Horizontal Phoria Research Articles

Visual Performance of Two Designs of Myopia Management Soft Contact Lenses Compared with a Monofocal One in Young Adults.

To compare the visual performance of two distinct types of soft contact lenses (CL) aimed at slowing down myopia progression with the performance of a monofocal soft CL. In a prospective double-masked, crossover trial, 18 myopic adults (aged 18-30 years old) were fitted in a randomized order with three types of disposable CL: MiSight (dual-focus), Mylo (extended depth of focus -EDOF-), and Clariti (single distance vision). Measurements were taken after wearing the CL for five days with five days off in between at two different optometry centers. High contrast distance visual acuity (VA) with spectacles and for each of the different CL, subjective refraction, slit lamp exam, aberrometry, stereopsis, monocular and binocular amplitude of accommodation and accommodative facility, and horizontal phorias were measured. The high contrast distance VAwas better for the single vision CL compared to the myopia control CL. No significant differences were observed between the r two myopia control CL. The overall root mean square (RMS) was higher for the double focus CL (RMS = 1.18 0.29 µm), followed by the EDOF CL (RMS = 0.76 0.35 µm) and then the single vision CL (RMS = 0.50 0.19 µm). The primary spherical aberration (SA) mean value was low for all of the three CL, without statistical differences among them. No other significant differences were detected. The overall RMS resulted in a higher value for the dual-focus than the EDOF CL, but no differences in high contrast distance VA and binocularity were detected between them. The monofocal CL's performance was better than the myopia control CL.

Altered Large-Scale Resting-State Functional Network Connectivity in Convergence Insufficiency Young Adults Compared With Binocularly Normal Controls.

To investigate the underlying resting-state functional connectivity (RSFC) of symptomatic convergence insufficiency (CI) compared with binocularly normal controls (BNC) using functional magnetic resonance imaging (fMRI) under The Convergence Insufficiency Neuro‑mechanism Adult Population Study (NCT03593031). A total of 101 participants were eligible for this study. After removing datasets with motion artifacts, 49 CI and 47 BNC resting-state functional magnetic resonance imaging datasets were analyzed. CI was diagnosed with the following signs: (1) receded near point of convergence of 6 cm or greater, (2) decreased positive fusional vergence of less than 15∆ or failing Sheard's criteria of twice the near phoria, (3) near phoria of at least 4∆ more exophoric compared with the distance phoria, and (4) symptoms using the Convergence Insufficiency Symptom Survey (score of ≥21). RSFC was assessed using a group-level independent components analysis and dual regression. A behavioral correlation analysis using linear regression method was performed between clinical measures and RSFC using the significant difference between the CI and BNC. On average, a decreased RSFC was observed within the frontoparietal network, default mode network and visual network in patients with CI, compared with the participants with BNC (P < 0.05, corrected for multiple comparisons). The default mode network RSFC strength was significantly correlated with the PFV, near point of convergence, and difference between the horizontal phoria at near compared with far (P < 0.05). Results support altered RSFC in patients with CI compared with participants with BNC and suggest that these differences in underlying neurophysiology may in part be in connection with the differences in optometric visual function used to diagnose CI.

Reliability and Agreement of an Integrated Platform for Intelligent Visual Function Measurement.

Phoropters are widely accepted for clinical use in refraction examination and visual function assessment. This study assessed the reliability of the new Inspection Platform of Visual Function (IPVF) in comparison with the conventional equipment phoropter (TOPCON VT-10) in visual function assessment. This prospective study enrolled 80 eyes of 80 healthy subjects. The horizontal phoria at distance and near (Phoria_D and Phoria_N, respectively) was measured with the von Graefe method, negative/positive relative accommodation (NRA/PRA) was measured with the positive/negative lens method, and accommodative amplitude (AMP) was measured with the minus lens method. Data of three consecutive measurements with each instrument were evaluated using the intraclass correlation coefficient (ICC) for repeatability, and the agreement of the two instruments was evaluated using a Bland-Altman plot. The ICCs of the three consecutive measurements for phoria, NRA/PRA, and AMP using the IPVF instrument were high (0.87-0.96), indicating high repeatability. The ICCs of the three consecutive measurements using the phoropter were high (0.914-0.983) for phoria, NRA, and AMP, indicating high repeatability, while that of PRA was 0.732 (between 0.4 and 0.75), indicating acceptable repeatability. The 95% limits of agreement of phoria, NRA/PRA, and AMP were narrow, indicating good agreement between the two instruments. The repeatability of both instruments was high, and the IPVF instrument was slightly better in terms of PRA repeatability than the phoropter. The agreement of phoria, NRA/PRA, and AMP measured by the new IPVF instrument and phoropter was also satisfactory.

