Comparison of the accommodative amplitude measured with and without the use of a specialised accommodative rule in children.

OBJECTIVE: To determine the agreement between measurements of accommodative amplitude (AoA) in children using a specialised accommodative rule and measurments without it. METHODS: A total of 502 children underwent optometric examinations, including the measurement of visual acuity, objective and subjective refraction. AoA measurements were done with and without the Berens accommodative rule. The measurements of AoA were conducted monocularly using a -4 D lens. A fixation stick containing English letters equivalent to 20/30 visual acuity and a long millimetre ruler was used to measure AoA without the accommodative rule. This measurement was performed by the two trained examiners. The agreement between these methods was reported by 95% limits of agreement (LoA) and interclass correlation coefficient (ICC). RESULTS: The mean age of the participants was 11.7±1.3 years (range: 9-15 years) and 52.4% were male. The mean AoA with and without the accommodative rule was 20.02±6.02 D and 22.46±6.32 D, respectively. The 95% LoA between the two methods was -12.5 to 7.5 D, and the ICC was 0.67 (95% CI 0.63 to 0.70). The 95% LoA was narrower in higher age groups and males compared with females (18.92 vs 20.87). The 95% LoA was narrower in hyperopes (16.83 D) compared with emmetropes (18.37 D) and myopes (18.27 D). The agreement was not constant and decreased in higher values of AoA. CONCLUSION: There is a poor and non-constant agreement between the measurements of the AoA with and without the accommodative rule. The mean AoA was 2.5 D lower with using the accommodative rule.

Ocular Accommodative and Pupillary Responses During Fixation on Augmented Reality With a Maxwellian Display.

Purpose: This study aimed to investigate the changes in ocular refraction and pupillary diameter during fixation on augmented reality (AR) images using a Maxwellian display. Methods: Twenty-two healthy young volunteers (average age, 20.7 ± 0.5 years) wore a Maxwellian display device in front of their right eye and fixated on an asterisk displayed on both a liquid-crystal display (real target) and a Maxwellian display (AR target) for 29 seconds (real as a baseline for 3 seconds, AR for 13 seconds, and real for 13 seconds) at distances of 5.0, 0.5, 0.33, and 0.2 meters. A binocular open-view autorefractometer was used to measure the ocular refraction and pupillary diameter of the left eye. Results: Accommodative (5.0 meters, 0.28 ± 0.29 diopter [D]; 0.5 meter, -0.12 ± 0.35 D; 0.33 meter, -0.43 ± 0.57 D; 0.2 meter, -1.20 ± 0.82 D) and pupillary (5.0 meters, 0.07 ± 0.22 mm; 0.5 meter, -0.08 ± 0.17 mm; 0.33 meter, -0.16 ± 0.20 mm; 0.2 meter, -0.25 ± 0.24 mm) responses were negative when the real target distances were farther away. The accommodative response was significantly and positively correlated with the pupillary response during fixation on the AR target (R2 = 0.187, P < 0.001). Conclusions: Fixating on AR images using a Maxwellian display induces accommodative and pupillary responses. Accommodative responses depend on the distance between real objects. Overall, the Maxwellian display does not completely eliminate accommodation in real space.

The impact of different postures on acute intraocular pressure and accommodation responses during reading.

INTRODUCTION: To investigate the effects of different reading postures on intraocular pressure (IOP) and near-work-induced transient myopia (NITM) in children with myopia. METHODS: Sixty myopic children were instructed to read a book text placed at 33 cm for 30 min with two different reading postures: head bowed and head upright postures. The participants' IOP and NITM were assessed using a rebound tonometer and an open-field autorefractor. The measurement of IOP was conducted prior to reading, during reading sessions (at 5, 10, 20, and 30-min intervals), and after a 5-min recovery period. RESULTS: For the head bowed posture, the mean baseline IOP was 16.13 ± 2.47 mmHg. A significant rise in IOP was observed after 5 min of reading (17.17 ± 2.97 mmHg; +1.03 ± 2.29 mmHg; p = 0.014). Subsequent measurements revealed a further increase after 20 min (17.87 ± 2.90 mmHg; +1.73 ± 2.58 mmHg; p < 0.001), which continued to persist even after 30 min of reading (17.57 ± 3.46 mmHg; +1.43 ± 2.66 mmHg; p = 0.002). The IOP at different time points measured in the head upright posture did not show any significant difference in comparison to the baseline measurement (all p = 1.000). Compared to reading with the head upright, reading with the head bowed resulted in a greater increase in IOP at each time point (p < 0.05). Furthermore, the NITM was higher for reading with the head bowed than for reading with head upright at 30 min (-0.24 ± 0.53 D vs. -0.12 ± 0.47 D, p = 0.038). CONCLUSION: Reading in a head bowed position resulted in greater increases in IOP and NITM compared to reading in a head upright posture.

