PURPOSE: To evaluate the accuracy of the Smith method, van Herick technique, and Shaffer grading system, using a slit-lamp biomicroscope and gonioscope that measure anterior chamber depth (ACD), peripheral chamber depth (PCD), and angle width. METHODS: The anterior chamber of 94 eyes of 53 subjects was evaluated by slit-lamp examination with a gonioscope. An A-scan was carried out on all of the subjects, but ultrasound biomicroscope (UBM) was performed on only 42 of 94 eyes. Slit-lamp biomicroscope-assisted measurements, such as ACD, PCD, and angle width, were compared with those by A-scan and UBM. RESULTS: The correlations among ACD measurements, obtained by the Smith method, and those obtained using A-scan (r=0.673, p<0.001) and UBM (r=0.824, p<0.001) were statistically significant. The mean PCD, measured by van Herick technique, was 14.01+/-15.04 %, and its correlation with that of UBM was statistically significant (r=0.706, p<0.001). In addition, the correlation between the mean angle width, measured by Shaffer grading system and by UBM, was also statistically significant (r=0.853, p<0.001). CONCLUSIONS: Assessments of the anterior segment, using a slit-lamp biomicrosope and a gonioscope, are comparable to those of A-scan and UBM measurements and are, therefore, useful for evaluation of the anterior chamber.
Anterior Chamber ; Ultrasonography

The ultrasonographic technique is an one of the safest, simplest and the most accurate methods of biometric measurement of the eyeball. Ultrasonography of A mode was performed to measure the anterior chamber depth and the ocular axial length of 60 emmetropic eyes and of 140 myopic eyes of greater than 3.00 Diopter. Interrelationship of the refractory error and the ocular axial length, the anterior chamber depth, as well as the myopic crescent(conus) was studied in 140 Korean myopic eyes from May 1st, 1985 through September 30th, 1985. The results of the study were as follows: 1. The mean axial length of the emmetropic eyes is 23.94mm and their mean anterior chamber depth, 3.08mm. 2. The mean axial length of the myopic eyes of greater than 3.00 Diopter is 25.76mm and their mean anterior chamber depth, 3.52mm. 3. As the refractory error in the myopic eyes increases by 1 Diopter, the mean axial length and the mean anterior chamber depth increases respectively by 0.29mm and 0.08mm. 4. The myopic crescent(conus) was observed in the 95% of myopic eyes.
Anterior Chamber* ; Ultrasonography

PURPOSE: To evaluate intraobserver reproducibility of measurements in images obtained by the ultrasound biomicroscopy (UBM plus, model P45, Paradigm(R), Inc., Utah, USA) and estimate the agreement of measurements by ultrasound biomicroscopy and A-scan ultrasound (model P37, Paradigm(R), Inc., Utah, USA). METHODS: The anterior segment images of fifteen normal patients were obtained twice by single examiner. Six different parameters were measured in each image. Among the parameters, anterior chamber depth was compared with that measured by A-scan ultrasound. RESULTS: The intraobserver reproducibility was high for all six parameters that includes central corneal thickness (coefficient of variation (%) 2.80), anterior chamber depth (coefficient of variation (%) 1.20), anterior chamber angle (coefficient of variation (%) 4.01), scleral thickness (coefficient of variation (%) 4.28), trabecular meshwork-iris distance (coefficient of variation (%) 6.09) and angle opening distance (AOD500, coefficient of variation (%) 6.09). The correlation between ultrasound biomicroscopy and A-scan ultrasound in measuring the anterior chamber depth was statistically significant (correlation coefficient = 0.79, p=0.002). CONCLUSIONS: The measurements of anterior segment parameters by ultrasound biomicroscopy have high reproducibility and will be useful in evaluating the anterior segment structure.
Anterior Chamber ; Humans ; Microscopy, Acoustic* ; Ultrasonography* ; Utah

We measured the lens thickness and anterior chamber depth on 214 eyes (162 cataract eyes, 52 normal control eyes) using the EAS-1000 Scheimpflug camera. And the results was compared with measurement of A-scan ultrasonography in 49 cataract eyes. The thickness of cataract lens, especially in anterior subcapsular opacities in over 61 years old was significantly thin rather than control lens (panterior chamber depth was statistically deeper, especially in anterior subcapslar type of the 5th and 7th decades compared with control group (p<0.05, p0.05). Lens thickness was increased with age by an annual rate of 0.0l5mm in monnal eyes (panterior chamber depth was found to be 5% shallower. We confirmed that thickening rates of lens is decreased in cataract and there is differences between the measurement of Scheimpflug camera and that of A-scan ultrasonography.
Anterior Chamber ; Cataract* ; Humans ; Middle Aged ; Ultrasonography

