RESUMEN

Objective: To investigate the pathogenesis of Primary Angle-Closure Glaucoma (PACG) and its relationship with the anatomical structure of the anterior segment by obtaining biometric parameters using the IOL-Master 700. Methods: A retrospective case-control study was conducted. Clinical data from 39 PACG patients and 40 normal controls treated at the Aier Eye Hospital affiliated with Wuhan University from January to December 2022 were collected. Anterior chamber depth (AC), white-to-white (WTW), lens thickness (LT), central corneal thickness (CCT), axial length (AL), corneal curvature (K1), corneal curvature (K2), and lens position (LP) were measured using the IOL-Master 700 to analyze the characteristics and differences in the anterior segment structure of both groups. Statistical methods included independent sample t-tests and logistic regression analysis. Results: Significant differences were found in the anterior segment biometric parameters between PACG patients and normal controls (p < 0.05). Anterior chamber depth, white-to-white, lens thickness, central corneal thickness, axial length, and K2 were all related to the occurrence of PACG (p < 0.05). The occurrence of PACG was negatively correlated with ACD, CCT, and AL (OR = 0.12-0.64, p < 0.05), and positively correlated with LT. Conclusion: Compared to the normal control group, PACG patients in the Hubei region have a smaller anterior segment space, narrower angles, thicker lens, thinner cornea, shorter axial length, flatter cornea, and more anteriorly positioned lens.

RESUMEN

Background: This study aims to compare the refractive outcomes of cataract surgery using two different biometry devices, the IOL Master 500 and IOL Master 700, and to investigate the influence of patient-related factors on these outcomes. Methods: In this retrospective study, we analyzed data from 2994 eyes that underwent cataract surgery. Multiple linear regression analyses were performed to examine the impact of the biometry device (IOL Master 500 or IOL Master 700), patient age, time elapsed between biometry and surgery, gender, and insurance status, as well as biometric parameters (anterior chamber depth, axial length, and corneal curvature), on postoperative refractive outcomes, specifically the deviation from target refraction. Results: The choice of the IOL Master device did not result in a statistically significant difference between the two devices (p = 0.205). Age (p = 0.006) and gender (p = 0.001) were identified as significant predictors of refractive outcomes, with older patients and males experiencing slightly more hyperopic outcomes compared to younger patients and females, respectively. The time elapsed between biometry and surgery and insurance status did not significantly influence the refractive outcomes. Conclusions: Our study, supported by a large cohort and a diverse group of patients representing typical anatomical variants seen in cataract surgery, supports the thesis that the IOL Master 500 and IOL Master 700 can be regarded as equivalent and effective for biometry in cataract surgery. The differences between the devices were negligible. Therefore, switching between the devices is safe for bilateral patients.

RESUMEN

AIM: To analyze and compare the differences among ocular biometric parameters in Han and Uyghur populations undergoing cataract surgery. METHODS: In this hospital-based prospective study, 410 patients undergoing cataract surgery (226 Han patients in Tianjin and 184 Uyghur patients in Xinjiang) were enrolled. The differences in axial length (AL), anterior chamber depth (ACD), keratometry [steep K (Ks) and flat K (Kf)], and corneal astigmatism (CA) measured using IOL Master 700 were compared between Han and Uyghur patients. RESULTS: The average age of Han patients was higher than that of Uyghur patients (70.22±8.54 vs 63.04±9.56y, P<0.001). After adjusting for age factors, Han patients had longer AL (23.51±1.05 vs 22.86±0.92 mm, P<0.001), deeper ACD (3.06±0.44 vs 2.97±0.37 mm, P=0.001), greater Kf (43.95±1.40 vs 43.42±1.69 D, P=0.001), steeper Ks (45.00±1.47 vs 44.26±1.71 D, P=0.001), and higher CA (1.04±0.68 vs 0.79±0.65, P=0.025) than Uyghur patients. Intra-ethnic male patients had longer AL, deeper ACD, and lower keratometry than female patients; however, CA between the sexes was almost similar. In the correlation analysis, we observed a positive correlation between AL and ACD in patients of both ethnicities (rHan =0.48, rUyghur =0.44, P<0.001), while AL was negatively correlated with Kf (rHan =-0.42, rUyghur =-0.64, P<0.001) and Ks (rHan =-0.38, rUyghur =-0.66, P<0.001). Additionally, Kf was positively correlated with Ks (rHan =0.89, rUyghur =0.93, P<0.001). CONCLUSION: There are differences in ocular biometric parameters between individuals of Han ethnicity in Tianjin and those of Uyghur ethnicity in Xinjiang undergoing cataract surgery. These ethnic variances can enhance our understanding of ocular diseases related to these parameters and provide guidance for surgical procedures.