Focusing on mixed narrow band stimuli: Implications for mechanisms of accommodation and displays.

The eye has considerable chromatic aberration, meaning that the accommodative demand varies with wavelength. Given this, how does the eye accommodate to light of differing spectral content? Previous work is not conclusive but, in general, the eye focuses in the center of the visible spectrum for broadband light, and it focuses at a distance appropriate for individual wavelengths for narrowband light. For stimuli containing two colors, there are also mixed reports. This is the second of a series of two papers where we investigate accommodation in relation to chromatic aberration Fernandez-Alonso, Finch, Love, and Read (2024). In this paper, for the first time, we measure how the eye accommodates to images containing two narrowband wavelengths, with varying relative luminance under monocular conditions. We find that the eye tends to accommodate between the two extremes, weighted by the relative luminance. At first sight, this seems reasonable, but we show that image quality would be maximized if the eye instead accommodated on the more luminous wavelength. Next we explore several hypotheses as to what signal the eye might be using to drive accommodation and compare these with the experimental data. We show that the data is best explained if the eye seeks to maximize contrast at low spatial frequencies. We consider the implication of these results for both the mechanism behind accommodation, and for modern displays containing narrowband illuminants.

Visual training for the treatment of retinal photoreceptor inner and outer segment connection (IS/OS) fracture: A case report.

BACKGROUND: The inner segments and outer segments (IS/OS) of the retinal photoreceptors are the areas that receive light signals and are the most initial sites for generating visual impulses, and the integrity of the IS/OS has a direct impact on visual sensitivity. METHODS: We performed OCT on a 6-year-old child with vision loss and found that the cause of his vision loss was a retinal IS/OS fracture, and the child underwent some treatments to improve microcirculation and nourish the retina at a higher-level hospital, but his vision never improved. Our examination of this child revealed that this child not only had decreased visual acuity, but also hypermetropia, but his near stereopsis was normal. The symptoms were similar to those of amblyopia, so we tried to use visual training as a treatment. RESULTS: First, 6 sessions of fine visual stimulation were given, followed by 3 sessions of accommodation training, and we followed the 4 stages of accommodation training: perception of accommodation, amplitude of accommodation, sensitivity of accommodation, and autonomic accommodation. After 9 consecutive visual training sessions, the child's visual acuity was stabilized at 0.6, and then we added eye movement training, and after the child's visual acuity was improved to 0.7, we suppressed the visual acuity of the left eye to 0.6, so as to make the visual acuity of both eyes similar, which would promote the establishment of binocular stereo vision, and then we carried out 9 more visual training sessions, and the patient's visual acuity was stabilized at 0.8 gradually. OCT review showed that the child's retinal IS/OS fracture was basically closed. CONCLUSION SUBSECTIONS: In conclusion, our study found that visual training can restore visual acuity in children with monocular IS/OS fracture and also promote repair of IS/OS fracture, which increases our understanding and knowledge of the treatment of retinal IS/OS fracture, and this case may provide some lessons for the treatment of retinal IS/OS fracture in children. We hope to have more samples of retinal IS/OS fracture in the future to evaluate the efficacy of visual training for retinal IS/OS fracture.

From convergence insufficiency to functional reorganization: A longitudinal randomized controlled trial of treatment-induced connectivity plasticity.

