Research Update

Research Update Issue 9

September 2017  

Welcome to our monthly research update
Welcome to Research Update, a new resource available to IACLE and BCLA members to support your teaching and practice. Each month we will send you a summary of some of the interesting findings appearing in peer-reviewed journals that month. Our aim is to help you keep up to date with the latest contact lens and anterior eye research, and to locate articles when you want to know more about a particular topic.
More information on Research Update and how to use it in your contact lens teaching here. Access archived issues via Member Login under Research.
Issue 9 – September 2017
Mucin balls are in the spotlight again this month. In this issue, we look at the microstructural characteristics of mucin balls and their correlation with ocular surface properties. We also include a study that investigates tear cytokine levels in lens wearers with Acanthamoeba keratitis.

Contact lens material properties are also highlighted. Could hyaluronan be incorporated into hydrogels as a built-in lubricant? And does lipid deposition differ between combinations of lenses and lens care solutions? An Australian group examines tear film biochemistry of symptomatic and asymptomatic lens wearers. American researchers report on compliance and patient responses to eyelid hygiene. And finally, we describe a fascinating study that explores the association between constricted living space in Hong Kong and myopia development.


The IACLE Education Team
Journals reviewed in this issue  

  Contact Lens & Anterior Eye 40:5
  Cornea 36:7
  Journal of Biomedical Materials Research B Early view
  Optometry and Vision Science 94:9
  Eye & Contact Lens 43:4
  Ophthalmic & Physiological Optics 37:5

Microstructural evaluation of mucin balls
Grupcheva et al conducted this prospective, comparative analysis of two groups of patients, continuously wearing silicone hydrogel lenses for therapeutic (20 eyes) or optical (22 eyes) purposes. Clinical examination was reinforced with laser scanning in vivo confocal microscopy, and qualitative analysis of mucin balls included shape and reflectivity. Mucin balls affected the corneal surface at microstructural level including transient epithelial alteration and keratocyte activation. The main predisposing factor for mucin ball formation appeared to be irregular ocular surface.

Cont Lens Anterior Eye 2017;40:5 340-345 Click here for full text


Tear cytokine levels in Acanthamoeba keratitis
Carnt et al conducted this prospective study of CL wearers with Acanthamoeba keratitis (AK) to determine differences in key tear film cytokines between mild and severe cases of AK and control CL wearers. Basal tear specimens were collected by 10mL capillary tubes and tear protein levels were measured (132 tear samples from 61 AK cases – 15 severe and 46 mild/moderate – and 22 controls). Profiling patients with AK during disease showed differences in cytokine levels between severe and milder disease that may help clinical management.

Cornea 2017;36:7 791-798. Click here for abstract


Hydrogel lubrication with bulk incorporated hyaluronan (HA)
The objective of this experiment conducted by Samson et al was to assess the effect of crosslinked HA into the bulk of model CL materials on (a) surface wettability, (b) protein sorption, and (c) boundary lubricating properties, both alone and synergistically with PRG4 in solution. Surface wettability was assessed by water contact angle measurement, protein sorption by lysozyme sorption assay, and boundary lubricating properties using an in vitro friction test method. HA incorporation can reduce friction of hydrogels alone and in combination with PRG4 in solution.

J Biomed Mater Res B 2017; DOI: 10.1002/jbm.b.33989. Click here for abstract


Lipid deposition on soft CLs with contemporary solutions
To determine the effect of lens/care system combinations on levels of lipid deposits, Babaei Omali et al recruited 236 experienced spherical soft CL wearers. Combinations of three CL and four CL care solutions were investigated. The study did not demonstrate conclusively that any of the solution/ CL combinations was superior to any of the other combination for amounts of lipid deposition. This limits the ability to make specific recommendations regarding lens care solution-CL material combinations. The possibility remains that certain lipid deposits may allow for greater comfort during wear.

Optom Vis Sci 2017;94:9 919-927. Click here for abstract


Tear film biochemistry of lens wearers
To quantify concentrations of tear lipids and proteins in CL wearers, Masoudi et al recruited 45 (22 symptomatic and 23 asymptomatic) healthy, adapted wearers. Proteins were assayed using selected reaction monitoring mass spectrometry and enzyme immunoassay kits were used to measure prostaglandins, leukotriene B4 (LTB4), and cysteinyl leukotrienes. On a scale of 1 to 100, average comfort was above 70 for asymptomatic and equal or below 70 for symptomatic group. LTB4 was significantly higher in symptomatic CL wearers compared to asymptomatic wearers, which may partly mediate their discomfort response.

Optom Vis Sci 2017;94:9 914-918. Click here for abstract


Compliance and patient responses to eyelid hygiene
This cross-sectional study by Alghamdi et al assessed patient compliance with lid hygiene and which factors predict a favourable symptomatic response to treatment. Investigators assessed dry eye symptoms and lid margin signs, then instructed patients to perform warm compresses and lid scrubs. A follow-up phone survey assessed compliance and subjective therapeutic response after 6 weeks. Patients who self-reported dry eye symptoms at the first visit were more likely to be compliant with lid hygiene than those who did not report symptoms. Patients who performed the routine noted improvement in symptoms.

Eye & Contact Lens 2017;43:4 213-217. Click here for abstract


Constricted living space and myopia development in children
Choi et al investigated whether the crowded habitat in Hong Kong is associated with refractive error among children. Information such as demographics, living environment, parental education and ocular status were collected using parental questionnaires. Ocular axial length and refractive status of all 1,075 subjects from 12 schools were measured. Axial length in children and childhood refractive error were associated with high population density and small home size. A constricted living space may be an environmental threat for myopia development in children.

Ophthalmic Physiol Opt 2017;37:5 568-575. Click here for full text

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