RESUMEN

One of the most recent advancements in the field of cataract surgery is optical biometry. With the advent of optical biometry ocular measurements are now simpler, quicker, and more precise. The devices have made intraocular lens (IOL) power calculations easier in difficult situations too, such as in cases with extremes of axial lengths, silicone filled eyes, cataract surgery in post-keratoplasty eyes, post Laser-Assisted in Situ Keratomileusis (LASIK) eyes, etc. The gold standard for IOL power calculation in the present day is by the use of optical biometry devices. The anatomical measurements by these devices are highly precise and because of these measurements and the incorporation of various IOL power calculation formulas the optical biometry devices give the accurate power and the post-operative visual outcome is highly satisfactory among the patients. The growing use of these devices has made cataract the most commonly performed refractive surgical procedure nowadays. In the current scenario, optical biometry has widespread acceptance in almost all countries and has many advantages over ultrasound or immersion biometry. Cataract surgeons can obtain easy and reliable measurements from these devices. Refractive surprises have also decreased considerably with their use. This article will comprehensively review the principles of the various optical biometry devices, the parameters used in each of the devices, the advantages and disadvantages, and add more like what all this article will add.

RESUMEN

PURPOSE: To report a case of phacolytic glaucoma with atypical presentation in a patient which was diagnosed with biometry swept source optical coherence tomography (SS-OCT) and anterior segment spectral domain OCT (SD-OCT). METHODS: A 56-year-old male with a history of cytomegalovirus (CMV) chronic anterior uveitis in the right eye presented with a white cataract, minimal anterior chamber reaction and intraocular pressure (IOP) of 56 mmHg. Visual acuity was light perception. The anterior chamber was deep, without evidence of macroscopically visible capsular rupture. A surgical intervention was necessitated with the puzzle being whether to proceed with a trabeculectomy or a combined phaco-trabeculectomy. After a routine preoperative assessment with intraocular lens Master700, the disintegration of the natural lens was noticed. Anterior segment Spectralis OCT confirmed a lamellar separation of the anterior one third of the lens, resembling a poultaceous material. After an uneventful phacoemulsification, visual acuity was 6/6, IOP was well-controlled on maximum topical antiglaucoma treatment and no CMV recurrence was observed. RESULTS: The diagnosis of phacolytic glaucoma was established with the aid of current imaging OCT systems. Both OCT images were suggestive of a phacolytic nature of our case, despite the fact that the clinical presentation was not in concordance with such a typical case. In view of our findings the decision was to proceed with cataract extraction alone. CONCLUSION: This is the first time that we image and document the phacolytic nature of a natural lens. Our patient did not have the typical clinical presentation and was differentially diagnosed with biometry SS-OCT and confirmed by anterior segment SD-OCT.

Asunto(s)

RESUMEN

Objectives: The study aims to explore the ocular biometry of a myopic population in Northern China, focusing specifically on anterior and posterior segment lengths. Methods: This is a cross-sectional study. The medical records of 3458 myopic patients who underwent refractive surgery were evaluated. Axial length (AL), anterior chamber depth (ACD), lens thickness (LT) and other biometric parameters were measured using the IOL Master 700. The study determined the anterior segment length (ASL = ACD + LT), the posterior segment length (PSL = AL - ASL) and the ratio of ASL to PSL (ASL/PSL). Results: This study included 3458 eyes from 3458 myopic patients (1171 men and 2287 women). The mean age was 27.38 ± 6.88, ranging from 16 to 48 years old. The mean ASL was 7.35 ± 0.27 mm, and the mean PSL was 18.39 ± 1.18 mm. The ASL and PSL trends demonstrate an age-related increase for both genders, with notable gender-specific variations. Across most age groups, males typically exhibited higher ASLs and PSLs than females, with the exception of the 35-40 and 40-45 age groups. The ASL and PSL consistently increased with a rising AL. The AL strongly correlates with the PSL and negatively correlates with the ASL/PSL ratio. The ACD and LT moderately correlate with the ASL, but an increased LT does not imply a longer posterior segment. The CCT and SE show little correlation with axial eye parameters. Conclusions: Among Chinese myopic patients, a longer ASL and PSL were correlated with older age and the male gender. The AL strongly correlates positively with the PSL and negatively correlates with the ASL/PSL ratio. An elongation of the posterior segment may primarily account for an eyeball's lengthening.

