Research Update

Research Update Issue 18

June 2018

In this issue, we continue our quest to understand keratoconus and its treatment. A group of researchers from Israel attempts to determine the association of keratoconus with blepharitis and eye rubbing. Another paper reviews the success of corneal cross-linking in pediatric keratoconus 

June 2018  
 
 
 
 

Welcome to our monthly research update
 
Research Update is a resource available exclusively to IACLE and BCLA members to support your teaching and practice. Each month we 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 18 – June 2018
 
In this issue, we continue our quest to understand keratoconus and its treatment. A group of researchers from Israel attempts to determine the association of keratoconus with blepharitis and eye rubbing. Another paper reviews the success of corneal cross-linking in pediatric keratoconus.

We include a study that compares the clinical performance of large diameter soft lenses with optimally fit lenses in the same material and mono-curve back surface design. Another addresses the clinical performance of a large diameter rigid gas-permeable lens in low to moderate astigmats.

A Japanese group evaluates a novel povidone-iodine disinfection system. We report on a study that presents a link between contact lens wear and cell changes to the lid wiper epithelium, which were not visible by lip wiper staining. And finally, we include a review that provides an overview of the clinical management of digital eyestrain.

Happy reading!

The IACLE Education Team
 
 
 
Journals reviewed in this issue  
  JOURNAL VOLUME AND ISSUE NUMBER
  Clinical and Experimental Optometry 101:3, Early view
  Cornea 37:6
  Contact Lens & Anterior Eye Articles in Press, 41:1
  Eye & Contact Lens 44:3
  Optometry and Vision Science 95:6
 
 
 
 
 
 KERATOCONUS
 

Is blepharitis more prevalent with keratoconus?
To determine the association between blepharitis and keratoconus, Mostovoy et al conducted this prospective, observational study. A thorough survey of the eyelids – scales and foam on the eyelashes, missing eyelashes and meibomian gland expression – was performed on 50 keratoconus subjects and 72 controls. Blepharitis was more common in keratoconus than in the control group (24% vs 3%). A higher proportion of keratoconus participants reported rubbing their eyes more than once a day (36% vs 11%). Blepharitis-related inflammation and associated eye rubbing may contribute to keratoconus progression.

Clin Exp Optom 2018;101:3 339-344. Click here for abstract

 
 
 
 
 
 KERATOCONUS
 

Corneal cross-linking for pediatric keratoconus
Perez-Straziota et al conducted a comprehensive review of the literature on cross-linking in the pediatric population. Out of 210 shortlisted publications, 115 were considered relevant to this review. The standard Dresden protocol is at least temporarily effective in halting progression and even improving keratometry values in pediatric patients. Some studies demonstrate regression up to 3 years after treatment. Long-term effects and regression rates remain unclear, and further studies are needed in this population.

Cornea 2018;37:6 802-809. Click here for abstract

 
 
 
 
 
 FITTING
 

Comparing optimum and large diameter soft lenses
To compare the clinical effect of large diameter soft lenses with those of optimally fit lenses (in the same material and design), Wolffsohn et al recruited 25 myopes to this randomized, bilateral, unmasked, crossover study. Subjects wore optimum diameter lenses and large diameter lenses (1.2mm larger in diameter than the optimal lens and 0.6mm flatter in base curve to give a clinically equivalent fitting) in random order for 1 week each. The findings suggest that larger than optimal soft lenses may be worn without detriment to either comfort or ocular physiology, provided an optimal fit is otherwise maintained.

Cont Lens Anterior Eye (2018). DOI: https://doi.org/10.1016/j.clae.2018.03.004. Click here for full text

 
 
 
 
 
 ASTIGMATISM
 

Large diameter RGP vs soft torics in refractive astigmatism
In this multisite, prospective, cross-over study, Michaud et al compared the clinical performance of a large diameter rigid gas-permeable (LRGP) lens (Boston XO, 14.3mm diameter miniscleral) with soft toric lenses in 36 low to moderate astigmats. 75% preferred the vision with the LRGP lens as compared to the soft torics. Wear time, subjective comfort, and subjective vision ratings showed no significant difference between the two groups. In asymptomatic contact lens wearers, LRGP lenses can be considered a good alternative to soft toric lenses for correcting refractive astigmatism.

Eye & Contact Lens 2018;44:3 164-169. Click here for abstract

 
 
 
 
 
 LENS CARE
 

Antimicrobial efficacy of a novel disinfection system
Yamasaki et al evaluated a novel povidone-iodine (PI) contact lens disinfection system (cleadew, Ophtecs, Japan) against a range of bacteria, fungi and Acanthamoeba. Antimicrobial assays were conducted according to ISO 14729 using the recommended strains of bacteria and fungi, with and without the presence of organic soil. Activity on biofilms formed from Stenotrophomonas maltophilia and Achromobacter sp was evaluated. Efficacy against A castellanii trophozoites and cysts was also investigated. The PI system was effective against a variety of pathogenic microorganisms under a range of test conditions, including challenging conditions of use.

Cont Lens Anterior Eye 2018;41:3 277-281. Click here for full text

 
 
 
 
 
 PHYSIOLOGY
 

Contact lens wear and lid wiper epithelium
Alghamdi et al attempted to establish whether the duration of contact lens (CL) wear affects the cellular morphology of the lid wiper (LW) epithelium in this cross-sectional study of 100 individuals with different exposures to CL wear and non-wearers as controls. Impression cytology samples were collected from the central upper lid margin (LW area). Metaplasia of the LW epithelium was significantly greater in the early to moderate stages with CLs. This supports the view that mechanical irritation is responsible for LW changes in CL wear. Ceasing CL wear seems to lead to recovery.

Optom Vis Sci 2018;95:6 491-497. Click here for abstract

 
 
 
 
 
 DIGITAL EYESTRAIN
 

Management of digital eyestrain
Coles-Brennan et al provide an overview of the extensive literature on digital eye strain with particular reference to managing symptoms. Management strategies suggested are: (i) appropriate correction of refractive error, including astigmatism and presbyopia; (ii) managing accommodation and vergence anomalies; (iii) training to maintain normal blinking pattern; (iv) use of lubricating eye drops to help alleviate dry eye-related symptoms; (v) CLs with enhanced comfort, particularly at end-of-day and in challenging environments; (vi) prescription of color filters in all vision correction options, especially blue light absorbing filters. Prevention is the main strategy for management of digital eye strain.

Clin Exp Optom (2018). DOI:10.1111/cxo.12798. Click here for abstract

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