Accommodative Response Research Articles

Vergence and accommodation responses in the control of intermittent exotropia.

Vergence and accommodation responses in the control of intermittent exotropia.

Long-lasting impact of chito-oligosaccharide application on strigolactone biosynthesis and fungal accommodation promotes arbuscular mycorrhiza in Medicago truncatula.

• The establishment of arbuscular mycorrhiza (AM) between plants and Glomeromycotina fungi is preceded by the exchange of chemical signals: fungal released Myc-factors, including chitoligosaccharides (CO) and lipo-chitooligosaccharides (LCO), activate plant symbiotic responses, while root exuded strigolactones stimulate hyphal branching and boost CO release. Furthermore, fungal signaling reinforcement through CO application was shown to promote AM development in Medicago truncatula, but the cellular and molecular bases of this effect remained unclear. • Here we focused on long-term M. truncatula responses to CO treatment, demonstrating its impact on the transcriptome of both mycorrhizal and non-mycorrhizal roots over several weeks and providing an insight into the mechanistic bases of the CO-dependent promotion of AM colonization. • CO treatment caused the long-lasting regulation of strigolactone biosynthesis and fungal accommodation related genes. This was mirrored by an increase in root didehydro-orobanchol content, and the promotion of accommodation responses to AM fungi in root epidermal cells. Lastly, an advanced down-regulation of AM symbiosis marker genes was observed at the latest time point in CO-treated plants, in line with an increased number of senescent arbuscules. • Overall, CO treatment triggered molecular, metabolic and cellular responses underpinning a protracted acceleration of AM development.

FIAT: A Device for Objective, Optical Measures of Accommodation in Phakic and Pseudophakic Eyes.

To present FIAT, a novel optical instrument and analysis package that is designed to elicit and optically record accommodation in human eyes. FIAT employs a Shack-Hartmann wavefront sensor and a retro-illumination pupil camera that records from a single eye at video rates. It is effective at eliciting accommodation by offering the subject a full-field binocular view of an alternating distant target and a near-eye display. FIAT analysis software computes wave aberrations for each video frame over full- or subpupil sizes and computes accommodative dynamics and accommodative range. The system is validated by showing accurate refraction measurements in model eyes and human eyes with trial lenses. Robust accommodative responses are shown for young eyes, and a lack of accommodative response is shown for a known presbyopes. Accommodative stimulus-response curves from five phakic subjects over a range of ages show expected results. Results from two individuals with monofocal intraocular lenses are shown. FIAT is an effective instrument for making accurate, objective measures of accommodation in phakic and pseudophakic eyes. We present a device that can play an important role in the development and testing of accommodating intraocular lenses.

Scheimpflug Imaging of the Anterior Eye Segment during Standardized Accommodation Stimulation in Patients with Emmetropia, Myopia and Hypermetropia

Understanding of the biomechanics of the accommodative apparatus in the eyes with different refraction is important for solving the problems of theoretical and practical ophthalmology. Purpose: To determine the changes of anterior eye segment dimensions during accommodation response in normal eyes and in patients with myopia, hypermetropia. Methods and Material: 116 eyes (56 patients aged from 18 to 30 years, refraction from -2.0 to + 2.0 D) were examined. All the patients underwent a full ophthalmological examination. The ocular anterior segment was imaged using a rotational Scheimpflug camera Pentacam HR (Oculus, Wetzlar, Germany) under non- and 3.0 D of accommodative demands. The statistical data were represented as the mean value ± standard deviation (M ± SD). The Shapiro-Wilk test was used to assess the normality distribution. Wilcoxon test was used for comparison. Results: Results showed an increase in the optical density of the crystalline lens, a pupil diameter decrease and changing of the iris profile during accommodation in all patients. An increase in the total corneal aberrations and decrease in the corneal spherical aberration were revealed only in emmetropic eyes. Conclusions: The accommodative response is a multicomponent process. Scheimpflug visualization revealed the differences in the accommodative response in normal and ametropic eyes.

