Subjective and Objective Refraction in Pseudophakic Patients

Study Overview
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Brief Summary
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Targeting of post-cataract refraction depends mainly on the prediction of the post-operative lens position, but also on the post-operative refraction itself. Hence, aim of this study is to evaluate the agreement and variability of subjective refraction performed by two independent examiners, autorefraction, and wavefront aberrometry in pseudophakic patients after uneventful cataract surgery.

Detailed Description
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One of the main goals of modern cataract surgery, beside removing the cataractous lens, is to achieve the patient's desired post-operative refraction. Targeting this post-operative refraction depends mainly on the prediction of the post-operative lens position and the post-operative refraction itself. Reason for the contributing effect of post-operative refraction in the error-propagation analyses is that refraction in phakic patients was shown to have only moderate reproducibility. In the past, different studies evaluated refraction methods. However, there is no study that included reproducibility of subjective refraction in pseudophakic patients and compares it with objective refraction methods (autorefraction, wavefront aberrometry). 100 eyes of 100 patients, which underwent uneventful cataract surgery, will be included in the study. Refraction of one eye of each patient will be tested using subjective refraction by two different examiners, autorefraction, and wavefront aberrometry at two separate occasions.

Official Title
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Agreement and Variability of Subjective Refraction, Autorefraction, and Wavefront Aberrometry in Pseudophakic Patients

Conditions
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Pseudophakia

Intervention / Treatment
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* Device: Subjective refraction
* Device: Autorefraction
* Device: Wavefront aberrometry


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Minimum age: 21 years Cataract surgery (at least 8 weeks post-surgery) written informed consent Exclusion Criteria: Complications during or after cataract surgery Ophthalmic diseases, that might interfere with measurements (macular degeneration, glaucoma, diabetic retinopathia) Ophthalmic surgery other than cataract surgery Clinically significant posterior capsule opacification

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 105 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Refraction reproducibility and agreement<br>Subjective and objective refraction will be performed in all patients | Device: Subjective refraction<br>* Subjective refraction measurements will be performed by two testers for all the patients included<br>Device: Autorefraction<br>* Five autorefraction measurements will be performed for all the patients included<br>Device: Wavefront aberrometry<br>* Five wavefront measurements will be performed for all the patients included<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluation of the agreement between the subjective refraction measurements (in dioptres) of two examiners | To show the number of measurements within the limits of agreement, Bland-Altman plots will be created for subjective refraction measurements in dioptres between examiner 1 and examiner 2. | 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluation of reproducibility between the subjective refraction measurements between two study visits | To compare reproducibility of subjective refraction measurements between study visit 1 and study visit 2 Wilcoxon-signed rank test will be applied. | 12 months | 
| Evaluation of the agreement between the measurements performed by subjective refraction, autorefraction, and wavefront aberrometry (in dioptres) | To show the number of measurements within the limits of agreement, Bland-Altman plots will be created for subjective refraction measurements in dioptres between the 3 measurement methods. | 12 months | 
| Evaluation of the reproducibility between measurements done with subjective refraction, autorefraction, and wavefront aberrometry in dioptres | To compare reproducibility between the 3 measurement methods in dioptres, Friedman's multiple comparison will be applied. | 12 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Subjective Refraction, Autorefraction, Wavefront Aberrometry