Zeiss IOLMaster Research Articles

Reverse Pupillary Block after Implantation of a Sutureless Scleral Fixation Carlevale Intraocular Lens

PurposeTo describe the incidence, complications and management of reverse pupillary block (RPB) after implantation of Carlevale IOL. DesignMulticenter, retrospective, cross-sectional study. ParticipantsOut of a sample of 128 patients that had undergone Carlevale IOL implantation, 19 patients were found to present RPB. MethodsNineteen patients with RPB after Carlevale IOL implantation were evaluated and treated with laser peripheral iridotomy (LPI). Main Outcome MeasuresDemographic data (age, gender), data on preexisting medication, axial length (Zeiss IOLMaster 500 and Zeiss IOLMaster 700), presence of pseudoexfoliation material (PXF), presence of reverse pupillary block (Anterior segment swept-source SS-OCT Anterion, Heidelberg Engineering), presence of macular edema (Irvine Gass syndrome, OCT Spectralis, Heidelberg Engineering), anterior chamber depth (ACD) before and after LPI, best corrected visual acuity (BCVA) before and after LPI and intraocular pressure (IOP) before and after LPI were analyzed. ResultsAn incidence of RPB of 14.8% was found. The prevalence of pseudoexfoliation syndrome was 21.1% and 42.1% of patients presented an axial length >24.00 mm. Mean pre-LPI ACD was 4.78 ± 0.465 mm and post-LPI was 4.23 ± 0.404 mm, a statistically significant increase of 0.54 (p=0.000, IC 95% 0.26-0.83) mm of ACD was observed. There were no differences between pre- and post- LPI BCVA. Pre-LPI IOP was 17.10 (range 12-34) mmHg and post-LPI IOP was 14.47 (range 10-21) mmHg, (p= 0.391). Cystic macular oedema (Irvine Gass) was identified in 4 out of 19 patients, reporting an incidence of 21.1% in RPB cases. ConclusionReverse pupillary block is a relatively common complication after Carlevale lens implantation, which may be associated with an increase of macular oedema incidence but does not clearly correlate an increase of intraocular pressure. Our hypothesis is that indentation of the sclera induces a posterior rotation of the peripheral iris, causing RPB. Our results encourage to look over the Carlevale IOL implantation technique to consider a routinely intraoperative surgical peripheral iridotomy to avoid RPB and its further complications.

Comparative Analysis of Refractive Outcomes Using Optical and Ultrasound Biometry in Phacoemulsification Cataract Surgery

Background: Accurate biometry is critical for optimal visual outcomes in cataract surgery. Both optical and ultrasound biometry are widely used, but their comparative effectiveness remains under evaluation.Objective: To compare the refractive outcomes of optical and ultrasound biometry in patients undergoing elective phacoemulsification cataract surgery.Methods: This prospective cohort study included 352 patients aged 30-60 years undergoing elective phacoemulsification with in-the-bag IOL implantation. Patients were randomly assigned to either optical biometry using the Zeiss IOL Master 700 or ultrasound biometry with Axis Nano contact A-mode echography. Visual acuity and spherical equivalent were measured at baseline and 4 weeks post-operatively. Data were analyzed using SPSS version 25, with independent t-tests comparing outcomes between groups.Results: The mean post-operative visual acuity was 0.83 ± 0.22, with a mean spherical equivalent of -0.88 ± 0.16. No significant difference was found between the ultrasound (-0.89 ± 0.17) and optical biometry (-0.87 ± 0.16) groups (p=0.152, 95% CI -0.06 to 0.01).Conclusion: Both optical and ultrasound biometry provide comparable refractive outcomes in cataract surgery, with no significant difference in post-operative spherical equivalent.

Comparison of the IOL Master and Pentacam in the measurement of anterior segment parameters in patients with high myopia and cataracts