RESUMEN

PURPOSE: Predict intraocular lens position after cataract surgery using the IOL Master 700 and explore the associated ocular parameters compared with the results obtained from the anterior segment analysis system (Sirius, CSO Inc, Florence, Italy). METHODS: A total of 98 patients (106 eyes) were included in the retrospective study. The postoperative intraocular lens position was obtained using the IOL Master 700 and measured using Adobe Illustrator software. Correlation analysis and linear regression analysis were applied to study the correlation between the actual position of the postoperative intraocular lens (ALP) and the ocular parameters. In addition, Bland-Altman consistency analysis was used to compare the consistency between any two among the predicted intraocular lens position (ALPi) obtained using IOL Master 700 biometry, the predicted artificial lens position (ALPs) calculated using the anterior segment analysis system, or the ALP. RESULTS: Ocular parameters, including preoperative anterior chamber depth, lens thickness, axial length, white-to-white, and postoperative refractive error were all correlated with ALP after cataract surgery (P < 0.05) using univariate analysis. However, in multivariate linear regression, only the first three variables were correlated with ALP. Compared with the equation obtained by the anterior segment analysis, the equation from IOL Master 700 biometry provided a better fit. The results of the consistency analysis showed that ALP, ALPi, and ALPs were in good agreement. CONCLUSION: IOL Master 700 biometry can help predict intraocular lens position after surgery, and its accuracy is better than that provided by the anterior segment analysis system.

Asunto(s)

RESUMEN

AIM:To compare the differences, correlations and consistency of IOL Master 700 or Lenstar LS900 in preoperative ocular biometry and the accuracy of intraocular lens(IOL)degree calculation of cataract patients with high myopia.METHODS: Retrospective study. A total of 136 cases(136 eyes)of high myopia and cataract patients who underwent phacoemulsification at the ophthalmology department of Army Medical Center of PLA from March 2021 to March 2023 were collected, with a mean age of 57.38±8.08 years. Patients were divided into 3 groups based on axial length(AL): 41 eyes in group A(26 mm≤ AL ≤28 mm), 43 eyes in group B(28 mm&#x003C; AL ≤30 mm)and 52 eyes in group C(AL &#x003E;30 mm). AL, mean keratometry(Km), anterior chamber depth(ACD), lens thickness(LT)and white-to-white(WTW)were preoperatively measured by two instruments, respectively. Barrett Universal II formula was used to calculate the IOL degrees of all patients, the appropriate reserved diopter was decided individually, and the prediction error(PE)and absolute error(AE)of the two instruments were compared.RESULTS:The AL and ACD of patients in the three groups measured by Lenstar LS900 were higher than the AL measurd by IOL Master 700(all P&#x003C;0.05), with a difference of AL measured by the two devices: group C&#x003E;group B&#x003E;group A. However, there was no statistical significance in LT, Km, and WTW measured by the two instruments(all P&#x003E;0.05). All biometric parameters measured by the two devices were positively correlated(all r&#x003E;0.9, P&#x003C;0.05), and consistent(95% LoA of all groups were narrow). There was no statistically significant difference in AE calculated by the two devices(P&#x003E;0.05), but the IOL Master 700 calculated a smaller PE than Lenstar LS900(P&#x003C;0.05), with lower percentage of hyperopic shift in IOL Master 700.CONCLUSION:In cataract patients with high myopia, AL measured by Lenstar LS900 is longer than that by IOL Master 700, and the differences of AL increase along with the growth of AL. Both devices have a good prediction for IOL calculation, but IOL Master 700 has less refractive error, lower percentage of hyperopic shift, and greater clinical advantages IOL Master 700.