Extended perceptive field revealed in humans with binocular fusion disorders

Binocular vision disorders or dysfunctions have considerable impact on daily visual activities such as reading. Heterophoria (phoria) is a latent eye misalignment (with a prevalence of up to 35%) that appears in conditions that disrupt binocular vision and it may affect the quality of binocular fusion. Our recent study, which used lateral masking (LM), suggests that subjects with binocular fusion disorders (horizontal phoria) exhibit an asymmetry and an abnormal pattern of both binocular and monocular lateral interactions, but only for the horizontal meridian (HM). The perceptive field (PF) is the fundamental processing unit of human vision and both masking and crowding depend on its size. An increased PF size is found in amblyopic populations or in young children. We hypothesized that the PF’s size would be asymmetric only for the phoric group (larger along the HM). We estimated the PF’s size using two different methods (LM with equal-phase and opposite-phase flankers). Phoric subjects exhibited a larger binocular PF size, only for the HM, confirming our hypothesis of an asymmetric PF size. However, the monocular PF size of phoric and control subjects was similar. Phoria affects the PF’s size similarly to meridional amblyopia but without being attributed to abnormal refraction. We suggest that these findings could help explain the inter-observer variability found in the masking literature and the reading difficulties often encountered in subjects with high heterophoria. Since perceptual learning can reduce the PF’s size, further investigation of training may provide a novel therapy to reduce some symptoms related to heterophoria.

Transient change in the binocular visual function after femtosecond laser-assisted in situ keratomileusis for myopia patients.

The goal of this study was to compare the difference in binocular visual function for high and low-moderate myopes before and after femtosecond laser-assisted in situ keratomileusis (FS-LASIK). Thirty-three subjects (17 males and 16 females) were divided into two groups according to their preoperative refractive errors in spherical equivalent (SE): low-moderate myopia group (SE ≥-6.00 D) and high myopia group (SE <-6.00 D). The binocular visual function including accommodative amplitude (AA), accommodative facility (AF), positive and negative relative accommodation (PRA and NRA, respectively), horizontal phoria measurement, positive and negative fusion vergence, accommodative-convergence over accommodation (AC/A) ratio, and stereopsis were assessed with the best-corrected vision before patients received FS-LASIK and 7 and 30 days after the surgery. Repeated measures analysis of variance (ANOVA) was applied to study the change in binocular visual function. The AF values in both groups were significantly reduced after 7 days of FS-LASIK (baseline vs. day 7 (mean): high myopia group: 7.85 vs. 5.62 cpm, repeated ANOVA, P = 0.01; low-moderate myopia group: 5.95 vs. 4.40 cpm, repeated ANOVA, P = 0.04). This change returned to the baseline level 30 days after the operation. In addition, the horizontal phoria values in both groups were significantly reduced for both distant (P = 0.019 and P = 0.001, respectively) and near (P = 0.003 and P = 0.049, respectively) 7 days after the operation, but they rebound to preoperative state after 30 days. A transient change in binocular visual function was noticed after 7 days of FS-LASIK operation, which could cause symptoms of asthenopia. Our data showed all the binocular visual functions returned to baseline level after 30 days of operation.