This study aimed to compare the differences between the Zeiss IOL Master and Oculus Pentacam in keratometry and central anterior chamber depth (ACD) measurements in patients with high myopia and cataracts. Between January 2019 and December 2020, 89 patients (103 eyes) with cataracts and high myopia who underwent preoperative cataract evaluation at Nanchang First Hospital were selected for retrospective analysis. Keratometry (K1, K2) and ACD were measured with the IOL Master and Pentacam. Paired t-tests were performed to compare the differences, while the Bland-Altman method was used to evaluate the agreement. The K1 value was (43.15±2.44) D for the IOL Master and (42.98±2.47) D for the Pentacam, and the difference between the two instruments was statistically significant (P<0.01). The K2 value was (44.55±2.63) D for the IOL Master and (44.32±2.55) D for the Pentacam. The ACD was (3.44±0.33)mm for the IOL Master and (3.39±0.36)mm for the Pentacam. There were statistically significant differences between the two instruments in both keratometry and ACD (P<0.01). The absolute values of the maximum difference between the two instruments for K1 and K2 were 1.1 and 1.07; thus, the consistency of the two instruments with respect to this measurement was poor. However, the absolute value of the maximum difference between the two instruments for ACD was 0.34, so the consistency of the two instruments in relation to this measurement was good. Both the IOL Master and the Pentacam can be used in the measurement of keratometry and ACD in patients with high myopia and cataracts, but the keratometry measurements should be compared in clinical application.

Comparison of intraocular lens tilt after capsular sutured scleral fixation with capsular segments versus uneventful cataract surgery.

To evaluate and compare intraocular lens (IOL) tilt between uneventful phacoemulsification with in-the-bag IOL implantation and sutured scleral fixation (SSF) of the lens bag with a capsular tension segment (type 6 D / Morcher) using a Sheimpflug camera. Clinical Practice, Hospital. Barcelona and A Coruña, Spain. Retrospective, comparative multicenter study. IOL tilt was compared between patients who underwent sutured scleral fixation with a capsular tension segment in a single eye (SSF group, n = 15) with patients who underwent uneventful IOL implantation (control group, n = 12) that were matched by biometric measurements. Post-operative refractive accuracy of biometric formulas by means of mean absolute error (MAE) was also reported. All patients underwent a general ophthalmic evaluation, anterior segment photography, and postoperative optical biometry (Zeiss IOLMaster® 500). In addition, IOL tilt was measured with a Scheimpflug camera (Pentacam R, Oculus Optikgerate Gmbh). Mean vertical tilt was similar in both groups (2.20+/-2.47° SSF vs 1.97 +/- 1.79° control; p = 0.836) but mean horizontal tilt tended to higher values in the SSF series (2.09 +/- 2.74° vs 0.94 +/- 1.17°; p = 0.139). Considering post-operative refractive error in diopters by MAE calculations, there was an underestimation of IOL power in the SSF group which was only statistically significant for Barrett Universal II (1.07 vs 0.32; p = 0.028) and Hill-RBF (0.95 vs 0.26; p = 0.024) formulas, but not for SRK/T (0.99 vs 0.42; p = 0.285) and Kane (0.96 vs 0.33; p = 0.083). Sutured scleral fixation of capsular tension segments in the presence of zonular instability does not seem to induce clinically significant IOL tilt compared to uneventful cataract extraction cases.

Значение анатомо-структурных параметров глаза в эффективности лечения близорукости ортокератологическими линзами

Aim of the study. To study the importance of anatomical and structural parameters of the eye in the effectiveness of treatment with orthokeratological lenses in myopia. 200 eyes (100 patients) were examined, including 160 eyes (80 patients) with myopia – 60 eyes (30 patients) with a mild degree and 100 eyes (50 patients) with an average degree; mean age 12.0± 0.38 years, control group – 40 eyes (20 people) – healthy individuals with emmetropia. Research methods. Along with the generally accepted methods, autorefractometry (Grand Seiko VR-2100), ophthalmometry (Topcon KR-7309), biometry (Zeiss IOLMaster 500), keratotopography (root otopographic system SW-600), accommodation study – AKA-01 device, and Shapovalov S.L. method, skiascopy against the background of cycloplegia, ultrasound of the eye, ultrasound of the retinal vessels, OST-angiography, study of the hydrodynamics of the eye (Glau Test 60). Follow-up in 1-3-6-12-24 Months. Results. With the formation of induced myopia against the background of the use of orthokeratological lenses in mild and moderate myopia, an increase in the difference in corneal curvature between the central and peripheral zones was revealed – the coefficient «Q» is equal to (-) 0,56±0,05 mm and (-) 0,57 ±0,054 mm (Р &lt;0,001), in CG (-) 0,26±0,03 mm; increase in the index (asymmetry) «I-S» – before 2,78±0,18D and 3,22 0,12D (Р &lt;0,001), in CG –&gt;1,2±0,18D (Р &lt;0,01); increase in the frequency of refractive power amplification along the vertical and horizontal meridians (SimK1, Sim K2) by 37% and 44%; Normalization of hydrodynamic parameters: «Po» is normal in в 30%; increase «C» – up to 0,22 мм3/min (Р&lt;0,05); increase in AAA to 7,6 D±0,23 and 8,5D±0,01 (Р &lt;0,05) and 1,5 times – ZOA; increase in LSC in CAC to 15.0±0.64 cm/sec and in CVD – up to 5.5±0,59 cm/sec (Р &lt;0,05) with choroidal thickening to 301±1,9 мкм (Р &lt;0,05). Effectiveness of treatment with orthokeratological lenses: increase in NCOZ to 0.9-1.0 in 100%; reduction of the degree of myopia to (-) 0.55D±0.21 (P &lt;0.01); lack of reliable stretching of the AXL. Conclusion: One of the additional factors contributing to the effectiveness of the use of orthokeratological lenses in mild and moderate myopia are: activation of accommodation, normalization of hydrodynamics and hemodynamics of the eye.

