Research Update

Research Update Issue 5

May 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 5 – May 2017
Many contact lens experts are intrigued by keratoconus and its management. In this issue, we present two systematic reviews on treatments for keratoconus, especially highlighting corneal collagen cross-linking.
In other reviews, a study conducted in Hong Kong evaluates the effect of discontinuation of orthokeratology on eyeball elongation. A research group from Spain reports on the success of rigid gas-permeable lens fits for refractive and therapeutic reasons. We include a study that tests the hypothesis that sleep position may affect dry eye and meibomian gland dysfunction. And finally, a comparison of theoretically optimized bifocal contact lens designs to those commercially available suggests that these designs should be prototyped and tested in a clinical setting.

Happy reading!

The IACLE Education Team
Journals reviewed in this issue  

  Eye & Contact Lens 43:3
  Acta Ophthalmologica 95:3
  Contact Lens & Anterior Eye 40:2
  Cornea 36:5
  Ophthalmic & Physiological Optics 37:3

Keratoconus management: a review of treatment modalities
Mandathara et al conducted a systematic review of 241 articles on keratoconus (KC) management options from the past 20 years. About 41% of them were prospective case series; randomized controlled trials (RCTs) were limited to corneal collagen cross-linking (CXL). Contact lenses (CLs) were the mainstream of KC management and were associated with reversible and non-sight-threatening complications. Surgical procedures were generally associated with transient inflammatory events and permanent sequelae. High-quality, longer follow-up RCTs are required to evaluate the long-term effects of KC interventions.

Eye & Contact Lens 2017;43:3 141-154. Click here for abstract


Cross-linking in children with keratoconus
In this systematic review to determine the effectiveness of corneal collagen cross-linking (CXL) in children, McAnena et al analyzed 13 papers, examining 490 eyes of 401 patients with a mean age of 15.25 (+1.5) years. Nine papers were included in the meta-analysis. The review found that standard CXL may be effective in halting progression of keratoconus in pediatric patients at 1 year. However, larger, more long-term studies are required to ascertain its effectiveness.

Acta Ophthalmol 2017;95:3 229-239. Click here for abstract


Does axial elongation increase when ortho-k is discontinued?
This single-masked, prospective study was conducted by Cho & Cheung to evaluate changes in axial elongation, over a 14-month period, in subjects who discontinued (for 7 months) and then resumed orthokeratology lens wear. Significant increase in axial elongation was found in subjects when they discontinued lens wear. Stopping ortho-k lens wear at or before the age of 14 years led to a more rapid increase in axial length that slowed again with resumed lens wear after 6 months.

Cont Lens Anterior Eye 2017;40:2 82-87. Click here for full text


Success of RGPs: refractive and therapeutic fittings
To evaluate the success of rigid gas permeable (RGP) contact lens (CL) fitting, Ortiz-Toquero et al retrospectively analyzed 232 new fits, of which 166 were refractive fittings (71.6%) and 66 therapeutic (28.4%). Of the refractive fittings, 88 subjects (53%) were initially fitted with RGP CLs and 61 (69.3%) of them met the success criteria. Of the therapeutic fittings, 61 subjects (92.4%) were initially fitted with RGP CLs and 59 (96.7%) of these were successful. A relatively high percentage of successful RGP fits was achieved for refractive (7/10 subjects) and even higher for therapeutic (9/10 subjects) prescriptions.

Eye & Contact Lens 2017; 43:3 168-173. Click here for abstract


EYE Effect of sleep position on ocular surface
To validate their observation that sleep position in some cases may significantly affect dry eye and meibomian gland dysfunction (MGD), Alevi et al conducted this cross-sectional, non-interventional, single-masked study involving 100 study patients and 25 in a control group. The Ocular Surface Disease Index score was found to be elevated in patients who slept on their sides or face down as opposed to on their backs. In addition to treatment, changing sleep pattern to a supine position may lead to improvement of patients’ disease.

Cornea 2017;36:5 567-571. Click here for abstract


Commercial vs theoretically optimized CLs for presbyopia
To compare optical designs of theoretically optimized bifocal CLs to those of commercially available designs for presbyopia, Legras & Rio simulated retinal images using a numerical eye model and tested 10 optical designs – 4 commercially available and 6 optimized. Twenty subjects graded the quality of simulated images. Commercial contact lens profiles did not give an image quality and depth-of-focus as good as the theoretically optimized optical designs. The best bifocal profiles were those with 5 and 8 concentric zones. Inter-individual variations were observed for all profiles.

Ophthalmic Physiol Opt 2017;37:3 297-304 Click here for abstract

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