INTRODUCTION: Convergence Insufficiency (CI) is the most prevalent oculomotor dysfunction of binocular vision that negatively impacts quality of life when performing visual near tasks. Decreased resting-state functional connectivity (RSFC) is reported in the CI participants compared to binocularly normal control participants. Studies report that therapeutic interventions such as office-based vergence and accommodative therapy (OBVAT) can improve CI participants' clinical signs, visual symptoms, and task-related functional activity. However, longitudinal studies investigating the RSFC changes after such treatments in participants with CI have not been conducted. This study aimed to investigate the neural basis of OBVAT using RSFC in CI participants compared to the placebo treatment to understand how OBVAT improves visual function and symptoms. METHODS: A total of 51 CI participants between 18 and 35 years of age were included in the study and randomly allocated to receive either 12 one-hour sessions of OBVAT or placebo treatment for 6 to 8 weeks (1 to 2 sessions per week). Resting-state functional magnetic resonance imaging and clinical assessments were evaluated at baseline and outcome for each treatment group. Region of interest (ROI) analysis was conducted in nine ROIs of the oculomotor vergence network, including the following: cerebellar vermis (CV), frontal eye fields (FEF), supplementary eye fields (SEF), parietal eye fields (PEF), and primary visual cortices (V1). Paired t-tests assessed RSFC changes in each group. A linear regression analysis was conducted for significant ROI pairs in the group-level analysis for correlations with clinical measures. RESULTS: Paired t-test results showed increased RSFC in 10 ROI pairs after the OBVAT but not placebo treatment (p < 0.05, false discovery rate corrected). These ROI pairs included the following: Left (L)-SEF-Right (R)-V1, L-SEF-CV, R-SEF-R-PEF, R-SEF-L-V1, R-SEF-R-V1, R-SEF-CV, R-PEF-CV, L-V1-CV, R-V1-CV, and L-V1-R-V1. Significant correlations were observed between the RSFC strength of the R-SEF-R-PEF ROI pair and the following clinical visual function parameters: positive fusional vergence and near point of convergence (p < 0.05). CONCLUSION: OBVAT, but not placebo treatment, increased the RSFC in the ROIs of the oculomotor vergence network, which was correlated with the improvements in the clinical measures of the CI participants.

Case report: Topical pilocarpine ameliorated the accommodation loss and pupillary dilation after micropulse transscleral laser treatment.

BACKGROUND: The present study elucidates a common significant postoperative complication of micropulse transscleral laser treatment (mTLT) and explores its potential management strategies for younger patients with good central vision. CASE PRESENTATION: Three younger Chinese glaucoma patients with good central vision maintained high intraocular pressures (IOPs) (36, 25, and 30 mmHg) on maximally tolerated topical anti-glaucoma medications. All patients were treated with mTLT because of a higher risk of complications with filtering surgery. After the procedure, their best-corrected visual acuities were not significantly changed, IOPs were significantly decreased, and the number of topical anti-glaucoma medicines was gradually decreased. However, all patients complained about reduced near visual acuity (NVA) for 1-5 months. Slit-lamp examination revealed pupillary dilation, and binocular accommodative function examination indicated accommodation loss. After treatment with 2% topical pilocarpine, all patients reported an improvement in NVA. Among them, we could observe pupillary constriction, recovery of accommodation function, and improved NVA, even discontinuation of pilocarpine in Patient 2. CONCLUSION: In younger patients with good central vision, topical pilocarpine might ameliorate accommodation loss and pupillary dilation after mTLT.

Association of Accommodation and Convergence with Axial Length Elongation in Children with Basic Intermittent Exotropia: A 12-Month Observational Study.

INTRODUCTION: The aim of the study was to investigate the association of parameters related to accommodation and convergence and axial elongation in basic intermittent exotropia (IXT) patients and the potential clinical predictors of axial length (AL) growth. METHODS: A total of 140 basic IXT patients were recruited in this study. The medians of AL growth in different age brackets were chosen to divide the subjects into group A (slower axial elongation group, n = 69) and group B (faster axial elongation group, n = 71). Parameters of dominant and nondominant eyes were compared and analyzed during the 12-month follow-up period. The parameters, including baseline refraction, angle of deviation, Newcastle control score (NCS), accommodative amplitude (AMP), accommodative facility (AMF), accommodative response, positive or negative relative accommodation (PRA/NRA), and near point of convergence (NPC), were analyzed via univariate and multivariate regression. RESULTS: Subjects in the faster axial elongation group tended to have more myopic spherical equivalents (t = 3.956, p < 0.001), greater AMPs of dominant eyes (t = -2.238, p = 0.027), and fewer near points of convergence (t = 2.347, p = 0.020) than in the slower axial elongation group. For dominant eyes, logistic and linear regression analysis revealed that more negative spherical equivalents (OR = 0.603, p < 0.001; ß = -0.045, p < 0.001), greater AMPs (OR = 1.201, p = 0.027; ß = 0.023, p = 0.010), and less near points of convergence (OR = 0.883, p = 0.021; ß = -0.012, p = 0.019) were correlated with the faster axial elongation. For nondominant eyes, a more myopic spherical equivalent (OR = 0.682; p = 0.001; ß = -0.029, p = 0.005) was the only parameter correlated with faster axial elongation through regression analysis. CONCLUSION: In children with basic IXT, faster axial elongation in the dominant eyes was associated with more myopic spherical equivalents, greater AMPs, and lower NPCs. These accommodative parameters can serve as potential clinical indicators for monitoring myopia progression in addition to AL.

