Welcome to our monthly Research Update, available exclusively to IACLE and BCLA members to support your teaching and practice.

ISSUE 44 - AUGUST 2020

As myopia continues play an important part in the field of research this issue begins with a paper that determines the effects of multifocal contact lenses of high and medium powers on myopia progression. Another study investigates the relationship between defocus characteristics in the near-work environment and subsequent myopia progression.

Another paper included assesses the impact of toric contact lenses on astigmatic patients using digital devices. A group from the USA reports the effects of photochromic contact lenses on visual functions indoors. Researchers from Japan investigate the use of multifocal contact lenses in presbyopes with monofocal intraocular lenses.

A Turkish team studies the corneal changes in daily disposable contact lens wear. A review paper discusses the efficacy and safety of overnight orthokeratology. Finally, there is a paper that examines the trend in the fitting of scleral lenses worldwide.

Happy reading!!

The IACLE Education Team

JOURNALS

Journals reviewed in this issue:

Journal of American Medical Association 324:6
Ophthalmic & Physiological Optics 40:4
Optometry & Vision Science 97:7
Eye & Contact Lens 46:4
Contact Lens & Anterior Eye 43:4
Clinical & Experimental Optometry 103:4

MYOPIA

Multifocal add powers and myopia progression

This 3-year, double masked, randomized clinical trial was conducted by Walline et al to determine whether soft multifocal CLs slow myopia progression in children, and whether high add power (+2.50D) slows myopia progression more than medium (+1.50D) add power lenses. A total of 294 myopic children were randomly assigned to wear high add power, medium add power, or single-vision CLs. Treatment with high add power multifocal CLs significantly reduced the rate of myopia progression over 3 years compared with medium add power multifocal and single-vision CLs.

JAMA 2020;324:6 571-580. DOI:10.1001/jama.2020.10834. Read the full text

Defocus profile at home and myopia

To quantify the amount of relative scene defocus in a near-work environment, and investigate its relationship with refractive development, Choi et al recruited 50 children and followed them for 1 year. The home near-work environment was measured at a home visit and the defocus characteristics were quantified as the dioptric volume. The authors concluded that the defocus profile in the home environment, especially within the para-central field of view, is associated with childhood refractive error development and is likely a potential myopia risk factor.

Ophthalmic Physiol Opt 2020;40:4 463-471. doi: 10.1111/opo.12698. Read the full text

TORIC LENSES

Digital near visual performance with toric lenses

Logan et al conducted this randomized, double masked crossover study to quantify subjective and objective benefits of toric corrections in astigmatic patients compared with the mean spherical equivalent, using real-world digital devices. A total of 34 non-presbyopic adult astigmatic (0.75-1.50D astigmatism) patients completed five follow-ups in 10 days. The subjects underwent a battery of objective near vision tests and completed a Near Activity Visual Questionnaire. Participants were able to read smaller print size more comfortably and preferred toric contact lenses when using digital devices. 

Optom Vis Sci 2020;97:7 518-525. DOI:10.1097/OPX.0000000000001540. Read the abstract

PHOTOCHROMICS

Photochromic lenses and indoor visual function

In this prospective, randomized, subject-masked, contralateral study, Renzi-Hammond et al tested whether a photochromic contact lens improved visual function under conditions where the lens was minimally activated. Sixty adult subjects wore the photochromic test contact lenses in one eye and the nonphotochromic control contact lens in the other. The primary endpoints were four visual function outcomes: photostress recovery time, glare disability, glare discomfort, and chromatic contrast. The minimally activated lenses improved many aspects of visual function under bright light compared with nonphotochromic lenses.

Optom Vis Sci 2020;97:7 526-530. DOI:10.1097/OPX.0000000000001537. Read the abstract

PRESBYOPIA

Multifocal soft CLs in patients with monofocal IOL

Kaida et al conducted this prospective case series study to investigate the improvement in binocular visual function using multifocal soft contact lenses (MF SCLs) for pseudophakic subjects with monofocal intraocular lenses (IOLs). Eleven subjects after monofocal IOL implantation used disposable MF SCLs daily, for 3 months. Binocular visual acuity and contrast sensitivity were measured and compared before and during MF SCL wear. The binocular visual functions demonstrated that the use of the MF SCL was effective for presbyopia corrections after implantation of monofocal IOLs.

Eye & Contact Lens 2020;46:4 234-237. Read the abstract

DAILY DISPOSABLES

Corneal changes in daily disposable CL wear

To evaluate the changes in corneal epithelial thickness and corneal anterior and posterior curvatures during the day, Turhan et al enrolled 32 neophytes in this prospective, randomized, crossover study. Corneal and epithelial thickness maps and keratometric measurements were performed before and 8 hours after daily disposable (DD) CL wear. The corneal and epithelium thickness were not affected by DD CLs, whereas corneal thickness decreased in the natural diurnal variation. Anterior corneal topographic indices steepen depending on the natural diurnal variations. DD CLs seem to mask this steepening.

Cont Lens Anterior Eye 2020;43:4 389-394. Read the full text

ORTHOKERATOLOGY

Overnight orthokeratology

In this review, Bullimore & Johnson reviewed the literature on the efficacy of orthokeratology for myopia control, sustainability after treatment is discontinued, and the safety concerns of overnight contact lens wear. The effectiveness of overnight orthokeratology for myopia control is well established, with a two-year slowing of axial elongation of around 0.25mm. The authors concluded that overnight orthokeratology, either alone or in combination with other therapies, will play a role in future efforts to obtain greater treatment magnitudes and suggested future research direction.

Cont Lens Anterior Eye 2020;43:4 322-332. Read the full text

SCLERALS

Extent of scleral lens fitting worldwide

Woods et al administered this international survey to contact lens fitters around the world, every year for 20 consecutive years (2000-2019) to examine trends in the fitting of scleral lenses from a broad range of countries. A total of 369,209 contact lens fits were recorded from 40 eligible countries, comprising 2,309 (0.76% of all fits) scleral lens fits. Scleral lens use has increased since 2011 with these specialised lenses more likely to be fitted to males and older patients than non-scleral lenses.

Clin Exp Optom 2020;103:4 449-453. DOI:10.1111/cxo.13105. Read the full text

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