Blue light stimulation of the blind spot in human: from melanopsin to clinically relevant biomarkers of myopia.

The protective effects of time spent outdoors emphasize the major role of daylight in myopia. Based on the pathophysiology of myopia, the impact of blue light stimulation on the signaling cascade, from melanopsin at the blind spot to clinically relevant biomarkers for myopia, was investigated. Parameters and site of light stimulation are mainly defined by the photopigment melanopsin, that is sensitive to blue light with a peak wavelength of 480 nm and localized on the intrinsically photosensitive retinal ganglion cells (ipRGC) whose axons converge to the optic disc, corresponding to the physiological blind spot.

Enhancement of the Inner Foveal Response of Young Adults with Extended-Depth-of-Focus Contact Lens for Myopia Management.

Background: Myopia management contact lenses have been shown to successfully decrease the rate of eye elongation in children by changing the peripheral refractive profile of the retina. Despite the efforts of the scientific community, the retinal response mechanism to defocus is still unknown. The purpose of this study was to evaluate the local electrophysiological response of the retina with a myopia control contact lens (CL) compared to a single-vision CL of the same material.

Neural binocular summation and the effect of defocus on the pattern electroretinogram and visual evoked potentials for different pupil sizes.

Purpose: To evaluate the influence of defocus and pupil size on subjective (visual acuity [VA]) and objective (electrophysiology) descriptors of human vision and their effect on binocular visual performance by means of neural binocular summation (BS).

Methods: Fifteen healthy young subjects were recruited in this crossover study. Pattern electroretinogram (PERG) and visual evoked potentials (VEP) were measured under two levels of positive (+1.

Changes in Choroidal Thickness and Retinal Activity with a Myopia Control Contact Lens.

Purpose: The axial elongation in myopia is associated with some structural and functional retinal changes. The purpose of this study was to investigate the effect of a contact lens (CL) intended for myopia control on the choroidal thickness (ChT) and the retinal electrical response.

Methods: Ten myopic eyes (10 subjects, 18-35 years of age) with spherical equivalents from -0.

Peripheral Refraction and Visual Function of Novel Perifocal Ophthalmic Lens for the Control of Myopia Progression.

This study aimed to evaluate the peripheral defocus induced with a novel perifocal ophthalmic lens for myopia progression control and the potential impact on visual function. This experimental, non-dispensing crossover study evaluated 17 myopic young adults. The peripheral refraction was measured using an open-field autorefractor, at 2.

Pupil size effect on binocular summation for visual acuity and light disturbance.

Purpose: Smaller pupil size under binocular conditions could justify partially the improvement of visual performance when compared to monocular conditions. The purpose of this study was to assess the binocular summation for increasing levels of spherical and cylindrical defocus when the pupil size factor is ruled out as a confounding factor.

Methods: Fifteen young subjects were recruited in this crossover study.

Mathematical Estimation of Axial Length Increment in the Control of Myopia Progression.

This study aims to evaluate the existing mathematical approach for the theoretical estimation of axial length (AL) in a cross-sectional study, developing a new mathematical model and testing it in a longitudinal sample. Many professionals do not have a device to measure the AL due to clinic space and cost of equipment. However, this parameter plays an important role in the assessment of myopia progression to monitor treatment effects with myopia control strategies.

Short-term delay in neural response with multifocal contact lens might start at the retinal level.

Introduction: Multifocal simultaneous imaging challenges the visual system to process the multiple overlaps of focused and defocused images. Retinal image processing may be an important step in neuroadaptation to multifocal optical images. Our aims are, firstly to evaluate the short-term effect of different multifocal contact lenses (MF) on retinal activity in young healthy subjects (Experiment#1) and secondly, to evaluate any changes in retinal activity in presbyopic patients fitted with MF over a 15-day period (Experiment#2).

Increase in b-wave amplitude after light stimulation of the blind spot is positively correlated with the axial length of myopic individuals.

Altered retinal dopamine and ON-pathway activity may underlie myopia development. It has been shown that the stimulation of the blind spot with short-wavelength light increases the electroretinogram (ERG) b-wave amplitude of myopic eyes and may engage the retinal dopaminergic system. This study evaluated the impact of various durations of blind spot stimulation on the electrophysiological response of the myopic retina and their relationship to axial length.

Blue light blind-spot stimulation upregulates b-wave and pattern ERG activity in myopes.

Upregulation of retinal dopaminergic activity may be a target treatment for myopia progression. This study aimed to explore the viability of inducing changes in retinal electrical activity with short-wavelength light targeting melanopsin-expressing retinal ganglion cells (ipRGCs) passing through the optic nerve head. Fifteen healthy non-myopic or myopic young adults were recruited and underwent stimulation with blue light using a virtual reality headset device.

Multifocal Electroretinogram in Keratoconus Patients without and with Scleral Lenses.

: To investigate changes in the multifocal electroretinogram (mfERG) response in eyes with keratoconus when corrected with scleral lenses (SL) compared with the best correction in glasses.: The mfERG responses in 10 eyes with keratoconus were recorded with the best correction using both a trial frame (baseline) and a hexafocon A SL using an electrophysiological diagnostic system. Electrophysiologic measurements were performed with the pupils fully dilated with instillation of 1% phenylephrine.

The Impact of Overnight Orthokeratology on Accommodative Response in Myopic Subjects.

This study aimed to evaluate the effects of two months of orthokeratology (OK) treatment in the accommodative response of young adult myopes. Twenty eyes (21.8 ± 1.

Retinal Response of Low Myopes during Orthokeratology Treatment.