RESUMEN

AIM: To evaluate the accuracy of the formulas, including Haigis, SRK/T, Holladay 1, and Holladay 2, in predicting the diopter of the intraocular lens implanted in high myopia cataract patients.METHODS: Prospective study. A total of 168 cases(168 eyes)of age-related cataract with an axial length(AL)≥26 mm who were treated in our hospital from August 2017 to November 2021 were selected. According to the preoperative AL measured by IOL Master 700, the patients were divided into five groups, including 37 cases(37 eyes)in group A with 26 mm≤AL&#x003C;27 mm, 34 cases(34 eyes)in group B with 27 mm≤AL&#x003C;28 mm, 42 cases(42 eyes)in group C with 28 mm≤AL&#x003C;29 mm, 28 cases(28 eyes)in group D with 29 mm≤AL&#x003C;30 mm, and 27 patients(27 eyes)in group E with AL ≥ 30 mm. Subjective refraction was performed at 3 mo postoperatively, and the mean numerical error(MNE)and mean absolute error(MAE)of each formula for predicting diopters were calculated.RESULTS: The MNE and MAE of the Haigis and Holladay 2 formulas were relatively less in each group, and MNE and MAE did not significantly increase with the growth of the axial length. However, the MAE and MNE of the SRK/T and Holladay 1 formulas significantly increased with the growth of the axial length, with the MNE and MAE of the Holladay 1 formula increasing more significantly in groups C, D, and E.CONCLUSION: For patients with age-related cataract, with an axial length of ≥26 mm, the accuracy of predicting the diopter of the intraocular lens using the Haigis and Holladay 2 formulas were higher.

RESUMEN

AIM:To observe the accuracy of infiltrating B ultrasound guided A-scan segment biometric measurement of axial length in dense cataract.METHODS: Perspective study. A total of 86 patients(90 eyes)with dense cataract were selected from Chengdu Aier Eye Hospital from August 2020 to August 2022. There were 61 males(59 eyes)males and 25 females(31 eyes)females, with an average age of 66.49±14.55 years. The axial length(AL), anterior chamber depth(ACD)(including corneal thickness), corneal curvature(K), lens thickness(LT), central corneal thickness(CCT), and white-to-white(WTW)were measured preoperatively by contact A-scan, infiltrating B ultrasound guided segmented A-scan, and IOL Master 700, respectively. At 1 wk postoperatively, AL was retested by IOL Master 700 in aphakic mode. Furthermore, the agreements and correlations of AL obtained by the three kinds of devices were analyzed.RESULTS:The AL measured by contact A-scan and infiltrating B ultrasound guided segmented A-scan were 23.40(22.63, 23.89)mm and 23.70(23.04, 24.25)mm, respectively, and the AL measured by IOL Master 700 at 1 wk postoperatively was 23.72(23.01, 24.27)mm. There were statistical significant difference in AL measured by the three methods(P=0.018), while there were no statistical significant difference in AL measured by infiltrating B ultrasound guided segmented A-scan and IOL Master 700(P=0.991). Bland-Altman analysis showed that there was a good agreement in AL measured by infiltrating B ultrasound guided segmented A-scan and IOL Master 700(P=0.0809). The AL measured by infiltrating B ultrasound guided segmented A-scan and IOL Master 700 was positively correlated(rs=0.992, P&#x003C;0.0001), and the AL was positively correlated between preoperative contact A-scan and postoperative IOL Master 700(rs=0.989, P&#x003C;0.0001).CONCLUSION:For dense cataract, infiltrating B ultrasound guided A-scan segment biometric measurement, which has good correlations and agreement, is closer to the AL measured by IOL Master 700 postoperatively than that measured by contact A-scan.

RESUMEN

AIM: To observe the changes in the Chang-Warning chord(CW chord)before and after cataract surgery using the IOL Master 700 and predict the CW chord using an artificial intelligence prediction model and preoperative measurement data.METHODS: The analysis was conducted on the preoperative and postoperative IOL Master 700 measurements of 304 cataract patients. This included astigmatism vector value, average keratometry, axial length, anterior chamber depth, lens thickness, corneal central thickness, white-to-white, the position of the Purkinje reflex I image relative to the corneal center and pupil center, and the CW chord. A prediction model based on the SVR algorithm and the BP neural network algorithm was established to predict the postoperative CW chord using the preoperative CW chord and ocular biological parameters.RESULTS: The X component of the CW chord showed a slight shift in the temporal direction in both the left and right eyes after cataract surgery, while the Y component changed little. The SVR model, using the preoperative CW chord and other preoperative biometric parameters as input data, was able to predict the X and Y components of the CW chord more accurately than the BP neural network.CONCLUSION: The CW chord can be directly measured with a coaxial fixation light using various biometers, corneal topographers, or tomographers. The use of the SVR algorithm can accurately predict the postoperative CW chord before cataract surgery.

