Comparative study of the ciliary body and iris morphology in the anterior eye chamber of five different vertebrate classes.

One crucial component of the optical system is the ciliary body (CB). This body secretes the aqueous humour, which is essential to maintain the internal eye pressure as well as the clearness of the lens and cornea. The histological study was designed to provide the morphological differences of CB and iris in the anterior eye chambers of the following vertebrate classes: fish (grass carp), amphibians (Arabian toad), reptiles (semiaquatic turtle, fan-footed gecko, ocellated skink, Egyptian spiny-tailed lizard, Arabian horned viper), birds (common pigeon, common quail, common kestrel), and mammals (BALB/c mouse, rabbit, golden hamster, desert hedgehog, lesser Egyptian jerboa, Egyptian fruit bat). The results showed distinct morphological appearances of the CB and iris in each species, ranging from fish to mammals. The present comparative study concluded that the morphological structure of the CB and iris is the adaptation of species to either their lifestyle or survival in specific habitats.

Ciliary muscle and anterior segment characteristics in pre-presbyopic adults with Down syndrome.

PURPOSE: Previous research has shown that accommodation deficits are common in individuals with Down syndrome (DS), but the origin and mechanisms behind these deficits are still unknown. The aim of this study was to investigate the characteristics of different ocular structures involved in accommodation, in particular the ciliary muscle (CM), in a population of individuals with DS to further understand this deficit and its mechanisms. METHODS: Thirty-two volunteer participants of pre-presbyopic age with (n = 16) and without DS (n = 16) were recruited. Temporal and nasal images of the CM were acquired using anterior segment optical coherence tomography (AS-OCT) while participants fixated an eccentrically located target. Analysis of CM parameters was undertaken using validated semi-automated software. Axial length, anterior chamber depth, lens thickness and corneal curvature were obtained with the Topcon Aladdin Optical Biometer and Corneal Topographer. Non-cycloplegic refractive error and accommodative ability were obtained with an open-field autorefractor and dynamic retinoscopy, respectively. Independent t-tests were conducted to determine differences in CM and other anterior segment parameters between participants with and without DS. RESULTS: No significant differences were found in the CM parameters studied between participants with and without DS (p > 0.05). In contrast, significant differences were found in visual acuity (p < 0.001), accommodative response (p < 0.001) and corneal curvature (K1 p = 0.003 and K2 p < 0.001) between participants with and without DS. CONCLUSIONS: Despite having poorer accommodation, pre-presbyopic adults with DS do not have a different CM morphology to that found in typically developing adults. These findings suggest that the accommodative deficit found in this population is not due to a mechanical deficit of the CM.

Pilot study supporting the existence of novel lymphatic channels within the canine anterior uveal tract using Lyve-1 and CD31.

OBJECTIVE: To demonstrate the existence of lymphatics in the canine anterior uvea using lymphatic-specific markers Lyve-1, Prox-1, and podoplanin, the endothelial cell marker CD31, and basement membrane matrix marker collagen IV. DESIGN: Prospective Study. ANIMALS: Eight normal globes from animals euthanized for unrelated health problems. PROCEDURES: Sagittally cut serial sections of six normal canine eyes were immunofluorescence double-stained with Lyve-1 and CD31 and single-stained with colorimetric Prox-1 and collagen IV. Three serial sections from 2 additional eyes were cut in the coronal plane at the level of the ciliary body and immunofluorescence double-stained with Lyve-1 and CD31 to map lymphatic channel distribution. Lymphatics from normal canine lymph nodes were used for validation of podoplanin. RESULTS: Four of 6 of the sagitally sectioned eyes had Lyve-1-positive lymphatic-like structures that were distinct from CD31-positive blood vessels in the iris base and ciliary body. Both of the coronally sectioned globes had Lyve-1-positive lymphatic-like structures in the ciliary body. The location of these structures was evaluated and found to be diffusely present circumferentially around the ciliary body. CONCLUSION AND CLINICAL RELEVANCE: These results support the existence of lymphatic channels in the anterior uveal tract of the canine eye. This could indicate the presence of a novel uveolymphatic outflow pathway, which may play a role in aqueous humor outflow. Future studies are needed to confirm the existence and elucidate the role of this proposed uveolymphatic outflow pathway and potentially develop novel treatment options for managing glaucoma.

Histologic effects of MicroPulse™ transscleral cyclophotocoagulation in normal equine eyes.

