Sulcus Diameter Research Articles

Direct Measurement of the Ciliary Sulcus Diameter Using Optical Coherence Tomography—Inter-Rater Variability

The determination of sulcus-to-sulcus measurements has been challenging due to the limitations of current approaches. Ultrasound methods are highly operator-dependent and require extensive training, while traditional optical devices cannot visualize structures posterior to the iris. However, modern optical anterior segment coherence tomography (AS-OCT) devices are changing this paradigm by identifying some anatomical landmarks posterior to the iris. This study evaluates the reproducibility of optical sulcus measurements in the context of sizing a novel accommodative intraocular lens (IOL). Preoperative OCT scans of patients scheduled for cataract surgery were analyzed regarding the dimensions of the ciliary sulcus using a custom scan method with a clinically available anterior segment optical coherence tomographer. Measurements were compared between two different readers, and various derived parameters were compared. The measurements by both readers were highly correlated (R2 > 0.96), and their agreement was excellent (mean difference 0.02 mm with 95% limits of agreement from −0.11 to 0.15 mm). In contrast, the sulcus diameter measurement did not agree well with automatically calculated values, such as the anterior chamber width or white-to-white. This leads to the conclusion that modern swept-source AS-OCT measurements of the ciliary sulcus dimensions are feasible, reproducible, and may be a clinically useful tool.

Ocular features in myopic eyes with longer horizontal ciliary sulcus diameters for intended implantable collamer lens surgery.

To assess the ocular anterior segment characteristics in myopic eyes intended for ICL surgery with horizontal ciliary sulcus-to-sulcus (STS) diameters being greater than vertical STS diameters. This retrospective, comparative case study included 1230 eyes of patients who underwent ICL implantation for the treatment of myopia or myopic astigmatism at the Zhongshan Ophthalmic Center from September 2020 to November 2021. The myopic eyes were divided into two groups according to the relatively long diameter of the ciliary sulcus. General parameters and anterior chamber parameters were compared between the two groups. 1230 eyes of 694 patients were included. The proportion of myopic eyes with longer horizontal STS diameters was 4.63%. Horizontal STS distances exceeding vertical meridians in these eyes were mainly attributed to the shortening of vertical STS distances (horizontal STS: P = 0.112; vertical STS: P < 0.001). Eyes with longer horizontal meridians of the ciliary sulcus displayed larger steep keratometry value (P = 0.001), larger corneal volume (P = 0.002), larger corneal astigmatism (P < 0.001), larger ocular residual astigmatism (P = 0.017), worse visual acuity (logMAR UDVA: P = 0.021; logMAR CDVA: P = 0.001), and more iridociliary cysts (P = 0.017) compared to eyes with vertically oval shapes. Myopic eyes with longer horizontal STS diameters are commonly accompanied by a change in corneal morphology and more iridociliary cysts. The anatomical features of the ciliary sulcus should be given sufficient consideration to ICL size and placement selection, contributing to more personalized and precise surgery.

Оценка смещений интраокулярной линзы по данным ультразвуковой биомикроскопии

Purpose. To analyze the postoperative IOL displacements toward the haptic plane using ultrasound biomicroscopy (UBM). Material and methods. Biometry data of 172 patients (211 eyes) 71.32 ± 7.75 years old were analyzed, among whom 41.25% were men. IOL position were analyzed at 1 and 3 months after standard phacoemulsification. Results. The IOL was visualized with UBM. Stabilization of lens position was observed by the 3rd month of observation. The displacement of optical part IOL in forward was determined in 24.95%, backward – in 16.57% of cases. Eyes with opposite IOL displacements differed significantly in crystalline lens diameter, ciliary sulcus diameter and the power of implanted IOL. Conclusions. An important technique in the search for possible causes of changes in postoperative refraction is visualization of IOL displacement. The number of displacements of the intraocular lens increases by 3 months, which may cause in visual acuity changes. Keywords: Intraocular lens (IOL) optical part displacement, ultrasound biomicroscopy (UBM), phacoemulsification

Analysis of intraocular lens displacement relative to the haptic plane by ultrasound biomicroscopy data

