Review of Cornea and Contact Lenses

RCCL E-NEWS - MARCH 11, 2016

Proper solution use and lens care compliance is just as important as fitting the patient with the right lens—yet patients consistently downplay this aspect of contact lens wear. To help you prepare for the consequences of patient noncompliance, the February 2016 issue of Review of Cornea & Contact Lenses is aimed at improving your knowledge of lens/solution interactions and strategies to improve patient behavior. Below are 20 pearls from several experts in the field. Click through to read the original articles in full for each.

1. Gas permeable lens cleaners that contain abrasive surfactants are more effective when used with lower-permeability, early-generation GP lenses that bind more protein. Higher-permeability lenses are more easily scratched, inducing minus power by reducing center thickness. More

2. Direct patients to avoid soaking GPs in cleaners for more than 30 minutes to avoid material discoloration, and rinse before insertion into the eye to prevent discomfort. More

3. Suggest that patients with dry eye consider hypo-osmotic artificial tears. These blunt the effects of high osmolarity, generally improving OSDI scores. Younger patients and those with hyperosmotic tears are especially suited for this type of drop. More

4. Be aware of differences between solutions and tailor the recommendation for each patient. For instance, patients with inconsistent lens wear schedules may prefer a faster neutralization of hydrogen peroxide than the usual six-hour soak. More

5. Move patients prone to developing GPC to hydrogen peroxide disinfection systems. These are best for avoiding resurgence once the patient’s presentation has been appropriately managed with topical treatments. More

6. Stress the importance of thorough cleaning to patients by explaining the role of bacterial biofilm, especially silicone hydrogel lens wearers. Microbial adhesion and biofilm formation is enhanced in SiHy lenses due to the increased hydrophobic phases, increased protein/lipid deposits on the lens and higher oxygen transmissibility/availability. More

7. Keep in mind structural differences exist between branded basket-and-disc hydrogen peroxide systems and generic formulations. Use of non-branded systems can affect the neutralization profile of the hydrogen peroxide due to the delay in lens exposure time. More

8. Be aware that solutions designed to improve wettability may be linked to enhanced rates of Acanthamoeba encystment and increased resistance to biocidal activity. Instead, recommend patients try lens materials with inherently better wettable properties if comfort is a concern. More

9. Although benzalkonium chloride increases drug penetration and extends product shelf life, it disrupts tight cellular junctions, accelerates epithelial desquamation, promotes apoptosis at low concentrations and necrosis at high concentrations, stimulates production of inflammatory cytokines, reduces aqueous production and causes neurotoxicity. More

10. Consider active and inactive ingredients in artificial tears when recommending options to a patient. Each has a different makeup and may interact differently with a patient’s ocular surface, depending on presence and type of disease or corrective lenses. For example, the inactive ingredient hyaluronic acid lowers tear osmolarity and adheres to the ocular surface, stabilizing the tear film. More

11. Switch patients with preservative sensitivities to a hydrogen peroxide-based solution to prevent exacerbation. Recommend solutions with a 3% hydrogen peroxide concentration, as these are particularly effective against pathogens. More

12. GPs with especially heavy protein deposits benefit from an additional enzymatic or solvent cleaner that can be used periodically; these can be added directly to a storage solution. More

13. Direct patients wary of discomfort from artificial tear use to consider drops with lower pH and osmolarity; these more closely match the baseline pH of a patient’s tears and will result in less stinging upon installation and better overall comfort. More

14. Consider the variables affecting a solution’s preservative uptake and release. These include the material’s water content, charge, hydrophobicity, surface treatment and porosity as well as the care system’s concentration, charge, iconicity, molecular weight and hydrophobicity. More

15. Be mindful of how artificial tears could interfere with solution disinfection efficacy. Pathogens may use certain artificial tear components as a source of energy or to enhance growth of biofilm on the lens surface. More

16. Look for signs of corneal staining when evaluating a patient’s lens care system. If patients who use PHMB-based systems or who wear silicone hydrogel lenses exhibit higher levels of staining, reinforce education on the cleaning process. More

17. During the patient examination, inform your GP lens wearers of the risks for tap water rinsing as part of their care process, as this practice raises the risk for Acanthamoeba keratitis. Instead, suggest use of a sterile saline rinse as an alternative. More

18. Remind patients to keep hands clean when touching contact lenses. Certain solutions do not currently account for presence of organic contaminants. More

19. Keep in mind silicone hydrogel and conventional hydrogel contact lenses respond to solutions differently. Recommend patients consider solution type upon switching lens types to ensure best compatibility. More

20. Avoid using abrasive cleaners on plasma-treated lenses to prevent accelerating the coating’s breakdown. Most plasma treatments last for several weeks. More