Accommodation and vergence function in children using atropine combined with orthokeratology

PurposeThis study aimed to evaluate binocular vision in terms of vergence and accommodative measurements in children treated with 0.01% atropine combined with orthokeratology (OK). MethodsThis was a prospective and randomized controlled clinical trial involving participants aged 8 to 12 years, with a spherical equivalent (SE) ranging from − 1.00 to − 6.00D. Participants were randomly divided into four groups: 1) a combination group using 0.01% atropine solution and OK lens; 2) an OK group using placebo solution and OK lens; 3) an atropine group using 0.01% atropine solution and wearing spectacles; and 4) a control group using placebo solution and wearing spectacles. Binocular vision was determined at baseline and at 3-month visits, with evaluations including horizontal phoria, fusional vergence, the accommodative convergence/accommodation (AC/A) ratio, accommodative lag, and accommodative amplitude (AA). The Wilcoxon signed-rank test was used to compare the changes in binocular vision in each group, and the Kruskal–Wallis test was used for comparisons of four groups. ResultsSixty-two participants completed the study. There was no significant difference in baseline refraction, accommodation or vergence measurements among the groups (all P > 0.05). Three months later, the accommodative lag significantly decreased in the OK group (P = 0.002) but remained unchanged in the other three groups (all P > 0.05). In addition, binocular accommodative facilities and positive relative accommodations increased in the combination and OK groups (both P < 0.05) but remained unchanged in the atropine and control groups (both P > 0.05). Only the participants with esophoria in the OK group had a significant decrease in esophoria (P = 0.008). Moreover, the changes in fusional vergence and AC/A did not significantly differ between the four groups (all P > 0.05). ConclusionAccommodative measurements changed similarly in the groups treated with OK. Changes in vergence measurements after treatment with 0.01% atropine were not significant.

Virtual reality-based vision therapy versus OBVAT in the treatment of convergence insufficiency, accommodative dysfunction: a pilot randomized controlled trial

BackgroundVirtual reality is being increasingly applied in vision therapy. However, the differences in effectiveness, optimal treatment cycle, and prognosis between virtual reality-based vision therapy and traditional therapies remain unknown. The purpose of this study was to compare the effectiveness of virtual reality-based vision therapy and office-based vergence/accommodative therapy in young adults with convergence insufficiency or accommodative dysfunction.MethodsThe patients were randomly assigned to either the virtual reality-based vision therapy group or the office-based vergence/accommodative therapy group. The vision therapy lasted 12 weeks (1 h/week) in both groups. Binocular visual functions (vergence and accommodation) were measured and a subjective questionnaire-based assessment was performed at baseline and after 6 and 12 weeks of therapy.ResultsIn total, 33 patients with convergence insufficiency and 30 with accommodative dysfunction completed the study. After 12 weeks of treatment for convergence insufficiency, the Convergence Insufficiency Symptom Survey score (F2,31 = 13.704, P < 0.001), near point of convergence (F2,31 = 21.774, P < 0.001), positive fusional vergence (F2,31 = 71.766, P < 0.001), and near horizontal phoria (F2,31 = 16.482, P < 0.001) improved significantly in both groups. Moreover, the monocular accommodative amplitude (F2,25 = 22.154, P < 0.001) and monocular accommodative facility (F2,25 = 86.164, P < 0.001) improved significantly in both groups after 12 weeks of treatment. A statistically significant difference was observed in monocular accommodative facility (F1,25 = 8.140, P = 0.009) between the two groups, but not in other vergence and accommodative functions (0.098 < P < 0.687).ConclusionVirtual reality-based vision therapy significantly improved binocular vision functions and symptoms in patients with convergence insufficiency and accommodative dysfunction, thereby suggesting its effectiveness as a new optional or additional treatment for young adults with these conditions.Trial registrationThis study was registered at the Chinese Clinical Trials Registry on 16/04/2019 (identifier: ChiCTR1900022556).

