Intraocular Lens Master Research Articles

Intraocular Lens Power and Corneal Topographic Change After Pterygium Surgery

PurposeTo investigate the impact of pterygium excision on intraocular lens (IOL) power calculation and corneal astigmatism. DesignsProspective cohort study MethodsWe enrolled 30 eyes with primary pterygium that underwent pterygium excision with a conjunctival autograft. IOL power calculation and keratometry using the IOL Master 700, along with topographic parameters using the Pentacam Scheimpflug topography system, were performed preoperatively and at 1, 3, 6, and 12 months postoperatively. We analyzed correlations between pterygium length/area and IOL power, as well as corneal topographic changes. ResultsThe mean pterygium length was 2.08 ± 0.58 mm, and the mean area was 6.05 ± 2.41 mm2. One year after pterygium surgery, the calculated IOL power values using all formulas were lower than the preoperative values. Pterygia with a horizontal length of 1.73 mm and an area of 4.45 mm2, and those with a horizontal length of 2.25 mm and an area of 6.95 mm2 created 0.5 D and 1.0 D errors in calculated IOL power, respectively (p<0.001). The calculated IOL power values changed significantly from preoperative to six months postoperatively but did not change significantly from six to 12 months postoperatively. Pterygia with a horizontal length greater than 1.83 mm (p<0.001) and an area greater than 5.1 mm2 (p < 0.001) created a 2.0 D error in anterior corneal astigmatism. ConclusionsPterygium causes errors in IOL power calculation, with greater pterygium length/area exerting a larger effect. Cataract surgery with IOL implantation is recommended at least six months after pterygium surgery. In combined case, calculated IOL power should be decreased by 0.5-1.5 D based on the pterygium length/area.

Comparative analysis of surgically induced astigmatism following cataract surgery: influence of previous myopic correction and corneal parameters.

This retrospective study investigated the impact of corneal parameters on surgically induced astigmatism (SIA) in eyes with prior myopic correction undergoing cataract surgery. Department of Ophthalmology, San Marino Hospital, San Marino, Republic of San Marino. This case-control study analyzed existing data retrospectively, without randomization or masking. Eighty eyes divided in group 1 (40 eyes previous underwent refractive surgery for myopia) and group 2 ( 40 myopic eyes) that underwent cataract surgery with intraocular lens (IOL) implantation were included. SIA was calculated using values from the IOL Master Zeiss 700 and mean pupil power (MPP) derived from the CSO Sirius Topographer (based on 3mm pupil size) with vectorial analysis from doctor Hill software. No significant difference in SIA was observed between eyes with prior myopic photorefractive keratectomy and the control group (p > 0.05). SIA calculations using the IOL Master and CSO Sirius Tomographer yielded similar results. There was no significant correlation between SIA and axial length, corneal curvature, peripheral corneal thickness, or anterior chamber depth (p > 0.05). However, an inverse correlation was found between SIA and horizontal corneal diameter (p < 0.05). Corneal parameters, such as axial length, corneal curvature, peripheral corneal thickness, and anterior chamber depth, showed no significant influence on SIA. The inverse correlation between SIA and horizontal corneal diameter in study group suggests potential influence of white-to-white distance on SIA. These findings highlight the importance of considering corneal parameters for optimizing surgical outcomes.

Treatment of dry eyes with lifitegrast 5% before cataract surgery: A prospective trial

Abstract Objective: The objective of the study was to evaluate the impact of dry eye treatment on intraocular lens (IOL) biometry measurements and postoperative refractive outcome. Design: This study involves a prospective interventional study. Participants: Consecutive patients with dry eye disease undergoing cataract surgery were included in the study. Materials and Methods: All participants underwent a comprehensive dry eye assessment including the ocular surface disease index (OSDI) questionnaire, Schirmer’s test without anesthesia, corneal fluorescein staining, and conjunctival lissamine green staining. Optical biometry was performed using swept-source optical coherence tomography (IOL Master® 700, Zeiss), and corneal aberrometry was measured using a scanning-slit aberrometer (OPD SCAN III, Nidek). Diagnosis of dry eye was made according to Dry Eye Workshop II. Patients received 6 weeks of treatment of lifitegrast 5% and preservative-free artificial tear eye drops and had repeat testing at the end of 6 weeks. The change in subjective and objective dry eye tests and biometry measurements and the difference in target and postoperative refraction before and after treatment were compared. Results: Forty eyes of 21 patients were included in the study. Subjectively, OSDI improved from 26.35 ± 6.24 at baseline to 20.97 ± 8.41 after treatment (P = 0.03). Objectively, corneal staining improved from 1.42 ± 1.78 at baseline to 0.39 ± 0.67 after treatment (P = 0.006). No changes were observed in Schirmer’s test without anesthesia, conjunctival staining, or corneal aberrometry (P &gt; 0.05). Repeated biometry after dry eye treatment showed a change in IOL power difference ≥0.5 diopters in 50% (20) of eyes. Mean absolute error was within 0.25D in 87.5% (35) of eyes after treatment compared to 67.5% at baseline (P = 0.05). Conclusion: Dry eye treatment leads to subjective symptom improvement and changes in IOL power calculations and postoperative refractive outcomes. Assessing and treating patients for dry eyes before cataract surgery is important in maximizing refractive outcomes.

