Abstract
Objectives
To compare central corneal topography (CT) obtained using the IOLMaster 700® biometer to corneal topography obtained using a Swept-Source OCT-based predicated topographer (PT), in candidates for toric intraocular lens (IOL) implantation.
Methods
A retrospective comparative study was conducted in consecutive patients undergoing a routine cataract surgery assessment with significant astigmatism on keratometry. Each patient was examined using both the IOLMaster 700® (Carl Zeiss Meditec, Jena, Germany) and the Anterion® (Heidelberg Engineering, Heidelberg, Germany) for routine preoperative measurements. The corneal axial anterior power map obtained with each device was then anonymized and analysed independently by two ophthalmologists using a reading grid. The reading grid assessed the usual parameters describing astigmatism and evaluated if a toric IOL was indicated or a second topography examination was needed to confirm the indication.
Results
In total, 169 eyes of 120 patients were included. The inter-examination agreement for the astigmatism description ranged from 56 to 85% depending on the reader and parameter. The decision to implant a toric IOL based on the axial map was the same in 59–60% of cases depending on the examiner. A second examination was needed in 18–25% and 8–14% of cases after CT and PT, respectively. The IOLMaster 700® central anterior axial map allowed toric IOL implantation in 58–70% of cases with no need for second corneal examination.
Conclusion
The agreement between the anterior axial maps obtained using both devices was good. However, in about a quarter of the cases, dedicated topography had to be performed to confirm the surgical indication.
Subject terms: Surgery, Anatomy, Diagnosis
Introduction
Corneal astigmatism greater than 1 dioptre is found in more than 30% of patients assessed for cataract surgery [1–3]. In addition to keratometry and biometry, topography is considered by many surgeons as an important part of the preoperative assessment for cataract surgery to determine corneal astigmatism regularity before considering premium IOL implantation [4]. The IOLMaster 700® (Carl Zeiss Meditec AG, Jena, Germany) is a widely used biometer based on swept-source optical coherence tomography (SS-OCT). It can now measures central topography (CT) and its acquisition time is thus reduced by two-thirds compared to separate acquisitions using a biometer and a topographer [5]. In addition, reducing the number of acquisitions during the preoperative assessment could optimize patients’ flow in large practices and improve patients’ experience. Therefore, using the IOLMaster 700® for biometry and topography would be an attractive solution.
However, to our knowledge, only one study has assessed central topography by simultaneously reading CT and a predicated topography (PT) map acquired using a Placido disk-dual Scheimpflug topographer. It showed that the overall shape and the decision to consider a premium IOL were the same in most cases (75 to 97% of cases depending on the examiner) [6].
The aim of this study was to compare CT acquired with the IOLMaster 700® and PT acquired with the SS-OCT-based Anterion® topographer (Heidelberg Engineering, Heidelberg, Germany). To this end, a reading grid was used to assess the primary endpoint: the agreement on the corneal shape description. The secondary endpoint was to determine if CT and PT were sufficient for the decision making regarding the choice of a toric IOL.
Subjects and methods
A retrospective study was conducted in consecutive patients who underwent an assessment for cataract surgery between March and June 2022. Each patient underwent biometry using the IOLMaster 700®, including systematically CT as well as PT using the Anterion®, which is routinely performed in our department. A drop of artificial tears was systematically instilled 1 minute before measurements as described in the TORIDE study [7].
CT and PT
CT obtained with the IOLMaster 700® (Carl Zeiss Meditec AG, Jena, Germany) is generated from biometric data using a proprietary program developed by Carl Zeiss Meditec, Jena, Germany. Telecentric keratometry is measured from 18 points in 3 concentric circles of 1.5 mm, 2.5 mm and 3.2 mm in diameter [8], then 6 SS-OCT B-scans, at 30° intervals, are used to estimate the pachymetry map and construct the shape of the posterior cornea [6, 8, 9]. Two CT maps are available: the anterior axial power map and the total axial power map. CT is referred to as central because it displays a zone of approximately 4-mm diameter, the exact diameter depending on the acquisition and being displayed at each examination. The topography diameter is larger for flat corneas. For average corneas, CT uses a 10 D scale from 39 D to 49 D with 0.5 D steps. The green colour always represents the 44 D power. For flat or steep corneas, the colour scale is shifted up to 54 D or down to 34 D, and in case of highly irregular corneas, the 10 D range may be increased.