The aim of this study was to evaluate the changes in retinal activity during orthokeratology (OK) treatment in 20 myopic eyes. Pattern electroretinography (PERG) and visual evoked potential (VEP) were assessed with the RETI-port/scan21 (Roland Consult, Wiesbaden, Germany). Measurements were taken at baseline (BL) and 1 night (1N), 15 nights (15N), 30 nights (30N), and 60 nights (60N) of OK lens wear.

Bifocal and Multifocal Contact Lenses for Presbyopia and Myopia Control.

Bifocal and multifocal optical devices are intended to get images into focus from objects placed at different distances from the observer. Spectacles, contact lenses, and intraocular lenses can meet the requirements to provide such a solution. Contact lenses provide unique characteristics as a platform for implementing bifocality and multifocality.

A Minimal-Model Approach to Analyze Neuronal Circuit Dynamics from multifocal ERG (mERG).

The multifocal electroretinogram (mERG) is a valuable non-invasive tool used by clinicians for studying both the local physiology of the normal human retina, as well as retinal function affected by disease. However, the neural basis of the major components of the mERG is not well understood. Computational modeling of neural circuits has lead to important insights into the structure and workings of nervous systems.

Refractive, biometric and corneal topographic parameter changes during 12 months of orthokeratology.

Background: The aim of this study was to monitor refractive, topographic and biometric changes in Singaporean myopic children fitted with orthokeratology over a period of 12 months.

Methods: Data from 62 myopic eyes from an Asian population corrected with orthokeratology were retrospectively collected from an optometric clinic in Singapore. Anterior segment parameters were analysed with a Pentacam.

Clinical Findings and Ocular Symptoms Over 1 Year in a Sample of Scleral Lens Wearers.

Purpose: To report the fitting aspects, clinical findings, and symptoms over 12 months of scleral lens (SL) wear.

Methods: Sixty-nine patients with irregular cornea due to ectasia or surgical procedures (IC group) or regular corneas with high ametropia (RC group) completed the 12-month prospective follow-up period. Patients were evaluated at baseline, lens dispensing visit, 1 month, 3 months, 6 months, and 12 months for assessment of comfort, fitting aspects, and slitlamp findings.

Impact of contact lens materials on the mfERG response of the human retina.

Purpose: To investigate the effect of different hydrophilic and rigid gas-permeable contact lens (CL) materials on multifocal electroretinography (mfERG).

Methods: The mfERG was recorded in 18 healthy subjects with RETI-port/scan21™: 11 subjects underwent mfERG recording wearing two different hydrophilic CLs with different water contents in a randomized order (1 silicone hydrogel-Comfilcon A, 48%EWC, and 1 hydrogel-Omafilcon A, 62% EWC) and 7 other subjects wore a hydrophobic rigid gas-permeable scleral lens (SL)-Hexafocon A. Control measures were recorded without CL in both groups.

Visual Performance and High-Order Aberrations with Different Contact Lens Prototypes with Potential for Myopia Control.

: Contact lenses (CLs) used for myopia control incorporate variable power distribution across the optic zone potentially creating degradation of the high-order aberrations. The present study aims to evaluate the retinal image quality and visual performance in three prototypes of CLs intended to control axial elongation of the eye before they are considered for clinical trials.: This is a non-dispensing cross-over, double-blind study where 30 right eyes of myopic subjects worn 3 multifocal test lenses and 1 monofocal control lens in random order.

Determination of central corneal clearance in scleral lenses with an optical biometer and agreement with subjective evaluation.

Purpose: To compare three methods to measure central corneal clearance (CCC) during scleral lens wear: subjective (slit lamp), image processed (ImageJ) and with an optic biometer. The optic biometer technique was validated in comparison to an OCT in the first part of the study.

Methods: Twenty-two eyes (11 subjects) with healthy corneas were recruited.

Corneal morphology and visual outcomes in LASIK patients after orthokeratology: A pilot study.

A Statement Of Significance: For the first time, this study shows that corneas that previous undergone orthokeratology treatment do not respond differently to LASIK compared with previous soft contact lens wear experience.

Purpose: To evaluate and compare the corneal morphology and visual outcomes of long-term soft and orthokeratology (OK) contact lens fitting in wearers undergoing corneal refractive surgery (LASIK) for myopia correction.

Methods: Sixteen (16) myopic patients wearing hydrophilic soft contact lens (SCL, n = 8 subjects, control group) and OK (n = 8 subjects, OK group) lenses who undergone LASIK were retrospectively evaluated.

Age-Related Variations in Corneal Asphericity and Long-Term Changes.

Purpose: Corneal front-surface asphericity is directly related with the optical quality of the eye and with contact lenses fitting. The purpose of this study was to evaluate the corneal asphericity as a function of age, sex, and refractive error measured with autokeratometry and corneal topography and its long-term changes (5- to 10-year period).

Methods: The asphericity and corneal curvature were obtained with the autorefractometer/autokeratometer NIDEK ARK-700A and with the videokeratoscope MODI 2.

Relationship of placido corneal topography data with scleral lens fitting parameters.

Purpose: To analyze the relationship between corneal sagittal height and asymmetry parameters derived from Placido-videokeratoscopy with the parameters of fitted scleral lenses (ScCLs).

Methods: Corneal topographies were measured with MedmontE300 in a total of 126 eyes with irregular and regular corneas before ScCL fitting were analyzed. Measurements of sagittal height (OC-SAG) at steep and flat corneal meridians were obtained for 10 mm and 12 mm chords.

Relative peripheral refraction across 4 meridians after orthokeratology and LASIK surgery.

Background: To characterize the axial and off-axis refraction across four meridians of the retina in myopic eyes before and after Orthokeratology (OK) and LASIK surgery.

Methods: Sixty right eyes with a spherical equivalent (M) between - 0.75 to - 5.