Changes in accommodation in children with hyperopic anisometropia and unilateral amblyopia after laser refractive surgery and pleoptic treatment

This study comparatively analyzes the state of accommodation in children with hyperopic anisometropia and amblyopia after femtosecond laser-assisted in situ keratomileusis (Femto-LASIK) combined with pleoptic treatment, and after conventional pleoptic treatment. The first group consisted of 30 children with medium and high hyperopia, high and medium amblyopia, and anisometropia greater than 3.0 diopters, who underwent Femto-LASIK in the amblyopic eye. The second group consisted of 28 children with similar local status, who were prescribed traditional correction and received conservative treatment. The follow-up period was 1.5 years. After 1.5 years, higher visual acuity (p<0.05) was achieved in the first group. A significant increase in the coefficient of accommodative response (CAR) was observed in the operated amblyopic eyes in group 1 - by 0.1±0.02 c.u. compared to the control group (p<0.05). In both groups there was an upwards trend for the coefficient of microfluctuations (CMF) in the amblyopic eye, but in the first group CMF increased more significantly (p<0.05). The objective accommodative response (OAR) and positive relative accommodation (PRA) of the amblyopic eye showed a double increase - by 1.0±0.23 and 0.9±0.38 diopters, respectively, at the end of treatment in the first group. The increase in similar indicators in the second group was insignificant (p<0.05). In children of the first group the difference in ciliary muscle thickness (CMT) of the amblyopic eye with disabled and enabled accommodation increased by 0.04±0.01 mm (p<0.05) in the anterior part of the ciliary muscle at the levels of CMTmax and CMT1. The data obtained in this study indicate the strong effect of refractive laser surgery in combination with pleoptic treatment on improving the visual acuity and the state of accommodation of the amblyopic and paired dominant eyes in children with hyperopic anisometropia, in contrast to conventional methods of treatment.

Real-time wavefront aberrometry in subjects with accommodative excess

The purpose of this study was to use real-time wavefront aberrometry to detect accommodative excess (AE) and to analyse the optical quality of the eye in subjects with this dysfunction. AE was detected from the accommodative response obtained by real-time wavefront aberrometry. These subjects had a significant accommodative lead to all stimuli and had difficulty relaxing accommodation. The root mean square (RMS) of high order aberrations (HOA) was higher in subjects with AE for lower stimulus and for disaccommodation than in the control group. However, the subjects with AE showed a decrease in the RMS of HOA with an increase in accommodative response. Primary spherical aberration tended to become more negative with accommodation in both subjects and there was no difference between the groups. Real-time wavefront aberrometry can be used as an objective method to detect accommodative excess.

Effectiveness of non-pharmacological treatments for vestibular and oculomotor dysfunction in patients with persistent post-concussive symptoms: protocol for a systematic review and meta-analysis

IntroductionConcussion is a form of mild traumatic brain injury that disrupts brain function. Although symptoms are mostly transient, recovery can be delayed and result in persistent postconcussive symptoms (PPCS). Vestibular...

Situations in which individuals with mental disabilities perceive the need for advocacy support and how to deal with them

