Ultrasound biomicroscopic findings in aniridia

PURPOSE: To describe the ultrasound biomicroscopic features of eyes with aniridia. DESIGN: Observational case series. METHODS: Nineteen eyes of 10 patients with aniridia (six males and four females) ranging in age from 3 months to 53 years (21.0 +/- 16.4, mean +/- SD), and 50 normal subjects (30 men and 20 women) ranging from 16 to 56 years (31.1 +/- 13.2) were evaluated. Ultrasound biomicroscopic findings were recorded in the 3-, 6-, 9-, and 12-o'clock directions. Adult patients (aged 16 years or older) with aniridia were compared with the age-matched controls. RESULTS: Ultrasound biomicroscopy (UBM) detected extremely tiny irises in all eyes with aniridia. The eyes with aniridia showed significantly smaller values than the controls in ciliary body length (4.49 +/- 0.63 versus 5.79 +/- 0.44 mm, P <.001, unpaired Student t test), ciliary body thickness (0.75 +/- 0.17 versus 1.24 +/- 0.22 mm, P <.001), iris root thickness (0.47 +/- 0.14 versus 0.61 +/- 0.07 mm, P <.001), scleral-ciliary process angle (31.7 +/- 3.26 versus 43.1 +/- 4.48 degree, P <.001), and anterior chamber depth (1.99 +/- 0.43 versus 2.94 +/- 0.34 mm, P <.001). In the aniridia eyes, there was a significantly positive correlation between iris thickness and ciliary body thickness (Pearson r = 0.829, P =.001). CONCLUSION: Ultrasound biomicroscopic imaging demonstrated that not only iris hypoplasia but also ciliary body hypoplasia exist in aniridia. Anterior inclination of the ciliary process was also found, which was thought to be at least partly responsible for the shallow anterior chamber.     

Narrowing of the anterior chamber angle during Valsalva maneuver: a possible mechanism for angle closure

PURPOSE: To evaluate changes at the anterior chamber angle during Valsalva maneuver in eyes suspected to have a primary adult glaucoma. METHODS: Seventy-six consecutive patients underwent recording of applanation tonometry, measurement of the anterior chamber angle recess, angle opening distance, angle recess area, scleral spur-iris root distance, iris thickness, iridociliary angle, ciliary body thickness, anterior chamber depth, and pupil size on ultrasound biomicroscopy before and during the Valsalva maneuver. The Valsalva maneuver was standardized to a pressure of 40 mmHg for 15 seconds, using a manometer. RESULTS: The mean baseline intraocular pressure changed from 19.5+/-4.1 mmHg to 29.5+/-4.8 mmHg during Valsalva (p<0.0001). The anterior chamber angle recess narrowed from 17.9+/-9.5 to 7.8+/-9.2 degrees (p=0.0001). The angle recess area diminished from 0.15+/-0.14 mm2 to 0.14+/-0.12 mm2 (p=0.03) and the scleral spur to iris distance decreased from 0.19+/-0.2 mm to 0.16+/-0.18 mm (p=0.0001). The iridociliary angle narrowed from 72.6+/-33.5 degrees to 62.5+/-32.8 degrees (p=0.04). There was a significant increase in the thickness of the ciliary body, from 0.99+/-0.19 mm to 1.12+/-0.16 mm (p=0.001) and in iris thickness from 0.47+/-0.07 mm to 0.55+/-0.09 mm (p=0.0001). There was no significant change in the angle opening distance, anterior chamber depth, or pupillary diameter. A significant narrowing of the angle to less than 5 degrees was seen in 37 eyes, with iridocorneal apposition present in 28 eyes. After multivariate regression analysis it was found that the baseline ciliary body thickness and angle recess were significant predictors of narrowing of the angle (R2=96.1%). CONCLUSIONS: Significant elevation of the intraocular pressure, narrowing of the anterior chamber angle recess, thickening of the ciliary body, and increase in the iris thickness is seen during the Valsalva maneuver. The Valsalva maneuver may lead to angle closure in eyes anatomically predisposed to primary angle closure glaucoma.     