The effect of concentric and aspheric multifocal soft contact lenses on binocular vision in young adult myopes

PurposeMultifocal soft contact lenses (MFCLs) are prescribed to inhibit myopia progression; these include aspheric and concentric designs. The effects of MFCLs on visual quality, accommodation and vergence in young-adult myopes were evaluated. MethodsParticipants were twenty-six myopes (19–25 years, spherical equivalent −0.50 to −5.75D), with normal binocular vision and no past myopia control. Pupil sizes were 4.4 ± 0.9 mm during distance viewing and 3.7 ± 0.8 mm at near. In random order, participants wore four MFCLs: Proclear single vision distance, MiSight concentric dual focus (+2.00D), distance center aspheric (Biofinity, +2.50D) (CooperVision lenses), and NaturalVue aspheric (Visioneering Technologies). Testing included visual acuity, contrast sensitivity (Pelli-Robson), stereoacuity, accommodation response, negative and positive relative accommodation, horizontal phorias, horizontal fusional vergence and AC/A ratio, and a visual quality questionnaire. ResultsThe four lenses differed in distance (p = 0.001) and near visual acuity (p = 0.011), and contrast sensitivity (p = 0.001). Compared with the single vision lens, the Biofinity aspheric had the greatest visual impact: 0.19 ± 0.14 logMAR distance acuity reduction, 0.22 ± 0.15 log contrast sensitivity reduction. Near acuity was affected less than distance acuity; the reduction was greatest with the NaturalVue (0.05 ± 0.07 logMAR reduction). The MFCLs altered the autorefraction measure at distance and near (p = 0.001); the accommodation response was less with aspheric lenses. Negative relative accommodation reduced with the aspheric lenses (p = 0.001): by 0.9 ± 0.5D with Biofinity and 0.5 ± 0.7D with NaturalVue. Exophoric shifts were greater with aspheric lenses (1.8 ± 2.4Δ Biofinity, 1.7 ± 1.7Δ NaturalVue) than with the concentric MiSight (0.5 ± 1.3Δ). ConclusionsMFCLs alter visual performance, refraction and vergence; two aspheric lenses had greater effect than a concentric lens.

The relationship between vision and simulated remote vision system air refueling performance

United States Air Force (USAF) vision tests have largely remained unchanged since WWII and therefore, it is unclear whether current standards are applicable for users of new humane-machine interfaces (e.g., stereoscopic remote vision system (RVS) in the KC-46 refueling tanker). This study examined the relationships between a range of early vision assessments, including Operational Based Vision Assessment (OBVA) lab-developed tests, an electronic version of the standard Titmus test, and the current Armed Forces Vision Tester (AFVT), and air refueling task performance using a stereoscopic RVS. Additionally, the relationships of these vision test scores to operationally-relevant subjective measures of visual fatigue were assessed. Results showed that OBVA measures of disparity discrimination, horizontal fusion, and horizontal phoria correlated with air refueling performance. OBVA measures of acuity, contrast sensitivity, disparity discrimination, and radial motion sensitivity were significantly associated with subjective measures of discomfort and visual fatigue. Notably, neither the electronic Titmus results, nor the AFVT measures were not associated with either air refueling task performance or subjective measures of discomfort and visual fatigue. Adjustments to the vision standards and test methods used for USAF aeromedical vision screening should therefore be considered.

Assessment of types of phorias in myopic patients before and after refractive correction