This study analyzed cases with postoperative displacement of intraocular lens (IOL) relative to the haptic plane using ultrasound biomicroscopy (UBM). The study analyzed biometry data of 231 patients (277 eyes) aged 72.39±7.77 years, among them 43.25% were males. IOL position and refraction were analyzed at 1, 3 and 6 months after standard phacoemulsification. UBM was performed to analyze the position of the IOL. Stabilization of lens position was observed by the 3rd month of observation. Among the cases with displacement of the optical part relative to the haptic plane, the forward shift was determined in 24.85%, backward - in 16.67% of cases. Eyes with opposite IOL displacements differed significantly in lens diameter, ciliary sulcus diameter and the power of implanted IOL. IOL shift towards the retina produced significant hyperopic refractive error. A discriminant function was compiled using preoperative biometry data comprising the model for predicting backward IOL displacement with high probability. However, we failed to obtain a qualitative model for forward IOL displacements. Calculation error in modern formulas could occur because of IOL displacement, including the shift of the optical part relative to the haptic plane in postoperative period. Analysis of biometry data allows calculating IOL displacement towards the retina with a high probability, which could help avoid hyperopic refraction error postoperatively.

Validation of the vault prediction model based on the sulcus-to-sulcus diameter and lens thickness: a 925-eye prospective study

BackgroundTo verify the accuracy and stability of the prediction formula based on the ciliary sulcus diameter and lens thickness and to analyse factors influencing the prediction results.MethodsIn total, 925 eyes from 506 subjects were enrolled in this prospective study between July 1, 2020, and June 30, 2021. Subjects were divided into four seasons, each spanning three months. The target vault was set to be between 300 μm and 700 μm according the prediction formula. The actual vault was measured one month postoperatively. The Bland–Altman test, 95% confidence intervals (95% CI) and 95% limits of agreement (95% LoA) were used to evaluate the agreement between the predicted vault and the actual vault. Eyes with absolute prediction errors greater than 300 μm were further analysed.ResultsThe mean predicted vaults for the four seasons were 503 ± 99, 494 ± 96, 481 ± 92 and 502 ± 93 μm, while the mean actual vaults were 531 ± 189, 491 ± 179, 464 ± 179 and 529 ± 162 μm, respectively. The predicted and actual vaults of the overall subjects were 493 ± 95 and 500 ± 180 μm, respectively. Of the 925 eyes, 861 eyes (93.08%), 42 eyes (4.54%), and 22 eyes (2.38%) showed a normal vault, high vault, and low vault, respectively. Bland–Altman plots showed that the mean difference between the actual vault and predicted vault overall (± 95% LoA) was 6.43 ± 176.2 μm (-339 to 352 μm). Three UBM features may lead to large prediction errors (more than 300 μm): wide iris-ciliary angle (ICA), iris concavity and anteriorly positioned ciliary body.ConclusionsThis study demonstrated the accuracy and stability of the prediction formula through the validation of a large sample size and a long time span. Wide ICA, iris concavity and anteriorly positioned ciliary body may have an effect on vault.

Characteristics of the Ciliary Body in Healthy Chinese Subjects Evaluated by Radial and Transverse Imaging of Ultrasound Biometric Microscopy.

Background: The imaging and analysis of the ciliary body (CB) are valuable in many potential clinical applications. This study aims to demonstrate the anatomy characteristics of CB using radial and transverse imaging of ultrasound biometric microscopy (UBM) in healthy Chinese subjects, and to explore the determining factors. Methods: Fifty-four eyes of 30 healthy Chinese subjects were evaluated. Clinical data, including age, body mass index (BMI), intraocular pressure (IOP), axial length (AL), and lens thickness (LT), were collected. Radial and transverse UBM measurements of the ciliary body were performed. Anterior chamber depth (ACD), ciliary sulcus diameter (CSD), ciliary process length (CPL), ciliary process density (CPD), ciliary process area (CPA), ciliary muscle area (CMA), ciliary body area (CBA), ciliary body thickness (CBT0, CBT1, and CBTmax), anterior placement of ciliary body (APCB), and trabecular-ciliary angle (TCA) of four (superior, nasal, inferior, and temporal) quadrants were measured. Results: The average CPL was 0.513 ± 0.074 mm, and the average CPA was 0.890 ± 0.141 mm2. CPL and CPA tended to be longer and larger in the superior quadrant (p < 0.001) than in the other three quadrants. Average CPL was significantly correlated with AL (r = 0.535, p < 0.001), ACD (r = 0.511, p < 0.001), and LT (r = −0.512, p < 0.001). Intraclass correlation coefficient (ICC) scores were high for CPL (0.979), CPD (0.992), CPA (0.966), CMA (0.963), and CBA (0.951). Conclusions: In healthy Chinese subjects, CPL was greatest in the superior quadrant, followed by the inferior, temporal, and nasal quadrants, and CPA was largest in the superior quadrant, followed by the tempdoral, inferior, and nasal quadrants. Transverse UBM images can be used to measure the anatomy of the ciliary process with relatively good repeatability and reliability.