Comparison of anterior segment optical coherence tomography and ultrasound biomicroscopy for assessment of the anterior segment

PURPOSE: To compare anterior segment parameters using quantitative imaging by anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM). SETTING: Tertiary-care glaucoma research center. METHODS: Sixty-three eyes of 63 subjects had anterior segment evaluation by AS-OCT (Visante-Zeiss) and UBM (Paradigm). Central corneal thickness (CCT), anterior chamber depth (ACD) (measured from the central corneal endothelium to the anterior lens capsule), and the peripheral iridocorneal angles (temporal and nasal) were assessed and compared. RESULTS: There was an excellent correlation between AS-OCT and UBM measurements for the nasal angle (r = 0.84; P<.0001), temporal angle (r = 0.86; P<.0001), ACD (r = 0.97; P<.0001), and CCT (r = 0.91; P<.0001). There was no significant difference (paired t test) between the mean ACD, CCT, and angle parameters measured by AS-OCT or UBM. The mean values of the parameters measured by AS-OCT and UBM were, respectively, as follows: nasal angle, 26.25 degrees +/- 11.0 (SD) and 28.27 +/- 11.3 degrees (P = .3); temporal angle, 25.1 +/- 11.4 degrees and 28.3 +/- 13.5 degrees (P = .15); ACD, 2.85 +/- 0.5 mm and 2.78 +/- 0.5 mm (P = .2); and CCT, 512 +/- 46 microm and 502 +/- 46 microm (P = .25). The AS-OCT images showed sharper definition of the scleral spur than the UBM images. CONCLUSION: Anterior segment optical coherence tomography and UBM can both be used for anterior segment measurements and yielded comparable results.     

Ocular structure changes during vacuum by the Hansatome microkeratome suction ring

PURPOSE: To evaluate whether the vacuum of a microkeratome suction ring induces ocular structure changes. METHODS: A prospective case series using A-scan ultrasonography to measure anterior chamber depth, lens thickness, vitreous body, and axial length was performed. Measurements before and during application of a Hansatome microkeratome suction ring were performed on 69 eyes of 39 consecutive patients scheduled to undergo a first-time LASIK procedure with mechanical creation of a corneal flap. RESULTS: Mean patient age was 43 +/- 12.1 years. Of the 69 eyes, 63 (91.3%) had refractive myopia with a mean spherical equivalent refraction of -2.93 +/- 1.56 diopters (D) and 6 (8.7%) had refractive hyperopia with a mean spherical equivalent refraction of 1.37 +/- 0.31 D. Overall, the mean spherical equivalent refraction of all eyes was -2.56 +/- 1.94 D. Ultrasound measurements during suction revealed a decrease in the anterior chamber depth of -0.06 +/- 0.36 mm (P < .05) and lens thickness by -0.14 +/- 0.45 mm (P < .05) whereas the vitreous body increased 0.25 +/- 0.36 mm (P < .05). Although insignificant, a trend toward increasing axial length was noted. No measurements changed over time during the application of vacuum. CONCLUSIONS: Vacuum by a microkeratome suction ring induced a compression of the anterior chamber and lens with commensurate expansion of the vitreous body. The assessment of vacuum effects during LASIK suggests that measurements of intraocular compartments are more informative than axial length.     

Central corneal thickness, tonometry, and ocular dimensions in glaucoma and ocular hypertension.

PURPOSE: To assess possible correlations between central corneal thickness, tonometry, and ocular dimensions. PATIENTS AND METHODS: One hundred seventeen eyes of 117 patients who were not taking any intraocular pressure-lowering medications were studied prospectively. Forty-one patients had ocular hypertension; 13 patients had primary open-angle glaucoma; and 10 patients had normal-pressure glaucoma. Twenty-three healthy eyes were included. Thirty glaucoma suspects (10 patients monitored for possible normal-pressure glaucoma and 20 patients with intermittent ocular hypertension) were included for correlation analysis. Tonometry was performed with Goldmann applanation and pneumotonometry, and central corneal thickness, anterior chamber depth, lens thickness, and axial length were measured ultrasonically. RESULTS: Central corneal thickness was lowest in eyes with normal-pressure glaucoma (538 +/- 51 microm), highest in eyes with ocular hypertension (570 +/- 32 microm), and intermediate and similar in eyes with primary open-angle glaucoma and healthy eyes (547 +/- 34 microm and 554 +/- 32 microm, respectively). These differences were significant (P = 0.028). Goldmann applanation tonometry and central corneal thickness were weakly correlated (r = 0.12, P = 0.205), with a 0.2-mm Hg change per 10-microm variation in central corneal thickness. Pneumotonometry measurements were more strongly correlated with central corneal thickness (r = 0.21, P < 0.05). Lens thickness was strongly correlated with age (r = 0.57, P < 0.001). Anterior chamber depth was negatively correlated with lens thickness and age (r = -0.29, P < 0.005 and r = -0.25, P < 0.01). Axial length was correlated with anterior chamber depth and age (r = 0.5, P < .001 and r = -0.19, P < 0.05). CONCLUSION: Eyes diagnosed as having ocular hypertension have thicker corneas and eyes labeled as having normal-pressure glaucoma have thinner corneas, when compared with healthy eyes or eyes with primary open-angle glaucoma. The effect of central corneal thickness on Goldmann applanation tonometry accuracy appears to be small and usually not clinically relevant. When corneal thickness is markedly different from normal, the clinician may need to factor this into diagnosis and management.     