Distance stereopsis in patients with accommodative esotropia.

PURPOSE: We aimed to evaluate distance stereoacuity (DS) in patients with successfully treated accommodative esotropia (AET) and its association with other clinical factors. METHODS: The medical records of 176 children with refractive AET with a follow-up period ≥ 1 year were reviewed to identify a cohort of patients who achieved a stable alignment within 4 prism diopters (PD) of orthotropia at both distance and near fixation. Age of onset, duration of misalignment, uncorrected near and distance deviation, accommodative convergence/accommodation ratio, refractive error, presence of anisometropia and amblyopia, near stereopsis were evaluated as predictors of outcome. DS was measured using the Distance Randot Stereo test and near stereoacuity by Randot Stereotest. The patient group was compared with 50 age-matched normal controls for DS. RESULTS: Fifty-six patients were included, and 38 patients had DS at the final visit. All patients with DS attained uncontoured near stereopsis (UCNS). UCNS was present only in 11 patients without DS (p = 0.001). Anisometropia (p = 0.997), uncorrected near deviation (p = 0.224), distance deviation with correction (p = 0.255), and high hypermetropia (p = 0.998) were not associated with DS. The multivariable regression model showed a significant positive correlation between UCNS and DS (OR = 31.14 (95% CI 2.25-430.48); p = 0.01). Contoured near stereopsis outcome was significantly different between the patients with and without DS (p = 0.001 for animals and p = 0.003 for circles). Compared with the control group, the patient group yielded lower DS scores (p = 0.001). CONCLUSION: Distance Randot Stereotest can be useful in measuring binocular vision recovery after successful realignment in refractive AET patients. Patients attaining normal scores for near stereopsis tests after optical correction revealed subnormal thresholds for DS.

BCLA CLEAR presbyopia: Management with scleral techniques, lens softening, pharmaceutical and nutritional therapies.

The aging eye undergoes the same progressive crosslinking which occurs throughout the body, resulting in increased rigidity of ocular connective tissues including the lens and the sclera which impact ocular functions. This offers the potential for a scleral treatment that is based on restoring normal biomechanical movements. Laser Scleral Microporation is a laser therapy that evaporates fractional areas of crosslinked tissues in the sclera, reducing ocular rigidity over critical anatomical zones of the accommodation apparatus, restoring the natural dynamic range of focus of the eye. Although controversial and challenged, an alternative theory for presbyopia is Schachar's theory that suggests a reduction in the space between the ciliary processes and the crystalline lens. Widening of this space with expansion bands has been shown to aid near vision in people with presbyopia, a technique that has been used in the past but seems to be obsolete now. The use of drugs has been used in the treatment of presbyopia, either to cause pupil miosis to increase depth of focus, or an alteration in refractive error (to induce myopia in one eye to create monovision). Drugs and laser ablation of the crystalline lens have been used with the aim of softening the hardened lens. Poor nutrition and excess exposure to ultraviolet light have been implicated in the onset of presbyopia. Dietary nutritional supplements, lifestyle changes have also been shown to improve accommodation and the question arises whether these could be harnessed in a treatment for presbyopia as well.

Comparison between cycloplegic and noncycloplegic refraction in young adult myopes.