RESUMEN

AIM: To compare the difference and consistency of corneal refractive power and astigmatism measured by CASIA2 and IOL Master 700 in patients with age-related cataract.METHODS: Retrospective study. A total of 153 patients(232 eyes)with age-related cataract admitted to Daping hospital from November to December 2021 were selected. The flat keratometry(Kf), steep keratometry(Ks), mean keratometry(Km), degree and axis of astigmatism(vector representation J0 and J45)of the anterior, posterior surfaces together with the total cornea from cataract patients were measured by CASIA2 and IOL Master 700, respectively. The difference, correlation and consistency of the two instruments were analyzed.RESULTS:There was no significant difference in J45 values of posterior corneal surface measured by CASIA2 and IOL Master 700(-0.006±0.038D vs. -0.005±0.044D, P&#x003E;0.05), but there were significant differences in other parameters(all P&#x003C;0.05). All parameters measured by the two instruments were significantly positive correlated(all r/rs&#x003E;0.7, P&#x003C;0.001); Bland-Altman analysis showed that the refractive power and astigmatism of the anterior cornea surface measured by the two facilities were in good consistency, while the refractive power of the posterior surface and the whole cornea showed poor consistency.CONCLUSION: CASIA2 and IOL Master 700 showed little differences and good consistency in the refractive power and astigmatism of the anterior, posterior and total corneal surface in cataract patients, which seems interchangeable. However, the refractive power of the posterior surface and the whole cornea has significant differences and poor consistency, which should not be interchange casually.

RESUMEN

PURPOSE: The purpose of the study is to evaluate the comparability of corneal power measurements, anterior chamber depth (ACD), and white-to-white (WTW) distance between a high-resolution Scheimpflug-based tomography (Pentacam HR; Oculus GmbH, Wetzlar, Germany) and a swept-source optical biometry, IOL Master 700; Carl Zeiss Meditec AG, Jena, Germany) in patients having undergone a myopic refractive surgery. METHODS: This prospective, interinstrument reliability analysis included 31 individuals with a previous myopic laser refractive correction. Standard keratometry and total keratometry (TK) of the flattest and steepest axis of the IOL Master 700 were compared with standard keratometry (simulated keratometry [SimK]), true net power (TNP), equivalent keratometer readings (EKR), and total corneal refractive power of the Pentacam. The Bland-Altman analysis evaluated the agreement between the measurements of both devices. A paired t-test was performed to compare the mean values of the variables obtained by the two devices. RESULTS: Mean age of the participants was 31.87 ± 13.17 years. Ten patients (32.3%) had undergone laser in situ keratomileusis surgery, and 21 (67.7%) had undergone photorefractive keratectomy surgery. The two devices generated statistically significant differences in almost all the comparisons between their corneal keratometry values, ACD, and WTW. The two devices agreed in some of the flat axis values and more specifically on SimK1 and K1, EKR K1 along 1 mm-zone and K1, as well as on the comparison between the EKR keratometry values along 1, 2, and 3 mm-zone with their corresponding TKs. CONCLUSION: IOL Master 700 and Pentacam HR do not show good concordance and cannot be used interchangeably when measuring keratometry values in postrefractive eyes, rendering the IOL power calculation in postrefractive eyes really challenging.

