Impact of accommodative insufficiency and accommodative/vergence therapy on ciliary muscle thickness in the eye.

PURPOSE: Recent evidence suggests that the ciliary muscle apical fibres are most responsive to accommodative load; however, the structure of the ciliary muscle in individuals with accommodative insufficiency is unknown. This study examined ciliary muscle structure in individuals with accommodative insufficiency (AI). We also determined the response of the ciliary muscle to accommodative/vergence therapy and increasing accommodative demands to investigate the muscle's responsiveness to workload. METHODS: Subjects with AI were enrolled and matched by age and refractive error with subjects enrolled in another ciliary muscle study as controls. Anterior segment optical coherence tomography was used to measure the ciliary muscle thickness (CMT) at rest (0D), maximum thickness (CMTMAX) and over the area from 0.75 mm (CMT0.75) to 3 mm (CMT3) posterior to the scleral spur of the right eye. For those with AI, the ciliary muscle was also measured at increasing levels of accommodative demand (2D, 4D and 6D), both before and after accommodative/vergence therapy. RESULTS: Sixteen subjects with AI (mean age = 17.4 years, SD = 8.0) were matched with 48 controls (mean age = 17.8 years, SD = 8.2). On average, the controls had 52-72 µm thicker ciliary muscles in the apical region at 0D than those with AI (p = 0.03 for both CMTMAX and CMT 0.75). Differences in thickness between the groups in other regions of the muscle were not statistically significant. After 8 weeks of accommodative/vergence therapy, the CMT increased by an average of 22-42 µm (p ≤ 0.04 for all), while AA increased by 7D (p < 0.001). CONCLUSIONS: This study demonstrated significantly thinner apical ciliary muscle thickness in those with AI and that the ciliary muscle can thicken in response to increased workload. This may explain the mechanism for improvement in signs and symptoms with accommodative/vergence therapy.

Maximal total population of species in a diffusive logistic model.

In this paper, we investigate the maximization of the total population of a single species which is governed by a stationary diffusive logistic equation with a fixed amount of resources. For large diffusivity, qualitative properties of the maximizers like symmetry will be addressed. Our results are in line with previous findings which assert that for large diffusion, concentrated resources are favorable for maximizing the total population. Then, an optimality condition for the maximizer is derived based upon rearrangement theory. We develop an efficient numerical algorithm applicable to domains with different geometries in order to compute the maximizer. It is established that the algorithm is convergent. Our numerical simulations give a real insight into the qualitative properties of the maximizer and also lead us to some conjectures about the maximizer.

Ciliary muscle thickness in adults with Down syndrome.

PURPOSE: The relationship between ciliary muscle thickness (CMT), age and refractive error was investigated to determine if CMT, like other anterior ocular anatomy, differs in adults with Down syndrome (DS). METHODS: The CMT of 33 adults with DS was imaged using anterior segment optical coherence tomography. Images from the right eye obtained 45 minutes after cycloplegia (1% tropicamide, 2.5% phenylephrine) were analysed to calculate thickness at 1, 2 and 3 mm posterior to the scleral spur (CMT1, CMT2, CMT3), maximum thickness (CMTMAX) and apical thickness (AT = CMT1 - CMT2). Spherical equivalent refractive error was determined by clinical refraction using both non-dilated and dilated measures. Multivariate regression analysis evaluated the relationship between CMT and refractive error while controlling for subject age. RESULTS: Images were analysed from 26 subjects (mean age (SD) 29 years; mean refractive error (SD): -0.90 (5.03) D, range: -15.75 to +5.13D). Mean (SD) CMT decreased with posterior position (CMT1: 804 (83) µm; CMT2: 543 (131) µm; CMT3: 312 (100) µm). Mean (SD) CMTMAX and AT was 869 (57) µm and 260 (84) µm, respectively. There was a significant linear correlation indicating thinning CMT with increasing age for CMT1 and CMT2 (p ≤0.05). CMT2 and CMT3 had a significant negative correlation (thicker muscle with increasing myopic refractive error) (p ≤0.01). AT had a significant positive correlation (thicker muscle with increasing hyperopic refractive error) (p <0.01). CONCLUSIONS: Ciliary muscle thickness in participants with DS was found to be in a similar range with similar refractive error trends to previous reports of individuals without DS. However, it is important to note that the refractive error trends were driven by individuals with moderate to high levels of myopia.

