Completed

NCT Number: NCT07346456

Comparison of IOL Formulas in Eyes With PCE≥15µm

The goal of this observational study is to evaluate the long-term refractive outcomes of advanced intraocular lens (IOL) power calculation formulas in cataract patients with posterior corneal elevation (PCE ≥ 15 μm).

The main question it aims to answer is:

Do PK-based formulas provide superior refractive accuracy compared with Without-PK-based formulas in patients with elevated posterior corneal surfaces?

Participants undergoing routine cataract surgery will have their biometry measured by both Pentacam AXL and IOLMaster 700, and postoperative refraction will be collected at 1 month, 3 months, and 6 months postoperatively.

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Key information

Conditions

The Comparison of IOL Formulas in Eyes With PCE≥15um Undergoing Cataract Surgery

Age range

18 year–85 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Department of Ophthalmology, The Second Affiliated Hospital of Xi'an Jiaotong University

Xi'an, Shaanxi, China

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Meeting the indications for cataract surgery, and undergoing Phacoemulsification + IOL implantation performed by the same surgeon.
Preoperative biometry performed with IOLMaster 700 and Pentacam AXL, with a posterior corneal elevation greater than 15 μm within the central 5 mm zone on Scheimpflug imaging, and a central corneal thickness > 500 μm.
Surgery completed successfully without any intraoperative or postoperative complications.
Postoperative subjective refraction performed at 1 month after surgery by the same experienced optometrist.

Exclusion criteria

Patients with pterygium, corneal diseases, glaucoma, uveitis, or fundus diseases (such as macular edema, retinal detachment), excluding high myopia.
History of ocular trauma or previous intraocular surgery.
Occurrence of intraoperative or postoperative complications, such as iris injury, posterior capsule rupture, IOL dislocation, vitreous prolapse, or vitreous hemorrhage.
Postoperative best corrected visual acuity (BCVA) worse than 0.5.
Difference between postoperative subjective refraction and preoperative target refraction greater than 2.00 D.
Incomplete measurement data.

Treatment and study plan

Intraocular lens calculation formulas

Other

The study evaluates four groups of intraocular lens (IOL) power calculation formulas, totaling 13 distinct formulas, to compare their accuracy in predicting postoperative refractive outcomes in cataract patients.

Group 1 - Without PK: Barrett Universal II (BUⅡ), EVO 2.0, Kane, Hill-RBF 3.0, LADAS, Pearl-DGS, and K6, which do not incorporate PK.

Group 2 - Measured PK-I: Barrett TK measured (I) and EVO Advanced (I), which use measured PK from IOLMaster 700.

Group 3 - Measured PK-P: Barrett TK measured (P) and EVO Advanced (P), which use measured PK from Pentacam AXL.

Group 4 - Predicted PK: Barrett TK predicted and Kane KC, which estimate PK through prediction algorithms rather than direct measurement.

This observational study does not introduce experimental procedures; all data are collected during routine cataract surgery and postoperative follow-up to determine the comparative accuracy of these formulas

Primary outcomes

absolute SEQ-PE(accuracy)

Time frame: From enrollment to the end of treatment at 6 months

the absolute values of SEQ-PE
SEQ-PE(trueness)

Time frame: From enrollment to the end of treatment at 6 months
Spherical Equivalent Prediction Error
- SEQ=Sphere+2Cylinder
- PE=Postoperative Manifest SEQ-Predicted SEQ
Precision

Time frame: From enrollment to the end of treatment at 6 months

Precision refers to the consistency of the prediction errors (PE) of a formula across a study population, indicating how closely the individual prediction errors cluster around the central tendency (e.g., mean or median). A formula with higher precision shows smaller variability in its prediction errors.

Sponsors and collaborators

Lead sponsor

Second Affiliated Hospital of Xi'an Jiaotong University

Other

Registry information

Official study title

Intraocular Lens Power Calculation Formulas in Eyes With Posterior Corneal Elevation ≥15 µm: An Eyetemis-based Comparative Analysis

Important dates

Study start: 2025
Primary completion: 2025
Study completion: 2025
First posted: Jan 16, 2026
Registry last updated: Jan 16, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.