Feasibility and repeatability of ocular biometry measured with IOLMaster 700 in a large population‐based study

To evaluate the feasibility and repeatability of IOLMaster 700 biometry measurements in an adult population. Furthermore, to assess the value of the Quality Indicators (QIs) provided by the device. As part of the large population-based Leipzig Research Centre for Civilization Diseases (LIFE) Adult-Study, randomly selected participants from Leipzig, Germany were evaluated with the ZEISS IOLMaster 700. Age range was 26-85 years, with 53% of participants above 70 years of age. Axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT) and keratometry (K) were assessed in 1767 right eyes. Measurements were repeated twice and in a subset of 1331 eyes, three times. Measurement feasibility was evaluated for three levels; successful, with warnings and failed, using the inbuilt QIs. Repeatability was assessed as within-subject standard deviation (SD) and repeatability limits were calculated. First measurement success rate for phakic eyes was over 99% for AL, CCT, ACD, over 98% for LT and over 97% for K. K had 16% eyes with warnings and the recommendation to repeat the measurement. Excluding the measurements with warnings resulted in a reduction of mean SD for AL from 48 to 4 μm and for mean K from 0.08 to 0.04 D. Repeatability for phakic eyes was 8 μm for AL, CCT, ACD and LT and 2.3 μm for CCT; 0.07 D and 0.12 D for mean K and delta K, respectively, for phakic cases without warnings (two measurements). In our population-based sample, the IOLMaster 700 collected data for AL, CCT, ACD, LT and K from the vast majority of eyes. Considering the built-in QIs improved the measurement variability substantially. Repeatability measurements indicate that clinically meaningful changes can be detected reliably with this instrument.

The association between time spent on screens and reading with myopia, premyopia and ocular biometric and anthropometric measures in 6- to 7-year-old schoolchildren in Ireland.

More time spent on near tasks has consistently been associated with the promotion of myopia. The World Health Organization advises limiting daily screentime to less than 2h for children aged five and over. This study explored the relationship between time spent on screens and reading/writing with refractive status, ocular biometric and anthropometric factors in 6- to 7-year-olds in Ireland. Participants were 723 schoolchildren (377 boys [51.8%]), mean age 7.08 (0.45) years. The examination included cycloplegic autorefraction (1% cyclopentolate hydrochloride), ocular biometry (Zeiss IOLMaster), height (cm) and weight (kg). Screentime and reading/writing time were reported by parents/legal guardians by questionnaire. Myopia (≤-0.50D) and premyopia (>-0.50D ≤ 0.75D) risk assessments were performed using logistic regression, and multivariate linear regression was used to analyse continuous variables. Reported daily screentimes were 31% <1h, 49.5% 1-2h, 15.6% 2-4h and 3.9% >4h. Reading/writing times were 42.2% frequently, 48.0% infrequently and 9.8% seldom/never. Linear regression, controlling for age and ethnicity, revealed >2h/day on screens was associated with a more myopic spherical equivalent [β=-1.15 (95% confidence intervals {CIs}: 1.62-0.69, p < 0.001)], increased refractive astigmatism (β=0.29, CI: 0.06-0.51, p=0.01), shorter corneal radius (β=0.12, CI: 0.02-0.22, p=0.02), higher axial length/corneal radius (β=0.06, CI: 0.03-0.09, p < 0.001), heavier weight (β=1.60, CI: 0.76-2.45, p < 0.001) and higher body mass index (BMI) (β=1.10, CI: 0.28-1.12, p < 0.001). Logistic regression, controlling for age and ethnicity, revealed daily screentime >2h was associated with myopia (OR=10.9, CI: 4.4-27.2, p=0.01) and premyopia (OR=2.4, CI: 1.5-3.7, p < 0.001). Frequent reading/writing was associated with screentime ≤2h/day (OR=3.2, CI: 1.8-5.8, p < 0.001). Increased screentime was associated with a more myopic refraction, higher axial length/corneal radius ratio, increased odds of myopia, premyopia, higher degrees of astigmatism, increased weight, BMI and decreased reading/writing time. Dedicated education programmes promoting decreased screentime in children are vital to prevent myopia and support eye and general health.