Total and simulated keratometry measurements using IOLMaster 700 and Pentacam AXL after small incision lenticule extraction.

Calculating the intraocular lens (IOL) in patients after corneal refractive surgery presents a challenge. Because an overestimation of corneal power in cases undergone this surgery leading to a subsequent under-correction of IOL power. However, recent advancements in technology have eliable measurement of total corneal power. The aim of this research was to assess the agreement in simulated keratometry (SimK) and total keratometry (TK) values between IOLMaster 700 and Pentacam AXL. The study involved 99 patients (99 eyes) undergone small incision lenticule extraction (SMILE) surgery. Each patient underwent scans using IOL Master 700 and Pentacam AXL. The following parameters were recorded: SimK1, SimK2, Total K1 (TK1), and Total K2 (TK2) for IOLMaster 700; and SimK1, SimK2, True Net Power (TNP) K1, TNPK2, Total Corneal Refractive Power (TCRP) K1, and TCRP K2 for Pentacam AXL. Agreement between the two devices was evaluated using Bland-Altman plot, while paired t-test was utilized to compare any differences in the same parameter by both instruments. The results revealed a strong correlation between the two devices.Noticeable comparability was identified for all SimK variables. However, there were noticeable differences in TK measurements as well as TK1-TNPK1, TK2-TNP K2, TK1-TCRP K1, and TK2-TCRP K2 parameters when comparing the two devices. The IOLMaster 700 consistently measured steeper values than the Pentacam AXL, with significant and clinically relevant differences of 1.34, 1.37, 0.87, and 0.95 diopters, respectively. While there was a noticeable correlation between the IOLMaster 700 and Pentacam AXL in SimK measurements, a marked difference was noted in TK values. The two devices cannot be used interchangeably when quantifying TK values.

Comparative accuracy of intraocular lens power calculation formulas when targeting myopia

PurposeThis study aims to compare the accuracies of intraocular lens (IOL) power calculation formulas when targeting myopia versus emmetropia. MethodsA total of 450 patients were included, with 225 patients targeting emmetropia and 225 patients aiming for approximately −2.0 diopters of myopia. This retrospective analysis utilized data from a single eye of each patient, with preoperative biometric measurements obtained using the IOL Master 700. The study considered established formulas such as Haigis, Hoffer Q, Holladay 1, Holladay 2, and SRK/T, as well as modern formulas including Barrett Universal II, Cooke K6, EVO 2.0, Hill-RBF, Hoffer QST, Kane, Olsen, and PEARL-DGS. Statistical analyses, including Friedman test and post hoc analysis, were employed to compare the accuracy of each IOL power calculation formula between the two groups. Additionally, a multiple regression analysis was conducted to identify variables influencing the accuracy of intraocular lens power calculation formulas. ResultsIn targeting myopia, all IOL formulas tended to exhibit a greater refractive error compared to when targeting emmetropic eyes. Notably, the Haigis, SRK/T, and Holladay 2 formulas were found to be highly influenced by this trend, while the modern formulas were less affected. ConclusionThe accuracy of IOL power calculation formulas diminishes when targeting myopia in comparison to emmetropia. However, the modern formulas appear less susceptible to this trend. Consequently, when aiming for myopia, the use of the modern formulas is recommended for enhanced accuracy in IOL power calculation.

Axial length and keratometry characteristics of patients undergoing cataract surgery in Saudi Arabia.