OBJECTIVE: Determine the immediate post-operative effects of MicroPulse™ transscleral cyclophotocoagulation (MP-TSCPC) in healthy equine eyes. ANIMALS STUDIED: Ten adult horses. METHODS: MP-TSCPC was performed on sedated horses in 12 eyes (4 groups) using the following parameters (power, duration, duty cycle): (1) 2000 mW, 180 seconds, 31.3%; (2) 3000 mW, 180 seconds, 31.3%; (3) 3000 mW, 270 seconds, 31.3%; and (4) 3000 mW, 270 seconds, 50%. Three additional eyes were left untreated (control). Eyes were monitored clinically until euthanasia (mean = 3 hours post-procedure). Histologic sections were assessed with light microscopy and transmission electron microscopy (TEM). RESULTS: MP-TSCPC was well tolerated by sedated horses. Adverse effects were only noted in Group 4: ocular hypertension (n = 3/3), conjunctival burns (3/3), aqueous flare (2/3), and a corneal erosion (1/3). Histologic scoring of Group 4 was statistically greater than other treated groups (1-3) and control eyes (P ≤ .021). TEM showed subtle changes to the mitochondria and plasma membrane infoldings of the basilar surface of the nonpigmented epithelium in all treated eyes. CONCLUSIONS: MP-TSCPC does not cause immediate post-procedure adverse clinical effects or pronounced morphological changes to the ciliary body, except with the highest laser settings evaluated (power 3000 mW, duration 270 seconds, duty cycle 50%).

Effect of age in the ciliary muscle during accommodation: Sectorial analysis.

PURPOSE: To compare changes in the ciliary muscle area at different sectors between pre-presbyopic and presbyopic eyes during accommodation by means of an anterior segment optical coherence tomographer (OCT). METHODS: The anterior ciliary muscle area was measured in 20 healthy and phakic pre-presbyopic eyes, whose mean age was 23.3±4.4 years, and in 20 healthy and phakic presbyopic eyes, whose mean age was 46.5±5.2 years. The relative change in the cross-sectional area of the ciliary muscle was measured at the nasal, inferior, and temporal sectors between 0 and -3 D of vergence, in -1 D step. A linear model was used to assess the correlation of each eye parameter with the accommodative demand. RESULTS: Each population group showed a significant increase in the anterior ciliary muscle area for each sector. The maximum increase in the ciliary muscle area within the pre-presbyopic group was about 30%, and for the presbyopic one was about 25%. At the same time, it was obtained that the larger the vergence, the larger the variability. Furthermore, the linear model showed a positive tendency between the change in the ciliary muscle area of each sector and the vergence for both population groups, which coefficient of determination was in all cases greater than 0.93. CONCLUSION: The anterior ciliary muscle area tends to increase with accommodation. The presbyopic nasal, inferior, and temporal ciliary muscle seem to have the same contractile capability as the young presbyopic ciliary muscle. These results might help to increase the evidences in the knowledge regarding the modern understanding of accommodation biometry and biomechanics.

Anatomy of the ciliary sulcus and the optimum site of needle passage for intraocular lens suture fixation in the living eye.

PURPOSE: To determine the relationship of the anatomic position of tissue surrounding the ciliary sulcus using ultrasound biomicroscopy (UBM) for measurement of ciliary sulcus parameters and the surrounding tissue after intracapsular cataract extraction (ICCE) and determine the correct suture site for intraocular lens (IOL) suture fixation. SETTING: Sugiura Eye Clinic, Asahi General Hospital, Shizouka-ken, Japan. DESIGN: Prospective case series. METHODS: Using UBM, the angle of the ciliary sulcus and several areas of the tissue surrounding the ciliary sulcus were measured from 8 orientations in eyes after ICCE. These measurements and endoscopic observation of the ciliary sulcus indicated the optimum points of needle insertion and needle emergence on the sclera for IOL suture fixation. Endoscopic observation of the ciliary sulcus also showed its shape. RESULTS: The shape of the surrounding tissue of the ciliary sulcus was measured in 16 eyes after ICCE, and endoscopy was used to observe the ciliary sulcus during surgery in 150 eyes. For ab interno ciliary sulcus suture fixation, the correct point of needle emergence on the sclera was 2.5 mm from the posterior surgical limbus when a straight needle was used. For ab externo pars plana suture fixation, the correct point of needle insertion on the sclera was 3.0 mm from the posterior surgical limbus. Endoscopic observation showed that the lower surface of the ciliary sulcus was formed by the fusion of neighboring ciliary processes. CONCLUSION: Knowing the detailed shape of ciliary sulcus will allow for more precise IOL suture fixation.

