Research Update

Research Update Issue 4

April 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 4 – April 2017
Physiological response to contact lens wear is a fascinating topic and worth revisiting. In this issue, we take a look at the corneal endothelial response to RGP lens wear and also investigate the relationship between mucin balls and corneal infiltrative events.

A research group in the US surveys practitioner reports of ocular complications in patients wearing decorative contact lenses purchased through unauthorized sellers. Another survey compares vision correction preferences of non-presbyopes and presbyopes. We also include a study that tests the hypothesis that tear break-up (TBU) presents a direct noxious stimulus to the ocular surface. And we report on the effect of multifocal contact lenses on disability glare by means of ocular straylight.

Happy reading!

The IACLE Education Team
Journals reviewed in this issue  

  Contact Lens & Anterior Eye 40:2 and Articles in Press
  Optometry & Vision Science 94:4
  Eye & Contact Lens 43:2
  The Ocular Surface Articles in Press

Corneal endothelium in RGP lens wearers
To assess whether polymegethism and pleomorphism were evident after medium-term rigid gas permeable (RGP) CL wear, Doughty conducted a cross-sectional, observational study following 46 subjects over 12 years. Compared to a historical database, most endothelia (37/46) showed some changes. Endothelial polymegethism appeared to be a consequence of RGP lens wear with the magnitude of change related to the cumulative duration of wear.

Cont Lens Anterior Eye 2017;40:2 109-115. Click here for full text


Mucin balls and corneal infiltrative events
A randomized clinical trial was nested within a cohort study by Szczotka-Flynn et al to determine whether mucin ball (MB) formation is protective against corneal infiltrative events (CIEs). Of 282 participants, 218 entered phase 2, i.e. randomized trial, during which 33 CIEs occurred. Repeated, longer-term MB presence did not significantly reduce the incidence of CIEs; however, it significantly decreased the rate of CIEs by 62%. The hypothesis that MB formation is protective against CIEs throughout extended wear was not supported.

Optom Vis Sci 2017; 94:4 448-457. Click here for full text


Decorative CLs purchased through unauthorized sellers
Gaiser et al reported results of a survey completed by 22 optometrists regarding ocular complications in patients wearing decorative CLs. Concurrently, the authors evaluated 18 independent, online decorative CL sellers. A majority of respondents (77%) reported having patients with complications from decorative CLs. The most common age group for complications was 18 to 25 years (61%). A quarter of the lenses were purchased illegally. Of the 18 online sites examined, 72% of sellers failed to adhere to FTC and FDA regulations. The authors call for better regulation and oversight of unlicensed vendors.

Eye Contact Lens 2017;43:2 135-139. Click here for abstract


Challenging assumptions about presbyopes and CLs
This prospective, cross-sectional study was conducted by Rueff and Bailey to survey opinions on refractive correction among adults wearing spectacles or CLs (n=304). There was no difference in the proportion of presbyopes and non-presbyopes who had tried CLs or who would prefer to wear CLs. Presbyopes and non-presbyopes had similar opinions about spectacles and CLs. Eye care practitioners should not assume that presbyopia, refractive error, or gender are factors that preclude a patient from being interested in CLs.

Cont Lens Anterior Eye DOI: Click here for full text


Tear break-up and symptoms of ocular irritation
Zhang et al tested the hypothesis that tear break up (TBU) presents a direct noxious stimulus to the ocular surface. Ten subjects kept one eye open as long as possible, termed sustained tear exposure (STARE), while discomfort was monitored with and without a CL in place. Discomfort was significantly higher during trials without a CL. TBU during STARE trials was associated with increased discomfort, which was partially blocked by a CL. This supports the hypothesis that TBU directly stimulates the corneal surface.

The Ocular Surface DOI: Click here for abstract


Ocular straylight with multifocal CLs
To investigate the effect of multifocal CLs on disability glare by means of ocular straylight, Labuz et al conducted this prospective, randomized, comparative study in 16 subjects. Straylight was measured using a commercial straylight meter with the natural and dilated pupil, and measurements were repeated with a CL in situ after pupil dilation. After pupil dilation, straylight increased significantly. Straylight-pupil size dependency should be considered to avoid elevated straylight in multifocal CL wearers. Some types of multifocal might be more beneficial for some wearers, e.g. professional drivers, when straylight is taken into account.

Optom Vis Sci 2017;94:4 496-504 Click here for abstract

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