NEWS

Corneal Diameter Affects Postoperative Astigmatism
Corneal diameter should be determined prior to cataract surgery, as it can lead to varying degrees of corneal astigmatism depending on the type of incision used, reports a study in the January 2016 issue of Cornea. Other factors already known to impact postoperative astigmatism include incision size, configuration and location relative to the limbus, as well as the axis on which the main incision is performed. More

Lipid-binding Differences Noted
Deposition of cholesterol on contact lenses varies significantly between lens materials, reports a study in the January 2016 Optometry and Vision Science. Though silicone hydrogel (SH) materials are known to increase oxygen transport to the ocular surface, certain chemical components within these materials may also negatively impact wettability (and potentially patient comfort) if exposed to very high levels of lipids. To date, however, no study has investigated the degree to which daily disposable lenses uptake lipids—in particular, cholesterol. More

Chicken Pox Vaccine Linked to Keratitis
Researchers from the University of Missouri School of Medicine have identified a link between administration of the varicella zoster virus vaccine for chickenpox and shingles and presentation of keratitis. Though the potential for corneal inflammation as a side effect of the vaccine is low, primary care physicians should inform all patients prior to administration, the researchers say. More

More Orthokeratology Focus Needed
Consider reinforcing orthokeratology education, particularly for male patients, reports a study in the January 2016 issue of Eye & Contact Lens. Researchers in southern Taiwan identified a total of 86 microbial strains from 38 culture-positive specimens taken from orthokeratology lens case fluids of 41 pediatric wearers. Interestingly, frequently reported pathogens (i.e., Serratia marcescens, Pseudomonas aeruginosa and Staphyloccocus aureus) in contact-lens related microbial keratitis were identified less commonly in this study; additionally, the lens cases of male subjects exhibited a higher microbial bioburden than those of female subjects. More

Surgical Procedure Comparison Suggests Benefits
A comparison of femtosecond laser-assisted LASIK and small-incision lenticule extraction (SMILE), published in the February 2016 issue of Cornea, suggests both procedures achieve similar good visual outcomes in the correction of myopia and myopic astigmatism; however, patients who underwent SMILE exhibited a lower induction rate of spherical aberration six months postoperatively, suggesting long-term outcomes of the procedure may ultimately be more beneficial. However, further research is needed based on a larger sample size to confirm this. More

Lens Rinse Announced
Menicon America has announced FDA approval for its LacriPure non-preserved saline for rinsing both soft and rigid lenses. Packaged in 5ml unit-dose vials, the saline is also approved as a first-of-its-kind scleral lens insertion solution as an alternative to irrigation saline, according to Menicon. More

SPEED Questionnaire Vetted
The Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire is comparable to the Ocular Surface Disease Index (OSDI) questionnaire for separating asymptomatic and symptomatic dry eye patients, reports a study published in the February 2016 issue of Cornea. Investigators compared the answers of 657 undergraduate students at the University of Cape Coast in Ghana, determining the internal consistencies of the OSDI and SPEED questionnaires to be approximately the same (i.e., 0.897 and 0.895, respectively). However, the SPEED questionnaire was relatively better in terms of internal consistency compared with the OSDI questionnaire, indicating it is a valid measure for dry eye and could be used in epidemiological studies and clinical practice, the researchers say. More

VIEW MORE FROM THE FEBRUARY ISSUE OF RCCL HERE!

Departments:

My Perspective:
This Year, Strive to Avoid Stress

Pharma Science & Practice:
Dextenza on Deck

Out of the Box:
What’s in a Name?

Corneal Consult:
The Case of the Finicky Fungus

Practice Progress:
Solution Savers

The GP Expert:
Good Chemistry

Features:

Putting it On the Map: Fitting Rigid Lenses Using Corneal Topography

Forward Thinking: Where Can New Lenses Lead Your Practice?

Artificial Tears: Looking Beneath the Surface

Reality Check: How FDA Testing Falls Short

Have a topic you want to see discussed? Want to comment on an article? We want to hear from you! Contact Us with your feedback and suggestions.

Review of Optometry^® is published by the Professional Publications Division of Jobson Medical Information LLC (JMI), 11 Campus Boulevard, Newtown Square, PA 19073.

To subscribe to other JMI newsletters or to manage your subscription, Click here.

To change your email address, reply to this email. Write "change of address" in the subject line. Make sure to provide us with your old and new address.

To ensure delivery, please be sure to add revoptom@lists.jobsonmail.com to your address book or safe senders list.

Click here if you do not want to receive future emails from Review of Optometry.

Review of Cornea and Contact Lenses
Review of Optometry
11 Campus Blvd.,
Suite 100
Newtown Square, PA 19073