Geometric computation of human gyrification indexes from magnetic resonance images.

Human brains are highly convoluted surfaces with multiple folds. To characterize the complexity of these folds and their relationship with neurological and psychiatric conditions, different techniques have been developed to quantify the folding patterns, also known as the surface complexity or gyrification of the brain. In this study, the authors propose a new geometric approach to measure the gyrification of human brains from magnetic resonance images. This approach is based on intrinsic 3D measurements that relate the local brain surface area to the corresponding area of a tightly wrapped sheet. The authors also present an adaptation of this technique in which the geodesic depth is incorporated into the gyrification computation. These gyrification measures are efficiently and accurately computed by solving geometric partial differential equations. The presentation of the geometric framework is complemented with experimental results for brain complexity in typically developing children and adolescents. Using this novel approach, the authors provide evidence for a gradual decrease in brain surface complexity throughout childhood and adolescence. These developmental differences occur earlier in the occipital lobe and move anterior as children progress into young adulthood.

Ciliary muscle thickness in anisometropia.

PURPOSE: The purpose of this study was to investigate the relationships between ciliary muscle thickness (CMT), refractive error, and axial length both across subjects and between the more and less myopic eyes of adults with anisometropia. METHODS: Both eyes of 29 adult subjects with at least 1.00 D of anisometropia were measured. Ciliary muscle thickness was measured at the maximum thickness (CMTMAX) and at 1.0 (CMT1), 2.0 (CMT2), and 3.0 mm (CMT3) posterior to the scleral spur, and also at the apical region (Apical CMTMAX = CMTMAX - CMT2, and Apical CMT1 = CMT1 - CMT2). Multilevel regression models were used to determine the relationship between the various CMT measures and cycloplegic refractive error or axial length, and to assess whether there are CMT differences between the more and less myopic eyes of an anisometropic adult. RESULTS: CMTMAX, CMT1, CMT2, and CMT3 were negatively associated with mean refractive error (all p ≤ 0.03), and the strongest association was in the posterior region (CMT2 and CMT3). Apical CMTMAX and Apical CMT1, however, were positively associated with mean refractive error (both p < 0.0001) across subjects. Within a subject, i.e., comparing the two anisometropic eyes, there was no statistically significant difference in CMT in any region. CONCLUSIONS: Similar to previous studies, across anisometropic subjects, a thicker posterior region of the ciliary muscle (CMT2 and CMT3) was associated with increased myopic refractive error. Conversely, shorter, more hyperopic eyes tended to have thicker anterior, apical fiber portions of their ciliary muscle (Apical CMTMAX and Apical CMT1). There was no difference between the two eyes for any CMT measurement, indicating that in anisometropia, an eye can grow longer and more myopic than its fellow eye without resulting in an increase in CMT.

Propagation of cutaneous thermal injury: a mathematical model.

Cutaneous burn wounds represent a significant public health problem with 500,000 patients per year in the USA seeking medical attention. Immediately after skin burn injury, the volume of the wound burn expands due to a cascade of chemical reactions, including lipid peroxidation chain reactions. Such expansion threatens life and is therefore highly clinically significant. Based on these chemical reactions, the present paper develops for the first time a three-dimensional mathematical model to quantify the propagation of tissue damage within 12 hours post initial burn. We use the model to investigate the effect of supplemental antioxidant vitamin E for intercepting propagation. We show, for example, that if tissue levels of vitamin E tocotrienol are increased, postburn, by five times then this would slow down the lipid peroxide propagation by at least 50%. We chose the alpha-tocotrienol form of vitamin E as it is a potent inhibitor of 12-lipoxygenase, which is known to propagate oxidative lipid damage. Our model is formulated in terms of differential equations, and sensitivity analysis is performed on the parameters to ensure the robustness of the results.

The effect of phenylephrine on the ciliary muscle and accommodation.