Neonatal and Juvenile Ocular Development in Sprague-Dawley Rats: A Histomorphological and Immunohistochemical Study.

As in many altricial species, rats are born with fused eyelids and markedly underdeveloped eyes. While the normal histology of the eyes of mature rats is known, the histomorphological changes occurring during postnatal eye development in this species remain incompletely characterized. This study was conducted to describe the postnatal development of ocular structures in Sprague-Dawley (SD) rats during the first month of age using histology and immunohistochemistry (IHC). Both eyes were collected from 51 SD rats at 13 time points between postnatal day (PND)1 and PND30. Histologic examination of hematoxylin and eosin-stained sections was performed, as well as IHC for cleaved-caspase-3 and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) to evaluate apoptosis, and IHC for Ki-67 and phospho-histone-H3 to evaluate cell proliferation. Extensive ocular tissue remodeling occurred prior to the eyelid opening around PND14 and reflected the interplay between apoptosis and cell proliferation. Apoptosis was particularly remarkable in the maturing subcapsular anterior epithelium of the lens, the inner nuclear and ganglion cell layers of the developing retina, and the Harderian gland, and was involved in the regression of the hyaloid vasculature. Nuclear degradation in the newly formed secondary lens fibers was noteworthy after birth and was associated with TUNEL-positive nuclear remnants lining the lens organelle-free zone. Cell proliferation was marked in the developing retina, cornea, iris, ciliary body and Harderian gland. The rat eye reached histomorphological maturity at PND21 after a rapid phase of morphological changes characterized by the coexistence of cell death and proliferation.

Semiautomatic procedure to assess changes in the eye accommodative system.

PURPOSE: The aim of this pilot study was to evaluate a new semiautomatic procedure to assess in vivo changes in the crystalline lens and ciliary muscle during accommodation. METHODS: A total of 14 subjects were divided into two groups, young (aged between 20 and 25 years) and adult (aged between 35 and 40 years), and measured with an anterior segment optical coherence tomography. A semiautomatic procedure was implemented to measure the central lens thickness (CLT), anterior lens radius (ALR) and the ciliary muscle area (CMA) for the unaccommodated eye and for a vergence of - 3.00 D. RESULTS: The CLT increase for each population group was smaller than 5%, and the dispersion of each group was similar between them. Contrariwise, the reduction in the ALR was about 30% for both groups, although the young one showed the largest variability. The CMA increase was smaller than 30% for both groups, and the dispersion was similar between them. For each metric, differences between both groups were not statistically significant. CONCLUSIONS: The semiautomatic procedure seems to be useful for the in vivo analysis of the accommodative system. Additionally, the results obtained showed that changes in the CLT were much smaller compared to those obtained for the ALR or CMA.

Intrasession repeatability of ocular anatomical measurements obtained with a multidiagnostic device in healthy eyes.

BACKGROUND: To evaluate the intrasession repeatability of anterior chamber depth (ACD), central (CCT) and peripheral corneal thickness (PCT), white-to-white diameter (WTW), and irido-corneal angle (IA) measurements obtained with a multidiagnostic device in healthy eyes. METHODS: A total of 107 eyes of 107 patients ranging in age from 23 to 65 years were examined with the VX120 system (Visionix-Luneau Technologies). Three consecutive measurements were obtained with this device to assess the intrasession repeatability of ACD, CCT, PCT at different nasal and temporal locations, WTW, and nasal and temporal IA. Data analysis included the calculation of within-subject standard deviation (Sw), intrasubject precision (1.96xSw), coefficient of variation (CV) and intraclass correlation coefficient (ICC). RESULTS: The Sw and CV for ACD was 0.03 mm and 1.16%, respectively, with an ICC of 0.992. The Sw values for central and peripheral pachymetric measurements were below 9 µm, with CV of less than 1.6% and ICC of 0.976 or higher. For IA measurements, Sw values of 0.84 or lower were found, with a CV between 1 and 2%, and an ICC of more than 0.970. The Sw for WTW was 0.24 mm and the CV was 1.95%. No statistically significant correlations were found between any anatomical parameter evaluated and their Sw and CV values associated (-0.220 ≤ r ≤ 0.204, p ≥ 0.125). CONCLUSIONS: The VX120 system is able to provide repeatable measurements of anatomical parameters in healthy eyes. Inter-observer repeatability should be evaluated in future studies.

