Eye morphometry, body size, and flexibility parameters in myopic adolescents.

The aim of this study was to investigate the anatomical and physiological ocular parameters in adolescents with myopia and to examine the relations between refractive error (SER), ocular biometry, body size and flexibility parameters in myopic adolescents. A cross-sectional study of 184 myopic adolescents, aged 15 to 19 years was conducted. Refractive error and corneal curvature measures of the eye were evaluated using an autorefractometer under cycloplegia. Central corneal thickness was determined by contact pachymetry. The ocular axial length, anterior and vitreous chamber depth, and lens thickness were measured using A-scan biometry ultrasonography. Height and body weight were measured according to a standardized protocol. Body mass index (BMI) was subsequently calculated. Beighton scale was used to measure joint flexibility. Body stature was positively correlated with ocular axial length (r = 0.39, p < 0.001) and vitreous chamber depth (r = 0.37, p < 0.001). There was a negative correlation between height and SER (r = - 0.46; p < 0.001). Beighton score and body weight had weak positive correlations with axial length and vitreous chamber depth, and a weak negative correlation with SER. A significantly more negative SER was observed in the increased joint mobility group (p < 0.05; U = 5065.5) as compared to normal joint mobility group: mean - 4.37 ± 1.85 D (median - 4.25; IQR - 6.25 to - 3.25 D) and mean - 3.72 ± 1.66 D (median - 3.50; IQR - 4.75 to - 2.25 D) respectively. There was a strong association between height and axial length, as well as SER. Higher degree of myopia significantly correlated with greater Beighton score (increased joint mobility).

Comparison Between Ocular Biometric Parameters and Intraocular Pressure With and Without Contact Lenses.

OBJECTIVES: To compare the values of central corneal thickness, anterior chamber depth (ACD), lens thickness (LT), vitreous length (VL), axial length (AL), and corneal-compensated intraocular pressure performed with and without contact lenses (CL). METHODS: Forty volunteer participants (16 men and 24 women, 24.2±2.9 years) were recruited. In a single visit, participants underwent autorefraction, keratometry, biometry, topography, pachymetry, and tonometry with the naked eye (without CL). Then, biometry, pachymetry, and tonometry were repeated twice wearing two CL (somofilcon A and nesofilcon A) fitted in a random order. RESULTS: Many of the ocular biometric values were affected by the use of CL during measurements (paired t test; all P ≤0.003), except for LT and VL (Wilcoxon test; both P ≥0.272). Corneal-compensated intraocular pressure was also affected by contact lens wear during measurements, obtaining lower values when wearing them (Wilcoxon test; all P ≤0.001). CONCLUSIONS: Central corneal thickness, ACD, AL, and corneal-compensated intraocular pressure measurements cannot be performed while wearing CL. However, LT and VL measurements were not affected by any contact lens use. In addition, it was observed that ACD results from both devices are not interchangeable either when measured with the naked eye or using any contact lens.

Anterior chamber depth in mice is controlled by several quantitative trait loci.

Anterior chamber depth (ACD) is a quantitative trait associated with primary angle closure glaucoma (PACG). Although ACD is highly heritable, known genetic variations explain a small fraction of the phenotypic variability. The purpose of this study was to identify additional ACD-influencing loci using strains of mice. Cohorts of 86 N2 and 111 F2 mice were generated from crosses between recombinant inbred BXD24/TyJ and wild-derived CAST/EiJ mice. Using anterior chamber optical coherence tomography, mice were phenotyped at 10-12 weeks of age, genotyped based on 93 genome-wide SNPs, and subjected to quantitative trait locus (QTL) analysis. In an analysis of ACD among all mice, six loci passed the significance threshold of p = 0.05 and persisted after multiple regression analysis. These were on chromosomes 6, 7, 11, 12, 15 and 17 (named Acdq6, Acdq7, Acdq11, Acdq12, Acdq15, and Acdq17, respectively). Our findings demonstrate a quantitative multi-genic pattern of ACD inheritance in mice and identify six previously unrecognized ACD-influencing loci. We have taken a unique approach to studying the anterior chamber depth phenotype by using mice as genetic tool to examine this continuously distributed trait.

Association between anterior chamber biometry and posterior capsular defects.