PURPOSE: To objectively measure changes in the human ciliary muscle dimensions in vivo after instillation of topical phenylephrine, a mydriatic and vasodilating agent. METHODS: A cross-sectional study of 25 healthy young adults was conducted. Measurements of pupil size, accommodation, and ciliary muscle thickness were made both before and 30 min after instillation of 1% proparacaine and 2.5% phenylephrine. Accommodation was measured in three ways: subjectively using a push-up technique and Royal Air Force (RAF) rule, and objectively using both the Grand Seiko autorefractor and PowerRefractor. Images of the temporal ciliary muscle were acquired using the Visante Anterior Segment Optical Coherence Tomographer (OCT). Ciliary muscle images were objectively analyzed using a computer-based segmentation technique. RESULTS: Amplitude of accommodation using the push-up test was reduced by about 1 D with phenylephrine (p < 0.001). Phenylephrine did not change the accommodative response to a 4 D Badal target as measured by either autorefraction or photorefraction (p > 0.30). There was statistically significant thickening of the anterior region and thinning of the posterior region of the ciliary muscle with accommodation (p < 0.001, all locations). Phenylephrine did not affect either baseline ciliary muscle thickness or the accommodative contraction of the muscle (p > 0.09). CONCLUSIONS: Low-dose phenylephrine does not affect ciliary muscle dimensions, ciliary muscle contractility, or accommodative response to a 4 D near target.

Measuring changes in ciliary muscle thickness with accommodation in young adults.

PURPOSE: To develop a measurement protocol for changes in the shape and size of the ciliary muscle with accommodation using the Zeiss Visante™ anterior segment optical coherence tomography (AS-OCT) and to determine the test-retest repeatability of these measurements. METHODS: Subjects were 25 adults aged 23 to 28 years. The ciliary muscle was imaged at two visits with the Visante™ while accommodative response was monitored during imaging using the PowerRefractor. Ciliary muscle thickness (CMT) was measured at 1 mm (CMT1), 2 mm (CMT2), and 3 mm (CMT3) posterior to the scleral spur and at the point of maximal thickness (CMTMAX). Thickness was measured at these locations while subjects viewed a target at distance and at a 4.00 D accommodative stimulus. Outcome measures were the change in thickness between distance and the 4.00 D stimulus and the change in thickness per diopter of accommodative response (PowerRefractor). Finally, the repeatability measurements between visit 1 and visit 2 were determined with a Bland-Altman analysis. RESULTS: The statistically significant modeled changes in CMT were as follows: CMTMAX = 69.2 µm (4.00 D stimulus) and 18.1 µm (per diopter of accommodation); CMT1 = 45.2 µm (4.00 D stimulus) and 12.3 µm (per diopter of accommodation); and CMT3 = -45.9 µm (4.00 D stimulus) and -12.0 µm (per diopter of accommodation); p < 0.0001 for all. CONCLUSIONS: The combination of the Visante™ and the PowerRefractor is a feasible tool for measuring thickening of ciliary muscle at more anterior locations and thinning at more posterior locations during accommodation. We noted a wide range of accommodative responses during the time of image capture in this study indicating that the most accurate estimates of the change in ciliary muscle dimensions with accommodation may be obtained by using accommodative response rather than stimulus values and by using measurements taken simultaneously with image capture.

Changes in ciliary muscle thickness during accommodation in children.

PURPOSE: To investigate the morphology of the ciliary muscle during the act of accommodation in a population of children. METHODS: Thirty children aged 6 to 12 years were enrolled. Accommodative response was measured through habitual correction. Height was measured as a control variable. Central axial length was measured with the IOLMaster. Four images of the temporal ciliary muscle were taken with the Visante Optical Coherence Tomographer at three different stimulus levels (0, 4, and 6 D) while accommodative response was monitored concurrently with the PowerRefractor. Accommodative response monitoring was time-matched to ciliary muscle image capture, and the mean was calculated for 5 s surrounding this time point. Four cycloplegic images of the temporal ciliary muscle were also taken. Ciliary muscle thickness measurements were made at the point of maximum thickness (CMTMAX) and at 1 mm (CMT1), 2 mm (CMT2) and 3 mm (CMT3) posterior to the sclera spur. RESULTS: Increasing accommodative response was correlated with increases in the thickness of CMTMAX (p = <0.001) and CMT1 (p = <0.001) and decreases in the thickness of CMT3 (p = <0.001). Thicker values of CMTMAX under cycloplegic conditions were significantly correlated with values of CMTMAX (p = <0.001) and CMT1 (p = 0.001) while accommodating and approached significance in modeling CMT3 (p = 0.06). Mean axial length was correlated with the amount of thinning at CMT3 with accommodation (p = 0.002). Axial length was not significantly correlated with thickness values at CMTMAX (p = 0.7) or CMT1 (p = 0.6). CONCLUSIONS: In a manner similar to previous adult studies, ciliary muscle thickness at CMTMAX and CMT1 increased with accommodation and CMT3 thinned with accommodation. Further investigation is necessary to determine whether CMT2 is a "fulcrum" point along the length of the ciliary muscle where the net change with accommodation is always zero or whether that point varies across subjects or with varying levels of accommodative effort.

