International multi-centre study of potential benefits of ultraviolet radiation protection using contact lenses.

Purpose: To examine the effects of long-term ultraviolet radiation (UVR) blocking wearing contact lenses on ocular surface health, eye focus and macular pigment.

Method: 210 pre-presbyopic patients were recruited from Birmingham UK, Brisbane Australia, Hong Kong China, Houston USA and Waterloo Canada (n = 42 at each site). All patients had worn contact lenses for ≥ 5 years, half (test group) of a material incorporating a UVR-blocking filter.

Predicting corneal refractive power changes after orthokeratology.

This study aimed to characterise corneal refractive power (CRP) changes along the principal corneal meridians during orthokeratology (OK). Nineteen myopes (mean age 28 ± 7 years) were fitted with OK lenses in both eyes. Corneal topography was captured before and after 14 nights of OK lens wear.

CLEAR - Contact lens optics.

The most fundamental aspect of a contact lens is its optics; the manner in which the refraction of light is managed to optimise vision to the clinical benefit of the lens wearer. This report presents contemporary information on the optical structure of the eye and the optical models employed to understand the correction of refractive error. The design, measurement and clinical assessment of spherical, aspheric, toric, multifocal and myopia control contact lenses are described.

CLEAR - Effect of contact lens materials and designs on the anatomy and physiology of the eye.

This paper outlines changes to the ocular surface caused by contact lenses and their degree of clinical significance. Substantial research and development to improve oxygen permeability of rigid and soft contact lenses has meant that in many countries the issues caused by hypoxia to the ocular surface have largely been negated. The ability of contact lenses to change the axial growth characteristics of the globe is being utilised to help reduce the myopia pandemic and several studies and meta-analyses have shown that wearing orthokeratology lenses or soft multifocal contact lenses can reduce axial length growth (and hence myopia).

Nasal-temporal asymmetry in peripheral refraction with an aspheric myopia control contact lens.

A combination of human subject data and optical modelling was used to investigate unexpected nasal-temporal asymmetry in peripheral refraction with an aspheric myopia control lens. Peripheral refraction was measured with an auto-refractor and an aberrometer. Peripheral refraction with the lens was highly dependent upon instrument and method (e.

Stability of peripheral refraction changes in orthokeratology for myopia.

Purpose: Orthokeratology (OK) is known to alter relative peripheral refraction (RPR) with this presumed to be its key myopia control mechanism. A prospective, longitudinal study was performed to examine stability of OK-induced RPR changes in myopic children and young adults.

Methods: RPR of twelve children (C)(8-16 years) and eight adults (A)(18-29 years) with spherical equivalent refraction of -0.

Reducing treatment zone diameter in orthokeratology and its effect on peripheral ocular refraction.

Purpose: To determine whether orthokeratology (OK) induced treatment zone (TZ) diameter can be reduced by altering OK lens design, and if so the impact of modifying TZ diameter on relative peripheral refraction (RPR).

Methods: 16 subjects (mean age 23.4 ± 1.

Zone of Clear Single Binocular Vision in Myopic Orthokeratology.

Purpose: To examine the zone of clear single binocular vision (ZCSBV) in myopic children and young adults after 12 months of orthokeratology (OK) wear, in comparison with single-vision soft contact lens (SCL) wear.

Methods: Twelve children (8-16 years) and 8 adults (18-29 years) were assessed with a series of near-point binocular vision tests when myopia was corrected using single-vision SCLs and again after 1 and 12 months of OK wear, and axial length was measured. The ZCSBV was constructed for baseline SCL wear and after 12 months of OK wear.

Near binocular visual function in young adult orthokeratology versus soft contact lens wearers.

Purpose: To compare near point binocular vision function of young adult myopes wearing orthokeratology (OK) lenses to matched single vision soft disposable contact lens (SCL) wearers.

