A Comparison of the Accuracy of Toric Intraocular Lens Formulas

Study Overview
=================
Brief Summary
-----------------
To compare the accuracy of the Abulafia-Koch, the Barrett, the Barrett Post ,the EVO , the new Holladay with total surgical-induced astigmatism, the Kane and and the Næser-Savini toric intraocular lens (IOL) power formulas using a large database of toric IOL refractive outcomes

Detailed Description
-----------------
To compare the accuracy of the Abulafia-Koch, the Barrett, the Barrett Post ,the EVO , the new Holladay with total surgical-induced astigmatism, the Kane and and the Næser-Savini toric intraocular lens (IOL) power formulas using a large database of toric IOL refractive outcomes.Retrospective consecutive case series.One hundred seventy-two eyes of 172 patients who had a toric IOL inserted during surgery.One eligible eye from patients having uncomplicated cataract surgery with insertion of an Alcon SN6AT(2-9) IOL (Alcon Laboratories, Inc, Fort Worth, TX) from 1 surgeon were included in the study. pre-operative were measured using either the IOLMaster 500 or 700 (Carl Zeiss Meditec AG, Jena, Germany). Using vector calculation, the predicted postoperative refractive astigmatism was calculated for each formula. This was compared with the actual postoperative refractive astigmatism to give the prediction error.

Official Title
-----------------
A Comparison of the Accuracy of Many Different Toric Intraocular Lens Formulas

Conditions
-----------------
Astigmatism

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: uncomplicated cataract surgery with a temporal clear corneal incision,with preoperative biometry using either the IOLMaster 500 (softwareversions 5.5 and 7.7) or 700 (software version 1.50; Carl Zeiss Meditec AG, Jena, Germany) subjective manifest refraction performed by any of the orthoptists in the practice and measurement of the actual postoperative axis of the IOL alignment performed in the same visit an average of 1 or 3months after surgery. Exclusion Criteria: any corneal disease (keratoconus, other ectasia, pterygium, or previous trauma); previous ophthalmic operations, including laser vision correction, vitrectomy, pterygium surgery, penetrating glaucoma surgery, or scleral buckling procedures intraoperative or postoperative complications postoperative corrected distance visual acuity worse than 6/9

Ages Eligible for Study
-----------------
Minimum Age: 21 Years
Maximum Age: 90 Years

Sexes Eligible for Study
-----------------
All

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Group 1<br>group 1 includes patients who axial length(AL)<26mm | |
| Group 2<br>group 2 includes patients who axial length（AL）≥26mm | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| A Comparison of the Accuracy of Toric Intraocular Lens Formulas | percentage of eyes with a prediction error within ±0.50 diopter (D) | 5 years | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
calculators, cataract, intraocular lens power, toric