RESUMEN

Purpose: To evaluate the repeatability of biometry and intraocular lens (IOL) power using Galilei G6 and to determine the agreement of its measurements with those of IOL Master 700 and IOL Master 500. Methods: Hundred mature cataract eyes were examined twice with Galilei G6 and the results were compared with those of other two devices. Axial length (AL), minimum (K1), maximum (K2), and mean keratometry, anterior chamber depth (ACD), white-to-white (WTW) diameter, lens thickness (LT), and the calculated IOL power were the studied parameters. The correlation coefficient, within-subject standard deviation (Sw), Bland-Altman method, and 95% limits of agreement (LoA) were used for statistical analysis. Results: The intraclass correlation coefficient (ICC) was above 0.9 for all indices, and the LoA ranged from a minimum of 0.08 mm for AL to a maximum of 0.50 D for K1. Sw also ranged between a minimum of 0.02 for AL, ACD, and WTW and a maximum of 0.13 for K1. In the Galilei G6-IOL Master 700 pair, the narrowest and widest LoA were calculated for AL (0.07 mm) and K2 (0.49 D), respectively. In the Galilei G6-IOL Master 500 pair, the narrowest and widest widths of LoA were calculated for AL (0.17 mm) and K2 (0.92 D), respectively. In the first pair, the LoA of IOL power (0.57 D) were the best for Haigis formula and in the second pair, the best agreement (LoA: 0.35 D) was observed for Holladay-1. Conclusion: Galilei G6 provided repeatable biometric measurements. The agreement between biometry and IOL power calculation was better in the Galilei G6-IOL Master 700 pair compared to the Galilei G6-IOL Master 500.

Asunto(s)

RESUMEN

BACKGROUND: The study aimed to investigate the difference in refractive status and ocular parameters between ptotic and fellow eyes in patients with unilateral congenital ptosis. METHODS: Thirty patients (53% males, age 22.00 ± 11.41 years) with unilateral congenital ptosis diagnosed and treated at the First Affiliated Hospital of Sun-yat Sen University were enrolled and underwent detailed refractive examinations from March 2019 to February 2022. Ocular biometric measurements were performed by an IOL Master 700 biometer. The differences in refractive error characteristics, best-corrected visual acuity (BCVA), and ocular parameters including axial length (AL), central corneal thickness (CCT), aqueous depth (AQD), anterior chamber depth (ACD), lens thickness (LT), and keratometry values between ptotic and fellow eyes were analysed. RESULTS: A lower BCVA (logMAR, median (IQR), 0.00 (- 0.13,0.00), P = 0.009) and a higher incidence of amblyopia (n (%), 7(23%), P = 0.016) were observed in ptotic eyes. The CCT of ptotic eyes was greater than that of fellow eyes (mean ± SD, 539.83 ± 26.73 µm, P < 0.001). The keratometry values at the flat axis (K1) and mean corneal power (Km) were smaller in ptotic eyes (mean ± SD, 42.11 ± 1.49 D, 42.68 ± 1.52 D, respectively, both P = 0.001). There was no significant difference in AL between ptotic and fellow eyes. CONCLUSIONS: Congenital ptosis influences ocular parameters, mainly causing a thicker and flatter cornea. Patients with unilateral congenital ptosis might have lower BCVA in the ptotic eyes.

Asunto(s)

RESUMEN

Purpose: To investigate the differences and limits of agreement in measuring corneal thickness using Pentacam, Corvis, and intraocular lens (IOL)-Master 700 devices. Methods: This study was conducted on 37 right eyes of 21 males and 16 females (n = 37) with a mean age of 52.11 ± 6.30 years. The central corneal thickness was measured using three optical biometric devices, including Pentacam, Corvis, and IOL-Master 700. The inclusion criteria were normal eyes without any ophthalmological abnormalities, history of ocular pathology, or ocular surgery. The data obtained from these three devices were compared two by two. The correlation and agreement limits among them were analyzed using statistical techniques. Results: The mean standard deviation differences between Pentacam and Corvis, Pentacam and IOL-Master 700, as well as Corvis and IOL-Master 700 regarding the corneal thickness measurement, were 22.13 ± 8.05, 7.91 ± 8.02, and 14.21 ± 9.85 µm, respectively, which were statistically significant (P < 0.0001). Based on the investigation of the limits of agreement according to the Bland Altman method, the corresponding values between Pentacam and Corvis, Pentacam and IOL-Master 700, and Corvis and IOL-Master 700 were -16.2 to +15.4, -15.8 to +16.3, and -20.1 to +20.0 µm, respectively. Furthermore, the correlation coefficients of the measurements obtained by Pentacam and Corvis, Pentacam and IOL-Master 700, as well as Corvis and IOL-Master 700 were determined 0.957, 0.964, and 0.948, respectively (P < 0.0001). Conclusion: The results from this study indicate that the interchangeable use of these three devices is not appropriate due to statistically significant differences and broad limits of agreement among the three devices, especially between Corvis and IOL-Master 700.