SIGNIFICANCE: This study explores the difference between cycloplegic and noncycloplegic refraction in young adult myopes. PURPOSE: From the available literature, it is unclear whether cycloplegia is necessary when refracting young adults. This study investigates the agreement between noncycloplegic autorefraction and cycloplegic autorefraction and investigates factors affecting the agreement between the two methods. METHODS: In total, 125 myopes with ages ranging between 18 and 26 years were included from Australia and Vietnam. Each participant underwent noncycloplegic autorefraction and cycloplegic autorefraction. Cycloplegia was induced with 1% ophthalmic tropicamide. RESULTS: The mean spherical equivalent difference (95% confidence interval) between noncycloplegic autorefraction and cycloplegic autorefraction was -0.20 D (-0.25 to -0.14 D; t124 = -7.18, p<0.0001 ) . A mean difference of >0.25 D was seen in 46.8% of eyes. The lower and upper limits of agreement were -0.80 and 0.41 D, respectively. With univariate analysis, factors including age, degree of refractive error, accommodation amplitude, and distance phorias showed no impact on the average difference between cycloplegic autorefraction and noncycloplegic autorefraction. Yet, eyes with near exophoria ( F2,120 = 6.63, p=0.0019) and Caucasian eyes ( F3,121 = 2.85, p=0.040) exhibited the smallest paired differences. However, in the multivariate analysis, only near exophoria was associated with a lower mean difference. A significantly smaller proportion (34.9%) of eyes with near exophoria had a paired difference of -0.25 D or more compared with esophoria (50%) and orthophoria (65%; χ2 = 6.6, p=0.038). CONCLUSIONS: Noncycloplegic autorefraction results in more myopic refractive error than cycloplegic autorefraction in young adults.

Adaptive Changes in Neurovascular Properties With Binocular Accommodation Functions in Myopic Participants by 3D Visual Training: An EEG and fNIRS Study.

Although three-dimensional visual training (3DVT) has been used for myopia intervention, its neural mechanisms remain largely unknown. In this study, visual function was examined before and after 3DVT, while resting-state EEG-fNIRS signals were recorded from 38 myopic participants. A graph theoretical analysis was applied to compute the neurovascular properties, including static brain networks (SBNs), dynamic brain networks (DBNs), and dynamic neurovascular coupling (DNC). Correlations between the changes in neurovascular properties and the changes in visual functions were calculated. After 3DVT, the local efficiency and node efficiency in the frontal lobes increased in the SBNs constructed from EEG δ -band; the global efficiency and node efficiency in the frontal-parietal lobes decreased in the DBNs variability constructed from EEG δ -band. For the DNC constructed with EEG α -band and oxyhemoglobin (HbO), the local efficiency decreased, for EEG α -band and deoxyhemoglobin (HbR), the node efficiency in the frontal-occipital lobes decreased. For the SBNs constructed from HbO, the functional connectivity (FC) between the frontal-occipital lobes increased. The DNC constructed between the FC of the frontal-parietal lobes from EEG ß -band and the FC of the frontal-occipital lobes from HbO increased, and between the FC of the frontal-occipital lobes from EEG ß -band and the FC of the inter-frontal lobes from HbR increased. The neurovascular properties were significantly correlated with the amplitude of accommodation and accommodative facility. The result indicated the positive effects of 3DVT on myopic participants, including improved efficiency of brain networks, increased FC of SBNs and DNC, and enhanced binocular accommodation functions.

BCLA CLEAR presbyopia: Management with intraocular lenses.

Cataract surgery including intraocular lens (IOL) insertion, has been refined extensively since the first such procedure by Sir Harold Ridley in 1949. The intentional creation of monovision with IOLs using monofocal IOL designs has been reported since 1984. The first reported implantation of multifocal IOLs was published in 1987. Since then, various refractive and or diffractive multifocal IOLs have been commercialised. Most are concentric, but segmented IOLs are also available. The most popular are trifocal designs (overlaying two diffractive patterns to achieve additional focal planes at intermediate and near distances) and extended depth of focus designs which leave the patient largely spectacle independent with the reduced risk of bothersome contrast reduction and glare. As well as mini-monovision, surgical strategies to minimise the impact of presbyopia with IOLs includes mixing and matching lenses between the eyes and using IOLs whose power can be adjusted post-implantation. Various IOL designs to mimic the accommodative process have been tried including hinge optics, dual optics, lateral shifts lenses with cubic-type surfaces, lens refilling and curvature changing approaches, but issues in maintaining the active mechanism with post-surgical fibrosis, without causing ocular inflammation, remain a challenge. With careful patient selection, satisfaction rates with IOLs to manage presbyopia are high and anatomical or physiological complications rates are no higher than with monofocal IOLs.

0.01% Atropine Eye Drops in Children With Myopia and Intermittent Exotropia: The AMIXT Randomized Clinical Trial.