PT is acquired with the Anterion® (Heidelberg Engineering, Heidelberg, Germany), a new generation tomographer and biometer using the SS-OCT technology. It produces complete imaging of the anterior segment, from the cornea to the lens. It uses 65 B-scans (each composed of 256 A-scans) with an axial resolution of less than 10 µm and a scan depth of 14 mm. It provides anterior, posterior, and total corneal power maps and elevation data within an 8 mm diameter zone [10]. It can also measure the axial length with an A-scan that identifies the spike corresponding to the retinal pigment epithelium. Examples are shown in Fig. 1.
Fig. 1. Examples of central and predicated topography maps.
A Central topography; B predicated topography in the same patient as A. Regular congruent symmetrical against-the-rule astigmatism was seen on both examinations. C Central topography (CT) showing irregular asymmetric astigmatism. D Predicated topography (PT) in the same patient as (C, E) showing regular asymmetric against-the-rule astigmatism. The poor quality of the acquisition could be due to the presence of surface disorders as suggested by the failure to analyse the inferior cornea and an increase in keratometric values in the inferior part. For this patient, CT was considered asymmetric by the junior examiner and irregular by the senior examiner, and both examiners chose a non-toric IOL. On the contrary, PT was considered regular but still asymmetrical by both examiners, and they choose a toric IOL. However, the instability of the tear film also created a defect in the acquisition of the lower part of the PT map. E Image of the reflection of the keratometry test patterns on the cornea of the same patient as (C, D). Some points are blurred due to the alteration of the lacrimal film impacting the measurement.
Inclusion criteria and data collection
Inclusion criteria were based on keratometry obtained by the biometer. All patients with with-the-rule (WTR) anterior astigmatism greater than 1 dioptre or against-the-rule (ATR) or oblique anterior astigmatism greater than 0.75 dioptre were included. These values were based on our daily experience in decision making for toric IOL implantation.
Anterior corneal power maps obtained with both devices were anonymized and prepared to be read independently.
Readings
Corneal topography was assessed by two ophthalmologists, a senior examiner (SE) with refractive surgery experience and a high rate of toric IOL implantations (about 30%) and a junior examiner (JE) with some experience in refractive cataract surgery. A standardized reading grid assessing the usual parameters used to describe topography was then used in a double-blinded way (independently of the other examiner and of the other topography map).
The following parameters were assessed:
Topography interpretability
Astigmatism regularity: regular if the angle between the flat and steep axes ranged between 80° and 100°
Astigmatism type (WTR if the steep axis ranged between 60 and 120°, ATR if the steep axis ranged between 0° and 30° or between 150° and 180°, or oblique in other cases).
Astigmatism congruence (congruent if the Skewed Radial Axes [SRAX] were <21°)
Symmetry (asymmetric if the difference between the power of the two steepest axes was >1.4 dioptre at a distance of 3 mm from the centre)
Detected pathology: absence of pathology, suspected keratoconus, pellucid marginal corneal degeneration, signs of prior corneal refractive surgery.
Toric IOL implantation based on the topography and keratometry measurements: Yes or No; did the surgeon have enough data to make the decision with this single examination or was a second examination needed prior to make the decision?
Statistical analysis
Anonymized data was collected using Microsoft Excel®, a Visual Basic for Application form and a macro designed to ensure easy, fast, and reliable implementation of the database.
All statistical analyses were performed using R software, version 3.6.1 and open-source integrated development environment RStudio software, version 1.2.5001. Qualitative variables are presented as numbers and proportions, the distribution was assessed using a Chi-squared test. Quantitative variables are presented as means, standard deviations, and ranges. The agreements between readers and examinations are presented as percentages, differences between proportions were assessed using a Chi-squared test with continuity correction. The sample size calculation was performed using a bilateral chi-squared test with a significance level (alpha) of 0.05, a medium effect size (w = 0.3), and aimed for a power exceeding 0.9 (1-beta > 0.9). The calculation indicated a required a sample size greater than 158.
Ethics
Patients received information on the use of their anonymized data for research purposes and signed an informed consent.
This study was conducted in compliance with the principles of the Declaration of Helsinki and all applicable regulations and was approved by our institutional review board (IRB #00008855 Société Française d’Ophtalmologie IRB#1) according to the Jardé law no. 2012-300, including the decrees of April 12, 2018 concerning Research Involving the Human Person (called in French RIPH).