RESUMEN

@#AIM: To investigate the difference and consistency among iTrace, IOL Master 700 and Pentacam HR in measuring corneal astigmatism before cataract surgery.<p>METHODS: Across-sectional study. From May 2020 to May 2021, a total of 149 cataract patients(181 eyes)were collected in our hospital. Presurgery, steep keratometry(Ks), flat keratometry(Kf), mean keratometry(Km), astigmatism magnitude(Cyl), and steep astigmatic axis values measured by the three instruments of the iTrace, IOL Master 700 and the Pentacam HR. The difference and consistency of the measurement indexes of the three instruments were analyzed.<p>RESULTS: Statistical differences existed in Ks, Kf, Km among the three instruments(<i>F</i>=4.912, 3.514, 4.873, all <i>P</i><0.05)and there was no difference in Cyl and Axis(<i>F</i>=0.523, 0.128, all <i>P</i>>0.05). Bland-Altman analysis showed the outcomes revealed that the Ks and Kf measured by iTrace and the other two instruments have poor consistency, and the consistency of Cyl and Axis was good. But the difference of Axis is not clinically acceptable. There were no statistically differences between the iTrace and the other two devices among the low astigmatism(50 eyes), moderate astigmatism(34 eyes)and high astigmatism(18 eyes)groups(all <i>P</i>>0.05). <p>CONCLUSION: In the preoperative measurement of cataract patients except for the good consistency of astigmatism, the iTrace, IOL Master 700 and Pentacam HR showed different Ks and Kf, and the Axis difference exceeded the clinically acceptable range, especially in the highly astigmatism group. The measurement of corneal astigmatism before cataract surgery should be evaluated by multiple measurement methods and make comprehensive planning for the surgical plan.

RESUMEN

AIM:To evaluate the accuracy of A-ultrasound combined with corneal topography measurement in clinical application by analyzing the ocular-related biometric parameters and refractive error and comparing with those of IOL Master 700 in cataract patients. METHODS: A prospective study. Clinical data were collected from 113 patients(122 eyes)who underwent phacoemulsification in the First Affiliated Hospital of Soochow University from July 2020 to July 2021. The axial length(AL), anterior chamber depth(ACD), lens thickness(LT)and corneal curvature(Km)were measured respectively by IOL Master 700 and A-ultrasound combined with corneal topography measurement and the 3mo after the surgery of the refractive error was analyzed.RESULTS: There were differences in AL(24.09±1.65, 23.81±1.62mm), ACD(3.11±0.42, 2.97±0.43mm)and Km(44.12±1.59, 44.06±1.54D)measured by IOL Master 700 and A-ultrasound combined with corneal topography(P<0.05), while there was no difference in LT(4.34±0.46, 4.30±0.59mm)(P>0.05). The postoperative mean absolute refractive error(MAE)of intraocular lens(IOL)diopter calculation formulas with different measurement methods was significantly different(P<0.001). The Barrett Universal II formula MAE of the IOL Master 700 measuring instrument was different from the Holladay I, Haigis and SRK/T formulas(P<0.01), at the same time, compared with the A-ultrasound combined with corneal topography calculation formula SRK/T and Barrett Universal II formula, they were also different(P<0.01). However, there was no difference among the Holladay Ⅰ, Haigis, SRK/T formula MAE which come from the IOL Master 700 measuring instrument and the A-ultrasound combined with corneal topography calculation formula SRK/T formula(P>0.05). In addition, the Barrett Universal II formula of the IOL Master 700 measuring instrument has the smallest median absolute refractive error(MedAE)(0.260D), and the A-ultrasound combined with corneal topography calculation formula Barrett Universal II formula MedAE is the largest(0.765D).CONCLUSION: The values of AL, ACD and Km measured by A-ultrasound combined with corneal topography were smaller than those of IOL Master 700. When the SRK/T formula was used to calculate the IOL diopter, the results of the two group were similar. However, when using the Barrett Universal Ⅱ formula, the refractive error of the A-ultrasound combined with corneal topography group was large, resulting in hyperopia drift.