Reproducibility and Agreement of Anterior Segment Parameter Measurements Obtained Using the CASIA2 and Spectralis OCT2 Optical Coherence Tomography Devices.

PURPOSE: To assess the reproducibility and agreement of measurement values obtained from the Tomey CASIA2 and Heidelberg Spectralis OCT2 anterior segment optical coherence tomographic devices. METHODS: Twenty eyes from 10 subjects ranging from age 28 to 45 years with no history of eye conditions or intraocular surgery were included. Two scans were obtained with each device in a standardized dark room environment after a period of dark adaptation. One anterior segment optical coherence tomography image along the horizontal (temporal nasal) meridian was analyzed per eye and per scan. Lens vault, pupil diameter, anterior chamber width, angle opening distance, trabecular iris space area, and scleral spur angle were measured using manufacturer-provided image analysis programs. Intraclass correlation coefficient (ICC) values, coefficients of variation, and Bland-Altman plots were computed to assess the intradevice correlation and interdevice agreement of measurement values. RESULTS: There was excellent intradevice reproducibility of measurement values for both the CASIA (ICC range, 0.86 to 0.99) and Spectralis (ICC range, 0.79 to 1.00). There was also excellent interdevice correlation of measurement values (ICC range, 0.78 to 0.93) for all parameters except anterior chamber width (ICC 0.20). Linear regression models and Bland-Altman plots showed that this relationship was strongest when measurement values were small. CONCLUSIONS: There is excellent intradevice reproducibility and good interdevice agreement of anterior segment parameter measurement values for the CASIA2 and Spectralis OCT2. However, the measurements obtained with each device should not be considered interchangeable.

Tolerance of high and low amounts of PLGA microspheres loaded with mineralocorticoid receptor antagonist in retinal target site.

Mineralocorticoid receptor (MR) contributes to retinal/choroidal homeostasis. Excess MR activation has been shown to be involved in pathogenesis of central serous chorioretinopathy (CSCR). Systemic administration of MR antagonist (MRA) reduces subretinal fluid and choroidal vasodilation, and improves the visual acuity in CSCR patients. To achieve long term beneficial effects in the eye while avoiding systemic side-effects, we propose the use of biodegradable spironolactone-loaded poly-lactic-co-glycolic acid (PLGA) microspheres (MSs). In this work we have evaluated the ocular tolerance of MSs containing spironolactone in rat' eyes. As previous step, we have also studied the tolerance of the commercial solution of canrenoate salt, active metabolite of spironolactone. PLGA MSs allowed in vitro sustained release of spironolactone for 30days. Rat eyes injected with high intravitreous concentration of PLGA MSs (10mg/mL) unloaded and loaded with spironolactone maintained intact retinal lamination at 1month. However enhanced glial fibrillary acidic protein immunostaining and activated microglia/macrophages witness retinal stress were observed. ERG also showed impaired photoreceptor function. Intravitreous PLGA MSs concentration of 2mg/mL unloaded and loaded with spironolactone resulted well tolerated. We observed reduced microglial/macrophage activation in rat retina compared to high concentration of MSs with normal retinal function according to ERG. Spironolactone released from low concentration of MSs was active in the rat retina. Low concentration of spironolactone-loaded PLGA MSs could be a safe therapeutic choice for chorioretinal disorders in which illicit MR activation could be pathogenic.

Non-invasive measurements of the dynamic changes in the ciliary muscle, crystalline lens morphology, and anterior chamber during accommodation with a high-resolution OCT.