Modeling oxygen transport in surgical tissue transfer.

Reconstructive microsurgery is a clinical technique used to transfer large amounts of a patient's tissue from one location used to another in order to restore physical deformities caused by trauma, tumors, or congenital abnormalities. The trend in this field is to transfer tissue using increasingly smaller blood vessels, which decreases problems associated with tissue harvest but increases the possibility that blood supply to the transferred tissue may not be adequate for healing. It would thus be helpful to surgeons to understand the relationship between the tissue volume and blood vessel diameter to ensure success in these operations. As a first step towards addressing this question, we present a simple mathematical model that might be used to predict successful tissue transfer based on blood vessel diameter, tissue volume, and oxygen delivery.

Semiautomatic extraction algorithm for images of the ciliary muscle.

PURPOSE: To develop and evaluate a semiautomatic algorithm for segmentation and morphological assessment of the dimensions of the ciliary muscle in Visante Anterior Segment Optical Coherence Tomography images. METHODS: Geometric distortions in Visante images analyzed as binary files were assessed by imaging an optical flat and human donor tissue. The appropriate pixel/mm conversion factor to use for air (n = 1) was estimated by imaging calibration spheres. A semiautomatic algorithm was developed to extract the dimensions of the ciliary muscle from Visante images. Measurements were also made manually using Visante software calipers. Interclass correlation coefficients and Bland-Altman analyses were used to compare the methods. A multilevel model was fitted to estimate the variance of algorithm measurements that was due to differences within- and between-examiners in scleral spur selection vs. biological variability. RESULTS: The optical flat and the human donor tissue were imaged and appeared without geometric distortions in binary file format. Bland-Altman analyses revealed that caliper measurements tended to underestimate ciliary muscle thickness at 3 mm posterior to the scleral spur in subjects with the thickest ciliary muscles (t = 3.6, p < 0.001). The percent variance due to within- or between-examiner differences in scleral spur selection was found to be small (6%) when compared with the variance because of biological difference across subjects (80%). Using the mean of measurements from three images, achieved an estimated interclass correlation coefficient of 0.85. CONCLUSIONS: The semiautomatic algorithm successfully segmented the ciliary muscle for further measurement. Using the algorithm to follow the scleral curvature to locate more posterior measurements is critical to avoid underestimating thickness measurements. This semiautomatic algorithm will allow for repeatable, efficient, and masked ciliary muscle measurements in large datasets.

In Vivo Activity of Repurposed Amodiaquine as a Host-Targeting Therapy for the Treatment of Anthrax.

Anthrax is caused by Bacillus anthracis and can result in nearly 100% mortality due in part to anthrax toxin. Antimalarial amodiaquine (AQ) acts as a host-oriented inhibitor of anthrax toxin endocytosis. Here, we determined the pharmacokinetics and safety of AQ in mice, rabbits, and humans as well as the efficacy in the fly, mouse, and rabbit models of anthrax infection. In the therapeutic-intervention studies, AQ nearly doubled the survival of mice infected subcutaneously with a B. anthracis dose lethal to 60% of the animals (LD60). In rabbits challenged with 200 LD50 of aerosolized B. anthracis, AQ as a monotherapy delayed death, doubled the survival rate of infected animals that received a suboptimal amount of antibacterial levofloxacin, and reduced bacteremia and toxemia in tissues. Surprisingly, the anthrax efficacy of AQ relies on an additional host macrophage-directed antibacterial mechanism, which was validated in the toxin-independent Drosophila model of Bacillus infection. Lastly, a systematic literature review of the safety and pharmacokinetics of AQ in humans from over 2 000 published articles revealed that AQ is likely safe when taken as prescribed, and its pharmacokinetics predicts anthrax efficacy in humans. Our results support the future examination of AQ as adjunctive therapy for the prophylactic anthrax treatment.

The development of gyrification in childhood and adolescence.