PURPOSE: To analyze the association between anterior chamber biometric factors and posterior capsular defects (PCDs) that occur during extracapsular cataract extraction. SETTING: University Eye Hospital, Goethe University Frankfurt, Germany. DESIGN: Population-based study. PATIENTS AND METHODS: Extracapsular cataract extractions for inpatient cases within 4 years were retrospectively analyzed. The data on the occurrence of PCDs, age, sex, surgeon, and biometry were obtained. For cases with PCDs, the secondary ocular diseases, number of procedures, lens implant, visual acuity, and course were also recorded. Swept-source optical coherence tomography measurements allowed the measurement of lens thickness (LT) in addition to the usual biometry values. RESULTS: A total of 1967 cataract surgeries (patients age: 70.56 ± 8.42, 1005 women; 962 men) were included, and PCDs were documented for 59 (2.54%; 31 women, 28 men) cases (patient age: 70.95 ± 8.52 years). There were no differences ( P = .76) related to the surgeons (n = 9) with minimal effect sizes. The mean LT, axial length, corneal curvature, and anterior chamber depth were 4950.36 ± 466.63 µm, 23.73 ± 1.77 mm, 43.89 ± 1.36 diopters, and 3.02 ± 0.71 mm, respectively. The Wilcoxon-Mann-Whitney test showed significant associations between LT ( P = .01) and PCDs with moderate relevance for the Rosenthal effect size (LT R = 0.34; ACD R = 0.29). CONCLUSIONS: In addition to ACD, a tendency for the occurrence of PCD could be proven, especially for LT. Therefore, special attention should be paid to LT preoperatively for comprehensive risk stratification.

Comparison of the ocular ultrasonic and optical biometry devices in the different quality measurements.

PURPOSE: To compare the reliability and agreement of axial length (AL), anterior chamber depth (ACD), and lens thickness (LT) measurements obtained with optical biometry based on swept-source optical coherence tomography (IOLMaster 700; Carl Zeiss, Germany) and an ultrasound biometry device (Nidek; US-4000 Echoscan, Japan) in different qualities of AL measurement. METHODS: A total of 239 consecutive eyes of 239 cataract surgery candidates with a mean age of 56 ± 14 years were included. The quality measurements were grouped according to the quartiles of SD of the measured AL by IOLMaster 700. The first and fourth quartile's SD are defined as high and low-quality measurement, respectively, and the second and third quartiles' SD is defined as moderate-quality. RESULTS: The reliability of AL and ACD between the two devices in all patients and in different quality measurement groups was excellent with highly statistically significant (AL: all ICC=0.999 and P<0.001, ACD: all ICC>0.920 and P<0.001). AL and ACD in all quality measurements showed a very strong correlation between devices with highly statistically significant. However, there was poor (ICC=0.305), moderate (ICC=0.742), and good (ICC=0.843) reliability in measuring LT in low-, moderate-, and high-quality measurements, respectively. LT showed a very strong correlation (r = 0.854) with highly statistically significant (P<0.001) between devices only in patients with high-quality measurements. CONCLUSIONS: AL and ACD of the IOLMaster700 had outstanding agreements with the US-4000 ultrasound in different quality measurements of AL and can be used interchangeably. But LT should be used interchangeably cautiously only in the high-quality measurements group.

Lenstar LS900 vs EchoScan US-800: comparison between optical and ultrasound biometry with and without contact lenses and its relationship with other biometric parameters.

BACKGROUND: Due to the increasing use of contact lenses (CL) and the interest in ocular and body size relationships, this study aimed to compare measurements from two biometers (contact ultrasonic EchoScan US-800 and non-contact optical Lenstar LS900) with and without CL and to explore the relationship between ocular and body biometric parameters. DESIGN AND METHODS: This cross-sectional study measured ocular biometry using two biometers along with their body height and right foot length in 50 participants. Differences between biometry data from the two devices were compared and correlations between ocular and body biometric values were analyzed. RESULTS: All parameters showed interbiometric differences (p ≤ 0.030), except crystalline lens thickness during CL wear (p = 0.159). Comparing measurements with and without CL, differences were observed in axial length (p < 0.001), vitreous length measured by optical biometer (p = 0.016), and anterior chamber depth by ultrasonic biometer (p < 0.016). Lens thickness remained unaffected (p ≥ 0.190). Body height and foot length were correlated with anterior chamber depth, vitreous length, and axial length (p ≤ 0.019, r ≥ 0.330). Most biometric parameters were correlated among them using both devices (p ≤ 0.037, r ≥ 0.296). CONCLUSIONS: These biometers are not interchangeable and CL affects measurements. Body height and foot length correlate with ocular dimensions, and most ocular biometric values correlate positively.

