Research Update

Research Update Issue 2

 

February 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
 
 
 
Issue 2 – February 2017
 
In most countries around the world, hydrogels and silicone hydrogels account for an overwhelming majority of prescribed materials in contact lens practice. Yet we still have much to learn about their performance. In this issue, we take a look at some interesting new work in soft contact lenses.

A research group in the UK identifies factors associated with retention and dropout in the first year of CL wear, with surprising findings. Another study re-evaluates the inter-relationship of soft CL base curve radius, diameter and lens fit. An Australian team compares the performance of silicone hydrogel and hydrogel daily disposables. And we report on a new study assessing compliance with daily disposable lens replacement. We also include research that compares dry eye tests in older females and that reveals the interaction of bacteria in CL cases. Happy reading!
 

The IACLE Education Team
 
 
 
Journals reviewed in this issue  

  JOURNAL VOLUME AND ISSUE NUMBER
 
  Contact Lens & Anterior Eye 40:1
  Optometry & Vision Science Pre-publication
  Eye & Contact Lens Published ahead-of-print
  Investigative Ophthalmology & Visual Science 58:1
 
 
 
 
 
 DROPOUT
 

New wearers: when and why do they drop out?
To identify factors associated with retention and dropouts in first year of CL wear, Sulley et al reviewed records of 524 patients at 29 sites in this retrospective study. After 12 months, 74% were still wearing CLs. Of the 136 lapsed, 25% discontinued during the first month and 47% within 60 days. While handling and comfort were the most commonly cited performance-related reasons for discontinuing in new spherical lens wearers, visual problems were the most common among new wearers of toric and, in particular, multifocal CLs.

Cont Lens Anterior Eye 2017;40:1 15-24. Click here for full text

 
 
 
 
 
 FITTING
 

Re-evaluating soft lens fit
Using a mathematical model, Young et al evaluated the inter-relationship of soft CL base curve radius, diameter, and lens fit. The highest overall success rate (90%) was with an 8.60/14.2mm (BC/diameter) design. The recommended rules of thumb: for a 0.4 mm change in BC, change the diameter by 0.2 mm to maintain similar on-eye diameter. When changing diameter by 0.4 mm, a change in BC of 0.2 mm is required to maintain similar lens tightness.

Optom Vis Sci 2017; DOI: 10.1097/OPX.0000000000001048. Click here for abstract

 
 
 
 
 
 MATERIALS
 

Silicone hydrogels versus hydrogels
To compare subjective, objective and safety performance of silicone hydrogel (SiHy) with hydrogel (Hy) daily disposable CLs, Diec et al performed a retrospective analysis on 201 patients. In the Hy group, there was greater increase in limbal redness from baseline but less conjunctival staining and indentation compared to the SiHy group. Neither material showed superiority in comfort; adverse event rates were low with both types. However, SiHy materials should be considered for patients at risk of hypoxia-related complications.

Eye Contact Lens 2017;DOI: 10.1097/ICL.0000000000000363. Click here for abstract

 
 
 
 
 
 COMPLIANCE
 

Health beliefs and daily lens replacement
Livi et al conducted a multi-center survey to assess the compliance of daily disposable (DD) CL wearers with replacing lenses. Out of the 354 Italian respondents, 23% were non-compliant with manufacturer-recommended replacement frequency. The main reason for re-using DDCLs was ‘to save money’ (35%). It is important to warn DDCL wearers of the severity of a CL-related eye infection, and to underline the possibility of its prevention.

Cont Lens Anterior Eye 2017;40:1 25-32. Click here for full text

 
 
 
 
 
 DRY EYE
 

Comparing dry eye tests in older women
Ngo et al quantified the association of dry eye (DE) symptoms with diagnostic tests in older females. Twenty symptomatic females were age matched with 20 females without DE symptoms (age range 46-73 years). The tests most strongly associated with DE symptoms in older women were ocular staining, meibum quality, number of obstructed meibomian glands, and tear film stability. MGD was likely to be the main etiology of DE in this group.

Eye Contact Lens 2016; DOI: 10.1097/ICL.0000000000000344. Click here for abstract

 
 
 
 
 
 HYGIENE
 

Bacterial interactions in contact lens cases
To examine the interaction of commonly isolated bacteria from contact lens cases, Datta et al grew 4-5 strains each of the bacteria and allowed them to coaggregate for 24 hours. The study demonstrated, for the first time, that ocular isolates of P. aeruginosa and S. aureus could coaggregate. But this may not be related to buildup of biofilms in cases, as there was no evidence that coaggregation was associated with cohesion between the strains. The study also confirmed that P. aeruginosa can inhibit the growth of S. aureus.

Invest Ophthalmol Vis Sci 2017;58 50-58. Click here for full text

 
 
 
 
 
For more information on Research Update visit www.iacle.org.