Anterior chamber depth and change in axial intraocular lens position after cataract surgery with primary posterior capsulorhexis and posterior optic buttonholing

Purpose: Achieving the desired post-operative refraction in cataract surgery requires accurate calculations for intraocular lens (IOL) power. Latest-generation formulae use anterior-chamber depth (ACD)—the distance from the corneal apex to the anterior surface of the lens—as one of the parameters to predict the post-operative IOL position within the eye, termed the effective lens position (ELP). Significant discrepancies between predicted and actual ELP result in refractive surprise. This study aims to improve the predictability of ELP. We hypothesise that predictions based on the distance from the corneal apex to the mid-sagittal plane of the cataractous lens would more accurately reflect the position of the principal plane of the non-angulated IOL within the capsular bag. Accordingly, we propose that predictions derived from ACD + ½LT (length thickness) would be superior to those from ACD alone. Design: Retrospective cohort study, comparing ELP predictions derived from ACD to aproposed prediction parameter. Method: This retrospective study includes data from 162 consecutive cataract surgery cases, with posterior-chamber IOL (AlconSN60WF) implantation. Pre- and postoperative biometric measurements were made using the IOLMaster700 (ZEISS, Jena, Germany). The accuracy and reliability of ELP predictions derived from ACD and ACD + ½LT were compared using software-aided analyses. Results: An overall reduction in average ELP prediction error (PEELP) was achieved using the proposed parameter (root-mean-square-error [RMSE] = 0.50 mm), compared to ACD (RMSE = 1.57 mm). The mean percentage PEELP, comparing between eyes of different axial lengths, was 9.88% ± 3.48% and −34.9% ± 4.79% for predictions derived from ACD + ½LT and ACD, respectively. A 44.10% ± 5.22% mean of differences was observed (p < 0.001). Conclusion: ACD + ½LT predicts ELP with greater accuracy and reliability than ACD alone; its use in IOL power calculation formulae may improve refractive outcomes.

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Progress in Modern Cataract Surgery – New Steps and Algorithms for Precise Measuring and Intraocular-lens Calculations

European Ophthalmic Review ◽

10.17925/eor.2017.11.02.95 ◽

2017 ◽

Vol 11 (02) ◽

pp. 95

Author(s):

Fritz H Hengerer ◽

Gerd U Auffarth ◽

Ina Conrad-Hengerer ◽

◽

...

Keyword(s):

Cataract Surgery ◽

Anterior Chamber ◽

Intraocular Lens ◽

Axial Length ◽

Refractive Surgery ◽

Anterior Chamber Depth ◽

Corneal Surface ◽

Intraocular Lens Calculations ◽

Target Refraction ◽

Intraocular Lens Calculation

In standard cataract surgery, one of the major goals is to reach target refraction. Based on keratometry measurements, axial length and anterior chamber depth, most of the intraocular lens calculation formulae are suitable to achieve this aim. Further evaluation of corneal refractive parameters like anterior and posterior corneal surface by Scheimpflug devices led to a significant enhancement of precision in astigmatic and post-refractive surgery cases.

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Impact of Pseudoexfoliative Syndrome on Effective Lens Position, Anterior Chamber Depth Changes, and Visual Outcome After Cataract Surgery

Clinical Ophthalmology ◽

10.2147/opth.s307487 ◽

2021 ◽

Vol Volume 15 ◽

pp. 2867-2873

Author(s):

Michael Müller ◽

Katarzyna Pawlowicz ◽

Myriam Böhm ◽

Eva Hemkeppler ◽

Christoph Lwowski ◽

...

Keyword(s):

Cataract Surgery ◽

Anterior Chamber ◽

Anterior Chamber Depth ◽

Visual Outcome ◽

Lens Position

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Relationship between Crystalline Lens Thickness and Shape and the Identification of Anterior Ocular Segment Parameters for Predicting the Intraocular Lens Position after Cataract Surgery

BioMed Research International ◽

10.1155/2019/3458548 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 3

Author(s):

Tsukasa Satou ◽

Kimiya Shimizu ◽

Shuntaro Tsunehiro ◽

Akihito Igarashi ◽

Sayaka Kato ◽

...

Keyword(s):