RESUMEN

Purpose: To investigate the distributions of the ocular anterior and posterior segment lengths among a cataract surgical population in Shanghai. Design: Cross-sectional study. Methods: Ocular biometric parameters of 23,462 eyes of 23,462 cataract surgery candidates were reviewed. Axial length (AL), anterior chamber depth (ACD), and lens thickness (LT) were obtained using IOL Master. Anterior segment length (ASL = ACD + LT), posterior segment length (PSL = AL - ASL) and the ratio of ASL to PSL (ASL/PSL) were calculated. Results: The mean ASL was 7.58 ± 0.39 mm, the mean PSL was 17.12 ± 2.64 mm. As the age grew, the ASL increased, and PSL increased firstly then decreased. Male subjects tended to have significantly longer ASL and shorter PSL than female subjects. With the increasing AL, the ASL was firstly decreased to trough at 20-22 mm AL group, then increased gradually, while the PSL increased rapidly. The ASL correlated positively with AL in normal, moderate and highly myopic eyes, negatively in short eyes. The PSL correlated positively with AL across the entire study population. The ASL/PSL was not constant in the eyes with different AL but had a relatively steep downward trend with the increasing AL in the short eyes, then decreased smoothly in normal, moderate and highly myopic eyes. Conclusions: In Chinese cataractous eyes, longer ASL and shorter PSL were associated with elder age and male gender. The change of ASL over AL was not linear, and the ASL was smallest in the eyes with AL of 20-22 mm. The elongation of the eyeball was mainly due to the extension of the posterior segment.

RESUMEN

Objetivo: Comparar las mediciones biométricas realizadas con el IOL Master 700 y el Pentacam AXL en pacientes miopes con cirugía fotoablativa previa. Métodos: Se realizó un estudio transversal en 103 ojos de 103 pacientes miopes con cirugía fotoablativa previa, atendidos en el período de enero 2019 a enero 2020, en el Instituto Cubano de Oftalmología "Ramón Pando Ferrer". Las variables estudiadas fueron: edad, sexo, equivalente esférico y características biométricas posoperatorias (longitud axial, profundidad de la cámara anterior y queratometrías), así como su relación, aportadas automáticamente por el IOL master 700 y el pentacam AXL para evitar los factores dependientes del operador, tres meses después de la cirugía. El análisis estadístico se realizó con la prueba t para datos pareados, utilizando una significación del 95 por ciento. Resultados: La edad promedio fue de 25,72 ± 4,26 años. Se analizaron 53 ojos derechos y 50 izquierdos, todos tratados con láser de superficie. El equivalente esférico medio fue de -0,06 ± 0,34 dioptrías y el tiempo entre la cirugía y los exámenes fue de 6,32 ± 3,56 meses. No hubo diferencia estadísticamente significativa (p > 0,05) entre la longitud axial y la profundidad de la cámara anterior; mientras que sí la hubo (p < 0,01) con las queratometrías obtenidas con el IOL Master 700, en comparación con los del pentacam AXL. Conclusión: En pacientes miopes con cirugía fotoablativa previa, el IOL Master 700 y el pentacam AXL proveen mediciones biométricas similares, como la longitud axial y la profundidad de la cámara anterior, no así con la queratometría, la cual es diferente(AU)

Objective: Compare the biometric measurements taken with IOL Master 700 and Pentacam AXL in myopic patients with previous photoablative surgery. Methods: A cross-sectional study was conducted of 103 eyes of 103 myopic patients undergoing photoablative surgery at Ramón Pando Ferrer Cuban Institute of Ophthalmology from January 2019 to January 2020. The variables analyzed were age, sex, spherical equivalent and preoperative biometric characteristics (axial length, anterior chamber depth and keratometries) and the relationship to one another, automatically supplied by IOL Master 700 and Pentacam AXL to avoid operator-dependent factors. The analysis was performed three months after surgery. Statistical analysis was based on the paired Student's t-test with a significance level of 95 percent. Results: Mean age was 25.72 ± 4.26 years. Fifty-three right eyes and 50 left eyes were studied, all of them treated with surface laser. Mean spherical equivalent was -0.06 ± 0.34 diopters; the time elapsed between surgery and the tests was 6.32 ± 3.56 months. No statistically significant differences (p > 0.05) were found between axial length and anterior chamber depth, but statistically significant differences (p < 0.01) were observed between the keratometries obtained with IOL Master 700 and Pentacam AXL. Conclusion: IOL Master 700 and Pentacam AXL provide similar biometric measurements for axial length and anterior chamber depth in myopic patients with previous photoablative surgery, but keratometric measurements are different(AU)

Asunto(s)