Results
Population
A total of 169 eyes of 120 patients were included. The main characteristics of the patients are shown in Table 1. Patients’ mean age was 74 ± 9 years (range: 29-96 years); 99 (59%) patients were women and 70 (41%) were men; the right eye was examined in 91 (54%) patients and the left eye in 78 (46%) patients. The mean keratometry reading was 43.77 ± 1.78 D. No statistically significant difference was found for any of these parameters. Both CT and PT were performed for each patient. CT was not available for 6 eyes due to a measurement failure.
Table 1.
Patients’ characteristics.
| Gender | Male, % (n) | 41% (70) | P = 0.58 |
| Female, % (n) | 59% (99) | ||
| Mean age, year (SD) | 74 (9) | NA | |
| Side | Right, % (n) | 54% (91) | P = 0.58 |
| Left, % (n) | 46% (78) | ||
| Km (D), mean ± SD | 43.77 ± 1.78 | ||
| |ΔK| (D), mean ± SD | 1.58 ± 1.19 | ||
| |ΔTK| (D), mean ± SD | 1.68 ± 1.25 | ||
| |AAA| (D), mean ± SD | 1.39 ± 0.95 | ||
| |TCPA| (D), mean ± SD | 1.49 ± 0.96 | ||
AAA anterior astigmatism measured with the Anterion®, Km mean keratometry (measured with the IOLMaster 700®), SD standard deviation, TCPA Total Corneal Power Astigmatism measured with the Anterion®, ΔK anterior astigmatism measured with the IOLMaster 700®, ΔTK total corneal astigmatism measured with the IOLMaster 700®.
Reading agreements
Inter-examination agreement (Table 2)
Table 2.
Reading agreements.
| Inter-examination agreement | Inter-examiner agreement | |||
|---|---|---|---|---|
| JE | SE | CT | PT | |
| Interpretability | 96.4% | 96.4% | 100% | 100% |
| Regularity | 85.3% | 82.8% | 90.2% | 92.9% |
| Conformity | 79.3% | 80.3% | 78.4% | 79.8% |
| Congruence | 84.5% | 84.1% | 90.2% | 90.2% |
| Symmetry | 77.2% | 56.3% | 48.1% | 76.3% |
| Pathology | 88.2% | 79.1% | 87.7% | 83.4% |
| Toric IOL implantation decision | 60.3% | 58.6% | 75.1% | 75.1% |
CT central topography, IOL intraocular lens, JE junior examiner, PT predicated topography, SE senior examiner.
The reading agreements between CT and PT for the JE and the SE were respectively 96 and 96% for the interpretability, 85 and 83% for the regularity, 79 and 80% for the astigmatism type, 84 and 84% for the congruence, 77 and 56% for the symmetry, and 88 and 79% for the detection of a pathology. As a result, the morphological parameters of the cornea were comparable in 85 and 56% of cases .
Inter-observer agreement (Table 2)
Regarding interpretability, the reading agreements between the JE and the SE were 100% for CT and 100% for PT. Regarding regularity, the inter-observer agreements were 90% for CT and 93% for PT. Regarding astigmatism type, the inter-observer agreements were 78% for CT and 80% for PT. Regarding congruence, the inter-observer agreements were 90% for CT and 90% for PT. Regarding symmetry, the inter-observer agreements were 48% for CT and 76% for PT. Regarding the detection of a pathology, the inter-observer agreements were 88% for CT and 83% for PT.
IOL choice (Tables 2, 3, 4)
Table 3.
IOL choice.
| CT | PT | |||
|---|---|---|---|---|
| JE | SE | JE | SE | |
| Toric IOL % (n) | 70.4% (119) | 58.0% (98) | 62.7% (106) | 78.1% (132) |
| Non-toric IOL % (n) | 11.8% (20) | 16.6% (28) | 23.7% (40) | 13.6% (23) |
| Second examination required % (n) | 17.8% (30) | 25.4% (43) | 13.6% (23) | 8.2% (14) |
CT central topography, IOL intraocular lens, JE junior examiner, PT predicated topography, SE senior examiner.
Table 4.
Analysis of the reasons for not choosing a toric IOL based on central topography.
| Interpretability, n (%) | Regularity, n (%) | Congruence, n (%) | Symmetry, n (%) | Pathology, n (%) | |
|---|---|---|---|---|---|
| Non-toric IOL for the junior examiner (n = 20) | 1 (5%) Not interpretable | 15 (75%) Irregular | 2 (10%) Non-congruent | 5 (25%) Asymmetric | 2 (10%) Keratoconus |
| Non-toric IOL for the senior examiner (n = 28) | 1 (4%) Not interpretable | 22 (79%) Irregular | 2 (7%) Non-congruent | 4 (14%) Asymmetric | 0 (0%) |
IOL intraocular lens.