Cataract Surgery ◽

Intraocular Lens ◽

Prediction Error ◽

Anterior Segment ◽

Anterior Chamber Depth ◽

Crystalline Lens ◽

Lens Thickness ◽

Lens Position ◽

The Difference ◽

Segment Data

Purpose. This study was performed to investigate the relationships among crystalline lens shape, actual intraocular lens (IOL) position, and crystalline lens thickness (LT), as measured by anterior segment optical coherence tomography (AS-OCT), and to determine anterior ocular segment parameters that predict postoperative IOL position. Methods. Seventy-nine eyes of 79 patients who underwent uneventful cataract surgery were enrolled. For crystalline lens preoperative anterior segment data, the LT, and anterior, equatorial, and posterior surface depths (ASD, ESD, and PSD, respectively) of crystalline lenses were quantitatively determined. For postoperative anterior segment data, the actual IOL position was quantified. Moreover, the following correlations were analyzed: LT with the ASD, ESD, PSD, and IOL position; IOL position with the ASD, ESD, and PSD; and refractive prediction error with the difference between the predicted postoperative anterior chamber depth (ACD) of the SRK/T formula and the IOL position, ASD, ESD, and PSD (each depth minus the predicted postoperative ACD of the SRK/T formula). Results. The LT was significantly correlated with the ASD (r = -0.65) and PSD (r = 0.41), whereas it was not correlated with the ESD or IOL position. The IOL position was significantly correlated with the ASD (r = 0.67), ESD (r = 0.72), and PSD (r = 0.74). The refractive prediction error was significantly correlated with the difference between the predicted postoperative ACD of the SRK/T formula and the IOL position (r = 0.65), ASD (r = 0.46), ESD (r = 0.54), and PSD (r = 0.58). Conclusions. The ESD and PSD obtained using AS-OCT were highly correlated with the IOL position and significantly correlated with the refractive prediction error. These findings suggest that the ESD and PSD may enhance the accuracy of actual IOL position prediction.

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Relationship between Medium-Term Changes in Intraocular Lens Position and Refraction after Cataract Surgery with Two Different Models of Monofocal Lenses

Journal of Clinical Medicine ◽

10.3390/jcm10173856 ◽

2021 ◽

Vol 10 (17) ◽

pp. 3856

Author(s):

Hideki Fukumitsu ◽

Vicent J. Camps ◽

Sara Miraflores ◽

David P. Piñero

Keyword(s):

Cataract Surgery ◽

Intraocular Lens ◽

Statistical Significance ◽

Anterior Chamber Depth ◽

Strong Correlations ◽

Lens Position ◽

Single Piece ◽

Iol Power ◽

The Difference ◽

Group 2

The aim of this prospective descriptive study was to characterize the variations of the clinical effective lens position (ELP) (considering paraxial optics and postoperative data) and the intraocular lens (IOL) position, using “eye” data gathered from a 6-month follow-up of patients who underwent uneventful cataract surgery. Patients were implanted with two different monofocal IOLs: AcrySof IQ SN60WF (Alcon) (Group 1, 247 eyes) and Akreos MI60L (Bausch & Lomb) (Group 2, 104 eyes). No significant differences were found between groups concerning spherical equivalent (SE), axial length, and clinical ELP changes, from 1 to 6 months after surgery (p ≥ 0.516). A more positive change in postoperative anterior chamber depth was found in Group 2, but the difference did not reach statistical significance (p = 0.065). No significant moderate to strong correlations were found between the changes in clinical ELP and preoperative data. The correlation between the changes in SE and clinical ELP over time was strong and statistically significant (groups 1 and 2: r = 0.957 and r = 0.993, p < 0.001). In conclusion, changes in refraction from 1 to 6 months after cataract surgery, with single-piece monofocal IOLs, are not clinically relevant, which correlates with the presence of good positional stability. These changes cannot be predicted preoperatively and considered in IOL power calculations.

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Continuous Curvilinear Capsulorhexis in Cataract Surgery Using a Modified 3-Bend Cystotome

Journal of Ophthalmology ◽

10.1155/2015/412810 ◽

2015 ◽

Vol 2015 ◽

pp. 1-5

Author(s):

Yuan Zeng ◽

Jian-hua Gao

Keyword(s):

Cataract Surgery ◽

Anterior Chamber ◽

Intraocular Lens ◽

Completion Time ◽

Anterior Chamber Depth ◽

Corneal Edema ◽

Group A ◽

Capsular Rupture ◽

Phacoemulsification Cataract Surgery ◽

Capsular Bag

We modified a 2-bend cystotome for continuous curvilinear capsulorhexis (CCC) in manual or phacoemulsification cataract surgery to improve the safety and ease of performance. A 26G needle was converted into a cystotome with 3 bends. In this retrospective study, the performance of modified 3-bend cystotome was compared with conventional 2-bend cystotome. During cataract surgery, in the 3-bend cystotome group, mean completion time of CCC was shorter, mean times of viscoelastic agent supplement were less, and CCC success rate was higher than that in 2-bend group. Complication incidence, such as postoperative transient corneal edema and irreparable V-shaped tear, was also lower in 3-bend group. No posterior capsular rupture or no other complication was observed in either group. A polymethyl methacrylate intraocular lens or a hydrogel intraocular lens was implanted in the capsular bag in all eyes. We conclude that it is safe and efficient to accomplish a CCC using the 3-bend cystotome due to its ability to sustain the anterior chamber depth (ACD) and keep the posterior lip intact. Using the 3-bend cystotome also allowed for an adequate view into the anterior chamber from lack of wound deformation.