Importance: Exotropia and myopia are commonly coexistent. However, evidence is limited regarding atropine interventions for myopia control in children with myopia and intermittent exotropia (IXT). Objective: To evaluate the efficacy and safety of 0.01% atropine eye drops on myopia progression, exotropia conditions, and binocular vision in individuals with myopia and IXT. Design, Setting, and Participants: This placebo-controlled, double-masked, randomized clinical trial was conducted from December 2020 to September 2023. Children aged 6 to 12 years with basic-type IXT and myopia of -0.50 to -6.00 diopters (D) after cycloplegic refraction in both eyes were enrolled. Intervention: Participants were randomly assigned in a 2:1 ratio to 0.01% atropine or placebo eye drops administered in both eyes once at night for 12 months. Main Outcomes and Measures: The primary outcome was change in cycloplegic spherical equivalent from baseline at 1 year. Secondary outcomes included change in axial length (AL), accommodative amplitude (AA), exotropia conditions, and binocular vision at 1 year. Results: Among 323 screened participants, 300 children (mean [SD] age, 9.1 [1.6] years; 152 male [50.7%]) were included in this study. A total of 200 children (66.7%) were in the atropine group, and 100 (33.3%) were in the placebo group. At 1 year, the 0.01% atropine group had slower spherical equivalent progression (-0.51 D vs -0.75 D; difference = 0.24 D; 95% CI, 0.11-0.37 D; P < .001) and AL elongation (0.31 mm vs 0.42 mm; difference = -0.11 mm; 95% CI, -0.17 to -0.06 mm; P < .001) than the placebo group. The mean AA change was -3.06 D vs 0.12 D (difference = -3.18 D; 95% CI, -3.92 to -2.44 D; P < .001) in the atropine and placebo groups, respectively. The 0.01% atropine group had a decrease in near magnitude of exodeviation whereas the placebo group had an increase (-1.25 prism diopters [PD] vs 0.74 PD; difference = -1.99 PD; 95% CI, -3.79 to -0.19 PD; P = .03). In the atropine vs placebo group, respectively, the incidence of study drug-related photophobia was 6.0% (12 of 200 participants) vs 8.0% (8 of 100 participants; difference = -2.0%; 95% CI, -9.4% to 3.7%; P = .51) and for blurred near vision was 6.0% (12 of 200 participants) vs 7.0% (7 of 100 participants) (difference = -1.0%; 95% CI, -8.2% to 4.5%; P = .74). Conclusions and Relevance: The findings of this randomized clinical trial support use of 0.01% atropine eye drops, although compromising AA to some extent, for slowing myopia progression without interfering with exotropia conditions or binocular vision in children with myopia and IXT. Trial Registration: Chinese Clinical Trial Registry Identifier: ChiCTR2000039827.

Choroidal vascularity index in patients with computer vision syndrome combined with accommodative lead.

BACKGROUND: This study aimed to investigate the choroidal vascularity index (CVI) in patients with computer vision syndrome (CVS) combined with accommodative lead. METHODS: This retrospective case-control study enrolled patients diagnosed with CVS and accommodative lead at University-Town Hospital of Chongqing Medical University between July 2022 and May 2023. The control group included individuals without any ocular diseases. Ophthalmic assessments included basic visual acuity, refraction, ocular biometric parameters, and CVI. RESULTS: A total of 85 participants were included in the study, with 45 in the CVS group and 40 in the control group. The central corneal thickness of CVS group was found to be significantly thinner compared to the control group in both the right eye (532.40±30.93 vs. 545.78±19.99 µm, P = 0.019) and left eye (533.96±29.57 vs. 547.56±20.39, P = 0.014). In comparison to the control group, the CVS group exhibited lower CVI in the superior (0.40±0.08 vs. 0.43±0.09, P = 0.001), temporal (0.40±0.08 vs. 0.44±0.10, P < 0.001), inferior (0.41±0.08 vs. 0.46±0.08, P < 0.001), and nasal (0.41±0.08 vs. 0.44±0.08, P = 0.001) quadrants. Similar differences were observed in all four quadrants within the 1-3 mm radius, and in the temporal (P = 0.004) and inferior (P = 0.002) quadrants within the 1-6 mm and 3-6 mm radii (all P < 0.05). CONCLUSION: Compared to individuals without ocular issues, patients with CVS and accommodative lead were found to have thinner corneal central thickness and lower CVI.

[Q-value-guided femtosecond laser-assisted in situ keratomileusis for low-to-moderate myopia with age-related accommodation deficiency].