The surgical decision regarding the choice of a toric IOL was the same when comparing CT and PT in 60 and 59% of the 169 cases, respectively for the JE and the SE. When each device (CT and PT) was considered separately, the results regarding the IOL choice were similar between both observers in 75 and 75% of cases, respectively for CT and PT .
Toric IOL indication varied inversely between both examiners when they analysed CT first and then PT: from 70% (119) to 63% (106) for the JE and from 58% (98) to 78% (132) for the SE. This variation in indication was highly significant for the SE (p = 0.0001) but did not reach significance for the JE (p = 0.16). The SE seemed to be more comfortable with PT for the decision making, although his toric IOL indication did not reach 100%.
The rate of second examination varied from 18% (30) with CT to 14% (23) with PT for the JE (p = 0.36) and from 25% (43) with CT to 8% (14) with PT for the SE (p < 0.0001). Therefore, no second examination was requested in 82 and 75% of cases for CT, and in 86 and 92% of cases for PT, respectively for the JE and the SE. Thus, in about a quarter of the cases, CT alone was not sufficient to decide.
Results of the second examination
Regarding the JE: among the 30 (18%) cases for which a second examination was needed after CT, a toric IOL could be chosen based on PT for 15 (50%) cases. However, PT was inconclusive in 5 (17%) cases.
Regarding the SE: among the 43 (25%) cases for which a second examination was needed after CT, a toric IOL could be chosen based on PT for 31 (72%) cases. However, PT was inconclusive in 4 (9%) cases.
The choice of a non-toric IOL based on CT was mainly associated with astigmatism deemed irregular in 75% (15/20) and 79% (22/28) of cases, respectively for the JE and the SE. The other reasons were the presence of non-congruent and/or asymmetrical astigmatism seen on topography and the failure to analyse topography in one case for both examiners.
A suspected keratoconus was identified in two eyes and two other eyes had a history of refractive corneal surgery for which the visualization of the peripheral cornea helped to make the diagnosis, accounting for 2% of the cases.
Table 4 shows the reasons for not choosing a toric IOL. Figure 1 shows the example of a patient with tear film instability and its impact.
Discussion
Regarding the primary endpoint of this study, we showed a good agreement (>80%) between the two examinations, except for the symmetry which is discussed below. Despite a good overall agreement, the examinations were not interchangeable with regards to the descriptive parameters. Indeed, there was a greater discordance for the symmetry with the SE based on CT. This difference could be explained by the absence of numerical values on the corneal power map produced by the IOLMaster 700®, so that the analysis was mainly qualitative.
An intermediate agreement was found between CT and PT for the choice of the IOL for both examiners (60% for the JE and 59% for the SE). In case of high refractive requirement, e.g., with multifocal IOLs, care should be taken when a single examination is performed while the combination of both examinations appeared superior. The first corneal topographers available were based on Placido’s disks and then on Scheimpflug technology, and these are still the most widely used topographers. Topographers based on OCT technology, such as the Anterion®, are more recent arrivals in practices. We decided to compare the IOLMaster700® CT with this recent and less studied OCT-based topographer. Apart from Wang’s study comparing a Placido disk-dual Scheimpflug topographer with the central topography of the IOLMaster 700®, no other similar comparison has been published to our knowledge to date [6].
Wang et al. [6] have published the first study on CT acquired with the IOLMaster® 700 and compared it to PT acquired with a Placido disk-dual Scheimpflug topographer. The maps of 105 selected eyes with various corneal conditions have been read by three examiners and they have used the questionnaire focused on the general shape and premium IOL implantation. Their approach was different from ours because they have evaluated both maps at the same time and discussed the choice of a premium IOL (toric, multifocal, extended depth of focus). Regarding the overall astigmatism shape, they have found a similar shape in 69–89% of cases and the symmetry was comparable in 60-83% of cases, in line with our results since we found a similar astigmatism shape in 85-56% of cases. Regarding the choice of a toric IOL, they have reported a better agreement of 75–84% while we found an agreement of 59–60%. This could be explained by the fact that the reading of the examinations was not blinded as in our study. Indeed, our methodology allowed us to really assess our daily practice using only one device and then to determine whether CT alone was a good option or not.