PURPOSE: The purpose of the study was to assess non-invasively the changes in the anterior chamber eye, crystalline lens morphology, and ciliary muscle during accommodation by means of an anterior chamber optical coherence tomographer (OCT), and correlate them with vergence. METHODS: Twenty-five eyes of twenty-five healthy subjects, whose mean age was 29.9±7.1 years, were included and measured with an anterior chamber OCT. The central corneal thickness (CCT), anterior chamber depth (ACD), anterior crystalline lens radius of curvature (ALRC), crystalline lens thickness (CLT), and ciliary muscle area (CMA) were measured for each participant at 0, -1, -2, and -3 D of target vergence. A linear model was used to assess the correlation of each eye parameter with the vergence demand. RESULTS: The mean CCT showed no change for all the accommodative stimuli. The mean ACD and ALRC decreased with the vergence, about 4.5 and 30 % at -3 D, respectively. On the contrary, the CLT and CMA showed an opposite tendency, where the mean CLT was increased by 4.0 % and the mean CMA was done by 26% at -3 D. Statistical significant differences (p < 0.001) were obtained among all vergences for each eye metric, except for the CCT (p = 0.76). CONCLUSION: The ACD and ALRC decreased about 2 and 10 % per dioptre of accommodation, respectively; whereas the CLT and CMA increased about 2 and 9 %, respectively. These results add knowledge regarding the understanding of accommodation and give new perspectives for biomechanics and biometry.

Comparison of Ciliary Body Anatomy between American Caucasians and Ethnic Chinese Using Ultrasound Biomicroscopy.

PURPOSE: To compare the ciliary body morphology between the Caucasians and Chinese, and to determine the associated anterior segment parameters. METHODS: The study groups were comprised of four age- and gender-matched cohorts: American Caucasians, American Chinese, southern and northern mainland Chinese. Ultrasound biomicroscopy (UBM) was performed to assess the following measurements of the ciliary body: trabecular-ciliary process distance (TCPD), trabecular-ciliary process angle (TCA) and ciliary body thickness at 1 mm posterior to the scleral spur (CBT1). A-scan ultrasonography was used to measure lens thickness (LT) and relative lens position (RLP), defined as (ACD + LT/2)/AL. RESULTS: There were 109, 111, 115 and 117 subjects enrolled in the American Caucasian, American Chinese, and southern and northern mainland Chinese groups, respectively. Collectively, the Chinese had smaller TCPD (0.834 ± 0.234 versus 0.940 ± 0.236 mm, p < 0.001) and TCA (75.1 ± 17.9 versus 85.0 ± 21.5, p < 0.001) than Caucasians. No difference was found between the three Chinese subgroups, therefore they were combined as one for the following analyses. After multiple linear regression analysis, adjusting for age, gender, spherical equivalent (SE) and axial length (AL), TCPD and TCA were positively associated with CBT1 and RLP, but negatively correlated with LT in the whole sample. The ethnic Chinese had significantly smaller CBT1 (SRC = -0.177, p < 0.001) and RLP (SRC = -0.254, p < 0.001) than that of Caucasians. CONCLUSIONS: Compared with the Caucasians, the Chinese had a thinner ciliary body and a more anteriorly positioned lens, which may contribute to more anteriorly positioned ciliary processes in this population. These findings might help to explain the higher prevalence of angle closure in the Chinese.

Imaging the anterior eye with dynamic-focus swept-source optical coherence tomography.

A custom-built dynamic-focus swept-source optical coherence tomography (SS-OCT) system with a central wavelength of 1310 nm was used to image the anterior eye from the cornea to the lens. An electrically tunable lens was utilized to dynamically control the positions of focusing planes over the imaging range of 10 mm. The B-scan images were acquired consecutively at the same position but with different focus settings. The B-scan images were then registered and averaged after filtering the out-of-focus regions using a Gaussian window. By fusing images obtained at different depth focus locations, high-resolution and high signal-strength images were obtained over the entire imaging depth. In vivo imaging of human anterior segment was demonstrated. The performance of the system was compared with two commercial OCT systems. The human eye ciliary body was better visualized with the dynamic-focusing SS-OCT system than using the commercial 840 and 1310 nm OCT systems. The sulcus-to-sulcus distance was measured, and the result agreed with that acquired with ultrasound biomicroscopy

Ciliary Muscle Cell Changes During Guinea Pig Development.