Cataract surgery is one of the most successful surgical procedures, mainly due to the recent developments in surgical instruments and intraocular lens (IOL) measurements. Understanding the nature of axial length (AL) and keratometry readings (K) in patients with cataracts has significant implications for accurate postoperative IOL size selection. This study aimed to measure AL and K in patients undergoing cataract surgery in Saudi Arabia. This retrospective study included patients who underwent cataract surgery in Madinah, Saudi Arabia. The medical records of adult patients between May 2022 and May 2023 were reviewed, and those with a history of retinal detachment, refractive surgery, or trauma were excluded. The AL and K readings were obtained from the patient's IOL master results. A total of 691 eyes from 451 patients were included in the analysis. The mean age was 64.54 years old. Most of the patients were women (55%). The mean AL, K1, and K2 values were 23.27, 43.42, and 44.69, respectively. Linear regression analysis was used to measure the relationship between AL and K, revealing an inverse relationship in our findings. As AL increased by one unit, the mean K was estimated to decrease by 0.548, with a 95% confidence interval. Our results demonstrated an inverse relationship between AL and K, implying that when AL increases, K decreases, or the corneal curvature becomes flat. Further studies are needed to investigate the biomechanical mechanisms underlying this relationship.

Precision in IOL Calculation for Cataract Patients with Prior History of Combined RK and LASIK Histories.

This study aimed to evaluate the accuracy of 12 intraocular lens (IOL) power calculation formulae for eyes that have undergone both radial keratotomy (RK) and laser assisted in situ keratomileusis (LASIK) surgery to determine the efficacy of various IOL calculations for this unique patient group. Currently, research on this surgical topic is limited. In this retrospective study, 11 eyes from 7 individuals with a history of RK and LASIK who underwent cataract surgery at Hoopes Vision were analyzed. Preoperative biometric and corneal topographic measurements were performed. Subjective refraction was obtained postoperatively. Twelve different intraocular lens (IOL) power calculations were used: Barrett True K No History, Barrett True K (prior LASIK, Prior RK history), Barrett Universal 2, Camellin-Calossi-Camellin (3C), Double K-Modified Holladay, Haigis-L, Galilei, OCT, PEARL-DGS, Potvin-Hill, Panacea, and Shammas. The rankings of mean arithmetic error (MAE), from least to greatest, were as follows: 3C (0.088), Haigis-L-L (-0.508), Shammas (-0.516), OCT Average (-0.538), Barrett True K (-0.557), OCT RK (-0.563), Galilei (-0.570), IOL Master (-0.571), OCT LASIK (-0.583), Barrett True K No History (-0.597), Pearl-DGS (-0.606), Potvin-Hill SF (-0.770), Potvin-Hill TNP (-0.778), Panacea (-0.876), and Barrett Universal 2 (-1.522). The 3C formula achieved the greatest percentage of eyes within ±0.25 D of target range (91%), while Haigis-L, Shammas, Galilei, Potvin Hill, Barrett True K, IOL Master, PEARL-DGS, and OCT formulae performed similarly, achieving 45% of eyes within ±0.75D of target refraction. This study demonstrates the accuracy of the lesser known 3C formula in IOL calculation, particularly for patients who have undergone both RK and LASIK. Well-known formulae, such as Haigis-L, Shammas, and Galilei, which are used by the American Society of Cataract and Refractive Surgery (ASCRS), are viable options, although 3C formulae should be considered in this patient population. Furthermore, larger studies can confirm the best IOL power formulas for post-RK and LASIK cataract patients.

Comparison of Optical Biometry and Scheimpflug Device Keratometric Readings Accuracy in Predicting Intraocular Lens Power in Cataract Surgery