Adjustment formulae to improve the correlation of white-to-white measurement with direct measurement of the ciliary sulcus diameter by ultrasound biomicroscopy

PurposeThis study evaluates the correlation between horizontal white-to-white (WTW) distance using Caliper and Orbscan IIz with the ciliary sulcus diameter measured by high frequency ultrasound biomicroscopy (UBM) and presents an adjustment formula to improve the correlation. MethodsWe measured horizontal sulcus-to-sulcus (STS) dimension of 273 right eyes of 273 high myopic patients with 35 MHz UBM and horizontal WTW using Orbscan IIz and Caliper. Mean WTW diameter, differences, and the correlation of measurement methods were evaluated. ResultsThe mean spherical equivalent was −8.79 ± 4.87 diopters. Mean horizontal STS dimension with UBM was 12.13 ± 0.45 mm (range, 10.81–13.42 mm). Mean WTW diameter in the Caliper method was 11.70 ± 0.40 mm (range, 10.6–12.8 mm) and 11.70 ± 0.40 mm (range, 10.5–13.1 mm) in the Orbscan method. Mean difference of UBM STS and WTW with Caliper was 0.48 ± 0.28 mm (range, −0.19 to 1.37 mm). Mean difference of UBM STS diameter and Orbscan WTW was 0.38 ± 0.31 mm (range, −0.64 to 1.29 mm). The Pearson correlations of WTW diameter measured by Caliper and Orbscan with UBM's STS diameter were 0.778 and 0.773, respectively. This difference diminished after adjustment. The 95% limit of agreement was almost the same in Caliper and Orbscan (−0.07 to 1.03 compared with −0.23 to 0.99). ConclusionThere is a significant difference in measurements between STS diameter using UBM and WTW diameter utilizing Caliper and Orbscan. This difference diminished after our recommended adjustment.

Posterior Vault Distance of Ciliary Sulcus–Implanted Three-piece Intraocular Lenses According to Ciliary Sulcus Diameter

To investigate the correlation among preoperative biometry data, postoperative ciliary sulcus diameter, posterior vault distance, and effective lens position of ciliary sulcus-implanted intraocular lenses (IOLs). Retrospective interventional case series. Twenty-six eyes of 26 patients underwent phacoemulsification with implantation of a ZA9003 IOL (Abbott Medical Optics Inc, Santa Ana, California, USA) in the ciliary sulcus. We analyzed correlations among preoperative biometry data and ultrasound biomicroscopy measurements, ciliary sulcus diameter, posterior vault distance, and effective lens position. Regression analyses were performed to identify which combination of preoperative biometry data, average corneal power (keratometry [K]), anterior chamber depth (ACD), and axial length (AL) was best for predicting effective lens position. The sulcus diameter was shorter in eyes that had a steep cornea and shorter AL. The posterior vault distance was negatively correlated with sulcus diameter in subjects who had shorter postoperative time intervals (≤24months) (R2= 0.336 and P= .038). The posterior vault distance decreased with each passing postoperative month (R2= 0.158 and P= .045). The R2 value for predicting the effective lens positions of sulcus-implanted IOLs based on the entire average K, ACD, and AL was higher than those based on parts of these values. The effective lens position of sulcus-implanted IOLs can be affected by sulcus diameter, and lens position can change, especially in the early postoperative period. We recommend using the entire average K, ACD, and AL to predict the effective position of sulcus-implanted IOLs.