Conformation of the anterior segment in human myopia.

Topography of the in vivo anterior segment is of relevance in understanding its role in myopia and in the development of ocular surgical procedures. Using 3D magnetic resonance (MR) images of the human eye, regional variations in surface area (SA) and bulbosity of four anterior segment regions were investigated in association with refractive status (Rx), axial length (AL) and total ocular volume (OV). T2-weighted ocular MR images from 43 adults aged 18-40 years (mean ± SD; 28.65 ± 6.20) comprising 20 non-myopes (≥-0.50) 0.57 ± 1.38and 23 myopes (<-0.50) -6.37 ± 4.23 MSE (D) were collected. 2D representations of each quadrant (superior-temporal [ST], superior-nasal [SN], inferior-temporal [IT] and inferior-nasal [IN]) of the anterior section (3.5-9 mm) were fitted with second-order polynomials. Polynomials were integrated and rotated about the x-axis to generate SA; dividing the SA by 4 provided relative quadrantial SA. The x2 coefficient provides indices of bulbosity. OV was derived from the 3D MRI scans. Rx and AL were measured using cycloplegic autorefraction and the Zeiss IOLMaster, respectively. One- and two-way repeated-measures ANCOVAs tested differences in SA and bulbosity for Rx, gender, ethnicity and age. Pearson's correlation coefficient tested the relationship between MRI-derived metrics and biometry. Significant differences in SA were observed between quadrants (p< 0.001) with differences between ST versus IN, IN versus IT and SN versus IT. An interaction effect (p= 0.01) for Rx suggested smaller temporal (ST and IT) and larger nasal (SN and IN) SA in myopes. AL and myopic Rx were negative correlated (p< 0.05) with SA at IN, SN and IT. OV was significantly associated with SA at ST. Bulbosity showed no regional differences nor an effect of AL or Rx. Significant regional variation in SA exists across the anterior segment that is modulated by Rx and AL. It is unclear whether these structural characteristics are a precursor or consequence of myopia and may warrant investigation when developing biomechanical interventions.

Comparing ocular biometry and autorefraction measurements from the Myopia Master with the IOLMaster 700 and the Huvitz HRK-8000A autorefractor.

To compare axial length (AL) and corneal radius (CR) measured with the Oculus Myopia Master and the Zeiss IOLMaster 700, and cycloplegic refractive error measured with the Myopia Master and the Huvitz Auto Ref/Keratometer (HRK-8000A). The study included both eyes of 74 participants (16 male), with a mean (SD) age of 22.8 (3.7) years. The parameters indicated were measured under cycloplegia with these instruments: Myopia Master (AL, CR and refractive error), IOLMaster 700 (AL and CR) and HRK-8000A (refractive error and CR). Bland-Altman plots with mixed effects 95% limits of agreement (LoA) and corresponding 95% confidence intervals were used to assess the agreement in ocular biometry between the Myopia Master and the IOLMaster 700, and for refractive error between the Myopia Master and the HRK-8000A. The analysis included 139 eyes, of which 52 were myopic (spherical equivalent refractive error, SER ≤ -0.50 D), 32 emmetropic and 55 hyperopic (SER ≥ 0.50 D). The 95% LoA for AL between the Myopia Master and IOLMaster 700 was -0.097 to 0.089 mm. There was no mean difference in AL [mean (SD)=-0.004 (0.047) mm, p=0.34]. There was a significant difference in mean CR, with that measured with the Myopia Master being flatter than that found with the IOLMaster 700 [0.035 (0.028) mm, p < 0.001]. The 95% LoA for CR was -0.02 to 0.09 mm. Compared with HRK-8000A, the Myopia Master measured a significantly more negative SER [-0.19 (0.33)D, p < 0.001], with 95% LoA of -0.86 to 0.46 D. The LoA for measurements of SER, CR and AL when comparing the Myopia Master with the HRK-8000A and the IOLMaster 700 were wider than deemed acceptable for making direct comparisons. This indicates that the instruments cannot be used interchangeably in clinical practice or research.