Dynamic analysis of dark-light changes of the anterior chamber angle with anterior segment OCT

PURPOSE: To describe the use of anterior segment optical coherence tomography (OCT) in studying the dynamic dark-light changes of the anterior chamber angle. METHODS: Thirty-seven normal subjects with open angles on dark-room gonioscopy and 18 subjects with narrow angles were analyzed. The dynamic dark-light changes of the anterior-chamber angle were captured with real-time video recording. The angle opening distance (AOD500) and trabecular iris space area (TISA500) of the nasal angle and the pupil diameter in each of the representative serial images were measured. Linear regression analysis was performed to investigate the association between AOD500/TISA500 and pupil diameter. Demographic and biometry measurements associated with the AOD difference (AOD500((light)) - AOD500((dark))) and TISA difference (TISA500((light)) - TISA500((dark))) were analyzed with univariate and multivariate regression models. RESULTS: The AOD500/TISA500 measured in the light in the open-angle and the narrow-angle groups were 694 +/- 330 microm/0.24 +/- 0.10 mm(2) and 265 +/- 78 microm/0.10 +/- 0.03 mm(2), respectively. These values were significantly greater than the AOD500/TISA500 measured in the dark (492 +/- 265 microm/0.16 +/- 0.08 mm(2) and 119 +/- 82 microm/0.05 +/- 0.04 mm(2), respectively, all with P < 0.001). The ranges of the AOD/TISA difference were 13 to 817 microm/0.011 to 0.154 mm(2), with an average of 180 microm/0.073 mm(2). Multivariate regression analysis identified a positive correlation between anterior chamber depth and the AOD/TISA difference. Fifty eyes showed significant correlations between AOD/TISA and pupil diameter, whereas one eye showed no association. Four eyes in the narrow angle group developed appositional angle closure in the dark. CONCLUSIONS: The dynamic dark-light changes of the anterior chamber angle can be imaged and analyzed with anterior segment OCT. Although the angle width generally decreased linearly with increasing pupil diameter, the differences of the angle width measured in the dark and in the light varied substantially among individuals.     

Anterior chamber depth and complications during cataract surgery in eyes with pseudoexfoliation syndrome

PURPOSE: To look for associations of preoperative A-scan ultrasound ocular dimensions with complications during phacoemulsification in eyes with pseudoexfoliation.METHODS: A total of 174 eyes with pseudoexfoliation of 135 patients undergoing planned cataract surgery were included in a prognostic study based on the review of a clinical database. Preoperatively, A-scan ultrasound examination with measurement of anterior chamber depth, lens thickness, and total axial length was performed. Phacoemulsification with implantation of a posterior chamber intraocular lens was performed by a total of five surgeons. Intraoperative complications (zonular dialysis and/or vitreous loss) were correlated with preoperative findings including ultrasound dimensions. Multivariate logistic regression analysis with a generalized estimating equations method was used for statistical analysis.RESULTS: Intraoperative complications occurred in 12 eyes (6.9%) of 11 patients. The anterior chamber was significantly shallower in eyes with than in eyes without complications (mean, 2.36 +/- 0.44 mm vs 2.74 +/- 0.52 mm; P =.013). The differences in lens thickness (4.93 +/- 0.55 mm vs 4.72 +/- 0.54 mm; P =.30) and the differences in axial length (22.92 +/- 1.09 mm vs 23.66 +/- 1.36 mm; P =.07) between the two groups did not reach statistical significance. In eyes with pseudoexfoliation, an anterior chamber depth of less than 2.5 mm was associated with a risk of 13.4% for intraoperative complications compared with an overall incidence of intraoperative complications of 6.9% and an incidence of 2.8% for an anterior chamber depth of 2.5 mm or more. CONCLUSIONS: A small anterior chamber depth may indicate zonular instability in eyes with pseudoexfoliation syndrome and should alert the cataract surgeon to the possibility of intraoperative complications.     