Pseudophacomorphic Glaucoma Along with Pupillary Block after Visian&amp;lt;sup&amp;gt;TM&amp;lt;/sup&amp;gt; Implantable Collamer Lens Implantation for High Myopia

To report a case of bilateral glaucoma related to pseudophacomorphic mechanism in one eye and pupillary block in the other eye after Visian Implantable Collamer Lens (ICL, STAAR Surgical) insertion. A 44 year-old female with high myopia underwent bilateral ICL implantation of MICL12.6 after sulcus diameter measurements were performed by Pentacam. Pseudophacomorphic glaucoma-related angle closure occurred due to lens oversizing in the right eye. The mechanism was relieved via ICL explantation. In the left eye, pupillary block developed in a subacute manner after closure of the peripheral iridotomy (PI). The attack was ameliorated by reestablishing patency of the iridotomy. ICL-related glaucomatous attacks may result from improper sizing as well as from placement of a single PI. Identification of the proper mechanism is vital as treatments differ significantly. In pseudophacomorphic glaucoma, explantation is needed. In pupillary block glaucoma, treatment involves establishment of a patent PI.

Correlation between white-to-white diameter and ciliary sulcus diameter of high myopia eyes

To investigate the ciliary sulcus diameters in horizontal and vertical axes and to analyze the correlation between white-to-white diameter and horizontal ciliary sulcus diameter for high myopia eyes at different anterior chamber depths. IOL-Master was used to measure white-to-white diameters and anterior chamber depths of 108 high myopia eyes and verified by digital caliper. Based on the depth of central anterior chamber not including corneal thickness, the testing eyes were divided into three groups: shallow AC group (3.0 mm < ACD ≤ 3.2 mm), medium AC group (3.2 mm < ACD ≤ 3.4 mm), and deep AC group (ACD > 3.4 mm). Furthermore, the horizontal and vertical ciliary sulcus diameters were checked by full-scale 50-Hz ultrasound biomicroscopy. The data of three AC groups were analyzed separately. The paired sample t-test was used to compare: white-to-white diameters and horizontal sulcus diameters, horizontal and vertical suclus diameters. The correlations between white-to-white diameters and horizontal sulcus diameters were assessed using linear regression analysis. The difference in the three groups of white-to-white diameters and ciliary sulcus diameters were compared by Student Newman Keuls test. The mean diameters and standard deviations of WTW diameters and horizontal ciliary sulcus diameters in the shallow AC group was, respectively, (11.46 ± 0.38) and (11.57 ± 0.32) mm(t = -2.849, P = 0.007). Linear regression analysis found a statistically significant correlation between white-to-white diameters and horizontal sulcus diameters with a coefficient of determinant of 0.797 (P = 0.000). The mean vertical suclus diameters was (12.27 ± 0.48) mm. The difference between horizontal and vertical suclus diameters was statistically significant (t = -15.522, P = 0.000) . The mean diameters and standard deviations of WTW diameters and horizontal ciliary sulcus diameters in the medium AC group was, respectively, (11.58 ± 0.31) and (11.77 ± 0.26) mm. (t = -4.523, P = 0.000). Linear regression analysis found a statistically significant correlation between white-to-white diameters and horizontal sulcus diameters with a coefficient of determinant of 0.639 (P = 0.000). The mean vertical suclus diameters was (12.52 ± 0.37) mm. The difference between horizontal and vertical suclus diameters was statistically significant (t = -13.987, P = 0.001) . The mean diameters and standard deviations of WTW diameters and horizontal ciliary sulcus diameters in the medium AC group was, respectively, (11.68 ± 0.22) and (11.91 ± 0.23) mm (t = -5.157, P = 0.000). Linear regression did not reveal horizontal sulcus diameters were a significant predictor of white-to-white diameters with a coefficient of determinant of 0.253 (P = 0.126). The mean vertical suclus diameters was (12.69 ± 0.36) mm. The difference between horizontal and vertical suclus diameters was statistically significant (t = -18.433, P = 0.000) . The white-to-white diameter measuring technique is not identical to the horizontal diameter of the ciliary sulcus and the potential difference between them is increased with deepening anterior chamber depth. Our preliminary study illustrated that the ciliary sculus is not circular and a vertical diameter is longer than horizontal one.