Intraocular lens power calculation in eyes with a shallow anterior chamber depth and normal axial length.

We compared the accuracy of three intraocular lens (IOL) calculation formulas in eyes with a shallow anterior chamber depth (ACD) and normal axial length (AXL) and control eyes. We retrospectively reviewed eyes with a shallow ACD (<2.5 mm from the corneal epithelium) with normal AXL (22.5≤AXL<24.0 mm) and controls (3.0≤ACD<3.5 mm and normal AXL). Prediction error (PE) and median absolute error (MedAE) were evaluated with SRK/T, Barrett Universal II (BUII), and Kane formulas after adjusting the mean PE to zero for all patients. Percentages of eyes achieving a PE within 0.25 to 1.00 D, and correlations between ACD, lens thickness (LT), and PE were analyzed. Thirty-five shallow ACD and 63 control eyes were included. PE in the shallow ACD group showed more hyperopic results with BUII and Kane but not with SRK/T compared to controls. Within the shallow ACD group, PE showed more hyperopic results in BUII and Kane compared to SRK/T. However, the standard deviation (SD) of PE among formulas was not different. In the shallow ACD group, SRK/T showed a higher percentage of PE within 0.25 D than BUII and Kane, but the percentages within 0.50 to 1.00 D were similar. PE was negatively correlated with ACD in BUII and Kane, and positively correlated with LT in all formulas. BUII and Kane may induce slight hyperopic shift in eyes with a shallow ACD and normal AXL. However, the performance of the three formulas was comparable in the shallow ACD group in terms of MedAE, the SD of PE, and the percentage of eyes achieving PE within 0.50 D.

Evaluation and comparison of ocular biometric parameters obtained with Tomey OA-2000 in silicone oil-filled aphakic eyes.

PURPOSE: To evaluate a new non-contact instrument (OA-2000) measuring the ocular biometry parameters of silicone oil (SO)-filled aphakic eyes, as compared with IOLMaster 700. METHODS: Forty SO-filled aphakic eyes of 40 patients were enrolled in this cross-sectional clinical trial. The axial length (AL), central corneal thickness (CCT), keratometry ((flattest keratometry) Kf and (steep keratometry, 90° apart from Kf) Ks), and axis of the Kf (Ax1) were measured with OA-2000 and IOLMaster 700. The coefficient of variation (CoV) was calculated to assess the repeatability. The correlation was evaluated by the Pearson coefficient. Bland-Altman analysis and paired t test were used to analyze the agreements and differences of parameters measured by the two devices, respectively. RESULTS: The mean AL obtained with the OA-2000 was 23.57 ± 0.93 mm (range: 21.50 to 25.68 mm), and that obtained with the IOLMaster 700 was 23.69 ± 0.94 mm (range: 21.85 to 25.86 mm), resulting in a mean offset of 0.124 ± 0.125 mm (p < 0.001). The mean offset of CCT measured by OA-2000 and IOLMaster 700 was 14.6 ± 7.5 µm (p < 0.001). However, the Kf, Ks and Ax1 values from the two devices were comparable (p > 0.05). All the measured parameters of the two devices showed strong linear correlations (all r ≥ 0.966). The Bland-Altman analysis showed a narrow 95% limits of agreement (LoA) of Kf, Ks and AL, but 95%LoA of CCT and Ax1 was wide, which were - 29.3 ~ 0.1 µm and-25.9 ~ 30.7°respectively. The CoVs of the biometric parameters obtained with OA-2000 were lower than 1%. CONCLUSION: In SO-filled aphakic eyes, the ocular parameters (including AL, Kf, Ks, Ax1, and CCT) measured by the OA-2000 and IOLMaster 700 had a good correlation. Two devices had an excellent agreement on ocular biometric measurements of Kf, Ks and AL. The OA-2000 provided excellent repeatability of ocular parameters in SO-filled aphakic eyes.