Anterior segment changes with age and during accommodation measured with partial coherence interferometry

PURPOSE: To evaluate anterior segment alterations with age and during accommodation in different age groups. SETTING: Department of Ophthalmology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary. METHODS: Fifty-three subjects (101 normal eyes) were enrolled in this study and divided into 3 age groups: younger than 30 years (Group 1), between 31 years and 44 years (Group 2), and older than 45 years (Group 3). The total amplitude of accommodation was determined with a defocusing technique, and anterior segment measurements were performed by partial coherence interferometry. RESULTS: Group 1 comprised 32 eyes; Group 2, 37 eyes; and Group 3, 32 eyes. The total amplitude of accommodation decreased with age (P<.0001). With the target position at infinity, the lens thickness (LT) and anterior segment length (ASL) increased and the anterior chamber depth (ACD) decreased significantly with age (P<.0001). During accommodation in the youngest group, the mean change in LT was 36.3 mum/diopter (D) and in ACD, -26.7 mum/D. The mean accommodation-induced ACD change was -0.08 mm +/- 0.06 (SD) in Group 1, -0.064 +/- 0.087 mm in Group 2, and -0.03 +/- 0.06 mm in Group 3 (P = .0004). The mean LT change during near fixation was 0.109 +/- 0.063 mm in Group 1, 0.103 +/- 0.136 mm in Group 2, and 0.006 +/- 0.05 mm in Group 3 (P<.0001). The mean ASL change during accommodation was 0.029 +/- 0.037 mm, 0.039 +/- 0.114 mm, and -0.023 +/- 0.051, respectively (P<.0001). CONCLUSIONS: In addition to forward movement of the anterior lens surface with age, the posterior surface moved backward. Alterations in LT and ACD sufficient for a unit of refractive power change during accommodation might be smaller than previously thought. Anterior shifting of the lens may also participate in the accommodative response.     

应用超声生物显微镜探讨原发性闭角型青光眼的发病机制

目的探讨原发性闭角型青光眼的发病机制,研究睫状体改变在青光眼发病中的作用。方法应用超声生物显微镜（ｕｌｔｒａｓｏｕｎｄｂｉｏｍｉｃｒｏｓｃｏｐｙ,ＵＢＭ）结合Ａ超检测９９只原发性闭角型青光眼及５８只正常眼的活体眼前节结构,并对两组测量参数进行对比研究。其中急性闭角型青光眼（急闭）５０只眼,慢性闭角型青光眼（慢闭）４９只眼。结果原发性闭角型青光眼与正常眼相比,角膜小、前房浅、眼轴短、晶体厚、相对晶体位置偏前、睫状突肿胀、睫状体前置,以上差异均有显著性（Ｐ＜００５）。急闭与慢闭相比,前者前房更浅,相对晶体位置更偏前,差异有显著性（Ｐ＜００１）。急闭与正常眼相比,前者的睫状体与晶体距离较短,差异有显著性（Ｐ＜００５）;而慢闭与正常眼相比,前者的睫状体与晶体距离亦较短,但差异无显著性（Ｐ＞００５）。结论原发性闭角型青光眼的发病与其自身的解剖特点有关。其中晶体位置前移导致的瞳孔阻滞及继发的房角变窄是闭角型青光眼发病的共同机制;而睫状突肿胀、睫状体位置的改变及与年龄相关的晶体厚度增大是导致晶体位置前移的可能原发因素。对于急闭而言,瞳孔阻滞是其发病的更重要因素。     

Iridociliary apposition in plateau iris syndrome persists after cataract extraction