Ciliary sulcus diameters at different anterior chamber depths in highly myopic eyes

To determine the correlation between white-to-white (WTW) diameters and horizontal ciliary sulcus diameters at different anterior chamber depths (ACDs) in highly myopic eyes. First Affiliated Hospital of Anhui Medical University, Hefei, China. Cross-sectional observational study. Highly myopic eyes were divided into a shallow ACD group (2.8 to 3.2 mm), medium ACDgroup (3.2 to 3.4 mm), and deep ACD group (>3.4 mm). Ciliary sulcus diameters were measured by full-scale 50 MHz ultrasound biomicroscopy. In the shallow ACD group, linear regression showed that horizontal sulcus diameters were a significant predictor of WTW diameters (P<.001). The difference between them was greater than 0.50 mm in 13.1% of eyes. In the medium ACD group, linear regression showed horizontal sulcus diameters were a significant predictor of WTW diameters (P<.001). The difference between them was greater than 0.50 mm in 25.7% of eyes and greater than 1.0 mm in 2.8% of eyes. In the deep ACD group, linear regression did not show that horizontal sulcus diameters were a significant predictor of WTW diameters (P=.126). The difference between them was greater than 0.50 mm in 31.6% of eyes and greater than 1.0 mm in 5.3% of eyes. In all eyes, vertical diameters were greater than horizontal diameters. The WTW technique was inaccurate at predicting the horizontal diameter of the ciliary sulcus, and predictive errors increased with increasing ACDs. The posterior chambers were not perfectly circular, with vertical diameters being greater than horizontal diameters. No author has a financial or proprietary interest in any material or method mentioned.

Selection of the posterior chamber phakic intraocular lens length

To evaluate the efficacy, safety and clinical value of calculating the posterior chamber phakic intraocular lens (ICL) length according to the corneal horizontal diameter. This was a retrospective study. A Staar Visian implantable contact lens (ICL) was implanted in 32 patients (64 eyes) with high myopia in the Department of Ophthalmology, the First Affiliated Hospital, College of Medicine, Zhejiang University between November 15, 2005 and January 15, 2011. The lens length was calculated according to the corneal horizontal diameter measured by Orbscan II. Patients were followed up postoperatively at 1 day, 1 week, 1, 3, 6 and 12 months and every 6 months thereafter. The evaluations included visual acuity, manifest refraction, applanation tonometry, endothelial cell count, slit-lamp microscopy to detect cataract, and UBM to assess the degree of ICL tilt and distances between the corneal endothelium, the ICL, and the crystalline lens. All of the preoperative and 12-month follow-up observations were analyzed using SPSS 16.0 software. No anterior subcapsular cataracts were found in any of the eyes after surgery. Pigmentary dispersion was observed on the anterior and posterior surface of the ICL, but the difference was not statistically significant (χ(2) = 2.24, P = 0.13). The intraocular pressure changed from (15.67 ± 3.23) mm Hg (1 mm Hg = 0.133 kPa) to (15.78 ± 3.23) mm Hg, but the difference was not significant (t = 0.24, P = 0.38). The corneal endothelium-lens (central section) distance measured by UBM postoperatively was (2.97 ± 0.25) mm and the corneal endothelium-ICL (central section) distance was (2.24 ± 0.27) mm; the difference between them was statistically significant (t = 15.77, P < 0.01). The degree of ICL tilt measured by UBM was 1.20° ± 1.05 °. The percentage of eyes with a trabecular-iris angle (TIA) greater than 30°, between 21° and 30°, between 11°and 20°, and smaller than 10° were 29.1%, 50.0%, 11.6%, and 9.3%, respectively. The angle opening distance at 500 micron (AOD500) measured by UBM postoperatively was (0.32 ± 0.15) mm. The contact distance between the iris and the ICL measured by UBM postoperatively was (0.85 ± 0.46) mm and the ICL-lens central distance was (0.47 ± 0.25) mm. The Pearson's correlation coefficients between the ICL-lens central distance and the corneal horizontal diameter, sulcus diameter, anterior chamber depth(ACD) and ICL length were 0.11, 0.16, 0.04 and 0.19, respectively; none were statistically significant. The ICL-lens peripheral distance measured by UBM postoperatively was (0.25 ± 0.20) mm. Selecting the length of the ICL according to the corneal horizontal diameter is appropriate, and assures the safety, effectiveness and predictability of ICL implantation.

