Multi-formula Optimization of Second Eye Refinement According to Direction of the Prediction Error of the First Eye

Cataract Clinical Trial

Official title:

Multi-formula Optimization of Second Eye Refinement According to Direction of the Prediction Error of the First Eye

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02270879
• Other study ID #: CHBaixoVouga
• Status: Completed
• Phase: N/A
• First received: October 18, 2014
• Last updated: October 18, 2014
• Start date: June 2014
• Est. completion date: July 2014

Study information

• Verified date: October 2014
• Source: Centro Hospitalar do Baixo Vouga
• Contact: n/a
• Is FDA regulated: No
• Health authority: Portugal: Ethics Committee for Clinical Research
• Study type: Observational

Clinical Trial Summary

Prediction errors for the first (PE1) and second eyes (PE2) were obtained in the intra-ocular lens power calculation for 4 formulae (HofferQ, SRK II, SRK/T and Holladay 1). The optimal correction factor for each formula was determined as the one resulting in the lowest mean absolute error. A similar analysis was performed in the negative and positive PE1 subgroups.

Description:

Retrospective case series study. A retrospective chart review was conducted, which included demographics (age and gender) and several parameters for both the first and second eyes: surgery date, axial length, keratometric corneal power in 2 meridians, predicted intra-ocular lens (IOL) power recommended for plano target in each formulae (HofferQ, SRK II, SRK/T and Holladay 1), implanted IOL power, predicted post-operative refraction for the implanted IOL for the 4 formulae, observed post-operative refraction in spherical equivalent and post-operative best corrected visual acuity. The prediction error was calculated for the first eye (PE1) as the difference between the observed post-operative refraction in spherical equivalent and the predicted post-operative refraction by the IOL Master for the implanted IOL. This was obtained for the 4 formulae. The prediction error for the second eye (PE2) was obtained in a similar fashion. The optimal partial adjustment for second eye refinement was obtained subtracting a portion of the PE1 from the PE2 (PE2-xPE1, where 0≤x≤1) for the 4 formulae. The optimal correction factor was determined for all formulae by using an array of different proportions of PE1 that were applied to the second eye. The values ranged from 10% to 100%, with increments of 10% each.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 156
• Est. completion date: July 2014
• Est. primary completion date: July 2014
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Patients having performed bilateral cataract surgery between 1st October 2012 and 24th April 2014 in a single ophthalmological center (Centro Hospitalar Baixo Vouga, Portugal)

Exclusion Criteria:

• Inadequate follow-up

• Incomplete medical records

• Previous or combined ocular surgery

• Manual extracapsular cataract extraction and not phacoemulsification

• Corneal sutures

• Implantation of any other IOL type different from Abbott Tecnis® 1-piece IOL (Abbott Laboratories Inc., Illinois, USA), ZCB00

• IOL implanted in the sulcus

• Intra or postoperative complication

• Post-operative best corrected visual acuity worse than 5/10

• Corneal astigmatism>3.00 D

Study Design

Observational Model: Cohort, Time Perspective: Retrospective

Related Conditions & MeSH terms

• Cataract

Intervention

Procedure:
• Phacoemulsification cataract surgery
Phacoemulsification of cataract (opacified lens) using clear corneal approach. Implantation of a intra-ocular lens in the capsular bag

Locations

Country	Name	City	State
n/a

Sponsors (1)

Lead Sponsor	Collaborator
Centro Hospitalar do Baixo Vouga

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Second eye mean absolute error (mean of the absolute value of the prediction error)		6 weeks after date of cataract surgery	No
Secondary	Percentage of second eyes with a post-operative refraction within ±0.50 D and ±1.00 D of the targeted refraction		6 weeks after date of cataract surgery	No