Corneal Astigmatism Alteration after Combined Silicone Oil Removal and Cataract Surgery with Intraocular Lens Implantation.

To explore short-term changes in corneal astigmatism after combined silicone oil removal and cataract (SORC) surgery. We enrolled 89 patients (43 men and 46 women). Zeiss IOLMaster was used to measure corneal astigmatism status and axial length on the day before and after the SORC surgery. Best-corrected visual acuity (BCVA) and intraocular pressure (IOP) were recorded. The results were compared to the outcomes at 3 days, 1 week, and 1 month postoperatively. Compared to baseline, K1 decreased significantly at 3 days postoperatively (P = 0.016), 1 week (P = 0.009), and 1 month (P = 0.035), while K2 increased significantly at 3 days postoperatively (P = 0.002), 1 week (P < 0.001), and 1 month (P = 0.001), as well as corneal astigmatism (all P < 0.001). Compared to that at the baseline, BCVA significantly improved at 3 days, 1 week, and 1 month postoperatively (all P < 0.001). Meanwhile, IOP decreased significantly at 3 days postoperatively (P < 0.001), 1 week (P = 0.005), and 1 month (P = 0.007). Similarly, axial length decreased at all follow-up time points (all P < 0.001). Corneal astigmatism increased in the short term after the SORC operation but gradually decreased at 1 month postoperatively. BCVA improved steadily, and SORC was widely used in the clinic.

Ocular biometric dimensions according to gender. Are they different?

AbstractPurpose: To analyse ocular biometric parameters in men and women in a population of cataract surgery candidates and determine whether statistically significant differences exist.Methods: A cross‐sectional study of 5034 eyes of 2671 patients was performed. Biometric parameters of the eyes were measured by Zeiss IOLMaster 700. The axial length (AL), mean anterior radio (aR), mean posterior radio (pR), central corneal thickness (CCT), anterior chamber depth (ACD) (epithelium to lens), lens thickness (LT), and White to White corneal diameter (W2W) were evaluated. These data represent normative biometric values for the Valencian population.Results: The mean age in the male group was 73 ± 9.6 years, the mean age in the female group was 73.8 ± 8.3 years. The male/female ratio was 0.84. The male–female difference, with a 95% confidence interval (CI) in AL, ACD, and LT were 0.65 mm [0.57; 0.73] (p &lt; 0.01), 0.17 mm [0.14; 0.2] (p &lt; 0.01), and 0.031 mm [0.005; 0.5] (p &lt; 0.05), respectively. Differences (95% CI) in W2W and CCT were 0.18 mm [0.15; 0.20] (p &lt; 0.01), and 4.89 μm [2.55; 7.23] (p &lt; 0.01). Differences (95% CI) in aR and pR were 0.137 mm [0.12; 0.153] (p &lt; 0.01) and 0.122 mm [0.106; 0.139] (p &lt; 0.01). All biometric eye parameters (AL, aR, pR, CCT, ACD, LT, W2W) measured, were lower in females than in males, with a statistically significant difference.Conclusions: Statistically significant differences between genders were found in all the biometric parameters evaluated. In our population, women's eyes are smaller than men's in all biometric parameters that shape them. Gender must be taken into account in the biometric evaluation of the eye. These results may be relevant in intraocular lens power calculation and in the evaluation of refractive error.

Corneal and lenticular biometry in Chinese children with myopia

ABSTRACT Clinical relevance The measurement and simulation of corneal and lenticular curvature radii using a single swept-source biometry device enables a more thorough evaluation of the shape and refractive power of the cornea and lens during emmetropization or myopia progression in children. Background This study aimed to evaluate the distribution characteristics of corneal and lenticular parameters in Chinese children with myopia and explored their association with other ocular components. Methods In this cross-sectional study, all ocular biometric parameters were measured using a Zeiss IOLMaster 700 Biometry. Simulations of the corneal and lenticular curvature radii were implemented using a customised MATLAB program based on cross-sectional swept-source optical coherence tomography images obtained from the same device. The associations of the calculated and simulated refractive powers of the cornea and lens with other ocular parameters were evaluated. Results In total, 119 children with myopia were recruited. Boys had a deeper anterior chamber and longer axial length (AL) than girls, while girls had steeper anterior corneal and lenticular curvatures and greater corneal and lenticular power. Children aged 10 years and older showed a larger anterior lenticular radius of curvature (sRal) and less lenticular power (PL,OCT) than younger participants. There was a significant positive correlation between AL and the anterior corneal radius of curvature, regardless of sex or age. The sRal exhibited a significant increasing trend, and PL,OCT exhibited a declining trend with a longer AL only in children younger than 10 years. Conclusion AL is the most influential factor in the determination of spherical equivalent refractive error, while decreases in both corneal and crystalline lens power are significantly inversely correlated with axial elongation.