Comparison of Postoperative Vault Height Predictability Using White-to-White or Sulcus Diameter–based Sizing for the Visian Implantable Collamer Lens

To compare vault height predictability of Implantable Collamer Lens (ICL; Staar Surgical) sizing using a sulcus diameter-based formula or the manufacturer-recommended white-to-white-based method. In 50 myopic eyes, ICL size was calculated using both a formula including sulcus diameter and the traditional formula based on white-to-white diameter. Sulcus diameter was measured using Artemis 2 very high-frequency (VHF) digital ultrasound (ArcScan Inc). Implantation was based on the sulcus diameter derived size. Actual postoperative vault height achieved was measured by VHF digital ultrasound scanning. Circle segment trigonometry was used to calculate the vault height that would have resulted had lens sizing been based on the white-to-white formula. The same lens size would have been used in 60% of eyes, a smaller lens would have been used in 34% of eyes and a larger lens in 6% of eyes had lens sizing been based on the white-to-white formula. Mean vault for eyes with lenses sized using the sulcus diameter formula was 0.37±0.16 mm (range: 0.08 to 0.92 mm), with 2% <0.09 mm, the recognized low-vault height for risk of cataract. Circle segment trigonometry predicted that the vault height would have been 0.24±0.28 mm (range: -0.31 to 0.92 mm), with 26% <0.09 mm had lens sizing been based on the white-to-white formula. Significantly better predictability of postoperative vault height was achieved by including sulcus diameter into the ICL sizing formula compared with using the traditional white-to-white-based formula.

Sulcus anatomy and diameter in pseudophakic eyes and correlation with biometric data: Evaluation with a 50 MHz ultrasound biomicroscope

To evaluate the sulcus anatomy and possible correlations between sulcus diameter and white-to-white (WTW) diameter in pseudophakic eyes, data that may be important in the stability of add-on intraocular lenses (IOLs). University Eye Hospital, Tuebingen, Germany. Case series. In pseudophakic eyes, the axial length (AL) and horizontal WTW were measured by the IOLMaster device. Cross-sectional images were obtained with a 50 MHz ultrasound biomicroscope on the 4 meridians: vertical, horizontal (180 degrees), temporal oblique, and nasal oblique. Sulcus-to-sulcus (STS), angle-to-angle (ATA), and sclera-to-sclera (ScTSc) diameters were measured. The IOL optic diameter (6.0 mm) served as a control. To test reliability, optic measurements were repeated 5 times in a subset of eyes. The vertical ATA and STS diameters were statistically significantly larger than the horizontal diameter (P=.0328 and P=.0216, respectively). There was no statistically significant difference in ScTSc diameters. A weak correlation was found between WTW and horizontal ATA (r = 0.5766, P<.0001) and between WTW and horizontal STS (r = 0.5040, P=.0002). No correlation was found between WTW and horizontal ScTSc (r = 0.2217, P=.1217). The sulcus anatomy had a vertical oval shape with the vertical meridian being the largest, but it also had variation in the direction of the largest meridian. The WTW measurements showed a weak correlation with STS. In pseudophakic eyes, Soemmerring ring or a bulky haptic may affect the ciliary sulcus anatomy.

Assessment of a single-piece hydrophilic acrylic IOL for piggyback sulcus fixation in pseudophakic cadaver eyes

To evaluate a single-piece hydrophilic acrylic intraocular lens (IOL) designed for sulcus fixation in a piggyback configuration in postmortem pseudophakic human eyes. John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Experimental study. Pseudophakic human cadaver eyes were imaged by high-frequency ultrasound (Artemis) to assess the overall position of the primary IOL and the sulcus diameter. The piggyback IOL (Sulcoflex) was then injected into the ciliary sulcus of these eyes. After fixation in formalin, they were reevaluated by high-frequency ultrasound for assessment of IOL fixation, fit, centration, tilt, and clearance from the primary IOL and intraocular structures and analyzed after sectioning. Data could be obtained from 11 eyes, all in which the primary IOL was located in the capsular bag. Different foldable IOLs and different degrees of Soemmerring ring formation were represented. The piggyback IOL could be injected and positioned in the ciliary sulcus and had overall appropriate centration and minimum or no tilt. Clearance between the 2 IOLs ranged from 232 to 779 μm, mostly depending on the thickness of the primary IOL. Direct assessment of the sulcus-fixated haptics showed no disturbances to the ciliary processes. The new IOL has large optic and overall diameters, smooth and undulating haptics, and a convex-concave optic profile. Results show that these characteristics minimize the possibility of interaction with the primary IOL and uveal tissues, decreasing the likelihood of optical aberrations and pigmentary dispersion.