Objectives Policies promoting community integration of individuals with mental disabilities have increased the need for community advocacy. This study aimed to identify situations in which individuals with mental disabilities perceive the need for advocacy support and how to deal with them.Methods In this qualitative descriptive study, group interviews were conducted with 13 peer advocates and 12 individuals with mental disabilities. A verbatim transcript of the interviews was created. Categories were generated by raising the level of abstraction from the perspective of "Situations where individuals with mental disabilities require advocacy support and how to address them."Results Situations requiring advocacy support occurred in outpatient psychiatry settings, psychiatric hospitalizations, welfare facilities, schools, neighborhoods, and places of employment; among family and relatives; and at consultation services. In outpatient psychiatry, "difficulties in accessing medical care" were reported. In psychiatric hospitalizations, participants felt "pressured and unable to escape the environment." In welfare facilities, "romantic relationships between users were discouraged." Regarding familial difficulties, "limited understanding and acceptance of the disease," "relationship deterioration due to poor hospitalization conditions and forced hospitalization," and "marital difficulties due to mental illness" were prevalent. Participants in schools experienced "isolation due to their illness," and in the local community, there were "problems related to reasonable accommodation of individuals with disabilities in neighborhood association activities." Employed participants faced "inadequate consideration despite disclosing their illness to co-workers." At counseling institutions, participants felt "forced to endure without resolution when consulting." Individuals with disabilities coped with these situations by "transferring to a different clinic" or "changing facilities," but in the case of psychiatric hospitalization, they gave up and "did not go against the staff."Conclusion Individuals with mental disabilities need advocacy support for psychiatric care and diverse situations such as family, school, and community engagement. Efforts should be made to introduce an advocacy system in psychiatric hospitals and to disseminate accurate information about mental illness to high-risk age groups. Moreover, it is necessary to disseminate knowledge of reasonable accommodation and appropriate responses to individuals with mental illness. Peer advocates should educate individuals with disabilities about their rights and encourage proactive measures.

Wavefront sensing for objective assessment of vision therapy efficacy: Preliminary results

The aim of this study was to use wavefront sensing to objectively evaluate the effects of vision therapy in subjects with insufficiency (AI) and infacility of accommodation (AINF). Aberrometry was performed with a Shack-Hartmann wavefront aberrometer for different accommodative stimuli in one subject with AI and one with AINF before and after treatment with vision therapy (VT). A control subject received a placebo treatment. Real-time accommodative response, accommodation and disaccommodation reaction time, accommodative microfluctuations and root mean square of higher order aberrations were compared before and after VT/placebo. VT was effective and wavefront sensing can be used to detect AI and AINF and evaluate these subjects during VT.

Клиническое и экспериментальное обоснование применения фенилэфрина с гипромеллозой в лечении перенапряжения аккомодации у пациентов с миопией

Aim: to perform a comparative analysis of the clinical efficacy of 2.5% phenylephrine with and without hypromellose for the treatment of extra accommodation strain in schoolchildren with myopia and to perform an experimental evaluation of the pharmacological effective of active ingredient of the finished dosage form (FDF) of preparations containing 2.5% phenylephrine with and without excipients. Patients and Methods: this clinical study enrolled 122 schoolchildren, 11–17 years old, with extra accommodation strain of various severity. The children were split into two groups. The group 1 patients received Irifrin® BK, containing 2.5% phenylephrine with hypromellose, one eye drop at the bedtime during 30 days, and the group 2 patients — Preparation A (2.5% phenylephrine without hypromellose) according to the same dosage regimen. The accommodative function was evaluated using the Speedy-i accommodation analyzer, and the coefficients of accommodation response before and 30 days after the treatment were determined. The experimental study was carried out in 40 sexually mature male rabbits of the Soviet Chinchilla breed to evaluate the development and duration of mydriatic effect and to measure the concentration of active ingredient — phenylephrine with hypromellose, as an excipient (Irifrin® and Irifrin® BK), phenylephrine without hypromellose (Preparation A) and phenylephrine with sodium hyaluronate as an excipient (Preparation B) in the aqueous humor within the eye anterior chamber using high-performance gas-liquid chromatography with tandem mass spectrometric detection. Results: the drug therapy of extra accommodation strain comprising 2.5% phenylephrine hydrochloride solution with hypromellose as an excipient (Irifrin® BK) demonstrated a decrease in severity of extra accommodation strain after 30 days of treatment. At the same time, Preparation B did not demonstrate its efficacy. In the experimental study, Irifrin® and Irifrin® BK were superior to Preparations A and B (without hypromellose as an excipient) as regards the peak mydriatic effect and the time required to reach maximal mydriasis. The peak phenylephrine concentrations in the aqueous humor within the eye anterior chamber were reached five minutes after instilling 1 drop of 2.5% phenylephrine with hypromellose solutions. These peaks were significantly higher than those observed after instilling Preparations A and B — phenylephrine in the same concentration but without hypromellose. Conclusion: the addition of hypromellose as an excipient to FDF of 2.5% phenylephrine solution helps to optimize pharmacodynamics and pharmacokinetics of the active ingredient by accelerating its inflow in the aqueous humor within the eye anterior chamber, increasing the topical bioavailability, and extending the exposure interval. It is likely that the above factors have underpinned the efficacy of Irifrin® and Irifrin® BK drugs used for the treatment of extra accommodation strain. The same results were obtained in this study comparing the clinical efficacy of 2.5% phenylephrine solution with hypromellose and its preparations without hypromellose used for the treatment of schoolchildren with extra accommodation strain amid myopia, as proven by the significant improvement of the accommodation indices during the treatment. Keywords: extra accommodation strain, mydriatic effect, peak concentration, rabbit, myopia, phenylephrine, hypromellose. For citation: Makhova M.V., Shikh E.V., Strakhov V.V. et al. Clinical and experimental rationale for using phenylephrine with hypromellose for the treatment of extra accommodation strain in patients with myopia. Russian Journal of Clinical Ophthalmology. 2023;23(1):33–38 (in Russ.). DOI: 10.32364/2311-7729-2023-23-1-33-38