PURPOSE: To evaluate the ultrasound biomicroscopic appearance of the anterior segment before and after cataract extraction in eyes with plateau iris syndrome and to determine the effect of postoperative zonular relaxation on ciliary body position. DESIGN: Interventional case series. METHODS: Eyes with plateau iris syndrome scanned before and after cataract extraction between January 1994 and September 2001 were enrolled. The iridociliary relationship and the anterior chamber depth at a distance of 3 mm from the scleral spur were assessed. RESULTS: We examined six eyes of six patients. Mean patient age was 74.2 +/- 6.4 years (standard deviation [SD]) (range, 65-81 years). Mean refractive error was + 1.0 +/- 3.9 diopters [D] (range, -5.75-+5.50), and mean axial length was 21.85 +/- 0.77 mm (range, 20.90-22.95 mm). All eyes had undergone laser iridotomy and argon laser peripheral iridoplasty before cataract extraction. Ultrasound biomicroscopy examination revealed a narrow angle and absence of a ciliary body sulcus in all eyes with focal areas of iridotrabecular apposition in three eyes. Following cataract extraction, the anterior chamber depth increased (P =.0006, paired t test), while the iridociliary contact remained unchanged. CONCLUSIONS: Iridociliary apposition persists after cataract extraction in plateau iris syndrome. Whether the cause is congenital or acquired, or both, remains to be determined.     

Peripheral anterior synechiae and ultrasound biomicroscopic parameters in angle-closure glaucoma suspects

PURPOSE: To investigate the correlation between peripheral anterior synechia (PAS) and the quantitative anterior chamber angle parameters measured by ultrasound microscopy (UBM) in angle-closure glaucoma suspect (ACGS) eyes. METHODS: Eyes were defined ACGS as having occludable angles and intraocular pressure less than 21 mm Hg without glaucomatous optic nerve head. The gonioscopic criteria for ACGS were the trabecular meshwork invisible in 3 or more quadrants of the entire angle and the angular width less than 20 degrees by Shaffer classification. Twenty-seven eyes of 20 patients underwent anterior chamber angle and ciliary body imaging with UBM. Angle opening distance (AOD(500)), angle recess area (ARA), trabecular-ciliary process distance (TCPD) and trabecular-iris angle (TIA) were measured from the UBM images at each quadrant. RESULTS: The AOD(500), ARA, and TIA were not significantly different between the eyes with PAS (9 eyes) and without PAS (18 eyes) at each quadrant. However, the TCPD was significantly shorter in the superior quadrant when compared with the eyes without PAS (mean: 405.3+/-70.9 microm vs 536.4+/-140.5 microm) (p<0.05). CONCLUSIONS: The results suggest that the shorter distance from trabecular meshwork to ciliary body or the anterior placement of ciliary process may play a role in the development of PAS in ACGS eyes.     

Ultrasound biomicroscopic study of anterior segment changes after phacoemulsification and foldable intraocular lens implantation

PURPOSE: To report quantitative changes in the anterior segment configuration after clear corneal incision phacoemulsification and foldable intraocular lens (IOL) implantation by means of ultrasound biomicroscopy (UBM). DESIGN: Prospective, nonrandomized, comparative (self-controlled) trial. PARTICIPANTS: Twenty-one eyes of 19 patients with senile or presenile cataracts and no other ocular illness. METHODS: Patients were examined with UBM before and 1 and 3 months after surgery. At each UBM examination, axial images of the anterior chamber and radial sections of the angle at the superior, lateral, inferior, and medial quadrants were obtained. MAIN OUTCOME MEASURES: Central anterior chamber depth (ACD), iris-lens contact distance, iris-lens angle (ILA), angle opening distance at points 250 (AOD250) and 500 microm (AOD500) from the scleral spur, trabecular-iris angle (TIA), iris thickness 500 microm from the scleral spur (IT), trabecular-ciliary process distance (TCPD), iris-ciliary process distance (ICPD), iris-zonule distance, iris-sclera angle (ISA), and ciliary process-sclera angle (CPSA). After surgery, central anterior chamber depth was also measured from the cornea to the IOL (ACD) and from the cornea to the pupillary plane (ACD2). Each variable was measured twice in different days by the same observer. RESULTS: The variables IT, TCPD, ICPD, IZD, and CPSA did not significantly change after surgery (P > 0.01). Central anterior chamber depth increased approximately 30% after surgery (approximately 850 microm; P < 0.001), by both measurement methods used (ACD x ACD and ACD x ACD2). Anterior chamber angle significantly increased, by approximately 50% of the initial value, by the three measurement methods used: AOD250 (P 相似文献   

Ultrasound biomicroscopy dark room provocative testing: a quantitative method for estimating anterior chamber angle width