Our study showed that anterior CT acquired with the IOLMaster 700® used alone in a population of patients with corneal astigmatism candidates for cataract surgery allowed choosing a toric IOL in 58–70% of cases, depending on the examiner, with no need for further examination. In about three quarters of the patients (75–82%), CT was considered sufficient, and no second examination (PT) was required by the ophthalmologist. When a second examination was required, PT allowed reconsidering a toric IOL implantation in 50–72% of eyes and the final rate of toric IOL implantations was increased for both the JE and the SE (63 and 78%, respectively).
The SE had more confidence in PT as he made the decision to implant an IOL (toric or not) in more than 90% of cases with no need for further examination. This could be due to his greater experience with PT, which he uses routinely. In contrast, the SE made decisions based on CT in only 75% of cases. This could be due to the fact that it was a new device with no quantitative analysis (no numerical values obtained with CT).
In addition, our study highlighted different behaviours depending on the age and experience of the examiner. The JE was more confident with this new CT technology and the need for a second examination did not significantly differ between the two devices.
Beyond a more thorough analysis of the power map (zone of 8 mm versus about 4 mm for CT), PT provides elevation maps, pachymetry maps, total corneal wavefront maps, which all provide additional information to assess the cornea.
Two cases of suspected keratoconus and two cases with a history of refractive surgery were included. In these cases, a wider analysis of the corneal periphery helped to make the diagnosis. A history of corneal refractive surgery will be increasingly frequent in the future in our patients requiring cataract surgery. It can be easily identified during the preoperative interview and should prompt to perform a corneal topography.
The topography technology has been strongly improved over the last decade, but the literature comparing examinations remains limited. As there is no gold standard, only the concordance between different technologies may be measured, while the superiority of a technology over another may only be assessed in terms of acquisition time, additional information provided or reproducibility of the measurements. Topography is widely used in the preoperative assessment but, to our knowledge, no study has assessed the refractive outcomes with or without the use of corneal topography. In our experience, performing PT in addition to biometry (keratometry) is useful to identify the best candidates for toric IOLs. That is why using a combined device (biometer + topographer such as the updated IOLMaster 700®) could be relevant in daily practice. In our study, we wanted to determine if this combined device could be used alone without PT. Indeed, many surgeons still base their IOL choice solely on keratometry since PT is not available in their office.
The use of CT is interesting to manage patients’ flow with a single measurement, but in about a quarter of the patients, CT was not sufficient in our study. Our results showed that CT was not completely interchangeable with PT. Performing several measurements with different devices is more robust, especially in a population with a high prevalence of ocular surface diseases [11, 12], and higher expectations.
As recently reported by our team, the analysis of astigmatism for toric IOL calculation is improved when artificial tears are used before performing the measurements with the IOLMaster 700® [7]. We took these findings into account in our study in addition to the use of a reading grid with standard description of corneal astigmatism to limit subjectivity and the rate of non-interpretable examinations.
Our study has some limitations, in particular its retrospective design. The limited sample size could have resulted in an underestimation of the impact of a peripheral corneal pathology based on CT alone. Finally, our methodology did not allow comparison of the refractive outcomes.
Nevertheless, the comparative double-blind design allowed for a powerful comparison of the two devices and reflected a predictable situation in daily practice. This was an original study assessing a technological innovation that still requires validation to be used in daily clinical practice. To our knowledge, this was the first blinded study comparing CT obtained with the IOLMaster 700® and PT obtained with another SS-OCT topographer. Finally, our study allowed comparing two examiners of different age, representing general practitioners and refractive surgery specialists, and provided real-life information.
CT obtained with the IOLMaster 700® is a great technological advance, allowing the acquisition of corneal topography with a biometer in a single procedure. CT provides qualitative information on patient’s corneal astigmatism in addition to the numerical keratometry values obtained by a biometer. We found a good agreement between CT and corneal topography obtained with a dedicated topographer. However, in about a quarter of the cases, cataract surgeons will have to perform a dedicated topography to confirm or refine their surgical indication.
Summary
What was known before
Corneal topography is a valuable assessment tool when considering toric IOLs.
The IOLMaster 700 biometer can provide a central topography map without additional acquisitions. It is therefore an easy-to-access and easy-to-use solution.
What this study adds
The central topography of the IOLMaster 700 and the topography of Anterion are in good agreement.
In three quarters of patients with corneal astigmatism, the IOLMaster 700 central topography appears sufficient to confirm the toric IOL indication.