PURPOSE: To compare the accuracy and clinical usefulness of different devices by measuring anterior chamber depth (ACD) with three devices and central corneal thickness (CCT) with four devices. METHODS: In 180 eyes of 90 healthy subjects, ACD was measured using A-scan, Lenstar LS900®, Pentacam®, and CCT was measured using ultrasound pachymetry (USP), Lenstar LS900®, Pentacam®, and anterior segment optical coherence tomography (OCT). RESULTS: The average ACT measurements using Lenstar LS900®, A-scan, and Pentacam® were 3.27 ± 0.35 mm, 3.26 ± 0.36 mm, and 3.25 ± 0.36 mm, respectively. The measurements were significantly correlated (p < 0.001) but without statistically significant difference (p = 0.017). The Bland-Altman plots showed a low degree of agreement. The average CCT measurements using Pentacam®, USP, Lenstar LS900®, and OCT were 553.31 ± 25.23 µm, 547.26 ± 23.83 µm, 541.38 ± 24.49 µm, and 531.40 ± 22.33 µm, respectively. The measurements were significantly correlated (p < 0.001) and statistically significantly different (p < 0.05). The Bland-Altman plots showed a low degree of agreement. CONCLUSIONS: ACD and CCT measured using different devices were highly correlated, but the ACD measurements were not statistically different; however, the CCT measurements were statistically different, and agreement was low between both measurements.
Anterior Chamber* ; Healthy Volunteers ; Tomography, Optical Coherence ; Ultrasonography

PURPOSE: To establish quantified values for anterior segment of normal adult Koreans using ultrasound biomicroscopy (UBM) in relation to age and sex. METHODS: Anterior segment images were obtained in 114 normal Koreans (54 males and 60 females) using UBM. Six different parameters (central corneal thickness, anterior chamber depth, scleral thickness, trabeculariris distance, angle-opening distance 500 and anterior chamber angle) were measured by the same examiner in central chamber image and angle image. Among the parameters, anterior chamber depth was compared with that measured by A-scan. RESULTS: Average central corneal thickness was 495.2 +/- 29.6 micro meter in male and 488.8 +/- 20.6 micro meter in female, anterior chamber depth 2.997 +/- 0.297 mm in male and 2.763 +/- 0.314 mm in female, anterior chamber angle 38.86 +/- 3.62 degrees in male and 36.01 +/- 3.23 degrees in female and angle-opening distance 500 316.2 +/- 52.4 micro meter in male and 290.9 +/- 54.4 micro meter in female, respectively. Anterior chamber depth, anterior chamber angle, trabecular-iris distance and angle-opening distance 500 were smaller in female than male. Anterior chamber depth showed a significant decrease in relation to age in male and female. Values of anterior chamber depth were statistically significantly correlated between UBM and A-scan. CONCLUSIONS: Quantified values were established for anterior segment using UBM in normal adult Koreans. In the future, they will be useful in evaluating the anterior segment structures and diseases.
Adult* ; Anterior Chamber ; Female ; Humans ; Male ; Microscopy, Acoustic* ; Ultrasonography*

PURPOSE: To compare the axial lengths, anterior chamber depths, and keratometric measurements and to predict postoperative refractions of AL-Scan(R), IOL master(R), and ultrasound. METHODS: A total of 40 eyes in 30 patients who received cataract surgery were included in the present study. The axial length, anterior chamber depth, and keratometry were measured by 2 types of partial coherence interferometry (AL-Scan(R) and IOL master(R)) and ultrasound. The SRK/T formula was used to calculate IOL power, and the predictive error which subtracts predictive refraction from postoperative refraction was compared among the ocular biometry devices. RESULTS: Axial lengths were 23.08 +/- 0.62 mm, 23.09 +/- 0.62 mm, and 22.99 +/- 0.62 mm measured by AL scan(R), IOL master(R), and ultrasound, respectively. Axial length measured by ultrasound was statistically significantly shorter than AL scan(R) and IOL master(R) (p < 0.001, p < 0.001, respectively). The anterior chamber depth and keratometry were 3.11 +/- 0.06 mm and 44.82 +/- 1.34 D measured by AL scan(R), and 3.13 +/- 0.06 mm and 44.85 +/- 1.26 D measured by IOL master(R), respectively. The differences of anterior chamber depth and keratometry between the 2 devices were not statistically significant (p = 0.226, p = 0.331, respectively). The mean absolute prediction errors were 0.44 +/- 0.35 D, 0.40 +/- 0.34 D, and 0.39 +/- 0.30 D in AL-Scan(R), IOL master(R) and ultrasound, respectively, and were not statistically significantly different (p = 0.843, p = 0.847, p = 1.000, respectively). CONCLUSIONS: The ocular biometric measurements and prediction of postoperative refraction using AL-Scan(R) were as accurate as IOL master(R) and ultrasound.
Anterior Chamber ; Biometry* ; Cataract* ; General Surgery ; Humans ; Interferometry ; Ultrasonography