Investigation of ocular biometry in 4- to 9-year-old Chinese children.

PURPOSE: To investigate the distribution and changes in ocular biometry in 4-to to 9-year-old Chinese children and to compare the differences between age and genders in these parameters. METHODS: This was a school-based cross-sectional study. A total of 1,528 Chinese children, aged 4-9 years, from one primary school and 12 kindergartens, were included in the study. Axial length, corneal curvature, anterior chamber depth, and corneal diameter were measured for each child. RESULTS: AL and anterior chamber depth gradually increased with age in both genders. No significant changes in corneal curvature or corneal diameter were detected at different ages in either genders group. The mean ALs of males and females were 22.94 ± 0.80 mm and 22.38 ± 0.79 mm, respectively. The mean corneal curvatures of males and females were 43.05 ± 1.37 D and 43.75 ± 1.48 D, respectively. The mean anterior chamber depth of males and females were 3.47 ± 0.24 mm and 3.38 ± 0.25 mm, respectively. The mean corneal diameter of males and females were 12.08 ± 0.43 mm and 11.94 ± 0.44 mm, respectively. Females had consistently shorter ALs, shorter anterior chamber depth, smaller corneal diameter, and steeper corneal curvatures than males at any age. CONCLUSIONS: Boys had larger dimensions than girls for all ocular parameters except corneal curvature (flatter). Boys and girls showed similar trends for all parameters. Axial length and anterior chamber depth increased from 4 to 9 years of age, whereas corneal diameter and curvature did not change with age in either genders.

Global metrics on ocular biometry: representative averages and standard deviations across ten countries from four continents.

BACKGROUND/OBJECTIVES: We provide global averages and standard deviations for ocular biometry-axial length (AL), corneal radius of curvature (CR), anterior chamber depth (ACD), lens thickness (LT), white to white (WTW), and central corneal thickness (CT). We hope a better understanding of normal and abnormal values will help clinicians gain further insight into their surgical outcomes, especially for off-target eyes. SUBJECTS/METHODS: We searched the MEDLINE database using keywords "axial length, corneal power, anterior chamber depth, lens thickness, white to white, and corneal thickness." We included studies that reported averages and standard deviations on eye biometry for at least 1300 eyes. Global weighted averages and standard deviations were calculated using the Cochrane method. RESULTS: Fourteen studies were included, originating from Asia (Japan, Singapore, Myanmar, Iran, South Korea, China), Europe (Germany, United Kingdom, Portugal), Australia, and North America (United States). Global ocular biometry metrics were: AL-23.49 mm ± 1.35 mm, CR-7.69 mm ± 0.28 mm, ACD-3.10 mm ± 0.47 mm, WTW-11.80 mm ± 0.42 mm, LT-4.37 mm ± 0.43 mm, and CT-544 µm ± 38 µm. Total eyes per value ranged from 19,538 to 90,814. CONCLUSIONS: We report global ocular biometry averages and standard deviations. No eyes were from studies in Africa or South America, highlighting the need to publish eye biometry data from these continents. We hope that promoting a deeper understanding of biometry values will help clinicians gain insight into surgical outcomes and drive innovations in lens calculations.

Repeatability of new optical biometer and agreement with 2 validated optical biometers, all based on SS-OCT.

PURPOSE: To evaluate the repeatability of the measurements provided by a new optical biometer (EyeStar 900) based on swept-source optical coherence tomography (SS-OCT) and their agreement with the measurements given by 2 validated biometers based on the same technology, the IOLMaster 700 and Argos. SETTING: IRCCS G.B. Bietti Foundation, Rome, Italy. DESIGN: Prospective evaluation of diagnostic test. METHODS: In a series of unoperated eyes, 3 consecutive scans were acquired with the EyeStar 900, and 1 with the IOLMaster 700 and the Argos. The following biometry parameters were analyzed: axial length (AL), keratometry (K), corneal astigmatism, central corneal thickness, corneal diameter (CD), anterior chamber depth (ACD), lens thickness (LT), and lens tilting. Repeatability was assessed using test-retest variability, the coefficient of variation (CoV), and the intraclass correlation coefficient (ICC); agreement was based on the 95% limits of agreement. RESULTS: 56 eyes of 56 patients were analyzed. High repeatability was achieved for all measured parameters, as the CoV was <1% in most cases and ICC was >0.95 for all parameters. Good to high agreement was found among the measurements of the 3 optical biometers, although some statistically significant differences were detected between the EyeStar 900 and Argos (mean K, ACD, LT, and CD were higher with the Argos). The Argos measured a shorter AL in eyes >25 mm. CONCLUSIONS: The new generation SS-OCT EyeStar 900 optical biometer produces highly repeatable measurements that are in good agreement with those provided by 2 previously validated instruments.