Evaluation of ciliary sulcus diameter using ultrasound biomicroscopy in emmetropic eyes and myopic eyes

To measure the ciliary sulcus-to-sulcus (STS) diameter in 4 axes in emmetropic and myopic eyes using ultrasound biomicroscopy (UBM) and compare the measurements with automated horizontal white-to-white (WTW) diameter measurements. University Eye Hospital Freiburg, Freiburg im Breisgau, Germany. Evaluation of diagnostic technology. The STS diameter was measured at 0, 45, 90, and 135 degrees using 35 MHz UBM. The 0-degree WTW diameters were obtained using scanning-slit topography (Orbscan) and partial coherence interferometry (PCI) biometry (IOLMaster). The 0-degree STS and 90-degree STS were compared using the paired t test; the Pearson correlation was used to assess whether the 0-degree STS diameter could be predicted from the 0-degree WTW diameter. The mean SE refraction was -0.48 diopter (D) ± 0.35 (SD) in emmetropic eyes and -9.55 ± 3.70 D in myopic eyes. In 35 of 37 eyes, 90-degree STS was greater than 0-degree STS. The mean 90-degree STS was 12.51 ± 0.43 mm. The mean 0-degree STS was 12.19 ± 0.47 mm (P<.01). The mean 0-degree WTW diameters were 11.73 ± 0.37 mm (scanning-slit topography) and 12.20 ± 0.42 mm (PCI biometry). The correlations were good between 0-degree STS and 0-degree WTW with PCI biometry (r(2) = 0.82) and scanning-slit topography (r(2) = 0.86) in emmetropic eyes but weak between 0-degree STS and 0-degree WTW in myopic eyes (r(2) = 0.36 and r(2) = 0.40, respectively). Sulcus diameter measurements were most precise using UBM. The ciliary sulcus is vertically oval. The WTW diameter is not suitable for calculating a PC pIOL diameter, particularly in myopic eyes.

Relationship between ciliary sulcus diameter and anterior chamber diameter and corneal diameter

To evaluate the relationship between the horizontal ciliary sulcus diameter and anterior chamber diameter measured by 35 MHz ultrasound biomicroscopy (UBM) and the horizontal corneal diameter (white to white [WTW]) measured by scanning-slit topography and to assess the repeatability (intraexaminer difference) of the 2 methods. Department of Orthoptics and Visual Science, Kitasato University School, Sagamihara, Japan. The repeatability and agreement of UBM and scanning-slit topography were assessed using the intraclass correlation (ICC) and the Bland and Altman method (ie, mean difference and 95% limits of agreement [LoA]). Thirty-one normal eyes of 31 subjects (mean age 22.6 years +/- 4.8 [SD]) were evaluated. The mean differences between the repeated measurements were as follows: ciliary sulcus diameter, -0.05 mm (95% LoA, -0.38 to 0.28 mm); anterior chamber diameter, 0.02 mm (95% LoA, -0.42 to 0.45 mm); and WTW diameter, -0.02 mm (95% LoA, -0.18 to 0.13 mm). The agreement between ciliary sulcus diameter and WTW diameter was poor (ICC, 0.679). The mean difference was 0.41 mm (95% LoA, -0.46 to 1.28 mm). The agreement between the ciliary sulcus diameter and anterior chamber diameter was high (ICC, 0.918). The mean difference was 0.13 mm (95% LoA, -0.41 to 0.67 mm). Results suggest that direct measurement of the ciliary sulcus by UBM would reduce the percentage of complications related to intraocular lens sizing over the percentage when sizing is based on WTW diameter.