Toric IOL selection rate increases when corneal topographies from both devices are used.
Author contributions
RC and CD were responsible for study design. EA, AL, ID, CD, JB were responsible for patient inclusion and data collection. RC and AL were responsible for the interpretation of the examinations. RC was responsible for the statistical analysis. RC drafted the manuscript. CD, JB, EA, ID advised on data analysis and reviewed the manuscript. Each author reviewed the final manuscript and agrees to be responsible for all aspects of the work, ensuring that issues relating to the accuracy or integrity of any part of the work are considered and resolved appropriately.
Data availability
The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.
Competing interests
CD is a consultant for Carl Zeiss Meditec. The remaining authors have no financial or proprietary interest in the materials presented herein.
Footnotes
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
References
- 1.Ferrer-Blasco T, Montés-Micó R, Peixoto-de-Matos SC, González-Méijome JM, Cerviño A. Prevalence of corneal astigmatism before cataract surgery. J Cataract Refract Surg. 2009;35:70–5. 10.1016/j.jcrs.2008.09.027 [DOI] [PubMed] [Google Scholar]
- 2.Yuan X, Song H, Peng G, Hua X, Tang X. Prevalence of corneal astigmatism in patients before cataract surgery in Northern China. J Ophthalmol. 2014;2014:536412. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Hoffmann PC, Hütz WW. Analysis of biometry and prevalence data for corneal astigmatism in 23,239 eyes. J Cataract Refract Surg. 2010;36:1479–85. 10.1016/j.jcrs.2010.02.025 [DOI] [PubMed] [Google Scholar]
- 4.Visser N, Bauer NJC, Nuijts RMMA. Toric intraocular lenses: historical overview, patient selection, IOL calculation, surgical techniques, clinical outcomes, and complications. J Cataract Refract Surg. 2013;39:624–37. 10.1016/j.jcrs.2013.02.020 [DOI] [PubMed] [Google Scholar]
- 5.Ruiz-Mesa R, Ruiz-Santos M, Blanch-Ruiz J, Jiménez-Nieto A. Acquisition time for swept-source optical biometry plus corneal power measurement during cataract evaluation. Clin Ophthalmol Auckl NZ. 2022;16:661–8. 10.2147/OPTH.S351845 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Wang L, Canedo ALC, Wang Y, Xie KC, Koch DD. Comparison of central topographic maps from a swept-source OCT biometer and a Placido disk-dual Scheimpflug tomographer. J Cataract Refract Surg. 2021;47:482–7. 10.1097/j.jcrs.0000000000000459 [DOI] [PubMed] [Google Scholar]
- 7.Rochet E, Levron A, Agard E, Chehab HE, Plas H, Bouvarel H, et al. Should artificial tears be used during the preoperative assessment of toric IOLs before age-related cataract surgery? The TORIDE Study. J Refract Surg Thorofare NJ 1995. 2021;37:759–66. [DOI] [PubMed] [Google Scholar]
- 8.Montés-Micó R. Evaluation of 6 biometers based on different optical technologies. J Cataract Refract Surg. 2022;48:16–25. 10.1097/j.jcrs.0000000000000690 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Bullimore MA, Slade S, Yoo P, Otani T. An Evaluation of the IOLMaster 700. Eye Contact Lens Sci Clin Pr. 2019;45:117–23. 10.1097/ICL.0000000000000552 [DOI] [PubMed] [Google Scholar]
- 10.Tañá-Rivero P, Aguilar-Córcoles S, Ruiz-Mesa R, Montés-Micó R. Repeatability of whole-cornea measurements using a new swept-source optical coherence tomographer. Eur J Ophthalmol. 2021;31:1709–19. 10.1177/1120672120944022 [DOI] [PubMed] [Google Scholar]
- 11.Cochener B, Cassan A, Omiel L. Prevalence of meibomian gland dysfunction at the time of cataract surgery. J Cataract Refract Surg. 2018;44:144–8. 10.1016/j.jcrs.2017.10.050 [DOI] [PubMed] [Google Scholar]
- 12.Trattler WB, Majmudar PA, Donnenfeld ED, McDonald MB, Stonecipher KG, Goldberg DF. The prospective health assessment of cataract patients’ ocular surface (PHACO) study: the effect of dry eye. Clin Ophthalmol Auckl NZ. 2017;11:1423–30. 10.2147/OPTH.S120159 [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.