Changes in ocular biological parameters after cycloplegia based on dioptre, age and sex.

The effects of cycloplegia on ocular biological parameters in children have been extensively studied, but few studies have compared these parameters between different refractive states, ages, and sexes. Therefore, the purpose of this study was to investigate the changes in ocular biometry before and after cycloplegia in different groups based on dioptre, age and sex. We examined a total of 2049 participants in this cross-sectional study. A comprehensive eye examination was conducted before cycloplegia. Cycloplegia was implemented with the application of atropine or tropicamide. Ocular biological parameters were evaluated after cycloplegia, including axial length (AL), mean keratometry (K), flat keratometry (K1), steep keratometry (K2), central corneal thickness (CCT), anterior chamber depth (ACD) and white-to-white (WTW) distance. All the participants were categorized based on dioptre, age and sex. Statistical analysis was performed with paired t tests and Wilcoxon signed-rank tests. Regarding dioptre, AL was found to be increased significantly in the Fs, Ast and FA (p < 0.05) postcycloplegia groups. We observed significant increases in K, K1, K2 and ACD in the Fs group (p < 0.05) after cycloplegia. Regarding age, we found significant increases in AL, CCT and ACD in group 1 (p < 0.05), but AL decreased significantly in groups 2 and 3 (p < 0.05) postcycloplegia. There were no significant changes found in K, K1 and K2 in the three groups after cycloplegia (p > 0.05). Regarding sex, AL and WTW were found to decrease significantly among males and increase significantly among females (p < 0.05) postcycloplegia, while K, K1 and K2 showed the opposite trends. This study showed that there were differences in some ocular biological parameters after cycloplegia across different groups; in particular, there were significant differences in AL, CCT and ACD. Attention should be devoted to the influence of cycloplegia in clinical work.

Evaluation of three biometric devices: ocular parameters and calculated intraocular lens power.

Cataract surgery is among the most common medical procedures, and accurate ocular biometry measurements are key for successful visual outcome. The current study evaluated data obtained by the Eyestar 900, Anterion, IOLMaster700 biometers and the Pentacam corneal topographer. Compared values were axial length (AL), anterior chamber depth (ACD), steep- and flat-K, cylinder and axis. Clinical impact was assessed by calculating intraocular lens (IOL) power using the mean values of every parameter and the Barrett and Kane formulas, stratified by device and amount of cylinder. IOL was re-calculated for each device substituting Pentacam K-values. This study included 196 eyes (98 participants) of cataract surgery candidates. When comparing the IOLMaster to the Eyestar (157 eyes), no difference was found in mean AL or ACD measurements (P > 0.05). Steep-K measurements differed between these devices and the Pentacam (P = 0.01). AL and ACD measurements differed between the IOLMaster and Anterion (38 eyes; P < 0.05). Strong correlations (range 0.72-0.99) were found between all four devices. Bland-Altman analysis demonstrated excellent agreement between biometry devices other than ACD between the IOLMaster and Eyestar. Calculated IOL power was 0.50-1.00 diopter (D) lower with the IOLMaster. Cylinder power was 0.75D higher in all biometers when Pentacam K-values were substituted.

Comparison of Ocular Biometric Parameters Between Hispanic and Non-Hispanic Ethnicities in White Adults Undergoing Cataract Surgery.