Measurement of White-to-White Diameter and Anterior Chamber Depth by Dual Scheimpflug Camera

Purpose: To estimate the horizontal and vertical white-to-white diameters (WTW) and anterior chamber depths (ACD) with a dual Scheimpflug camera (GALILEI, Ziemer, Switzerland) and to compare the estimates measured by a measuring caliper and ultrasound biomicroscopy (UBM PlusTM, Paradigm Inc., Utah, USA) in normal subjects. Methods: Forty-four eyes of 23 subjects were evaluated. Corneal diameter as measured by GALILEI was directly compared with the white-to-white diameter (WTW) measured by a caliper and the correlation with ciliary sulcus diameter (STS) by UBM was evaluated. The anterior chamber depth (ACD) as measured by GALILEI was compared with the estimates measured by UBM. Results: The horizontal and vertical diameters of WTW by GALILEI were not significantly different from the measurements taken by calipers (p>0.05, p>0.05, respectively), and there were no correlations between the measurements (r=-0.074, p>0.05 at 180 r=0.297, p>0.05 at 90, respectively). The estimates by GALILEI did not correlate with those measured with UBM (r=-0.006, p>0.05 at 180 r=-0.222, p>0.05 at 90, respectively). However, the mean ACD by GALILEI was deeper than thatby UBM (p

Ciliary Sulcus Diameter and Two Anterior Chamber Parameters Measured by Optical Coherence Tomography and VHF Ultrasound

To evaluate the relationship between two anterior chamber anatomical parameters, angle-to-angle and iris pigment end-to-iris pigment end distances, and sulcus-to-sulcus diameter. Twenty eyes without active ocular pathologies or previous ocular surgeries from 20 patients ranging in age from 23 to 51 years were included in this study. Mean spherical equivalent refraction ranged from +5.50 to -7.00 diopters. Angle-to-angle and iris pigment end-to-iris pigment end distances were measured in all cases three times consecutively using two technologies: optical coherence tomography (OCT) and very high-frequency ultrasonography. Sulcus-to-sulcus diameter was additionally obtained by ultrasonography. Correlation, linear regression, intrasession, and interchangeability analysis between parameters was performed. Mean sulcus-to-sulcus diameter was 11.92+/-0.80 mm. Mean angle-to-angle distance was 12.14+/-0.52 mm for ultrasonography and 12.23+/-0.59 mm for OCT. Mean iris pigment end-to-iris pigment end distance was 12.18+/-0.51 mm for ultrasonography and 12.29+/-0.61 mm for OCT. No statistically significant differences were found among these anatomical parameters (unpaired Student t test, all P>.10). Statistically significant correlations were found between sulcus-to-sulcus diameter and angle-to-angle distance and between sulcus-to-sulcus diameter and iris pigment end-to-iris pigment end distance for both imaging techniques. For ultrasonography, range of agreement was 0.90 mm between sulcus-to-sulcus diameter and angle-to-angle distance and 0.74 mm between sulcus-to-sulcus diameter and iris pigment end-to-iris pigment end distance. These ranges increased to 1.22 mm and 1.14 mm, respectively, for OCT measurements. Angle-to-angle and iris pigment end-to-iris pigment end distances are correlated with sulcus-to-sulcus diameter, but they cannot be used as equivalent parameters.

Effects of White-to-White Diameter and Anterior Chamber Depth on Implantable Collamer Lens Vault and Visual Outcome

To investigate the effects of anterior chamber depth (ACD) and white-to-white (WTW) diameter on vault in eyes with implantable collamer lenses (ICL V4, STAAR Surgical AG) and to evaluate the effect of vault on visual outcomes and other biometric changes. Twenty-eight eyes of 16 patients who underwent ICL implantation were retrospectively reviewed. Patients were divided into two groups (A1, A2) according to preoperative ACD (> or = 3.3 mm and < 3.3 mm, respectively), two groups (B1, B2) based on WTW diameter (> or = 11.55 mm and < 11.55 mm, respectively), and two groups (C1, C2) according to the difference of ICL diameter and sulcus length (> or = 0.25 mm and < 0.25 mm, respectively). Vault, endothelial cell density, and visual performance were compared between each set of groups. Correlations of vault with WTW diameter, ACD, and diametric difference of the ICL from the sulcus were analyzed. The high ACD and WTW groups showed significantly higher vaults (0.59 +/- 0.32 mm and 0.57 +/- 0.36 mm, respectively) than the low ACD and WTW groups (0.26 +/- 0.17 mm and 0.25 +/- 0.14 mm, respectively; P = .01 and .01), whereas the differences of diameter between the sulcus and ICL were not related to significant vault differences. The WTW diameter wascorrelated more closely to the vault than the ACD or sulcus diameter (r = 0.70, P < .001), whereas the vault difference did not affect visual quality or endothelial cell density. A high WTW diameter or ACD is likely to render a high vault, regardless of any difference in the ICL and sulcus diameters.