PURPOSE: To describe a quantitative method for measuring the iridocorneal angle recess area, and, using this, to evaluate factors associated with appositional angle-closure during dark room provocative testing using ultrasound biomicroscopy (UBM). METHODS: All patients (178 patients, 178 eyes) with clinically narrow angles referred for UBM dark room provocative testing between September 1996 and March 1998 were enrolled in this study. Images of the inferior quadrant of the angle taken under standardized dark and light conditions were analyzed. The angle recess area (ARA) was defined as the triangular area demarcated by the anterior iris surface, corneal endothelium, and a line perpendicular to the corneal endothelium drawn from a point 750 microm anterior to the scleral spur to the iris surface. ARA, and acceleration and gamma-intercept of the linear regression analysis of the ARA were calculated. In the linear regression formula, y = ax + b, the acceleration a describes the rate at which the angle widens from the scleral spur; the y-intercept b describes the distance from the scleral spur to the iris. RESULTS: Under dark conditions, the angles in 99 patients (55.6%) showed evidence of appositional angle-closure during testing. ARA (0.11 +/- 0.04 vs. 0.15 +/- 0.05 mm2, P < .0001, Student t-test), acceleration a (0.22 +/- 0.15 vs. 0.26 +/- 0.17, P = .068), and y-intercept b (66 +/- 46 vs. 92 +/- 47 microm, P = .0003) were smaller in eyes that were occluded. In the eyes that were not occluded, y-intercept b showed no significant difference between light and dark conditions (P = .1, paired t-test), while acceleration a did (P < .0001). In the eyes that were occluded, both decreased significantly under dark conditions (P < .0001). CONCLUSIONS The ARA linear regression formula provides useful quantitative information about angle recess anatomy. The more posterior the iris insertion on the ciliary face, the less likely the provocative test will be positive.     

Biometric measurement of the mouse eye using optical coherence tomography with focal plane advancement

PURPOSE: To demonstrate that high-resolution biometry is possible in mouse eyes in vivo, using real-time OCT with focal plane advancement by a stepper motor. METHODS: OCT images of eyes were taken from nine 29-day-old C57BL/6 mice(18 eyes) on two consecutive days. A custom-built real-time OCT instrument with a stepper motor was used to advance the focal plane from the corneal apex to the retina along the ocular axis. The ocular dimensions were determined by advancement of the stepper motor as it displayed on the OCT scan images. RESULTS: OCT images of the entire eye, including the cornea, anterior chamber, lens, vitreous chamber, and retina, were successfully obtained from both eyes of all mice. The measured average corneal thickness from 18 eyes at the age of 29 days was 90.8+/-4.6microm, anterior chamber depth 707.4+/-21.4microm, lens thickness 1558.7+/-18.0microm, vitreous chamber depth 707.4+/-21.4microm and retinal thickness was 186.9+/-15.1microm. Total axial length (from the corneal apex to the nerve fiber layer of the retina) was 3003.3+/-44.1microm. None of them were significantly different if measured on two consecutive days, and no significant differences were found between measurements in the left and right eyes. CONCLUSION: By focal plane advancement of a real-time OCT instrument through the mouse eye, highly repeatable measurements of the ocular dimensions were obtained. This novel method may be used to study small animal models of normal and abnormal eye development.     

A case report on the change of the refractive power after a blunt trauma

PURPOSE: To determine the pathogenesis of transient myopia after blunt eye trauma. METHODS: In one patient, the refraction of both eyes (the left eye was injured, but the right eye was not) was measured with an autorefractometer. The cycloplegic refraction was measured at the early stage of trauma and again 3 months after the blunt eye injury. The angle and depth of the anterior chamber, the ciliary body, and the choroids were examined by ultrasound biomicroscopy (UBM) over 3 months. The depth of the anterior chamber, the thickness of the lens, and the axial length were measured by A-scan ultrasonography in both eyes. During the 3 months after the injury, we made comparisons between the menifest and the cycloplegic refractions, the depths of anterior chambers, the thickness of the lenses, the axial lengths, and the UBM-determined appearances of the angles and depths of the anterior chambers, the ciliary bodies, and the choroids in both eyes. RESULTS: We suspect that the depth reduction in the anterior chamber, the increase in anterior to posterior lens diameter, and the edema in the ciliary body are all related to the change in the refractive power following the blunt trauma. CONCLUSIONS: Ultrasound biomicroscopy (UBM) and ultrasonography of the anterior segment in the eye may be helpful to diagnose and confirm changes in the refractive power that occur after trauma.     