Gyrification is the process by which the brain undergoes changes in surface morphology to create sulcal and gyral regions. The period of greatest development of brain gyrification is during the third trimester of pregnancy, a period of time in which the brain undergoes considerable growth. Little is known about changes in gyrification during childhood and adolescence, although considering the changes in gray matter volume and thickness during this time period, it is conceivable that alterations in the brain surface morphology could also occur during this period of development. The formation of gyri and sulci in the brain allows for compact wiring that promotes and enhances efficient neural processing. If cerebral function and form are linked through the organization of neural connectivity, then alterations in neural connectivity, i.e., synaptic pruning, may also alter the gyral and sulcal patterns of the brain. This paper reviews developmental theories of gyrification, computational techniques for measuring gyrification, and the potential interaction between gyrification and neuronal connectivity. We also present recent findings involving alterations in gyrification during childhood and adolescence.

Cell cycle control at the first restriction point and its effect on tissue growth.

Cell cycle is controlled at two restriction points, R (1) and R (2). At both points the cell will commit apoptosis if it detects irreparable damage. But at R (1) an undamaged cell also decides whether to proceed to the S phase or go into a quiescent mode, depending on the environmental conditions (e.g., overpopulation, hypoxia). We consider the effect of this decision at the population level in a spherical tissue {r < R(t)}. We prove that if the cells have full control at R (1), they can manipulate the size of R(t) to ensure that 0 < c

Accommodative Exercises to Lower Intraocular Pressure.

PURPOSE: This study investigated how a conscious change in ocular accommodation affects intraocular pressure (IOP) and ocular biometrics in healthy adult volunteers of different ages. METHODS: Thirty-five healthy volunteers without ocular disease or past ocular surgery, and with refractive error between -3.50 and +2.50 diopters, were stratified into 20, 40, and 60 year old (y.o.) age groups. Baseline measurements of central cornea thickness, anterior chamber depth, anterior chamber angle, cornea diameter, pupil size, and ciliary muscle thickness were made by autorefraction and optical coherence tomography (OCT), while IOP was measured by pneumotonometry. Each subject's right eye focused on a target 40 cm away. Three different tests were performed in random order: (1) 10 minutes of nonaccommodation (gazing at the target through lenses that allowed clear vision without accommodating), (2) 10 minutes of accommodation (addition of a minus 3 diopter lens), and (3) 10 minutes of alternating between accommodation and nonaccommodation (1-minute intervals). IOP was measured immediately after each test. A 20-minute rest period was provided between tests. Data from 31 subjects were included in the study. ANOVA and paired t-tests were used for statistical analyses. RESULTS: Following alternating accommodation, IOP decreased by 0.7 mmHg in the right eye when all age groups were combined (p = 0.029). Accommodation or nonaccommodation alone did not decrease IOP. Compared to the 20 y.o. group, the 60 y.o. group had a thicker ciliary muscle within 75 µm of the scleral spur, a thinner ciliary muscle at 125-300 µm from the scleral spur, narrower anterior chamber angles, shallower anterior chambers, and smaller pupils during accommodation and nonaccommodation (p's < 0.01). CONCLUSION: Alternating accommodation, but not constant accommodation, significantly decreased IOP. This effect was not lost with aging despite physical changes to the aging eye. A greater accommodative workload and/or longer test period may improve the effect.

Minimization of region-scalable fitting energy for image segmentation.

Intensity inhomogeneities often occur in real-world images and may cause considerable difficulties in image segmentation. In order to overcome the difficulties caused by intensity inhomogeneities, we propose a region-based active contour model that draws upon intensity information in local regions at a controllable scale. A data fitting energy is defined in terms of a contour and two fitting functions that locally approximate the image intensities on the two sides of the contour. This energy is then incorporated into a variational level set formulation with a level set regularization term, from which a curve evolution equation is derived for energy minimization. Due to a kernel function in the data fitting term, intensity information in local regions is extracted to guide the motion of the contour, which thereby enables our model to cope with intensity inhomogeneity. In addition, the regularity of the level set function is intrinsically preserved by the level set regularization term to ensure accurate computation and avoids expensive reinitialization of the evolving level set function. Experimental results for synthetic and real images show desirable performances of our method.

A geometric method for automatic extraction of sulcal fundi.