Objective: To evaluate clinical outcomes and visual quality after femtosecond laser-assisted in situ keratomileusis (FS-LASIK) performed with the Q-value-guided optimized monocular vision protocol (Custom-Q) for correction of low-to-moderate myopia and compensation for age-related accommodation deficiency. Methods: A prospective study was performed based on patients with myopia and age-related accommodation deficiency, who underwent Custom-Q FS-LASIK in the Peking University Third Hospital from October 2022 to October 2023. Monocular and binocular distance, intermediate, and near visual acuities, simulated whole-course visual acuity (binocular defocus curve), objective and subjective refractions, anterior corneal Q factor, anterior corneal higher-order aberrations and a subjective questionnaire assessing near visual acuity and visual quality were evaluated at 3 months postoperatively. Visual acuity was recorded using the logarithm of the minimum angle of resolution. The data were analyzed using the t-test and the Wilcoxon rank-sum test. Results: A total of 45 patients (90 eyes) who met the inclusion criteria and completed the 3-month follow-up were included in the study. The mean age of the 21 men (42 eyes) and 24 women (48 eyes) was (42.82±2.72) years. During the 3-month follow-up, all the patients achieved binocular uncorrected distance visual acuity not less than 0.00 and uncorrected near visual acuity not less than 0.20. Defocus curves revealed better results at 3 months postoperatively [0.00 (-0.08, 0.00), -0.08 (-0.08, 0.00)] at intermediate and near vergence (-1.50 to -1.00 D) compared to the preoperative values [0.00 (-0.08, 0.05), -0.08 (-0.08, 0.00)] (P<0.05). All the 45 patients maintained 0.10 or better vision at the defocus range from -2.50 to 0.00 D. The Q value in the dominant eyes was more positive postoperatively (0.01±0.26 vs.-0.15±0.14, P<0.05), while in the nondominant eyes, the Q value and corneal spherical aberration coefficient became more negative than those before surgery (-0.27±0.32 vs.-0.14±0.11, P<0.05; 0.08±0.05 vs. 0.12±0.03, P<0.05). The questionnaire demonstrated 42 (93.3%) patients were satisfied with near vision. The three most commonly reported visual discomforts after surgery were blurred vision, glare and halos. These symptoms were all mild to moderate in severity and did not interfere with daily life. Conclusion: For myopic patients with age-related accommodation deficiency, the Custom-Q algorithm proved to be a safe and effective way to achieve acceptable near vision and visual quality without compromising distance vision.

Autostereoscopic 3D viewing can change the dimensions of the crystalline lens in myopes.

PURPOSE: Autostereoscopic displays have become increasingly common, but their impact on ocular dimensions remains unknown. We sought to identify changes in the crystalline lens dimensions induced by autostereoscopic three-dimensional (3D) viewing. METHODS: Forty young adults (age: 22.6 ± 2.0 years, male/female: 15/25) were consecutively enrolled and randomly divided into two groups (3D and two-dimensional [2D] viewing groups) to watch a 30-min movie clip displayed in 3D or 2D mode on a tablet computer. The lens thickness (LT), diameter, curvature, decentration and tilt were measured with anterior segment optical coherence tomography under both non-accommodating (static) and accommodating conditions. RESULTS: In the static condition, the LT decreased by 0.03 ± 0.03 mm (p < 0.001) and the anterior radius of curvature (ARC) increased by 0.49 ± 0.59 mm (p = 0.001) post-3D viewing. In contrast, following 2D viewing, the ARC decreased by 0.23 ± 0.25 mm (p = 0.001). Additionally, the increase in the steep ARC post-3D viewing was greater in high-myopic eyes than low to moderate myopic eyes (p = 0.04). When comparing the accommodative with the static (non-accommodative) condition, for 3D viewing the lens decentration decreased (-0.03 ± 0.05 mm, p = 0.02); while for 2D viewing, the posterior curvature radius (-0.14 ± 0.20 mm, p = 0.006) and diameter (-0.13 ± 0.20 mm, p = 0.01) decreased. CONCLUSIONS: Viewing with the autostereoscopic 3D tablet could temporally decrease the thickness and curvature of the lens under non-accommodating conditions. However, its long-term effect requires further exploration.

Wavefront Changes during a Sustained Reading Task in Presbyopic Eyes.