Abstract Background: A correct preoperative intraocular lens (IOL) power measurement in cataract surgery depends on accurate assessment of axial length (AL), anterior segment parameters, and using the suitable formula for the calculation of the power. Objectives: To determine the accuracy of IOL power calculations using keratometric measurements of the IOL Master compared to the Pentacam and to determine whether the results obtained can be used interchangeably in clinical practice in calculating IOL power in routine cataract surgery. Patients and Methods: In this prospective study, the biometric data including AL, keratometric readings, and anterior chamber depth (ACD) were obtained by both the IOL Master 500 and Pentacam Scheimpflug devices added to these measures the white-to-white (WTW) distance by IOL Master and central corneal thickness by Pentacam and calculation of the IOL power using SRK/T formula for the enrolled patients who undergone uneventful cataract surgery with IOL implantation. Postoperatively, spherical equivalent refraction was measured and the mean arithmetic error and the mean absolute error (MAE) for both keratometric readings were calculated to compare the accuracy between them in calculating the IOL power. Results: The study evaluated 57 eyes of 57 patient, the mean K value for the IOL Master was 43.92 (D) ± 1.5 (standard deviation [SD]) and the mean K value for the Pentacam was 43.77 (D) ± 1.7 (SD) (P = 0.62), ACD values between the two groups, was 3.19 ± 0.44 mm measure by IOL Master compared to 3.22 ± 0.48 mm in Pentacam (P = 0.769), with a very strong positive correlation between the two values (r = 0.995, P &lt; 0.001). MAE for the IOL Master was 0.230 (D) ± 0.187 (SD), while for the Pentacam was 0.255 (D) ± 0.204 (SD), with no statistically significant differences between two devices’ values (P = 0.54). Conclusions: Pentacam Scheimpflug measured keratometric and ACD data had good correlation with IOL Master data with good interchangeability between two devices readings in measuring the IOL power in routine cases of cataract surgeries.

Ocular parameters and anthropometry in Indo-Trinidadians.

To assess ocular parameters and their association with anthropometric measurements in Indo-Trinidadians adults. This was a clinical, descriptive, cross-sectional study of ocular parameters and anthropometry in adults Trinidadians of South Asian descent (Indo-Trinidadian). Ocular parameters were measured using optical coherence tomography, intraocular lens master biometer, and an autorefractor. Weight, height, and body mass index (BMI) were measured by anthropometry. Univariable and multivariable linear regressions were used to determine the association between demographic variables, anthropometric and ocular parameters. A total of 149 participants (298 eyes) comprising of 90 females (60.6%) and 59 males (39.4%). Aged 18 to 67 participated in the study. Males were taller, heavier, and had longer axial lengths than females which were statistically significant (P < .05). Age was negatively correlated with central corneal thickness (CCT) (r = -0.353, P = .044) and retinal nerve fiber layer thickness (r = -0.348, P = .047) but positively correlated with lens thickness (R = 0.881, P < .001). Education level was positively associated with CCT (R = 0.408, P = .018) but negatively associated with lens thickness (r = -0.521, P = .002). Weight was negatively correlated with corneal topography (r = -0.427, P = .013). Height was negatively correlated with cup-to-disc ratio (r = -0.410, P = .018), CCT (r = -0.382, P = .028), and corneal topography (r = -0.453, P = .008). There was no correlation between BMI, ocular parameters and CCT. There was a significant difference in the ocular parameters between males and females of South Asian descent in Trinidad and Tobago. Weight was negatively associated with the corneal topography. Height was negatively associated with the cup-to-disc ratio, central corneal thickness, and corneal topography. BMI had no statistically significant association with the ocular parameters investigated.

Comparison of ocular biometry and intraocular lens power using a novel biometer and a traditional biometer

The implantation of an intraocular lens (IOL) is the gold standard in today's cataract surgery. Calculating the power of the intraocular lens (IOL) has emerged as a central concern in cataract surgery over the last decade. The study aims to investigate the relationship between optical biometry and applanation ultrasound measurement of the eye's axial length. This prospective cohort study was done on 60 eyes from sixty patients undergoing phacoemulsification with primary intraocular lens implantation and scheduled for cataract surgery in the Ophthalmology Department of al-Imam al-Sadeq Hospital. Thirty eyes of patients were measured by ultrasound measurement (by A-Scan, Group 1) and the other thirty eyes by optical biometry (by IOL Master, Group 2). In Group 1There were 14 eyes of 14 males (47%) and 16 eyes of 16 females (53%) with a mean age was 71.6 ±4.33years. In Group 2, there were 16 eyes of 16 males (53%) and 14 eyes of fourteen females (47%), and the mean age of the patients in this Group was 66.13±8.61 years. The mean IOL of the patient in Group I was (19.96±1.81). At the same time, the mean IOL potent ion of the patient in Group II was (22.96±1.66). Keywords: Optical Biometry, Ultrasound Biometry, Intraocular lens (IOL), IOL Master partial coherence interferometry (PCI)

Accuracy of Intraocular Lens Power Estimation in Aphakic Eyes Filled with Silicone Oil