The effect of axial length to basement-membrane opening to fovea distance on optical coherence tomography.

Optical Coherence Tomography (OCT) lateral scaling is influenced by axial length (AL). There is a need to incorporate a method to correct this measurement bias for accurate lateral OCT measurement. To identify the correlation of optic-nerve-to-fovea distance measurement to AL by OCT) as an internal factor for lateral scaling. Using Heidelberg Spectralis OCT, distance from the basement membrane opening at the optic disc margin to the centre of the fovea (BMO-fovea distance) was measured in 135 eyes (77 subjects, ages 25-85). These measurements were correlated with AL measurements from Zeiss IOLMaster 700 using linear regression before and after correction for ocular magnification. Statistical analysis including Shapiro-Wilk test for normality, Pearson correlation, and multivariate analysis of the association between disc-fovea distance and AL was performed using Wizard statistical software for mac. After lateral scaling, the mean distance between the fovea and BMO was 3.60 ± 0.25 mm (median: 3.59; range 3.07-4.23 mm). There was a significant positive correlation between AL and Bennett's formula-corrected BMO-fovea distance (p <0.001, r = 0.354). While there is significant variability in BMO-fovea distances, it is positively correlated with AL. A standard method is needed to improve the lateral scaling measurements in order to unify the results for enface OCT imaging.

Change in axial length after vitrectomy with silicone oil tamponade for rhegmatogenous retinal detachment

BackgroundWe aimed to explore the changes in the axial length and related factors after vitrectomy for rhegmatogenous retinal detachment (RRD).MethodsThis study retrospectively evaluated patients who underwent vitrectomy with silicone oil (SO) tamponade for RRD and subsequent silicone oil removal at our clinic. Using a Zeiss IOLMaster 700, axial length was measured before vitrectomy for RRD and SO removal. The change in axial length (ΔAL) was calculated, and multivariate binary logistic regression analysis was performed to investigate the potential correlation between ΔAL and clinical factors, such as preoperative hypotony, extreme myopia, age, macular involvement, choroidal detachment, operation duration, and operation history.ResultsIn total, 213 eyes from 213 patients were included. The mean axial length changed significantly pre- and post-vitrectomy (25.98 ± 2.87 mm and 26.25 ± 3.07 mm, respectively, P < 0.001); the mean ΔAL was 0.37 ± 0.62 mm. Multivariate binary logistic regression analysis showed that preoperative hypotony and extreme myopia were significantly correlated with the ΔAL (P = 0.001 and P = 0.001, respectively). A higher proportion of hypotonic eyes had ΔAL ≥ 0.3 mm (33/76 in hypotony eyes and 32/137 in others; P = 0.003). A higher proportion of extremely myopic eyes also had a ΔAL ≥ 0.3 mm (23/46 in extremely myopic eyes and 42/167 in others; P = 0.002).ConclusionFor patients with RRD and cataracts, as axial length changed significantly after vitrectomy in those with hypotony or extreme myopia, secondary lOL implantation should be considered.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12886-022-02433-8.

Axial Elongation During Short-Term Accommodation in Myopic and Nonmyopic Children.