The objective of this study was to assess the effect of sustained reading on the temporal changes in the wavefront error in the presbyopic eye. The wavefront aberration of the eyes was measured using an IRX3 Shack-Hartmann aberrometer before and after (immediately, 5 min, and 10 min after) a reading task. Temporal changes in C20, C40, and C3-1 coefficient values of the eyes were plotted, showing a predominant number of V-shaped patterns (for C40 and C3-1) and inverse V-shaped patterns (for C20) among the study group, and the percentages (between 27 and 73%) were reported. The median of the total RMS of aberrations and the RMS of HOA (higher-order aberrations), which included comatic (3rd order) and spherical-like aberrations (4th and 6th order), increased immediately after finishing the near-vision reading task and then decreased. The median of RMS of comatic aberrations had a similar pattern of variations, while the median of RMS of spherical-like aberrations displayed an opposite pattern. Simulating the aberration changes due to lens decentration caused by relaxed zonules during 4 D accommodation in an eye model demonstrated that the expected range of changes for the vertical coma and spherical aberrations are in the order of 0.001 and 0.01 µm, respectively, which could justify why the observed changes were not statistically significant. The observed dynamic changes in HOA might be linked to the biomechanical characteristics and alterations in the displacement of the crystalline lens following prolonged near-vision tasks in presbyopic people. Although some predominant patterns under some conditions were shown, they exhibit considerable inter-subject and inter-ocular variability. This might be due to slight misalignments while fixating on the internal extended object in the aberrometer.

Diagnostic Protocol for Accommodative and Vergence Anomalies - A Review.

PURPOSE: To review the diagnostic protocols of non-strabismic binocular vision anomalies. METHODS: We carried out a literature search on published articles of non-strabismic accommodative and vergence anomalies in different international optometry and ophthalmology journals found in the Pubmed, ResearchGate, Google Scholar, and MEDLINE databases. RESULTS: The diagnostic criteria and normative data from the nine articles selected show discrepancies and variability in methodologies and techniques in the overall assessment of Non-Strabismic Binocular Vision Anomalies (NSBVA). Near point of convergence measurement is the most common assessment, whereas the vergence facility is the least commonly used assessment in terms of evaluating convergence insufficiency. Near point of convergence > 10 cm alone is the most sensitive sign to detect convergence insufficiency in a community set-up but high positive relative accommodation (>3.50D) is the most sensitive sign to diagnose accommodative excess. On the other hand, monocular accommodative facility < 7 CPM has the highest sensitivity to confirm the diagnosis of accommodative infacility. This review also indicates that the more clinical signs that are included in a set of diagnostic criteria, the lower the prevalence rate for that diagnosis. CONCLUSIONS: There is no standardized and diagnostically validated protocol for the assessment of NSBVAs. Variable cutoff values obtained using different methods and the selection of diagnostic criteria by various researchers have led to discrepancies that highlight the need for diagnostic validity of available protocols (combination of tests) for each anomaly. Clinical signs such as positive relative accommodation (PRA) for accommodative excess, near point of convergence (NPC) for convergence insufficiency and monocular accommodative facility (MAF) for accommodative infacility were found to be useful diagnostic signs of these anomalies. Studies should be carried out for accommodative and vergence dysfunctions using proper designs and methods to validate diagnostic criteria for all age groups. Standardization of assessment protocol and cutoff criteria will also aid in calculating prevalence for non-strabismic binocular vision anomalies.

Factors influencing the therapeutic effect of hyperopic correction on esotropia in patients with partially accommodative esotropia.

OBJECTIVES: To collate data on partially accommodative esotropia (PAET) to better understand this condition's aetiology and to evaluate and predict the therapeutic effect of a hyperopic correction on PAET. METHODS: Eighty-nine consecutive patients diagnosed with PAET with a spherical equivalent (SE) refractive error >+2.50 D were included in this retrospective review. Clinical characteristics, including gender, age, SE, angle of esodeviation, accommodative convergence/accommodation (AC/A) ratio, near-distance disparity (NDD) and anatomical features of the rectus muscles were compared among different PAET subgroups. Multiple linear regression was used to identify independent factors that influenced the therapeutic effect of a hyperopic correction on esotropia. RESULTS: No significant differences were observed for the angle of esodeviation as a function of age in individuals with PAET. The incidence of SE in PAET participants >9 years old was significantly greater than in those <5 and 6-8 years of age. The therapeutic effect of hyperopic correction on esotropia was positively associated with SE both at distance and near. In addition, the limbus insertion distance (LID) of the lateral rectus (LR) muscle was positively associated with NDD at distance, but negatively associated at near. CONCLUSION: A greater incidence of hyperopia was observed in older (>9 years old) PAET patients. A hyperopic correction had a greater effect on esotropia in individuals with a higher SE, larger LID of the LR muscle and a smaller NDD.