Purpose: To compare preoperative refractive power estimation and actual postoperative refraction after combined silicone oil removal and intraocular lens (IOL) sulcus implantation in silicone oil-filled aphakic eyes.Methods: Records of patients with silicone oil-filled aphakic eyes who received simultaneous silicone oil-removal and IOL sulcus implantation (Group1) and aphakic patients who received vitrectomy combined with IOL implantation (Group 2) were reviewed. Optical biometry including axial length measurements were obtained using IOL master&lt;sup&gt;®&lt;/sup&gt; 700 and predicted refractive errors, actual postoperative refractive errors were examined retrospectively.Results: Predicted refractive errors, calculated by subtracting 1 diopter (D) from myopic lens power closest to plano based on sulcus implantation, were 0.50 ± 0.12 D in Group 1, 0.45 ± 0.20 D in Group 2. Six months after operation, mean refractive errors measured -0.76 ± 0.49 D in Group 1, -0.23 ± 0.49 D in Group 2, showing significant myopic shift (&lt;i&gt;p&lt;/i&gt; &lt; 0.001, &lt;i&gt;p&lt;/i&gt; &lt;0.001). Group 1 showed larger significant myopic shift compared to Group 2 (&lt;i&gt;p&lt;/i&gt; = 0.001), especially in 3 eyes with insufficient filling of intravitreal silicone oil showing -1.5 D myopic shift.Conclusions: Ocular biometry of silicone oil-filled aphakic eyes undergoing simultaneous silicone oil removal and IOL sulcus implantation are difficult to measure, showing postoperative myopic shift compared to control. Incomplete intravitreal silicone oil filling showed larger refractive errors needing additional compensations.

Refractive outcome after cataract surgery with IOL master 700 optical biometry versus conventional ultrasonographic biometry

To compare the refractive outcomes after phacoemulsification with an Intra ocular lens (IOL) using IOL master 700 optical biometer versus conventional ultrasonographic biometer. A retrospective analysis of patients who underwent phacoemulsification with intra ocular lens implantation between April 2019 and March 2020 was done. Data of 654 eyes (607 patients) was shortlisted and analyzed. IOL power calculation was done with applanation ultrasonographic biometer and IOL Master 700 optical biometer by dividing patients into 2 groups. SRK/T formula was used in both cases for IOL power calculation. Refractive outcomes were determined at least four weeks after the surgery and the results were recorded. Data analysis was done using Microsoft Excel 2017 and SPSS software.In group A, applanation ultrasonographic biometer was used, 66.9% of patients were having post-operative refractive power between ±0 to ±0.75D and in group B IOL Master 700 was done 89.8% of patients, were having post-operative refractive power between ±0 to ±0.75D. Thus, refractive outcome was better in Group B eyes (89.80%) as compared to group A eyes (66.90%) and this difference was statistically significant (p value&amp;#60;.001).Biometry by IOL master 700 improves the refractive outcomes of patients of cataract surgery and is much more accurate than the applanation ultrasonography. It also ensures that the near total emmetropia, post cataract surgery by giving accurate axial length measurements and the better choice of formulas.

Interobserver agreement between central topography and Scheimpflug tomography for premium intraocular lens selection.

To assess the inter-observer agreement and reliability of central topography (CT) of IOL Master 700 with that of Pentacam HR, as a screening tool for determining the suitability for premium (toric, monofocal and presbyopia correcting) intraocular lens (IOL) implants. Nethradhama Superspeciality Eye Hospital, Bangalore, India. 200 eyes of eligible patients undergoing unilateral or bilateral phacoemulsification with premium IOL's were included in the study. Preoperatively, IOL Master 700 CT and Pentacam scans were performed for corneal topography evaluation. 2 experienced clinicians were randomised to interpret the axial map of either of the scans at a time and their responses were then enclosed in an envelope, and forwarded to a third observer for analysis. If there was a conflict, final decision was based on the interpretation of the Pentacam scan. Of the total scans interpreted by the 2 observers, 77.5% (n = 155) showed agreement whereas 22.5% (n = 45) showed disagreement. The sensitivity, specificity, positive predictive value and negative predictive value (NPV) of IOL Master 700 CT in diagnosing irregular corneas when compared with Pentacam HR, was 72.73%, 78.09%, 29.09% and 95.86% respectively. The Cohen's κ inter-observer agreement value was 0.44, signifying a moderate degree of agreement, which was statistically significant (P < .00). High NPV of IOL Master CT suggested that the device efficiently ruled out irregular corneas, while any suspicious scan should be confirmed with Pentacam HR or a similar device for appropriate decision-making regarding premium IOL selection. CTRI/2021/11/038053.