The effect of capsular tension ring[CTR]on prevention of contraction of capsular opening induced by continuous curvilinear capsulorhexis in cataract surgery has been evaluated. In this study, we performed cataract surgery on 15 patients[23 eyes]in Group I[IOL implantation with CTR] and 13 patients[24 eyes]in Group II[IOL implantation without CTR]from September 1998 to November 1998. We compared uncorrected visual acuity[UCVA], spherical equivalent[SE], astigmatism, size of capsular opening, IOL rotation and change of anterior chamber depth between two Groups. We used image analysis system to determine an actual size of capsular opening and measured a depth of anterior chamber than 5 times by using A-scan ultrasound. GroupIand IIshowed a similar pattern of change of UCVA, SE and astigmatism. Contraction rate of capsular opening 2 months after operation was 1.41%in Group Iand 3.95%in Group II. This difference was statistically significant [p<0.001].The anterior chamber depth increased temporarily in both groups, However, it was slightly decreased and maintained in Group I, while steadily decreased in Group II. Rotation of IOL was greater in Group IIthan Group I. However, it was not statistically significant. With these results it would be concluded that CTR might prevent a contraction of capsular opening and enhance a stability of IOL.
Anterior Chamber ; Astigmatism ; Capsulorhexis ; Cataract* ; Lenses, Intraocular* ; Ultrasonography

PURPOSE: To investigate the accuracy of the Haigis formula compared to other formulas using contact ultrasound biometry. METHODS: This study was performed on 94 patients (114 eyes) who underwent cataract surgery in our hospital. Axial length (AXL) and anterior chamber depth (ACD) were measured using both A-scan and intraocular lens (IOL) Master(R). Patients were divided into three groups based on AXL; Group I (AXL < 22.5 mm), Group II (22.5 mm < or = AXL < 25.5 mm), and Group III (AXL > or = 25.5 mm). Before cataract surgery, predicted refraction was calculated using the Haigis, SRK/T, Hoffer Q, and Holladay 1 formulas using both A-scan and IOL Master(R) measurements. Mean absolute error (MAE) were analyzed at one month after surgery using the various IOL formulas. RESULTS: Using contact ultrasound biometry, in Group I, MAE of Haigis was 0.80 +/- 0.67 D and was significantly lower than that using SRK/T. In Group II, the Haigis MAE was 0.72 +/- 0.55 D and was significantly lower than the results of all other formulas. In Group III, the Haigis MAE was 0.76 +/- 1.13 D and not significantly different from the results of other formulas. Comparing MAE of A-scan to IOL Master(R), the Haigis formula showed 0.16 D higher error that decreased when the AXL was close to the normal range. CONCLUSIONS: Using contact ultrasound biometry, the Haigis formula provided the best predictability of postoperative refractive outcome compared to other formulas in eyes with normal axial length.
Anterior Chamber ; Biometry* ; Cataract ; Humans ; Lenses, Intraocular ; Reference Values ; Ultrasonography*

PURPOSE: To investigate the accuracy of the Haigis formula compared to other formulas using contact ultrasound biometry. METHODS: This study was performed on 94 patients (114 eyes) who underwent cataract surgery in our hospital. Axial length (AXL) and anterior chamber depth (ACD) were measured using both A-scan and intraocular lens (IOL) Master(R). Patients were divided into three groups based on AXL; Group I (AXL < 22.5 mm), Group II (22.5 mm < or = AXL < 25.5 mm), and Group III (AXL > or = 25.5 mm). Before cataract surgery, predicted refraction was calculated using the Haigis, SRK/T, Hoffer Q, and Holladay 1 formulas using both A-scan and IOL Master(R) measurements. Mean absolute error (MAE) were analyzed at one month after surgery using the various IOL formulas. RESULTS: Using contact ultrasound biometry, in Group I, MAE of Haigis was 0.80 +/- 0.67 D and was significantly lower than that using SRK/T. In Group II, the Haigis MAE was 0.72 +/- 0.55 D and was significantly lower than the results of all other formulas. In Group III, the Haigis MAE was 0.76 +/- 1.13 D and not significantly different from the results of other formulas. Comparing MAE of A-scan to IOL Master(R), the Haigis formula showed 0.16 D higher error that decreased when the AXL was close to the normal range. CONCLUSIONS: Using contact ultrasound biometry, the Haigis formula provided the best predictability of postoperative refractive outcome compared to other formulas in eyes with normal axial length.
Anterior Chamber ; Biometry* ; Cataract ; Humans ; Lenses, Intraocular ; Reference Values ; Ultrasonography*