태블릿 PC를 통해 구현된 증강현실 영상 속 이동하는 시표와 카메라를 통해 실시간 시표가 이동하는 영상 관찰시 나타나는 눈의 조절력 변화에 관한 연구

태블릿 PC를 통해 구현된 증강현실 영상 속 이동하는 시표와 카메라를 통해 실시간 시표가 이동하는 영상 관찰시 나타나는 눈의 조절력 변화에 관한 연구

Особенности аккомодационной функции у детей при различных видах рефракционных нарушений

Nowadays, no single concept has been found that could interpret all morphological and functional changes in the eye during accommodation. This review of Russian and foreign publications is devoted to the analysis of accommodation function in various children's refractive disorders. The analysis shows that each refractive change is characterized by certain features in the accommodation process. The most significant changes in accommodation were found in anisotropic children, it's characterized by anisoacomodation, low accommodation response, and weak unstable accommodation. To exclude persistent functional disorders, it is necessary to diagnosis refractive disorders on early stages and manage their treatment. Key words: accommodation, anisoaccomodation, hyperopia, myopia, anisometropia

Objective Characteristics of Accommodation in Present-Day Schoolchildren with Different Levels of Myopia

Purpose: We study the state of the accommodative function in present-day schoolchildren using the method of computer accomodography. Patients and methods: 74 children (10–16 years old), 54 of them with different degrees of myopia and 20 children (control group) with emmetropia were tested on the computer accomodography devise Righton Speedy-K ver. MF-1. The strength of the accommodative response accorded to the presented accommodative stimulus was determined by calculating the accommodative coefficient response (CAO) and the contraction’s nature of the ciliary body fibers by determining the microfluctuation coefficient (KMF).

Binocular Vision Function and Migraine: A Review

Migraine is a multifactorial disease characterized by recurrent headaches and has complex neuronal and vascular mechanisms, including a wide range of clinical symptoms and other ocular findings. During migraine attacks in migraine sufferers, the accommodative response increases significantly. Migraine sufferers are predisposed to have a subtle deficit in binocular vision coordination, reduced stereopsis, reduced fixation disparity, slightly higher prevalence of heterophoria, and reduced stereopsis. Convergence insufficiency can be associated with migraine and may be the persistent cause of reduced visual functioning. Binocular vision coordination difficulties are the most common findings among migraine sufferers.