Comparison of the prediction accuracy of 13 formulas in long eyes.

To investigate the accuracy of modern intraocular lens (IOL) power calculation formulas in eyes with axial length (AL) ≥ 26.00mm. A total of 193 eyes with one type of lens were analysed. An IOL Master 700 (Carl Zeiss Meditec, Jena, Germany) was used for optical biometry. Thirteen formulas and their modifications were evaluated: Barrett Universal II, Haigis, Hoffer QST, Holladay 1 MWK, Holladay 1 NLR, Holladay 2 NLR, Kane, Naeser 2, SRK/T, SRK/T MWK, T2, VRF and VRF-G. The User Group for Laser Interference Biometry lens constants were used for IOL power calculation. The mean prediction error (PE) and its standard deviation (SD), the median absolute error (MedAE), the mean absolute error (MAE) and the percentage of eyes with PEs within ± 0.25 D, ± 0.50 D and < ± 1.00 D were calculated. The modern formulas (Barrett Universal II, Hoffer QST, Kane, Naeser 2 and VRF-G) produced the smallest MedAE among all methods (0.30 D, 0.30 D, 0.30 D, 0.29 D and 0.28 D, respectively). The percentage of eyes with a PE within ± 0.50 D ranged from 67.48% to 74.85% for SRK/T and Hoffer QST, Naeser 2 and VRF-G, respectively. Dunn's post hoc test of the absolute errors revealed statistically significant differences (P < 0.05) between some of the newer formulas (Naeser 2 and VRF-G) and the remaining ones. From a clinical perspective the Hoffer QST, Naeser 2 and VRF-G formulas were more accurate predictors of postoperative refraction with the largest proportion of eyes within ± 0.50 D.

Prediction of effective lens position (ELP) and its changes in different monofocal intraocular lens (IOL’s)

Objectives: To evaluate effective lens position (ELP) is more accurately predicted by anterior chamber depth (ACD) alone or by ACD + ½ lens thickness (LT) and to compare the ELP and refractive outcome of different monofocal intraocular lens (IOLs) in patients undergoing phacoemulsification. Materials and Methods: A total of 122 eyes with senile cataract underwent phacoemulsification with three different types of IOL implantation. Biometry data were obtained by IOL master 700 (SS-OCT) and IOL power was calculated using Barrett Universal II formula. Two prediction formulae for ELP were compared, one with ACD + ½ LT and other with ACD alone; furthermore, comparison was done among three types of IOL. Mean prediction error was calculated for both methods and among three IOL groups. Results: In the study, predicted ELP according to ACD + ½ LT was 5.27 ± 0.27 and Mean pre-op ACD was 3.069 ± 0.349 mm, achieved ELP (post-op ACD) was 4.98 ± 0.47 mm and between the two; ACD + ½ LT is closer to achieved ELP. The difference between mean ACD + ½ LT (5.22) and achieved ELP (4.71) was 0.50 in ALCON ACRYSOF IQ (SN60WF) and difference of ACD + ½ LT (5.33) and achieved ELP (5.07) was 0.25 in J and J TECNIS 1 (ZCB00), while the difference of ACD + ½ LT (5.28) and achieved ELP (5.16) was 0.114 in ZEISS CT LUCIA (611P). Residual refraction predicted by IOL master 700 and achieved residual refraction at post-op 1 month was −0.15 ± 0.19 and −0.10 ± 0.30 in ACRYSOF IQ, was −0.11 ± 0.18 and −0.01 ± 0.20 in TECNIS 1 and was −0.10 ± 0.20 and + 0.396 ± 0.22 in ZEISS CT LUCIA, respectively. Conclusion: ELP may be better predicted by formulae ACD + ½ LT than ACD alone with mean differences of 0.29 and 1.92 in two prediction groups, respectively. ALCON ACRYSOF IQ (SN60WF) and J and J TECNIS 1 (ZCB00) group had myopic shifts of 0.10 and 0.11, respectively, while ZEISS CT LUCIA (611P) group had hyperopic shifts of 0.5002 which was statistically significant, as ALCON ACRYSOF IQ (SN60WF) and J and J TECNIS 1 (ZCB00) ELP is positioned more anterior and ZEISS CT LUCIA (611P) relatively posterior.