Sulcal fundi are 3-D curves that lie in the depths of the cerebral cortex and, in addition to their intrinsic value in brain research, are often used as landmarks for downstream computations in brain imaging. In this paper, we present a geometric algorithm that automatically extracts the sulcal fundi from magnetic resonance images and represents them as spline curves lying on the extracted triangular mesh representing the cortical surface. The input to our algorithm is a triangular mesh representation of an extracted cortical surface as computed by one of several available software packages for performing automated and semi-automated cortical surface extraction. Given this input we first compute a geometric depth measure for each triangle on the cortical surface mesh, and based on this information we extract sulcal regions by checking for connected regions exceeding a depth threshold. We then identify endpoints of each region and delineate the fundus by thinning the connected region while keeping the endpoints fixed. The curves, thus, defined are regularized using weighted splines on the surface mesh to yield high-quality representations of the sulcal fundi. We present the geometric framework and validate it with real data from human brains. Comparisons with expert-labeled sulcal fundi are part of this validation process.

White matter tractography by anisotropic wavefront evolution and diffusion tensor imaging.

Determination of axonal pathways provides an invaluable means to study the connectivity of the human brain and its functional network. Diffusion tensor imaging (DTI) is unique in its ability to capture the restricted diffusion of water molecules which can be used to infer the directionality of tissue components. In this paper, we introduce a white matter tractography method based on anisotropic wavefront propagation in diffusion tensor images. A front propagates in the white matter with a speed profile governed by the isocontour of the diffusion tensor ellipsoid. By using the ellipsoid, we avoid possible misclassification of the principal eigenvector in oblate regions. The wavefront evolution is described by an anisotropic version of the static Hamilton-Jacobi equation, which is solved by a sweeping method in order to obtain correct arrival times. Pathways of connection are determined by tracing minimum-cost trajectories using the characteristic vector field of the resulting partial differential equation. A validity index is described to rate the goodness of the resulting pathways with respect to the directionality of the tensor field. Connectivity results using normal human DTI brain images are illustrated and discussed. We also compared our method with a similar level set-based tractography technique, and found that the anisotropic evolution increased the validity index of the obtained pathways by 18%.

Gyrification differences in children and adolescents with velocardiofacial syndrome and attention-deficit/hyperactivity disorder: a pilot study.

We used magnetic resonance imaging to investigate brain gyrification patterns between 19 children with attention-deficit/hyperactivity disorder (ADHD), 9 children with velocardiofacial syndrome (VCFS), and 23 control children. We found that VCFS is associated with widespread decreases in gyrification. In ADHD, we found minor differences from control children. No evidence was found for common gyrification patterns between VCFS and ADHD children.

Region-specific relationships between refractive error and ciliary muscle thickness in children.

PURPOSE: To determine if there is a relationship between refractive error and ciliary muscle thickness in different muscle regions. METHODS: An anterior segment optical coherence tomographer was used to measure cycloplegic ciliary muscle thicknesses at 1 mm (CMT1), 2 mm (CMT2), and 3 mm (CMT3) posterior to the scleral spur; maximum (CMTMAX) thickness was also assessed. An autorefractor was used to determine cycloplegic spherical equivalent refractive error (SPHEQ). Apical ciliary muscle fibers were obtained by subtracting corresponding CMT2 values from CMT1 and CMTMAX. Multilevel regression models were used to determine the relationship between ciliary muscle thickness in various regions of the muscle and refractive error. RESULTS: Subjects included 269 children with a mean age of 8.71 ± 1.51 years and a mean refractive error of +0.41 ± 1.29 diopters. In linear models with ciliary muscle thicknesses and SPHEQ, SPHEQ was significantly associated only with CMT2 (ß = -11.34, P = 0.0008) and CMT 3 (ß = -6.97, P = 0.007). When corresponding values of CMT2 were subtracted from CMT1 and CMTMAX, apical fibers at CMT1 (ß = 14.75, P < 0.0001) and CMTMAX (ß = 18.16, P < 0.0001) had a significant relationship with SPHEQ. CONCLUSIONS: These data indicated that in children the posterior ciliary muscle fibers are thicker in myopia (CMT2 and CMT3), but paradoxically, the apical ciliary muscle fibers are thicker in hyperopia (CMTMAX and CMT1). This may be the first evidence that hyperopia is associated with a thicker apical ciliary muscle region.