Effect of filters on the accommodation and colour discrimination

AbstractPurpose: To evaluate the effect of coloured filters on the accommodative response and colour discrimination in young subjects.Methods: Two long pass filters (LED light reduction and 511 nm filter), two selective absorption filters (ML41 and emerald filter), and no filter condition were evaluated. The photorefractor PowerRef3 (PlusOptix) was used to measure the objective refraction at 3 different distances (40, 100, and 400 cm). The measurement obtained at 400 cm was used as a reference to calculate the accommodative response. The fixation target consisted of five letter length words (size corresponding to 6/12 Snellen) that were presented in black font over white background. Words changed with a frequency of 2 Hz according to the rapid serial visual presentation paradigm. The Cambridge Colour Test (Metropsis) was used to measure the discrimination threshold in a 10‐vector ellipse at a 3 m viewing distance. The measurement was repeated twice, and it was performed monocularly. In total, 20 healthy volunteers with no accommodation problems or colour blindness were included.Results: On average, the accommodative response with no filter condition was larger compared to the measurements with filters for 40 and 100 cm. The differences were in all cases lower than 0.25D, and differences were not statistically significant (p &gt; 0.05). For the colour discrimination thresholds, the ML41 and 511 filters showed statistically significant different values compared to the other two conditions for most of the vectors. The filter 511 had the highest impact on the colour vision, as the results resemble to a Tritan defect.Conclusions: The accommodative response in healthy young adults was not significantly different than the no filter condition. The colour discrimination thresholds with the filter ML41 and 511 were significantly different compared to the no filter condition.

Assessment of central and peripheral accommodative lag by aberrometry

Accommodation lag is important factor for normal vision. Higher lag of accommodation may cause various ocular symptoms particularly during near tasks. In this study, the lag of accommodation was assessed in the peripheral retina and it was compared with the central accommodative lag with aberrometer. In this cross-sectional study, fifty-three young subjects with normal visual acuity and without any active ocular disease or past ocular surgery were included. Aberrations in the central and peripheral field of view up to 30° off axis from the centre in horizontal and vertical meridian in 10° steps were measured with Hartmann-Shack aberrometer with stimulation of accommodation by -2.50D lens. Accommodative stimulus and accommodative response were calculated with defocus and hence accommodative lag was obtained. Accommodative lag in the centre and periphery was compared. Repeated measure of ANOVA showed that there were significant differences in lag of accommodation in various eccentricities (F(8.912, 454.514) = 2.372, p = 0.013). Pairwise test showed that lag in the centre was similar with lag on other peripheral field of view (p > 0.05). However, accommodative lag at 10° nasal field was significantly lower than the lag at 20° temporal, 20° nasal, 30° temporaland 30° nasal (p < 0.05). Similarly, lag at 10° superior fixation was lower than lag at 20° temporal, 20° nasal, 30° temporal and 30° nasal fixations (p < 0.05). We found higher lag of accommodation in horizontal off-axis fixations in comparison to that of vertical off-axis fixations (p < 0.05). Lag of accommodation was positive correlated with vertical coma and primary spherical aberrations but negative correlated with secondary spherical aberrations (p < 0.05). Thus, Hartmann-Shack aberrometer was successfully used to assess accommodative lag in the peripheral field of view up to 60° visual field. Peripheral lag of accommodation depends up on eccentricity. Lag was found higher in horizontal off-axis fixation than at vertical fixations. Coma and spherical aberration had association with lag.

Comparison of ocular aberrations and retinal image quality provided by a validated aberrometer and a new open field aberrometer for VEMoS project