Comparison of Intraocular Lens Power Calculation between Standard Partial Coherence Interferometry-Based and Scheimpflug-Based Biometers: The Importance of Lens Constant Optimization.

To compare the intraocular lens (IOLs) power calculated with Haigis, Hoffer Q, Holladay 1, and SRK/T formulas between the IOLs Master 500 and Pentacam AXL according to the lens status. In this cross-sectional study, sampling was done in subjects above 60 years living in Tehran using multi-stage cluster sampling. All participants underwent optometric examinations including the measurement of visual acuity and refraction as well as slit-lamp biomicroscopy to determine the lens status. Biometric measurements and IOLs power calculation were done using the IOL Master 500 and Pentacam AXL. The order of imaging modalities was random in subjects. IOL power calculation was done according to optimized ULIB constants for the Alcon SA60AT lens. The IOL power was calculated according to a target refraction of emmetropia in all subjects. After applying the exclusion criteria, 1865 right eyes were analyzed. The mean IOL difference between the two devices was -0.33 ± 0.35, -0.38 ± 0.39, -0.41 ± 0.43, and -0.51 ± 0.43 according to the SRK/T, Holladay, Hoffer Q, and Haigis formulas, respectively. The Pentacam calculated larger IOL power values in all cases. The 95% limits of agreement (LoA) between the two devices for the above formulas were -1.01 to 0.35, -1.14 to 0.39, -1.25 to 0.43, and -1.35 to 0.33, respectively. The best LoA were observed in normal lenses for all formulas. The difference in the calculated IOL power between the two devices using the four formulas had a significant correlation with axial length, mean keratometry reading, and anterior chamber depth. According to the results of the four formulas, mean keratometry reading had the highest standardized regression coefficient in all formulas. Although the difference in the calculated IOL power between IOL Master 500 and Pentacam AXL is not significant clinically, the results of these two devices are not interchangeable due to the wide LoA, especially for the Haigis formula; therefore, it is necessary to optimize lens constants for the Pentacam.

Effect of pupil dilation on biometry measurements and intraocular lens power calculation formula with intraocular lens master 500

Effect of pupil dilation on biometry measurements and intraocular lens power calculation formula with intraocular lens master 500

Biometry and Intraocular Lens Power Calculation by Combined Scheimpflug-Placido Disc versus Optical Interferometry Devices.

To compare the results of the current gold standard, laser interferometry, and keratometry by the IOL-Master, with a newly developed Galilei G6 using raytracing software Okulix for intraocular lens (IOL) power calculations. For comparison of the IOL-power calculation of both devices, we analyzed the difference between the actual one-month postoperative subjective refraction and the theoretically calculated target refraction before cataract surgery. The IOL was selected according to the IOL Master recommendation aiming for emmetropia after surgery.We analyzed the differences of the measurements of the basic biometric data in 205 healthy eyes by each device. Our study included 205 healthy, unoperated eyes from 117 patients (61 women, 56 men) aged 20 to 75 years. Twenty-two eyes of cataract patients were also included in this retrospective study design. The mean difference between the prediction of the postoperative refraction and the refraction actually achieved was 0.03 D for the IOL Master and -0.23 D for the Galilei G6. The difference was not statistically significant (P = 0.059). The difference between the IOL power calculation of the IOL Master and the calculation of the G6 was not statistically significant (P = 0.064). The difference between the predicted refraction of the G6 and the refraction achieved after one month was also not statistically significant (P = 0.12) and neither was the difference between the predicted refraction of the IOL Master and the achieved refraction (P = 0.39). The mean axial length was calculated as 24.21 0.80 mm using the IOL Master and 24.27 0.82 mm using the Galilei G6 device. The mean value regarding anterior chamber depth (ACD) of the IOL master was 3.46 0.23 mm and for the Galilei was G6 3.51 0.25 mm. When comparing the white to white (WTW) values of the IOL master, it showed mean values of 12.32 0.31 and Galilei showed mean values of G6 12.21 0.28. All of these differences (between Galileo and IOL Master measurements) were statistically significant (P 0.001). Both the laser interferometry/keratometry performed by the IOL Master and the interferometry/raytracing biometry strategy performed by the Galilei G6 demonstrated equal results when executing the IOL power calculation before cataract surgery in eyes with no prior ocular surgery.