Methods: A retrospective clinical record analysis of all OK wearers (18-30 years) presenting over an 18 month period was undertaken. Data was extracted for 17 OK wearers, with 17 SCL wearers matched for age, refractive error and duration of contact lens wear.

Treatment Zone Decentration During Orthokeratology on Eyes with Corneal Toricity.

Purpose: To compare the magnitude of treatment zone decentration between eyes with minimally toric corneas (≤1.50 DC, LoTor group) and eyes with moderately toric corneas (1.50 to 3.

The Future of Myopia Control Contact Lenses.

The growing incidence of pediatric myopia worldwide has generated strong scientific interest in understanding factors leading to myopia development and progression. Although contact lenses (CLs) are prescribed primarily for refractive correction, there is burgeoning use of particular modalities for slowing progression of myopia following reported success in the literature. Standard soft and rigid CLs have been shown to have minimal or no effect for myopia control.

Variation in normal corneal shape and the influence of eyelid morphometry.

Purpose: To investigate variation in normal corneal shape and the influence of eyelid morphometry on corneal shape in primary gaze.

Methods: Corneal topography (Medmont E300) and external eye photographs (Nikon D5000 SLR camera) were captured in primary gaze from 32 East Asians (13 male and 19 female subjects, 18 to 37 years) and 32 non-East Asians (10 male and 22 female subjects, 18 to 30 years). Participants with refractive error within ±6.

Changes to corneal aberrations and vision after Presbylasik refractive surgery using the MEL 80 platform.

Purpose: To investigate changes to corneal surface aberrations and vision between PresbyLASIK and LASIK for correction of presbyopia using the MEL 80 platform (Carl Zeiss Meditec, Jena, Germany).

Methods: The retrospective data of 31 patients who underwent PresbyLASIK (the PresbyLASIK group) between January 2009 and November 2011 and 20 matched patients who underwent LASIK (the LASIK group) were analyzed for changes to refraction, corrected distance visual acuity, and corneal surface wavefront aberrations calculated over 4- and 6-mm pupils. Outcomes at the 3-month follow-up visit were compared to data collected immediately prior to surgery and between PresbyLASIK and LASIK correction.

Can manipulation of orthokeratology lens parameters modify peripheral refraction?

Purpose: To investigate changes in peripheral refraction, corneal topography, and aberrations induced by changes in orthokeratology (OK) lens parameters in myopes.

Methods: Subjects were fitted with standard OK lenses that were worn overnight for 2 weeks. Peripheral refraction, corneal topography, and corneal surface aberrations were measured at baseline and after 14 nights of OK lens wear.

Central and paracentral corneal curvature changes during orthokeratology.

Purpose: To investigate regional changes in corneal curvature and power induced by overnight orthokeratology (OK) contact lens wear over a period of 2 weeks.

Methods: Corneal topography data (Medmont E300) from 21 myopes (12 M, 9F, 20 to 40 years), who had worn BE OK lenses manufactured in Boston XO material for 14 nights, were analyzed retrospectively. Enrollment criteria were myopia up to 4.

Corneal versus ocular aberrations after overnight orthokeratology.

Purpose: To investigate relationships between changes to corneal and ocular aberrations induced by orthokeratology (OK) and their influence on visual function.

Methods: Eighteen subjects (aged 20 to 23 years) were fitted with OK lenses (BE Enterprises Pty Ltd, Australia), manufactured in Boston XO material (Bausch & Lomb Boston, Wilmington, MA), and worn overnight for seven nights. Corneal and ocular aberrations were simultaneously captured (Discovery, Innovative Visual Systems, Elmhurst, IL), and contrast sensitivity function was measured on days 1 and 7, within 2 and 8 hours after lens removal on waking.

Refractive changes from hyperopic orthokeratology monovision in presbyopes.

Purpose: To investigate the time course of refractive and corneal topographic changes in overnight hyperopic orthokeratology (OK) for emmetropic presbyopes.

