lenses are not available in the United States.
Procornea will continue to operate as a complementary company for the time being and will maintain its offices and brands. Customers will continue to work with their current representatives.
Ben Wanders, former CEO of Procornea, will continue to lead Oculentis, the intraocular lens-focused sister division, which was not part of the transaction and remains independent. The terms of the acquisition have not been announced.
B+L Receives 510(k) Clearance from FDA for the Therapeutic Use of Boston XO and Boston XO2 Materials
Bausch + Lomb (B+L) has received 510(k) clearance from the U.S. Food and Drug Administration (FDA) for the therapeutic use of its Boston XO and Boston XO2 materials in treating several ocular surface diseases. The Boston XO and Boston XO2 GP materials are used in a broad spectrum of custom specialty lenses, including the Zenlens scleral lens from Alden Optical, a part of the B+L Specialty Vision Products business, and are also indicated for daily wear for the correction of refractive ametropia and the management of irregular corneal conditions.
The expanded indication enables scleral lenses manufactured with the Boston XO and Boston XO2 GP materials to be utilized in the treatment of certain ocular surface conditions, including dry eye disease, as well as limbal stem cell deficiencies, skin disorders with ocular surface manifestations, neurotrophic keratitis, and corneal exposure that may benefit from the presence of an expanded tear reservoir and the saline-hydrated environment inherent in a scleral lens design.
Optovue Receives FDA Clearance for Corneal Epithelial Thickness Mapping
Optovue announced that the U.S. Food and Drug Administration (FDA) has cleared the company’s epithelial thickness mapping software (epi-mapping) for quantitative measurements of the epithelial and stromal layers of the cornea. Epi-mapping is the first non-contact, quantitative method for corneal epithelial and stromal measurements. It is also the first and only FDA-cleared product indicated to provide corneal epithelial and stromal measurements that aid in the diagnosis, documentation, and management of ocular health and diseases in the adult population, according to the company.
Optovue says that its new mapping software provides epithelial thickness information in a fast, non-contact, and easy exam. Traditional epithelial measurements require high-frequency digital ultrasound and saline. In addition, epi-mapping software complements other diagnostic tests by providing different information about ocular health that may be clinically valuable prior to testing, such as topography and tomography, or topography-guided procedures including laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). Epi-mapping is commercially available on the iVue and iFusion optical coherence tomography (OCT) systems.
PEN Offers Two Free Workshops in September Focused on OCT
Primary Eyecare Network (PEN), a division of ABB Optical Group, is offering two free workshops focused on optical coherence tomography (OCT) on Sept. 6 and Sept. 7. Presented by Mile Brujic, OD, the workshops will offer attendees the opportunity to explore OCT technology, its clinical applications, and how it has revolutionized patient care.
An hour of continuing education credit is pending approval from the Council on Optometric Practitioner Education.
The Sept. 6 workshop will be at Scribner Bend Vineyards in Sacramento, CA, and the Sept. 7 workshop will be at Lawrence Hall of Science in Berkeley, CA. Both workshops will take place from 6:00 p.m. to 7:00 p.m. Hors d’oeuvres will be served.
This image shows translucent jelly deposits on the front surface of a high-water-content soft contact lens. The patient is on an overnight extended wear regimen.
We thank Dr. Ibanez for this image and 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 a detailed explanation of the photo and your full name, degree or title, and city/state/country.
S. Barry Eiden, OD
Relationship of Corneal Elevation and Centration of Orthokeratology Treatment Zone
Lens decentration is common and unavoidable to some extent during orthokeratology (ortho-k) treatment. Designing an optimal sagittal relationship between the corneal shape and the contact lens can minimize decentration in general; however, the system is dynamic, and each occurence of wear presents a potential for variation in lens positioning to some degree. The implications of lens decentration with ortho-k are typically visual. Decentered treatment zones result in a potential for reduced visual acuity post-lens removal, induced regular and irregular astigmatism, and induced elevation of high-order aberrations, potentially reducing the overall quality of vision.
A study recently looked at the relationship between corneal elevation asymmetry and lens centration in orthokeratology.1 Thirty-six eyes of 36 subjects were fit with four-curve reverse geometry ortho-k contact lenses. Corneal topography was performed before and one month after ortho-k lens wear. The difference in corneal elevation at the 8mm chord of the respective two principal meridians of corneal astigmatism was calculated. Vector analyses were performed on these differences to calculate the magnitude and direction of a vector (corneal asymmetry vector). The relationship between the angle and magnitude of corneal asymmetry vector and lens decentration was analyzed.