PurposeAxial length increases during accommodation in adults and children; however, refractive error group differences are conflicting and have not been explored in pediatric populations. This study aimed to evaluate differences in accommodation-induced axial elongation between myopic and nonmyopic children.MethodsA range of ocular biometric measurements were captured during brief accommodation tasks (0, 3, 6, and 9 D) using a Badal optometer mounted to a noncontact optical biometer (Zeiss IOLMaster 700). Reliable measurements were captured for 15 myopic and 15 age- and sex-matched nonmyopic children. The average central corneal thickness (CCT), anterior chamber depth (ACD), crystalline lens thickness (LT), anterior segment length (ASL), vitreous chamber depth (VCD), and axial length (AL) were determined for each accommodation stimulus. Raw measurements of AL and VCD were corrected for the estimated error associated with LT increases during accommodation.ResultsAll biometric parameters, except CCT, changed significantly during accommodation (all P < 0.001). Myopic children exhibited significantly greater accommodation-induced axial elongation than nonmyopic children (P = 0.002) at the 3, 6, and 9 D accommodation stimuli, with a mean difference of 7, 10, and 16 µm, respectively (all pairwise comparisons, P ≤ 0.03). The changes in all other biometric parameters were not different between the refractive error groups (P ≥ 0.23).ConclusionsAccommodation-induced axial elongation was greater in myopic than nonmyopic children. This finding could support a potential mechanism linking near work, axial elongation, and myopia development in children or may reflect greater susceptibility to accommodation-induced axial elongation in children with established myopia.

Associations between anterior segment biometry and high axial myopia in 3438 cataractous eyes in the Chinese population

BackgroundTo investigate the associations between anterior segment biometry and high axial myopia in cataractous eyes in the Chinese population.MethodsData on 3438 eyes from 3438 subjects were analyzed in this cross-sectional study. Anterior segment biometry, axial length measurements, and intraocular pressure evaluation were implemented using an Oculus Pentacam HR, a Zeiss IOLMaster 500, and a Nidek TonoRef II, respectively. A multivariate-adjusted logistic model and a multivariate-adjusted linear model were used for statistical analysis.ResultsThe mean age of the subjects was 62.2 ± 10.6 years, and 56.4% were female. There were 2665 subjects with high axial myopia (axial length, ≥26.50 mm) and 773 without (axial length, < 26.50 mm). The characteristics independently associated with high axial myopia included lower total corneal refractive power, a more negative Q value, greater total corneal astigmatism, greater white-to-white corneal diameter, greater anterior chamber depth, and higher intraocular pressure (all P < 0.05). In addition, greater axial length correlated with a thicker temporal cornea and a thinner nasal cornea (both P < 0.001).ConclusionsFor cataractous eyes, high axial myopia was associated with corneal flattening, increased total corneal astigmatism, anterior segment enlargement, and intraocular pressure elevation. The findings may inform the choice of intraocular lenses and the calculation of their power, help improve the surgical practice of refractive cataract procedures, and provide useful information on the centration and stability of intraocular lenses.

Positions of the horizontal and vertical centre of rotation in eyes with different refractive errors.

PurposeTo determine how the position of the centre of rotation of the eyeball is related to axial length and refractive error when horizontal and vertical eye movements are performed.MethodsA custom‐built eye tracker was used that determined the centre of rotation of the eye (COR) from lateral displacements of the pupil centre. Horizontal and vertical eye movements were studied in the right eyes, and each measurement performed five times in 59 subjects (32 females) with an average age of 36.6 ± 9.1 years. Spherical equivalent refractive errors ranged from −9.7 to +6.8 D with an average error of −1.5 ± 2.9 D. Axial lengths were measured with the ZEISS IOL Master 500.ResultsThe mean horizontal centre of rotation (COR) of the right eye for a saccade from 0° to ±11.9° was 15.3 ± 1.5 mm behind the corneal apex, while the average vertical COR for the same angle of eccentricity was 12.5 ± 1.4 mm, indicating that the horizontal COR was 2.8 ± 1.7 mm behind the vertical COR. In right eyes, horizontal COR was significantly correlated with axial length (r = 0.28, p = 0.02) but not with the spherical equivalent refractive error (r = 0.39, p = 0.90). Similarly, vertical COR was significantly correlated with axial length (r = 0.25, p = 0.03) but not with the spherical equivalent refractive error (r = 0.17, p = 0.90).ConclusionsWhile it might be expected that the COR is dependent on axial length, the correlation was not strong. Interestingly, the location of the COR was substantially different for horizontal and vertical eye movements which may relate to the flatter curvature of the eyeball in the vertical meridian, compared to the horizontal, as described in previous studies.

An evaluation of the IOLMaster 700 and its agreement with the IOLMaster v3 in children.