The Refractive Outcomes of Sutured and Sutureless Scleral Fixation (the Yamane Technique)

Purpose: To evaluate the pre- and post-operative refractive powers of patients undergoing sutured and sutureless scleral fixation (the latter: the Yamane technique).Methods: Patients who had undergone sutured or sutureless scleral fixation to treat intraocular lens (IOL) dislocation or phacodonesis at Dong-A University Hospital from January 2017 to December 2021 were retrospectively investigated. The preoperatively predicted spherical equivalents (derived using the radii of corneal curvature) were measured via optical coherence topography and the axial lengths were determined using an IOL master ® (Zeiss, Carl Zeiss Meditec, Jena, Germany) device and A-scan biometry (AL-100; Tomey, Nagoya, Japan) ultrasound. The spherical equivalent was measured 1 month after surgery employing an automatic refractive keratometer. The extent of agreement between the predicted and actual spherical equivalents were compared between the sutured and sutureless scleral fixation groups.Results: The sutured scleral fixation group included 20 eyes and the sutureless group 12 eyes. The preoperatively predicted spherical equivalent of the sutured group was -0.158 ± 0.577 diopters (D) on A-scan (Tomey) ultrasound and -0.143 ± 0.617 D employing the IOL master ® (Carl Zeiss Meditec); both correlated poorly with the postoperatively measured spherical equivalent of -0.400 ± 0.923 D (p = 0.903, 0.563). However, the predicted spherical equivalent of the group undergoing sutureless fixation was -0.340 ± 0.368 D on A-scan ultrasound and -0.183 ± 0.251 D using the IOL master ® (Carl Zeiss Meditec); both correlated significantly with the postoperatively measured spherical equivalent of -0.313 ± 1.129 D (p = 0.038, 0.005).Conclusions: The preoperatively predicted refractive power correlated significantly with the postoperative refractive power after sutureless but not sutured scleral fixation. Sutureless fixation was safe and the postoperative refractive power was comparable to that of sutured fixation.

Effect of anterior chamber depth on the accuracy of different intraocular lens&amp;rsquo; formulas

&lt;div class="page" title="Page 1"&gt;&#x0D; &lt;div class="section"&gt;&#x0D; &lt;div class="layoutArea"&gt;&#x0D; &lt;div class="column"&gt;&#x0D; &lt;p&gt;&lt;strong&gt;Background and Objectives&lt;/strong&gt;: Due to the difference in anterior segments among different races, intraocular lens formulas behave differently. Asian eyes have smaller anterior segment dimensions than Caucasian eyes. This study was carried out to evaluate the effect of different values of anterior chamber depth on the accuracy of Sanders, Retzlaff, Kraff/Theoretical (SRK/T), Hill Radial Basis Function (Hill RBF 2), and Barrett Universal II (Barrett U II) formulas.&lt;br /&gt;&lt;strong&gt;Methods:&lt;/strong&gt; This was a descriptive observational study. Ninety-six eyes of patients, who underwent phacoemulsification with intraocular lens implantation and ended uneventfully, were included. The patients were divided into two groups based on the anterior chamber depth (ACD). Group 1 had ACD &amp;gt; 3 mm and group 2 had ACD &amp;lt; 3 mm. Intraocular lens (IOL) power with SRK/T was calculated with a built-in formula in IOL Master 500. Barrett Universal II and Hill RBF 2 formulas were calculated using online calculators. Descriptive statistics were calculated for both groups. An independent t-test was applied for group comparison.&lt;br /&gt;&lt;strong&gt;Results: &lt;/strong&gt;Comparisons of the mean prediction errors of groups 1 and 2 using three different formulas were not statistically significant (p &amp;gt; 0.05). However, SRK/T had the lowest median prediction error for both groups but the highest percentage of eyes within &amp;plusmn;0.5 D of absolute prediction error (APE) for group 1 and the lowest percentage of eyes within &amp;plusmn;0.5 D of APE for group 2.&lt;br /&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;There was no statistically significant effect of different anterior chamber depths on the accuracy of SRK/T, Barrett U II, and Hill RBF 2. The three formulas behaved similarly with different depths of the anterior chamber.&lt;/p&gt;&#x0D; &lt;/div&gt;&#x0D; &lt;/div&gt;&#x0D; &lt;/div&gt;&#x0D; &lt;/div&gt;