Methods: Sixteen adult emmetropic presbyopic subjects were fitted with rigid hyperopic OK lenses (BE Enterprises, Brisbane, Australia/Capricornia, Slacks Creek, Australia) targeted to correct +2.00 D, in one eye only.

Comparison of topcon optical coherence tomography and ultrasound pachymetry.

Purpose: To establish within-rater repeatability and minimum measurements required for reliable assessment of central corneal thickness (CCT) using Topcon three-dimensional OCT-2000 (Topcon Medical Systems, Oakland, NJ) Fourier-domain optical coherence tomography (FD-OCT) and to test agreement against ultrasound pachymetry (USP).

Methods: Twenty participants underwent five scans using FD-OCT followed by five CCT measurements using USP. Each FD-OCT scan produced 12 meridional optical sections, giving 60 sections in total.

Ocular aberrations and visual function with multifocal versus single vision soft contact lenses.

Purpose: To investigate differences in ocular aberrations induced by centre-near multifocal soft contact lenses (SCL) relative to single vision SCLs and their effect on contrast sensitivity function (CSF).

Methods: Ocular aberrometry was measured in 18 cyclopleged subjects (19-24 years) while wearing Ciba Air Optix low (AOlow) and high (AOhigh) add, Bausch & Lomb PureVision low (PVlow) and high (PVhigh) add multifocals, and a Bausch & Lomb PureVision single vision (PVsv) control with the same -3.00 D distance back vertex power.

Repeatability of internal aberrometry with a new simultaneous capture aberrometer/corneal topographer.

Purpose: To compare repeatability of internal eye aberrations derived from aberrometry and corneal topography (CT) measured simultaneously by the Innovative Visual Systems Discovery, against time displaced but same instrument measurement (Nidek OPD-Scan 3), and time displaced different instrument measurement (Medmont E300 and Imagine Eyes irx3).

Methods: Three aberrometry and CT measurements were captured with each instrument, except for the OPD-Scan 3 where three aberrometry scans were followed by a single CT. Measurements were repeated across 2 days.

Corneal thickness changes in hyperopic orthokeratology measured by optical pachometry.

Purpose: To investigate the time course of corneal thickness changes in overnight hyperopic orthokeratology (OK) lens wear for a 4-day lens-wearing period.

Methods: Fourteen subjects (age range, 20-37 years) were fitted with hyperopic OK lenses in one eye only. The fellow eye acted as a non-lens wearing control.

Peripheral refraction in different ethnicities.

Purpose: Peripheral refraction is commonly used to infer retinal shape. Because of the different prevalence of myopia in the white compared with East Asian populations, peripheral refraction along the horizontal meridian was compared in white and East Asian young adults with emmetropic, low myopic, and moderately myopic refractive errors.

Methods: Thirty-five white and 37 East Asian subjects were recruited with central refraction between +1.

The effect of treatment zone diameter in hyperopic orthokeratology.

Purpose: To investigate the time course of treatment zone (TZ) diameter changes in hyperopic orthokeratology (OK) lens wear from 1 h in the open eye through to seven nights in the closed eye.

Methods: Twelve subjects were fitted with rigid hyperopic OK lenses. Lenses were worn in the open eye for 1 h then one night in the closed eye, separated by a washout period of 4 days.

Mechanism for corneal reshaping in hyperopic orthokeratology.

Purpose: To investigate the mechanism underlying hyperopic orthokeratology (OK) by comparing the short-term clinical effect of lenses before and after central lens fenestration.

Methods: Twelve subjects (age 21 to 24 years) were fitted with rigid hyperopic OK lenses (BE Enterprises/Capricornia) in one eye only. The fellow eye acted as a non-lens wearing control.

Time course of corneal topographic changes in the first week of overnight hyperopic orthokeratology.

Purpose: To investigate the time course of refractive and corneal topographic changes in overnight hyperopic orthokeratology (OK).

Methods: Ten young adult subjects were fitted with rigid hyperopic OK lenses (BE Enterprises, Capricornia) targeted to correct +1.50 D, in one eye only.