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Research Update

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

Issue 38 – February 2020

This time we begin the issue with presbyopia. As monovision continues to divide opinions among practitioners, we review a paper that studies its impact on accommodation in early presbyopes. Another study checks the efficacy of a new, small aperture, presbyopia correcting contact lens.

A team from China investigates the much-debated association between long-term rigid lens wear and acquired blepharoptosis. Another paper on rigid lenses attempts to answer the age-old question in lens care: to rub or not to rub

Researchers in the US evaluate the efficacy of the fluorescein tear break-up time test in dry eye. Members of the British & Irish University & College Contact Lens Educators (BUCCLE) group investigate whether there are any benefits to gradual adaptation in soft daily disposable lenses. And finally, we include a systematic review and meta-analysis evaluating the association between obstructive sleep apnea and keratoconus.

Happy reading!!

The IACLE Education Team

JOURNALS

Journals reviewed in this issue:

Ophthalmic & Physiological Optics  40:1

Contact Lens & Anterior Eye  In Press 

Eye & Contact Lens  46:1

Cornea  39:1

Optometry and Vision Science  97:1

PRESBYOPIA

Impact of monovision on dynamic accommodation

To examine the impact of monovision on dynamic changes in accommodation, pupil responses, spherical aberration and resultant image quality in early presbyopes, Almutairi et al recruited nine presbyopic subjects aged 40-50 years who exhibited some accommodation. When accommodation was activated as stimuli approached the far point of the near-corrected eye, low gain accommodation could lead reduced binocular image quality. The results revealed a non-optimal accommodative strategy in early presbyopes fit with monovision which may play a significant role in the success of this type of correction.

Ophthalmic Physiol Opt 2020;40:1 47-59. Read the abstract

A novel soft lens with pinhole aperture

In this prospective, clinical study, Jun et al recruited 29 presbyopic patients to investigate the efficacy and safety of a newly developed pinhole soft contact lens (Eyelike Pinhole II) for presbyopia correction. All participants wore the test lens in the non-dominant eye for >3 hours/day for 1 week. The lens showed safe and effective outcomes, and shows promising potential although it may cause some discomfort. The safety and efficacy should be further investigated with long-term follow-up and larger samples, as well as studies involving comparisons with other multifocal contact lenses

Cont Lens Anterior Eye 2020. DOI: https://doi.org/10.1016/j.clae.2019.12.009. Read the full text

RGP LENSES

Long-term RGP wear and blepharoptosis

Yang et al recruited a total of 90 rigid contact lens wearers (45 RGP and 45 ortho-k) and 45 spectacle wearers (control) to determine whether long-term rigid lens wear leads to acquired blepharoptosis in Chinese eyes, and whether its development is affected by lens removal methods. No significant differences in margin reflex distance, palpebral fissure height or levator function were found between different lens removal techniques in the rigid lens groups. Long-term rigid lens wear did not lead to acquired blepharoptosis in Chinese eyes.

Eye & Contact Lens 2020;46:1 24-30. Read the abstract

LENS CARE

Which is more effective for RGPs: rub or no rub?

To compare the efficacy of cleaning rigid contact lenses with and without rubbing, Cho et al conducted a masked, randomized trial. The cleaning efficacy of two solutions, a one-step hydrogen peroxide solution and a povidone iodine-based solution, was evaluated on 64 unworn ortho-k lenses subsequent to cleaning by rubbing with a surfactant cleaner or without rubbing. Both solutions failed to remove stubborn deposits from ortho-k lenses without rubbing. Rubbing with a daily cleaner significantly removed most stubborn deposits from the lens surfaces and should be included in lens care instructions for these solutions.

Ophthalmic Physiol Opt 2020;40:1 17-23. Read the abstract

DRY EYE

Efficacy of fluorescein tear break-up time test

Paugh et al conducted this investigation to determine the efficacy of the tear break-up time (TBUT) test using sodium fluorescein (NaFl) without selection bias using a randomized and masked study design. A total of 46 subjects were assessed using various dry eye tests (DET) and randomized to the DET, standard strip, and liquid NaFl on separate days. The authors conclude that the TBUT test has excellent diagnostic accuracy and a cut-point of 5.3-6.0 secs is the optimum to differentiate normals from persons with dry eye.

Cornea 2020;39:1 92-98. Read the abstract

DAILY DISPOSABLES

Fast vs gradual lens adaptation

Wolffsohn et al carried out this multi-site clinical study to determine whether a gradual adaptation period is necessary for neophytes when fitted with modern hydrogel or silicone hydrogel (SiHy) daily disposable contact lenses. The 65 subjects were randomly assigned to fast or gradual adaptation with hydrogel and SiHy lenses. Ocular surface physiology and non-invasive tear break-up time were graded, and subjective scores for comfort, lens awareness and handling recorded. There appeared to be no clinical benefit to a gradual adaptation period in new wearers fitted with modern soft daily disposable lenses.

Cont Lens Anterior Eye 2020. DOI: https://doi.org/10.1016/j.clae.2019.08.011. Read the full text

KERATOCONUS

Obstructive sleep apnea and keratoconus

This systematic review and meta-analysis by Pellegrini et al assessed whether evidence for an association between obstructive sleep apnea (OSA) and keratoconus (KC). From 46 initially identified articles, five were finally included for analysis reporting on 16,922 patients with keratoconus and 16,922 control subjects. The published evidence indicates that KC is associated with an increased risk of OSA. A proper screening for OSA is recommended for KC patients to prevent various cardiovascular comorbidities.

Optom Vis Sci 2019;97:1 9-14. Read the abstract

© International Association of Contact Lens Educators 2020

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