The mean magnitude of lens decentration was 0.72mm ± 0.26mm (0mm to 1.34mm). For overall displacement, inferotemporal decentration was the most common as observed in 24 eyes (67%). The mean angle of the corneal asymmetry vector (202º ± 39º) was significantly correlated to the mean angle of lens decentration (200º ± 39º) (r = 0.76, P < 0.001). The magnitude of corneal asymmetry vector significantly contributed to the magnitude of lens decentration (standardized β = 0.448, p = 0.002), whereas the other tested variables did not affect lens decentration (all p > 0.05).
The authors concluded that lens decentration is a common phenomenon in ortho-k that mostly happens toward the inferotemporal quadrant of the cornea. The magnitude and direction of lens decentration are predetermined by paracentral corneal asymmetry.
1. Chen Z, Xue F, Zhou J, Qu X, Zhou X; Shanghai Orthokeratology and Study (SOS) Group. Prediction of Orthokeratology Lens Decentration with Corneal Elevation. Optom Vis Sci. 2017 Jul 24. [Epub ahead of print]
OCULAR SURFACE UPDATE
Katherine M. Mastrota, MS, OD
An Oily Situation
Recently, on an online forum, there was a question about the safety of an eyelash mascara made with maracuja oil. There are also mascaras made with argan oil, mamey seed oil, and other oils. Natural plant oils are commonly used as topical therapies worldwide. Many natural oils possess specific compounds with antimicrobial, antioxidant, anti-inflammatory, and anti-itch properties, making them attractive alternative and complementary treatments for xerotic and inflammatory dermatoses associated with skin-barrier disruption.
Unique characteristics of various oils are important when considering their topical use. Differing ratios of essential fatty acids are major determinants of the barrier repair benefits of natural oils. Oils with a higher linoleic acid to oleic acid ratio have better barrier repair potential, whereas oils with higher amounts of irritating oleic acid may be detrimental to skin-barrier function.
Akin to tea tree oil processing, various extraction methods for oils exist, including cold pressing or heat and chemical distillation. The addition of various chemicals to simulate a specific scent can also be used to fragrance the oils. The method of oil processing and refinement is an important component product preparation of selecting oil for topical care, or in this example, for use in mascaras. Cold pressing is the preferred method of oil extraction, as the heat- and chemical-free processes preserve beneficial lipids and limit irritating byproducts.1
It is important to consider this point when using products on the eyelashes or around the eye whose preparation regulation is limited or non-existent.
Q: What adverse side effects to the ocular surface can these products have?
A: We don’t know.
1. Vaugh AR, Clark AK, Sivamani RK, Shi VY. Natural Oils for Skin-Barrier Repair: Ancient Compounds Now Backed by Modern Science. Am J Clin Dermatol. 2017 Jul 13. [Epub ahead of print]
Diquafosol Delivery from Silicone Hydrogel Contact Lenses: Improved Effect on Tear Secretion
The aim of this study was to evaluate the ability to uptake and to deliver diquafosol from commercial contact lenses (CLs) and the effect on tear secretion.
For both in vitro and in vivo experiments, two commercial silicone hydrogel (SiHy) CLs (comfilcon A and balafilcon A) were used. The CLs were soaked overnight for 12 hours in diquafosol, and control CLs were soaked in saline (NaCl 0.9%). The CLs were introduced into a new well container with 1mL of saline solution, and aliquots of 100μL were extracted at different times during a period of six hours to measure the diquafosol release.
For in vivo experiments, nine male New Zealand white rabbits were used. CLs soaked in diquafosol were applied on the eye and compared with control CLs and diquafosol topical instillation. Schirmer’s tests were performed to evaluate tear secretion and diquafosol release at different times during the six-hour period.
For in vitro experiments, the largest amount of diquafosol was released during the first 24 hours for both CL materials under study, with no statistical differences between the materials (P < 0.05). The topical application showed the maximum release at one minute after instillation; meanwhile, the release from both CL materials was at 30 minutes of application. The effect on tear secretion was higher with CL delivery compared with topical instillation (P < 0.05), being 300 minutes for both CLs and 90 minutes for topical application.
The use of CLs increases the residence time of diquafosol on the ocular surface, with a concomitant enhancement in tear secretion during longer periods.
Dominguez-Godinez C, Carracedo G, Pintor J. Diquafosol Delivery from Silicone Hydrogel Contact Lenses: Improved Effect on Tear Secretion. J Ocul Pharmacol Ther. 2017 Jul 12. [Epub ahead of print]