OBJECTIVES: To compare ocular biometric parameters between Hispanic and non-Hispanic White adult patients undergoing cataract surgery. METHODS: We included 433 adult patients undergoing surgery for senile cataract. Only patients with race and ethnicities of Hispanic and non-Hispanic White were included. The following parameters measured by the IOLMaster 700 were compared between Hispanic and non-Hispanic patients: mean keratometry, corneal astigmatism, anterior chamber depth (ACD), lens thickness, vitreous length, axial length, white-to-white diameter, and emmetropic intraocular lens power. RESULTS: There were 219 Hispanic patients and 214 non-Hispanic patients with a mean age of 70.1±7.7 years (range, 50-88 years), and 66.7% were women. Although sex distribution was similar between the two groups, Hispanic patients had a lower age compared with non-Hispanic patients (69.3±8.3 vs. 70.9±6.9 years, P=0.02). In biometric values, ACD was significantly lower in Hispanic patients (3.07±0.40 mm) than in non-Hispanic patients (3.16±0.37 mm, P=0.01). Such statistically significant difference persisted after adjustment for age and sex (P=0.01). No other significant differences were found in other ocular parameters measured. CONCLUSIONS: Anterior chamber depth is significantly shorter in Hispanic patients compared with non-Hispanic patients. Such ethnic difference should be considered when performing cataract and corneal surgeries because this ethnic difference may be associated with a higher risk of corneal endothelial injury.

A comparison of IOLMaster 500 and IOLMaster 700 in the measurement of ocular biometric parameters in cataract patients.

To compare the agreement of ocular biometric parameters measured by IOLMaster 500 and IOLMaster 700. This is a prospective study. IOLMaster 500 and IOLMaster 700 were used to measure the axial eye length (AL), corneal flat keratometry (Kf), corneal steep keratometry (Ks), mean keratometry (Km), corneal astigmatism(CA), J0, J45, anterior chamber depth (ACD) and corneal horizontal diameter (white-to-white distance, WTW) of 518 eyes (392 patients) with cataracts. Patients were enrolled unilaterally. Subgroup analyses were done according to the AL and Km. The intraclass correlation coefficient (ICC) and Bland-Altman analysis were used to evaluate the agreement. A total of 275 eyes were analyzed. The 95% confidence interval of ICC of the mean AL, Ks, Kf, Km, J0, and ACD values measured by the two instruments are indicative of excellent reliability (P < 0.001). The measurement results of WTW show good reliability (P < 0.001). The ICC of CA is of good reliability in CA < 0.5 D group (P = 0.000) and moderate reliability in the other two groups (P = 0.000). The WTW is the widest range among 95% consistency of the limit range measured by the two instruments. The results of IOLMaster 500 and IOLMaster 700 in measuring AL, keratometry, and ACD in cataract patients are of high agreement.

Split-Window OCT biometry in pseudophakic eyes.

PURPOSE: To determine the utility of Split-Window optical coherence tomography OCT (SW-OCT) biometry in measuring ocular axial dimensions as well as imaging the intraocular lens (IOL) and posterior capsule in pseudophakic eyes. METHODS: Sixty-nine pseudophakic eyes of 69 subjects were enrolled in the study. The results of SW-OCT biometry implemented in the SD OCT device for posterior and anterior segment imaging (REVO NX, Optopol Technology) were compared with those obtained with the SS-OCT-based biometer IOLMaster 700 (Carl Zeiss Meditec). Differences in measurement values between the two biometers were determined using the paired t-test. Agreement was assessed through intraclass correlation coefficients (ICC) and Bland-Altman plots. RESULTS: The correlation between measurements obtained with SW-OCT and SS-OCT was very high (ICC for: axial length (AL) = 1.000; anterior chamber depth (ACD) = 0.997; IOL thickness (IOL LT) = 0.997; central corneal thickness (CCT) = 0.987). The mean AL measurement difference was 0.003 ± 0.021 mm (the 95% LoA ranged from -0.04 to 0.05); the mean ACD difference was -0.009 ± 0.025 mm (95% LoA, -0.06 to 0.04); mean LT difference was 0.001 ± 0.021 mm (95% LoA, -0.04 to 0.04); and mean CCT difference was 1.4 ± 5.4 µm (95% LoA, -9 to 12). CONCLUSION: The study shows small, non-significant differences between the biometric measurements obtained with REVO NX SW-OCT and IOLMaster 700 SS-OCT in pseudophakic eyes. However, SW-OCT offered significantly lower ACD and LT measurement failure rates. With high-resolution imaging, SW-OCT enables accurate assessment of IOL position relative to the posterior capsule and visualization of capsular fibrosis.