Attempted eyelid closure affects intraocular pressure measurement in open-angle glaucoma patients

PURPOSE: To evaluate the effect of attempted eyelid closure on intraocular pressure (IOP) measurements in normal-tension (NTG) and high-tension (HTG) open-angle glaucoma patients. DESIGN: Prospective clinical trial. METHODS: Forty randomly selected eyes of 40 patients underwent corneal pachymetry and IOP measurements using both Goldmann applanation tonometry and Tono-pen XL (Mentor, Inc., Norwell, Massachusetts, USA). Intraocular pressure was measured by the same examiner holding the eyelids open, both with and without the subject simultaneously attempting forced eyelid closure. Subjects were seated during all measurements and waited 5 minutes between measurements with each instrument; the order of measurement was randomized. RESULTS: Twenty NTG and 20 HTG eyes were enrolled. The mean age was 63.0 +/- 13.0 years (range, 31-80 years). The average corneal thickness was 540 +/- 32 microm (range, 480-608 microm) in NTG patients and 552 +/- 40 microm (range, 449-610 microm) in HTG patients (P =.07, analysis of variance [ANOVA]). Using Goldmann applanation tonometry, IOP measurement in eyes with NTG increased by 3.9 +/- 2.0 mm Hg with attempted eyelid closure (P <.0001, paired t test; range, 2-11 mm Hg). With the Tono-pen XL, IOP measurements increased 4.2 +/- 2.7 mm Hg (P <.0001, paired t test; range, 1-14 mm Hg). With attempted forced eyelid closure, the Goldmann applanation measurement in eyes with HTG increased 4.1 +/- 2.1 mm Hg (P <.0001, paired t test; range, 1-9 mm Hg). Using the Tono-pen XL, measurements increased 4.5 +/- 2.0 mm Hg (P <.0001, paired t test; range, 2-11 mm Hg). CONCLUSION: Attempted eyelid closure during tonometry is a significant and common source of error in eyes with glaucoma and may influence the clinical management and decision-making in the treatment of NTG and HTG.     

全景超声生物显微镜对人眼睫状沟距离及前房直径的测量

背景睫状沟距离的直接测量对人工晶状体（IOL）植人术中IOL尺寸的选择具有重要意义。全景超声生物显微镜（UBM）的问世使在活体眼直接进行睫状沟距离的测量成为可能。目的探讨人眼前房直径和睫状沟距离之间的相关性及其在不同前房深度人群中的差别。方法将疑似青光眼患者30例30只右眼作为浅前房组,而具有高度近视（-7— -18D）的30例30只右眼作为深前房组。应用全景超声生物显微镜（UBM）进行图像采集,每眼获取焦点位于虹膜平面的眼球水平方向3：00～9：00处的全景截面图像共3张。由同一测量者对每一幅图像的前房直径和睫状沟距离进行测量。取3幅图像测量值的均值为最终测量结果,用独立样本t检验和线性回归方程分析评估前房直径与睫状沟距离测量值的关系。结果浅前房组的30眼中,全景UBM测得的前房直径为（11．49±0．75）mm,睫状沟距离为（10．97±0．86）mm,二者间的平均差值为（-5．14±0．55）mm,差异有统计学意义（t=-5．092,P=0．000）,线性回归分析显示二者之间呈线性相关（R2=0．593,P=0．000）,Pearson相关系数为0．767。深前房组的30眼中,全景UBM测得的前房直径均值为（12．69±0．67）mm;睫状沟距离为（12．31±0．61）mm,二者之间平均差值为（-0．38±0．17）mm,差异有统计学意义（t=-5．531,P=0．000）;线性回归分析显示二者之间具有显著相关性（R2=0．699,P=0．000）,Pearson相关系数为0．836。结论全景UBM测得的睫状沟距离和前房直径呈明显正相关,深前房眼的相关性大于浅前房眼,该结果对于IOL植入术中IOL尺寸的选择具有重要意义。     

Assessment of anterior segment parameters under photopic and scotopic conditions in Indian eyes using anterior segment optical coherence tomography