AbstractPurpose: The aim of this observational study was to compare the retinal image quality and ocular aberrations provided by a validated aberrometer and by a new open field aberrometer.Methods: This is an observational and comparative study composed by healthy eyes not presenting cataract or ocular pathologies affecting media transparence or visual function. Patients underwent a measurement of ocular aberrations by a closed field aberrometer (Osiris, CSO) and by an open field aberrometer developed for VEMoS European project (OFA, CSO). Both measurements were performed by a qualified optometrist and the pupil size selected for the analysis was 4 mm. SPSS program was applied for the statistical analysis, particularly Wilcoxon test was used to compare both devices considering a significance of 0.05.Results: The study included 20 eyes of 20 patients with a mean age of 36.2 ± 9.7 years. The sphere was significantly more negative with Osiris in comparison with OFA (−0.33 ± 2.17 diopters vs. 0.29 ± 2.17 diopters, p &lt; 0.001), the spherical aberration was also slightly lower with Osiris (0.02 ± 0.03 microns vs. 0.03 ± 0.03 microns, p: 0.045). The rest of aberrometric coefficients including the cylinder, coma, trefoil, quadrefoil and secondary astigmatism showed no significant differences between devices (p &gt; 0.05). Moreover, the point spread function did not presented statistical differences, but a trend to obtain higher values was observed in Osiris (0.219 ± 0.127 vs. 0.189 ± 0.126, p: 0.370).Conclusions: The sphere provided by an open field aberrometer was significantly more positive comparing with a close field aberrometer probably associated to an accommodative response induced in close field aberrometers. Similarly, the spherical aberration assumed small changes between devices, which would be generated also by accommodation. The rest of parameters showed no differences between devices indicating a suitable agreement between devices for these coefficients.

Accommodation through simulated multifocal optics.

We evaluated the interaction of multifocal patterns with eye's accommodation. Seven patterns were mapped on the spatial light modulator and the deformable mirror of an adaptive optics visual simulator, and projected onto the subjects' eyes, representing different contact lens designs: NoLens, Bifocal Center Distance (+2.50D), Bifocal Center Near (+2.50D) and Multifocal Center Near-MediumAdd (+1.75D) and Center Near HighAdd (+2.50D), positive and negative spherical aberration (±1µm). The change in spherical aberration and the accommodative response to accommodative demands were obtained from Hartmann-Shack measurements. Positive spherical aberration and Center Distance designs are consistent with a higher accommodative response (p=0.001 & p=0.003): steeper shift of SA towards negative values and lower accommodative lag.

Gaming for Training Voluntary Control of Pupil Size

Users can “voluntarily” control the size of their pupil by switching focus from a far target A (large pupil size) to a near target B (small pupil size), according to the pupillary accommodative response (PAR). Pupil size is governed by smooth muscles and has been suggested as communication pathway for patients affected by paralysis of skeletal muscles, such as in amyotrophic lateral sclerosis (ALS). We here present a video game that relies on PAR: a 2d side-scroller game where the user, by varying pupil size, controls the height at which a spaceship is moving aiming at colliding with bubbles to burst them and score points. The height at which the spaceship flies inversely depends on pupil area. The game is implemented on a Raspberry Pi board equipped with a IR camera and may record the time course of pupil size during the game, for off-line analysis. This application is intended as a tool to train and familiarize with the control of pupil size for alternative augmentative communication.

Effects of Continuous Online Multiplayer Gaming on Ocular Health

Purpose: To study the ocular effects of continuous online multiplayer gaming and reading using smartphones. Methodology: In the study, inclusion criteria were 25 active gamers and 25 readers between the ages of 18 to 25 years of either sex, and the Indian population with ametropia &lt; ± 4.00D sph and -1.25 cyl. Exclusion criteria were subjects with a history of non-strabismic binocular vision anomalies, ocular surgery, strabismus, ocular trauma &amp; pathologies, and systemic illness. The GAMERS were allowed to play PUBG for 2hrs, and READERS were allowed to read for 2hrs on their smartphones. The pre- and post-activity values were collected and analyzed using SPSS software. Results: There were significant changes in NPC with accommodative target and RG filter, monocular and binocular accommodative amplitudes, monocular and binocular accommodative facility, and vergence facility (Wilcoxon signed-rank test, p&lt;0.05) among the GAMERS and READERS. No significant change in accommodative response, vergence amplitudes, tear film volume, and stability. The differences observed between the pre- and post-activity values of the binocular vision and tear film parameters were the same when compared between GAMERS and READERS (Mann Whitney U test, p&gt;0.05). Conclusion: The ocular effects of GAMING are similar to continuous READING on mobile phones. However, the addictive nature of the activity "GAMING" could aggravate the ocular symptoms of exhaustive use.