Agreement between Two Swept-Source Optical Coherence Tomography Biometers and a Partial Coherence Interferometer.

PURPOSE: To evaluate the level of agreement between ANTERION (Heidelberg Engineering, Heidelberg, Germany), OA-2000 (Tomey, Nagoya, Japan), and IOLMaster 500 (Carl Zeiss AG, Jena, Germany). METHODS: Fifty-one eyes of 51 patients were included in the study. Flat keratometry (K) and steep K, vector component of astigmatism (Jackson cross-cylinder at 0° and 90° [J0] and Jackson cross-cylinder at 45° and 135° [J45]), anterior chamber depth, and axial length were compared using the three devices. Repeated measures analysis of variance was conducted to compare the mean values of the biometrics. Pearson correlation test was conducted to analyze the correlations of the measured values, and a Bland-Altman plot was used to assess the agreement between the three devices. The predicted intraocular lens power of each device was compared to the others using the SRK/T, Haigis, Barrett Universal II, and Kane formulas. RESULTS: All K values measured using ANTERION were flatter than those of other instruments. However, good agreement was observed for flat K (ANTERION - OA-2000; 95% limits of agreement [LoA], 0.86 diopters [D]) and steep K (ANTERION - OA2000; 95% LoA, 0.93 D) and OA-2000 - IOLMaster 500 (95% LoA, 0.93 D). J0 and J45 vector components of astigmatism were not statistically different; however, the agreements were poor between the devices (95% LoA ≥1.97 D). Anterior chamber depth values of ANTERION and OA-2000 were interchangeable (95% LoA, 0.15 mm). The axial length showed a high agreement (95% LoA ≤0.17 mm) among the three devices. The predicted intraocular lens powers of the three devices were not interchangeable regardless of formulas (95% LoA ≥1.04 D). CONCLUSIONS: Significant differences in ocular biometrics were observed between ANTERION and the other two devices. This study demonstrated that only axial length showed good agreement among devices.

[Correlation between corneal refractive power and anterior chamber morphology in age-related cataract patients with shallow anterior chambers].

Objective: To investigate the relationship between corneal refractive power and anterior chamber parameters in age-related cataract patients with normal axial lengths and shallow anterior chambers. Methods: Retrospective case series study. Clinical data of 627 age-related cataract patients (627 eyes) with axial lengths between 22 mm and 24 mm and anterior chamber depths less than 2.20 mm treated in the Department of Ophthalmology of Peking University International Hospital from June 2018 to October 2021 were selected. There were 215 male patients and 412 female patients, with an average age of (75±10) years. According to the average corneal refractive power, eyes were divided into groups of keratometry (K)<42 diopters (D) (50 eyes), 42 D ≤K<45 D (398 eyes) and K ≥45 D (179 eyes). Axial length, anterior chamber depth, corneal diameter, anterior chamber volume and anterior chamber angle of 3 groups were recorded, and Spearman correlation analysis was used to analyze the correlation between parameters. The differences of parameters among different groups were compared by one-way analysis of variance or Kruskal-Wallis test, and multiple or pairwise comparisons using LSD-t test or Mann-Whitney U test. Results: There was a negative correlation between axial length and corneal refractive power in 627 eyes (r=-0.62, P<0.001). Corneal refractive power was positively correlated with anterior chamber depth (r=0.26, P=0.006), while in the K≥45 D group, corneal refractive power was also positively correlated with anterior chamber depth (r=0.23, P=0.025). Anterior chamber depth [M (Q1,Q3)] was 1.77 (1.64, 1.90) mm in the K<42 D group, 1.85 (1.70, 2.14) mm in the 42 D≤K<45 D group and 2.02 (1.81, 2.18) mm in the K≥45 D group. Multiple comparisons showed that there were significant differences in anterior chamber depth between the K<42 D group and the K≥45 D group, between the 42 D≤K<45 D group and the K≥45 D group (U=14 372.00, 18 226.00; both P<0.05). There was a negative correlation between corneal refractive power and corneal diameter in 627 eyes (r=-0.52,P<0.001), while in the 42 D≤K<45 D group and the K≥45 D group, corneal refractive power were also negatively correlated with corneal diameter (r=-0.20, -0.28; both P<0.05). Corneal diameter was (11.77±0.43) mm in the K<42 D group, (11.24±0.35) mm in the 42 D≤K<45 D group and (10.90±0.33) mm in the K≥45 D group, while there were significant differences in multiple comparisons (t=1.92, 2.96, 2.01; all P<0.05). There was no correlation between corneal refractive power and anterior chamber volume, or between corneal refractive power and anterior chamber angle in 627 eyes (all P>0.05). There was no significant difference both in anterior chamber volume and in anterior chamber angle among 3 groups (all P>0.05). Conclusion: For age-related cataract patients with normal axial lengths and shallow anterior chambers, the anterior chamber depth increase and the corneal diameter decrease with the increase of corneal refractive power, but there is no significant change in anterior chamber volume and anterior chamber angle.