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The Relationship between Anterior Chamber Depth, Axial Length and Intraocular Lens Power among Candidates for Cataract Surgery

Electronic physician ◽

10.19082/3127 ◽

2016 ◽

Vol 8 (10) ◽

pp. 3127-3131 ◽

Cited By ~ 3

Author(s):

Mohammad Reza Sedaghat ◽

Ali Azimi ◽

Peyman Arasteh ◽

Naghmeh Tehranian ◽

Shahram Bamdad

Keyword(s):

Cataract Surgery ◽

Anterior Chamber ◽

Intraocular Lens ◽

Axial Length ◽

Anterior Chamber Depth ◽

Intraocular Lens Power ◽

Lens Power ◽

The Relationship

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Gradient Boosting Decision Tree Algorithm for the Prediction of Postoperative Intraocular Lens Position in Cataract Surgery

10.1101/2020.08.26.20181156 ◽

2020 ◽

Author(s):

Tingyang Li ◽

Kevin Yang ◽

Joshua Stein ◽

Nambi Nallasamy

Keyword(s):

Decision Tree ◽

Cataract Surgery ◽

Intraocular Lens ◽

Anterior Chamber Depth ◽

Absolute Error ◽

Gradient Boosting ◽

Tree Model ◽

Lens Position ◽

Iol Power ◽

Testing Set

Purpose: To develop a method for predicting postoperative anterior chamber depth (ACD) in cataract surgery patients based on preoperative biometry, demographics, and intraocular lens (IOL) power. Methods: Patients who underwent cataract surgery and had both preoperative and postoperative biometry measurements were included. Patient demographics and IOL power were collected from the Sight Outcomes Research Collaborative (SOURCE) database. A gradient boosting decision tree model was developed to predict the postoperative ACD. The mean absolute error (MAE) and median absolute error (MedAE) were used as evaluation metrics. The performance of the proposed method was compared to five existing formulas. Results: 847 patients were assigned randomly in a 4:1 ratio to a training/validation set (678 patients) and a testing set (169 patients). Using preoperative biometry and patient sex as predictors, the presented method achieved an MAE of 0.106 (SD: 0.098) on the testing set, and a MedAE of 0.082. MAE was significantly lower than that of the five existing methods (p < 0.01). When keratometry was excluded, our method attained an MAE of 0.123 (SD: 0.109), and a MedAE of 0.093. When IOL power was used as an additional predictor, our method achieved an MAE of 0.105 (SD: 0.091) and a MedAE of 0.080. Conclusions: The presented machine learning method achieved accuracy surpassing that of previously reported methods in the prediction of postoperative ACD. Translational Relevance: Increasing accuracy of postoperative ACD prediction with the presented algorithm has the potential to improve refractive outcomes in cataract surgery.

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Intraocular Pressure Reduction after Femtolaser Assisted Cataract Surgery and Its Association with the Use of Ultrasound

Medicina ◽

10.3390/medicina57050437 ◽

2021 ◽

Vol 57 (5) ◽

pp. 437

Author(s):

Hana Abouzeid ◽

Walter Ferrini ◽

Murielle Bochud

Keyword(s):

Intraocular Pressure ◽

Linear Regression ◽

Cataract Surgery ◽

Anterior Chamber ◽

Anterior Chamber Depth ◽

Multiple Linear Regression Model ◽

Study Data ◽

Department Of Ophthalmology ◽

Duration Of Surgery ◽

Ocular Pressure

Background and Objectives: To quantify the change in intraocular pressure (IOP) after phacoemulsification in patients having undergone femtolaser assisted cataract surgery (FLACS), and study the influence of the use of ultrasound on this change. Setting: Jules-Gonin Eye Hospital, University Department of Ophthalmology, Lausanne, Switzerland. Materials and Methods: Interventional study. Methods: All consecutive cases operated with FLACS and with complete data for the studied parameters were selected for inclusion in the study. Data had been prospectively collected and was analysed retrospectively. Linear regression was performed to explore the association of change in IOP with time of measure, ultrasound use, sex, age, and duration of surgery. Results: There was a mean decrease in intraocular pressure of 2.5 mmHg (CI 95% −3.6; −1.4, p < 0.001) postoperatively. No association between the change in intraocular pressure and ultrasound time or effective phaco time was observed when the data were analyzed one at a time or in a multiple linear regression model. There was no association with sex, age, nuclear density, presence of pseudoexfoliation, duration of surgery, and time of ocular pressure measurement. Eyes with preoperative IOP ≥ 21 mmHg had a more significant IOP reduction after surgery (p < 0.0001) as did eyes with an anterior chamber depth <2.5 mm (p = 0.01). Conclusion: There was a decrease in intraocular pressure six months after FLACS in our study similar to that in the published literature for standard phacoemulsification. The use of ultrasound may not influence the size of the decrease, whereas the preoperative IOP and anterior chamber depth do. FLACS may be as valuable as standard phacoemulsification for cases where IOP reduction is needed postoperatively.

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