Purpose: To assess the types of phorias in different degrees of myopic patients and different age groups before and after refractive correction. Study design: Descriptive cross-sectional study. Material and methods: This was a comparative cross-sectional study that included 100 patients. Types of phorias in myopic patients were assessed before and after refractive correction. Patients involved are 15-35 years of age groups. Data was collected from the University of Lahore Teaching Hospital. Results: A total of 100 subjects were participated out of which 52% were males and 48% were females. 38% were 15-20 years, 42% were 21-25 years, 9% were 26-30 years, and 11% of participants were31-35 years of age. Visual acuity before the correction of refractive error was also recorded 42% of participants were observed with 6/6-6/12 visual acuity, 6/18-6/36 visual acuity was reported in 42% subjects and 16% subjects had &lt;6/60 visual acuity. After the correction of myopic error 87% subjects had 6/6-6/12 and 13% subjects had 6/18-6/36 best corrected visual acuity. Degree of myopia was recorded mild in 42% participants, moderate in 42% subjects and severe in 16% subjects. Before the correction of myopia 21% participants were observed with esophoria, 54% had exophoria and 25% subjects were orthophoric. After refractive correction 13% participants were esophoric, 28% were exophoric and 59% were orthophoric while measuring horizontal phoria at distance. In vertical phoria before correction 14% participants were hyperphoria, 1% were hypophoria and 85% were orthophoric. After best correction 5% participants were recorded as hyperphoria, 1% were hypophoria and 94% were orthophoric. Conclusion: Horizontal and vertical phorias were evaluated at distance with Maddox rod. It is concluded that after correction the frequency of horizontal phorias is high than vertical phorias. In horizontal phorias exophoric pattern has significant frequency. Exophoria can also result due to weak fusional reserves. Fusional convergence eliminates the disparity of retinal images and maintain exophoria in myopic patients. So, convergence weakness and excess of divergence leads to exophoria in myopic patients. Mostly exophoric participants are reported from age range of 15 to 20 years. After refraction if patient still have asthenopia symptoms proper evaluation and management should be made for latent squint. By treating and managing the latent squint the chances of phorias to convert in manifest squint will be minimize.

Deterioration of binocular vision after alcohol intake influences driving performance

In this study, we assessed the influence of moderate alcohol intake on binocular vision, vergence system and simulated driving performance by analyzing the interactions between visual deterioration and driving variables. Thirty young healthy subjects were recruited. For the analysis, we measured: visual function (visual acuity and stereoacuity), phorias and fusional reserves. Also, we checked Sheard’s and Percival’s criteria at near and far. The accommodative convergence/accommodation (AC/A) ratio was calculated and vergence facility was also obtained at near. A driving simulator was used to assess driving performance under natural conditions and after alcohol consumption with a breath alcohol content of 0.40 mg/l. Alcohol intake significantly reduced binocular visual performance and vergence function, except for vertical phorias, horizontal phoria at near and Sheard’s and Percival’s criteria at near. Driving performance parameters also presented a statistically significant deterioration after alcohol consumption. A statistically significant correlation was found between the deterioration in overall visual function and overall driving performance, highlighting the influence of the visual deterioration on the driving performance. Moderate alcohol consumption impairs binocular visual and simulated driving performances, implying a greater safety hazard. In addition, deteriorations in binocular visual function and vergence correlated with simulated driving impairment, which indicates that the deterioration of binocular vision due to alcohol consumption affects driving, thus reducing road safety.

Comparison of Visual Performance according to the Design Difference of Simultaneous Vision Multifocal Contact Lenses for Presbyopia

Purpose : To compare the visual performance of myopic presbyopia with low addition after wearing center-near and center-distance simultaneous vision multifocal contact lenses Methods : Visual performance of 13 subjects (46.92±5.91 years) was evaluated for accommodative lag, stray light, stereoacuity, horizontal phoria, near vergence and subjective vision satisfaction after wearing center-near and center-distance simultaneous vision multifocal contact lenses, respectively. Results : There were no significant differences in accommodative lag, stray light, stereoscopic acuity, horizontal phoria, near vergence and subjective vision satisfaction between center-near and center-distance simultaneous vision multifocal contact lenses with low addition in myopic presbyopes. Conclusion : There were no significant differences in visual performance related to visual quality, accommodative and vergence response after wearing center-near and center-distance simultaneous vision multifocal contact lenses with low addition in myopic presbyopes. Therefore, it is thought that it can be useful as a reference when selecting multifocal contact lenses.