PURPOSE: Guinea pig ciliary muscle (CM) increases robustly in volume, length, and thickness with age. We wanted to characterize CM cells during development to determine the contributions of hypertrophy (cell size increase) and hyperplasia (cell number increase) during development. METHODS: Six pigmented guinea pig eyes were collected at each of five ages: 1, 10, 20, 30, and 90 days. Refractive errors and axial lengths were determined. Eyes were temporally marked, enucleated, hemisected, and fixed. Nasal and temporal eye segments were embedded and 30-µm serial sections were collected; the two most central slides from each hemisection were analyzed with an epifluorescence microscope and Stereo Investigator software to determine normal morphologic parameters. RESULTS: Refractive errors became less hyperopic (P = 0.0001) while axial lengths and CM lengths, cross-sectional areas, volumes, and cell sizes all increased linearly with log age (all P < 0.00001). Ciliary muscle cell numbers increased only during the first 20 days of life (P = 0.02). Nasal and temporal CM lengths (P = 0.07), cross-sectional areas (P = 0.18), and cell numbers (P = 0.70) were not different, but CM cell sizes were initially larger temporally and became larger nasally after age 30 days. CONCLUSIONS: The mechanism of guinea pig CM cell growth during the first 90 days of life was characterized by early hyperplasia combined with hypertrophic cell growth throughout development that results in larger CM lengths, cross-sectional areas, and volumes. Nasal-temporal CM development was generally symmetric, but there was more CM hypertrophy nasally at older ages.

Reproducibility and Agreement Between 2 Spectral Domain Optical Coherence Tomography Devices for Anterior Chamber Angle Measurements.

PURPOSE: To compare anterior chamber angle parameters based on the location of Schwalbe line (SL) from 2 spectral domain optical coherence tomography (SD-OCT) instruments and to measure their reproducibility. METHODS: Forty-two eyes from 21 normal, healthy participants underwent imaging of the inferior irido-corneal angle with the Spectralis and Cirrus SD-OCT under tightly controlled low-light conditions. SL-angle opening distance (SL-AOD) and SL-trabecular iris space area (SL-TISA) were measured by masked, certified graders at the Doheny Imaging Reading Center using customized grading software. Interinstrument and intrainstrument, as well as interobserver and intraobserver reproducibility of SL-AOD and SL-TISA measurements were evaluated by intraclass correlation coefficients (ICCs) and Bland-Altman plots with limits of agreement (LoA). RESULTS: The mean SL-AOD was 0.662±0.191 mm in Spectralis and 0.677±0.213 mm in Cirrus. The mean SL-TISA was 0.250±0.073 mm in Spectralis and 0.256±0.082 mm in Cirrus. The agreement for intrainstrument (ICCs>0.979), intragrader (ICCs>0.992), and intergrader (ICCs>0.929) was excellent. Excellent agreement between the 2 devices was also documented with a mean difference of -0.016 (LoA -0.125 to 0.092) mm for SL-AOD and -0.007 (LoA -0.056 to 0.043) mm in SL-TISA. CONCLUSIONS: Both SD-OCTs provided comparable measurements and permitted calculation of SL-based angle metrics. There was excellent interinstrument and intrainstrument and intraobserver and interobserver reproducibility for Spectralis and Cirrus SD-OCTs, suggesting true interchangeability between SD-OCT devices. This has the potential to lead to development of standardized grading assessments and quantification of angle parameters that would be valid across various SD-OCT devices.

Age-related changes in the anterior segment biometry during accommodation.

PURPOSE: We investigated the dynamic response of human accommodative elements as a function of age during accommodation using synchronized spectral domain optical coherence tomography devices (SD-OCT). METHODS: We enrolled 33 left eyes from 33 healthy subjects (age range, 20-39 years, 17 males and 16 females). Two SD-OCT devices were synchronized to simultaneously image the anterior segment through pupil and the ciliary muscle during 6.00 diopter (D) accommodation for approximately 3.7 seconds in two repeated measurements. The anterior segment parameters included the lens thickness (LT), radius of curvature of the lens anterior surface (LAC), maximum thickness of ciliary muscle (CMTMAX), and anterior length of the ciliary muscle (CMAL). A first-order exponential equation was used to fit the dynamic changes during accommodation. The age-related changes in the dynamic response and their relationship were calculated and compared. RESULTS: The amplitude (r = -0.40 and 0.53 for LT and LAC, respectively) and peak velocity (r = -0.65 and 0.71 for LT and LAC, respectively) of the changes in LT and LAC significantly decreased with age (P < 0.05), whereas the parameters of the ciliary muscle remained unchanged (P > 0.05), except for the peak velocity of the CMAL (r = 0.44, P = 0.01). The difference in the time constant between the lens reshaping (LT and LAC) and CMTMAX increased with age (r = 0.46 and 0.57 for LT and LAC, respectively, P < 0.01). The changes in LT and LAC per millimeter of CMTMAX change decreased with age (r = -0.52 and -0.34, respectively, P < 0.05). The ciliary muscle forward movement correlated with the lens deformation (r = -0.35 and 0.40 for amplitude, while r = 0.36 and 0.58 for time constant, respectively, P < 0.05). CONCLUSIONS: Age-related changes in the lens reshaping and ciliary muscle forward movement were found. Lens reshaping was much slower than the contraction of the ciliary muscle, especially in aging eyes, and this process required the ciliary muscle to contract more to reach a given response.