Agreement between the biometric measurements used to calculate the size of the implantable collamer lenses measured with four different technologies.

Purpose: To evaluate the agreement between the biometric measurements used to calculate the size of the implantable collamer lenses (ICL) with different technologies: swept-source optical coherence tomography, spectral domain optical coherence tomography, and Scheimpflug tomography. Methods: This retrospective observational study included subjects undergoing refractive surgery with posterior chamber phakic IOL implantation to correct their myopia. The anterior chamber depth (ACD) and the horizontal white to white (WTW) or the angle to angle (ATA) distance were measured with the following four devices: the IOLMaster 700 biometer (Carl Zeiss Meditec, Jena, Germany), based on swept-source optical coherence tomography; the Cirrus and Visante optical coherence tomographs (Carl Zeiss Meditec) based on low-coherence interferometry; and the Pentacam rotating Scheimpflug camera (Oculus, Wetzlar, Germany). Results: In the horizontal corneal diameter measurements, there were statistically significant differences between Pentacam-IOLMaster 700 pair (P < 0.001) and Pentacam-Visante pair (P < 0.001). WTW from CIRRUS showed the lowest correlation when paired with Pentacam and IOLMaster 700 (R2 = 0.452 and 0.385 for Visante and R2 = 0.494 and 0.426 for Cirrus). Regarding the linear correlation of the ACD measurements, all pairs of devices were statistically significant and all of them showed a very good correlation index. Conclusion: There is a good agreement between the different devices under evaluation for ACD measurements. As for WTW, the values measured with the different devices showed large discrepancies with low correlation levels, especially when comparing the tomographs with the other devices under evaluation.

The repeatability and agreement of biometric measurements by dual Scheimpflug device with integrated optical biometer.

To determine the repeatability of biometric measurements by dual Scheimpflug Devices with Integrated Optical Biometers and its agreement with partial coherence interferometry according to the axial length (AL), and the presence of cataracts. The present population-based cross-sectional study was conducted on the geriatric population in Tehran. For participants, imaging was performed by dual Scheimpflug Devices with Integrated Optical Biometers (Galilei G6) and partial coherence interferometry (IOL Master 500). All measurements were performed by one person. In both normal and cataractous eyes, the ICC values were above 0.99 for three measurements of AL, intraocular lens (IOL) power target, anterior chamber depth (ACD), central corneal thickness (CCT), flat and steep keratometry readings, and mean total corneal power (MTCP). The repeatability coefficient for the AL measurements was 0.003 and 0.002 in eyes with and without cataracts, respectively. The mean difference of AL between IOL Master 500 and Galilei G6 in normal and cataractous eyes was 0.015 and -0.003 mm, respectively. The 95% limits of agreement (LoA) of AL between these two devices were -0.09 to 0.12 mm in normal and -0.09 to 0.08 mm in cataractous eyes. The 95% LoA of ACD between the two devices was -0.13 to 0.36 mm and -0.10 to 0.31 mm in eyes without and with cataracts, respectively. The 95% LoA of steep K between the two devices was -0.63 to 0.32 and -1.04 to 0.89 diopter in normal and cataractous eyes, respectively. The results of the present study indicate the high repeatability of Galilei G6 in ocular biometric measurements. Galilei biometric measurements, had a very high agreement with the IOL Master 500.