The effects of posterior chamber intraocular lens implantation on accommodative function in high myopia

Objective: To investigate the effects of implantable Collamer lens (ICL) with a central hole on the accommodative function of patients with high myopia at different ages after implantation. Methods: A retrospective cohort study was conducted on 75 patients (150 eyes, 23 men and 52 women) with high myopia who underwent ICL implantation in Department of Ophthalmology of First Affiliated Hospital of Army Medical University from January 2017 to December 2018. The age was (28.99±7.26) years (range, 18-48 years). Forty patients (80 eyes) aged 18-34 years were included in the younger group and 35 patients (70 eyes) aged 35-48 years were included in the elderly group. To compare the changes and differences of accommodative function between the two groups, the uncorrected visual acuity, best corrected visual acuity, spherical equivalent error, amplitude of accommodation (AMP), negative relative accommodation (NRA), positive relative accommodation, single and both eyes' accommodation of facility (AF), fused cross cylinder, near and far distance horizontal phoria, accommodative convergence/accommodation and visual satisfaction questionnaire before surgery and at 1, 3, 6 and 12 months after surgery were analyzed. ANOVA for repeated design, LSD, unpaired sample t-test, Paired t-test, Chi-square test and Fisher's exact test were used for data analyses. Results: At each time point before and after operation, there were significant differences between the two groups in the AMP (F=16.511, P<0.05). The AMP of the younger group increased from (8.88±2.27) D at baseline to (9.51±1.34) D at 12 months, while it was decreased in the elderly group from (7.67±2.36) D at baseline to (6.56±2.63) D at 12 months. The trend of changes was significantly different (F=15.044,P<0.05). The AMP of the elderly group was significantly lower than that of the younger group at all time points (F=47.678, P<0.05). The NRA of the younger group was better than that of the elderly group (F=13.459, P<0.05), but the NRA had no significant changes in both groups postoperatively (F=1.788, P=0.141). We could not find any significant changes of positive relative accommodation between two groups (F=1.447, P=0.233). The monocular and binocular AF of two groups was increased significantly after surgery (F=34.296, 21.839, P<0.05). The AF of the younger group was better than that of the elderly group (F=80.327, 43.08, P<0.05). The fused cross cylinder was improved from baseline (0.12±0.32) D to (0.38±0.49) D at 12 months (F=4.752, P<0.05), while the difference was not found in the younger group (F=2.110, P=0.151). We could not find any significant changes of accommodative convergence/accommodation between two groups (F=0.389, P=0.505) or in each group (F=1.049, P=0.309) preoperatively and at 1, 3, 6 and 12 months after surgery. Conclusions: ICL implantation is effective in the treatment of high myopia. The visual acuity, AMP, monocular and binocular AF may increase obviously. Big improvements in the accommodative function and high satisfaction of vision can be achieved, especially in younger patients. (Chin J Ophthalmol, 2021, 57: 113-121).

Comparison of near horizontal heterophoria tests in free space and with phoropter

Background: Measurements of phoria at near are important elements of the optometric assessment of binocular vision. It is important to know if different methods of measuring a phoria are interchangeable. This study was designed to compare phoria measures using in-phoropter (von Graefe) and in free space methods (Howell card). Methods: The study was conducted with 70 pre-presbyopic subjects, aged 23–35 years. Both near the von Graefe and near Howell card horizontal dissociated phorias along and with gradient +1.00 D and –1.00 D phorias were measured for each technique. Results: The mean values of the near dissociated phoria, for both test conditions (von Graefe and Howell card) showed a slight deviation in the two measures with von Graefe measures being generally more exophoric. The mean value of the phoropter phoria was 1.97 ∆ base-in and in free space, the value was 0.9 ∆ base-in. The phoropter phoria with the +1.00 D gradient was 5.24 ∆ base-in, and in free space, 2.73 ∆ base-in. Measurements of the phorometric phoria with a gradient of –1.00 D gave a mean of 0.42 ∆ base-out and 0.94 ∆ base-out in free space. The near phoria measures were significantly different for the basic near measure (p = 0.01) and for the +1.00 D gradient (p = 0.000002) but not for the –1.00 D measure (p = 0.36). Conclusion: The results of the differences in the near horizontal phoria in free space and in- phoropter were significantly different for the basic measure and for the +1.00 D gradient. The findings between the two methods of testing should therefore not be treated as equivalent or convertible. Each test method should have separate means and ranges established.