[Clinical analysis of malignant glaucoma after glaucoma surgery].

OBJECTIVE: To explore the risk factors, the ciliary body anatomy structures, the therapeutic methods and the prognosis for malignant glaucoma through retrospectively collecting the clinical data from primary angle-closure glaucoma (PACG) patients. METHODS: Clinical data in 1183 patients (1456 eyes) with PACG were collected between July, 2010 and May, 2014 from Xiangya Hospital, Central South University. Thirty patients (38 eyes) were diagnosed as malignant glaucoma. According to symptom, these patients were divided into a PACG group (1418 eyes) and a malignant glaucoma group (38 eyes); according to age, they were divided into a 3-40 years old group (171 eyes), a 41-70 years old group (1016 eyes) and a ≥71 years old group (269 eyes); according to therapeutic methods, they were divided into a drug therapy group (5 eyes), a lens extraction group (6 eyes) and a vitrectomy surgery group (27 eyes); according to the different method of surgery, they were divided into a vitrectomy group (27 eyes), a nonvitrectomy group (11 eyes). The age, sex, anterior chamber depth (ACD), axial length (AL), lens thickness (LT), visual acuity, intraocular pressure, therapeutic methods and surgery history were recorded. Meanwhile, the ciliary body thickness (CBT), trabecular ciliary process angle (TCA) and lens diameter were measured by ultrsound biomicroscopy (UBM). RESULTS: Male and female ratio was 1:2 in the malignant glaucoma group. The average age [(51.87±12.92) years] in the malignant glaucoma group was less than that in the PACG group [(57.87±8.78) years](P<0.05). Malignant glaucoma was more likely to occur in the first 3 months after PACG trabeculectomy with a rate of 85.7%. The LT [(4.33±0.67) mm], AL[(21.44±1.18) mm] and ACD [(2.12±0.41) mm] in the malignant glaucoma group were less than those in the PACG group [(4.81±0.50), (22.17±0.97) and (2.49±0.48) mm, respectively](all P<0.05). The CBT0, CBT1, CBTmax, TCA and lens diameter in the malignant glaucoma group were less than those in the PACG group (all P<0.05). CONCLUSION: Female PACG patients, with short axial length, shallow anterior chamber, thin lens, thin ciliary body, small trabecular ciliary process angle and short lens diameter, are more likely to suffer from malignant glaucoma. Vitrectomy can significantly reduce intraocular pressure.

A program to analyse optical coherence tomography images of the ciliary muscle.

PURPOSE: To describe and validate bespoke software designed to extract morphometric data from ciliary muscle Visante Anterior Segment Optical Coherence Tomography (AS-OCT) images. METHOD: Initially, to ensure the software was capable of appropriately applying tiered refractive index corrections and accurately measuring orthogonal and oblique parameters, 5 sets of custom-made rigid gas-permeable lenses aligned to simulate the sclera and ciliary muscle were imaged by the Visante AS-OCT and were analysed by the software. Human temporal ciliary muscle data from 50 participants extracted via the internal Visante AS-OCT caliper method and the software were compared. The repeatability of the software was also investigated by imaging the temporal ciliary muscle of 10 participants on 2 occasions. RESULTS: The mean difference between the software and the absolute thickness measurements of the rigid gas-permeable lenses were not statistically significantly different from 0 (t=-1.458, p=0.151). Good correspondence was observed between human ciliary muscle measurements obtained by the software and the internal Visante AS-OCT calipers (maximum thickness t=-0.864, p=0.392, total length t=0.860, p=0.394). The software extracted highly repeatable ciliary muscle measurements (variability ≤6% of mean value). CONCLUSION: The bespoke software is capable of extracting accurate and repeatable ciliary muscle measurements and is suitable for analysing large data sets.