PURPOSE: To compare the anterior segment parameters in photopic and scotopic conditions using anterior segment optical coherence tomography (AS OCT) in Indian eyes. MATERIALS AND METHODS: One hundred eyes of 100 normal subjects of both sexes, aged 19 to 76 years, underwent anterior segment evaluation by AS OCT (Visante OCT). Central corneal thickness (CCT), central anterior chamber depth (ACD), pupil diameter (PD) and the temporal and nasal peripheral irido-corneal angles were assessed in photopic and scotopic conditions. These anterior segment parameters were stratified for age, sex and refractive error. RESULTS: Mean values of the parameters measured in photopic and scotopic conditions respectively were as follows: ACD (mm) 2.88 +/- 0.32, 2.89 +/- 0.32 (P = 0.10); nasal angle (degrees) 28.80 +/- 5.91, 22.28 +/- 7.50 (P < 0.001); temporal angle (degrees) 29.95 +/- 6.74, 22.82 +/- 8.43 (P < 0.001); pupil diameter (mm) 4.08 +/- 0.91, 4.68 +/- 0.92 (P < 0.001); CCT (microm) 519 +/- 33.88, 519 +/- 33.88. CONCLUSIONS: There was no significant difference in the ACD in photopic and scotopic conditions. While the nasal and temporal angles showed a significant decrease, the pupil diameter showed a significant increase in scotopic conditions. Mean central ACD decreased with age and was shallower in females than in males. It was highest in myopes and lowest in hypermetropes. CCT was not influenced by photopic and scotopic conditions.     

孔源性视网膜脱离行巩膜外环扎和巩膜外加压术对眼球结构和眼压的影响

目的：观察巩膜外环扎术和巩膜外环扎联合巩膜外加压术对孔源性视网膜脱离(rhegmatogenous retinal detachment,RRD)患者眼球结构和眼压的影响。

方法：选取2014-05/2017-05在我院住院行手术治疗的RRD患者240例240眼,其中接受巩膜外环扎术100眼(巩膜外环扎术组),接受巩膜外环扎联合巩膜外加压术140眼(联合组)。术前、术后2、4、12wk,检测眼压、角膜厚度、角膜水平和垂直曲率、前房深度、晶状体厚度、眼轴长度、睫状体厚度及小梁虹膜夹角度数。

结果：术后12wk,两组患者240眼均获得解剖复位。术后2wk,两组眼压、角膜厚度、角膜水平和垂直曲率、晶状体厚度、睫状体厚度均较术前显著增加,前房深度及小梁虹膜夹角度数均较术前明显减小,差异均有统计学意义(P<0.05)。两组患者术后视力均较术前改善,且术后2wk联合组视力明显优于巩膜外环扎术组,差异均有统计学意义(P<0.05)。

结论：巩膜外环扎术和巩膜外环扎联合巩膜外加压术对角膜、前房、房角、晶状体厚度及小梁虹膜夹角度数在早期均有显著影响,巩膜外环扎联合巩膜外加压术对眼压的影响时间长,应予以关注。     

应用超声生物显微镜研究睫状肌麻痹剂对眼前节结构的影响

目的应用超声生物显微镜观察局部应用睫状肌麻痹剂前、后眼前节形态结构的改变及其与眼压的关系,同时对睫状体厚度、睫状体晶体赤道部距离进行观察。方法以４８只正常眼为研究对象,在局部应用２％后马托品前、后分别进行眼前节结构的超声生物显微镜定量测定,并测量眼压。对其结果进行统计学分析。结果用药后在反映房角改变的参数中,小梁虹膜夹角减小,房角开放距离２５０减小,虹膜厚度１增厚,前房加深,虹膜晶体接触距离缩短,差异均有显著性（Ｐ＜０．０５）;在反映睫状体改变的参数中,睫状体和睫状突的厚度减小,巩膜睫状体夹角增大,虹膜悬韧带距离减小,睫状体晶体距离增大,差异有显著性（Ｐ＜０．０５）。应用睫状肌麻痹剂后,眼压由２．３５±０．４６ｋＰａ（１ｋＰａ＝７．５ｍｍＨｇ）升高至２．４３±０．４７ｋＰａ,但差异无显著性（Ｐ＞０．０５）。结论局部应用睫状肌麻痹剂后,前房加深、房角变窄、睫状体变薄且向后运动、睫状体晶体距离增大。超声生物显微镜能动态观察眼前节结构的改变并行定量测定,在眼前节形态学研究中具有优越性。