To evaluate the repeatability and reproducibility of the swept-source optical coherence tomographer Zeiss IOLMaster 700 and compare its outputs with those obtained using partial coherence interferometry (Zeiss IOLMaster v3) in a healthy, paediatric population. This is a cross-sectional, observational study. Examiner 1 took two sets of biometric measurements (axial length [AL],mean corneal radius of curvature [Kmean ], anterior chamber depth [ACD] and lens thickness [LT]) using the IOLMaster 700, and one set of measurements (AL, Kmean and ACD) using the IOLMaster v3. Examiner 2 took one full set of measurements using the IOLMaster 700. Mean differences and 95% limits of agreement (LOA) were calculated, and Bland and Altman plots used to explore repeatability and reproducibility of the IOLMaster 700 alongside establishing its agreement with the IOLMaster v3. Mean participant age was 7.52±0.58years. Repeatability analyses demonstrated small mean differences and narrow 95% LOA for AL (0.001, -0.013 to 0.015mm),Kmean (0.002, -0.020 to 0.024mm),ACD (-0.003, -0.031 to 0.024mm)and LT (0.001, -0.024 to 0.026mm), respectively. Similarly, small mean differences and narrow 95% LOA established excellent reproducibility (AL 0.001, -0.016 to 0.018mm; Kmean -0.001, -0.027 to 0.025mm; ACD -0.010, -0.041 to 0.021mm; LT 0.002, -0.016 to 0.020mm). The IOLMaster 700 and IOLMaster v3 demonstrated good agreement with small mean differences and narrow 95% LOA (AL 0.009, -0.034 to 0.052mm; Kmean 0.016, -0.013 to 0.044mm;ACD 0.134, 0.055 to 0.212mm). When used within a paediatric population, these data demonstratethe IOLMaster 700 to be highly repeatable and reproducible for measures of AL, Kmean , ACD and LT. There is excellent inter-instrument agreement between the IOLMaster 700 and IOLMaster v3 for measures of AL and Kmean . ACD measurementsshowweaker agreement. These data will be useful when considering reports from population-based studies of refractive error and clinical myopia research.

Evaluation of Physiological Parameters on Discomfort Glare Thresholds Using LUMIZ 100 Tool.

PurposeTo assess the links between discomfort glare sensitivity and physiological factors such as eye biometry, refraction, skin phototype, age, and gender among a large sample of healthy human subjects.MethodsA total of 489 participants who were 20 to 70 years old (241 men, 248 women) underwent discomfort glare threshold measurements via the LUMIZ 100. Eye biometry and optical quality were measured using a Zeiss IOLMaster 700 biometer and i.Profiler aberrometer. Iris color, skin tone, age, gender, eyeglasses use, chronotype, fatigue level, self-evaluation of light sensitivity, and time spent outdoors were determined. Statistical analysis was carried out using nonparametric Mann–Whitney and Kruskal–Wallis tests for categorical data and correlation coefficients for numerical data.ResultsThe female subgroup had lower discomfort thresholds than the males (P < 0.001). There was no effect of age group, ametropia, eye biometry, iris color, skin tones, chronotype, or fatigue level on discomfort thresholds. Discomfort thresholds were related to self-assessment of light sensitivity, sunglasses ownership, and frequency of use (P < 0.001).ConclusionsExploration of easily measurable physiological parameters and questionnaire failed to provide reliable indicators of individual light sensitivity to discomfort glare.Translational RelevanceLight sensitivity is highly subjective and variable across the population. Patients frequently complain about light bothering their daily lives. Accessible physiological factors and questionnaires are unable to predict discomfort levels due to glare. The LUMIZ 100 provides a reliable, rapid, and safe way to determine light discomfort thresholds in order to better manage light sensitivity in clinical care.

Benefits and New Features of a Modern International Internet Database "IOLCon" for Updated and Optimized IOL Constants and IOL Specifications.

Cataract surgery has a history of about 2800 years. Harold Ridleyʼs invention of the intraocular lens in 1949 set a milestone in cataract surgery, supplying patients with a more or less satisfactory refractive implant for the first time. In the following 70 years, cataract surgery, IOL technology, and biometry have developed enormously. The invention of optical biometry in 1999 has again fundamentally changed cataract surgery. The introduction of the first optical biometer, the Zeiss IOLMaster, and Prof. Wolfgang Haigisʼ (University Wurzburg, Germany) ULIB database of formula constants (http://ocusoft.de/ulib/) paved the way for this most successful new technology. In parallel, the number of IOL manufacturers, as well as IOL models and their technical capabilities (e.g., aspheric, multifocal, EDOF, and toric IOLs) have multiplied, making it more difficult for ophthalmic surgeons to maintain a clear overview of all the available options.