동체시력에 따른 입체시와 원거리 수평사위에 관한 연구

동체시력에 따른 입체시와 원거리 수평사위에 관한 연구

A study of Comparison and Analysis of the Distance Subjective Associated Phoria Measured with MKH Chart, Mallett Unit and Chart Projector Cross Test with a Central Fusion Lock

Purpose : This study was intended to compare and analyze the distance subjective horizontal associated phoria using different tests. Methods : Thirty five symptomatic subjects (based on a symptoms questionnaire) were participated in this study. Distance subjective horizontal associated phoria were measured with the MKH chart, mallett unit and chart projector cross test with a central fusion lock, and minimum stereoscopic angle was measured before and after correction of fixation disparity for those subjects. Results : Distance subjective horizontal associated phoria measured with different methods such as MKH chart, mallet unit and chart projector cross test with a central fusion lock was 0.99±0.50 Δ, 0.31±0.30 Δ and 0.52±0.46 Δ, respectively, showing that there were statistically significant differences between tests(F=23.002, p=0.000). The mean of minimum stereoscopic angle before correction of fixation disparity was 85.43±54.68″. Increased minimum stereoscopic angle after correction of fixation disparity by the MKH chart, the mallett unit and the chart projector cross test with a central fusion lock was 58.00±40.21″(t=4.280, p=0.000), 75.14±54.0 9″(t=3.111, p=0.000) and 69.14±50.66″(t=2.503, p=0.000) respectively, showing that there were statistically significant differences between tests. Conclusion : There was a significant difference in the correction values of fixation disparity according to the design of the target, and after correction of fixation disparity minimum stereoscopic angle was improved significantly in all targets. In this study, minimum stereoscopic angle was improved the most after correction of fixation disparity measured with MKH chart among three targets of different designs.

Binocular and accommodative function in the controlled randomized clinical trial MiSight® Assessment Study Spain (MASS).

To evaluate the binocular and accommodative function in children wearing dual focus (DF) MiSight® contact lenses (CLs) for myopia control compared with children wearing single-vision (SV) spectacles. This was a randomized, controlled clinical trial involving subjects aged 8 to 12, with myopia ranging from - 0.75 to - 4.00D and astigmatism < 1.00D, allocated to MiSight® study CLs group or control group wearing SV. Binocular and accommodative function was determined at baseline, 12-, and 24-month visits, assessed by the following sequence of tests: distance and near horizontal phoria, accommodative convergence/accommodation (AC/A) ratio, stereopsis, accommodative amplitude (AA), and accommodative response (AR) at 33, 25 and 20 cm. Seventy-four children completed the study: 41 in the CL group and 33 in the SV group. CLs group did not show any significant differences in binocular and accommodative measurements throughout the study. In control group, distance and near phoria, stereopsis, AC/A and AR at 20cm did not show any significant change, but AA, AR at 33cm and AR at 25 cm were greater at 24-month visit compared with baseline (p < 0.05). DF lenses do not change the binocular and accommodative function in children wearing dual focus CLs. NCT01917110.

Short-Term Adaptation of Accommodative Responses in Myopes Fitted With Multifocal Contact Lenses.

To investigate whether adaptation of accommodative responses occurred in non-presbyopic myopes fitted with four multifocal contact lens (MFCL) designs. Prospective, subject-masked clinical investigation comprising 40 experienced myopic lens wearers (18-25 years) fitted bilaterally with single-vision (SV) control lens (Air Optix Aqua [Alcon, Fort Worth, TX]) and randomized to two of four test MFCL (Proclear MFCL [Distance and Near] [CooperVision, Pleasanton, CA], Air Optix Aqua MFCL, Purevision MFCL [Bausch & Lomb, Rochester, NY]). Lenses were dispensed on a daily wear basis and worn for a minimum of 8 (maximum 14) days over three assessment visits, with a 1-week wash out between stages. Paraxial curvature matched spherical equivalent (M) was measured with lenses on eye using the BHVI-EyeMapper with an internal movable fixation target positioned at target vergences of +1.00 diopter (D) (fogging) and -2.00 to -5.00 in 1.00 D steps (accommodative stimuli). Accommodative facility was assessed by several flips of ±2.00 D/min (cycles/min) at 33 cm and horizontal phoria with a Howell phoria card at distance (3 m) and near (33 cm). For center-distance MFCL (Proclear D), the spherical equivalent (M) at all near vergences became significantly more negative at the follow-up visits compared with the dispensing visit (P<0.029). For all center-near MFCLs and SV lens, M remained invariant during the adaptation period, however (P≥0.267). At distance, M became significantly less minus with Air Optix Aqua MFCL over time (P=0.049). Accommodative facility increased over the three assessment visits for participants wearing Air Optix Aqua SV, Air Optix Aqua MFCL, and PureVision MFCL (P=0.003). Distance and near horizontal phoria remained stable over the three assessment visits for all lens types (P≥0.181). Adaptation differences were not consistently found for static accommodative measures gauged by M, as measured with lenses on eye, and phoria but were found in dynamic measures (facility), perhaps indicating some learning effects. Accommodative adaptation seems unlikely to occur with long-term MFCL in non-presbyopes.

Visual performance of myopia control soft contact lenses in non-presbyopic myopes.

PurposeTo compare the visual performance of soft contact lenses reported to reduce myopia progression.MethodsIn a double-blind, randomized, crossover trial, 30 non-presbyopic myopes wore MiSight™, center-distance Proclear® Multifocal (+2.00 D add), and two prototype lenses for 1 week each. High- and low-contrast visual acuities at 6 m, and 70 and 40 cm; stereopsis at 40 cm; accommodative facility at 33 cm; and horizontal phoria at 3 m and 33 cm were measured after 1 week. Subjective performance was assessed on a numeric rating scale for vision clarity, lack of ghosting, vision stability, haloes, overall vision satisfaction, and ocular comfort. Frequency of eye-strain symptoms and willingness to purchase lenses were also reported with categorical responses. Participants reported wearing times (total and visually acceptable). Linear mixed models and chi-square tests were employed in analysis with level of significance set at 5%. Theoretical optical performance of all lenses was assessed with schematic myopic model eyes (−1.00, −3.00, and −6.00 D) by comparing the slope of the edge spread function (ESF), an indicator for optical performance/resolution and the blur patch size of the line spread function, an indicator for contrast, between the lenses.ResultsProclear Multifocal and MiSight provided the best distance acuities. However, the prototype lenses were rated significantly higher for many subjective variables, and there were no subjective variables where commercial lenses were rated significantly higher than the prototypes. Theoretical optical performance showed steeper slopes of the ESF and greater blur patch sizes of the LSP with commercial lenses, supporting the clinical findings of better visual acuities but reduced subjective performance. Participants wore prototypes longer and reported their vision acceptable for longer each day compared to MiSight. Both prototypes had the highest willingness-to-purchase rate.ConclusionsThe prototypes were better tolerated by myopes compared to the commercial soft contact lenses currently used for slowing myopia progression.

Prevalence of esophoria in concussed patients

PurposeTo assess the prevalence of esophoria at near in concussed patients in a neuro-optometric private practice setting. MethodsA retrospective analysis was performed involving a chart review in a neuro-optometric, private practice setting of consecutive patients with a medical diagnosis of concussion from January 1st 2016 to December 31st 2016. A total of 71 patients were included in the analysis. All received a comprehensive vision examination, with a near vision emphasis. The near horizontal phoria was assessed with the cover test and the von Graefe test. ResultsApproximately 30% of the patients with a medically based diagnosis of concussion exhibited esophoria at near, with good agreement (95%) between the two tests. Mean esophoria was 5.2 (SD=2.8) prism diopters (pd), with a range from 2pd to 14pd of esophoria. Convergence excess was diagnosed in 23%. DiscussionNear esophoria was found in nearly one-third of this practice-based sample of concussed patients. Thus, it was more common than typically believed to be the case. Two proposed oculomotor-based mechanisms related to these symptomatic esophoric patients included phoria decompensation and excessive accommodative vergence.