Clinical Evaluation of Reproducibility of Keratometric Measurements and Influencing Factors in Cataract Patients

Study Overview
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Brief Summary
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The investigational device is an approved biometry device to perform biometric measurements preoperatively to calculate the needed IOL power. First, two native measurements at the IOL Master will be performed. Thereafter randomly assigned artificial tears are instilled in the eye and biometry will be repeated within 30 seconds, as well as after 2 and 5 minutes. At least 24hours after those measurements, two native measurements at the IOL Master will be performed. Thereafter, the not yet used artificial tears are instilled in the eye and biometry will be repeated within 30 seconds, as well as after 2 and 5 minutes. Examinations will be implemented in accordance with the approved investigational plan on subjects and includes: repeated biometry without and with artificial tear drops.

Official Title
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Clinical Evaluation of Reproducibility of Keratometric Measurements and Influencing Factors in Cataract Patients

Conditions
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Cataract, Dry Eye

Intervention / Treatment
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* Device: High viscous artificial tears
* Device: Low viscous artificial tears


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: diagnosed uni- or bilateral age-related cataract Age 40 to 95 Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant Exclusion Criteria: Corneal abnormality (Corneal scaring) usage of artificial tears/eyedrops 24h before the examination necessity of any topical therapy of the eye (i.e. glaucoma) active ocular or nasal allergies or corneal or conjunctival infection abnormality of the nasolacrimal drainage apparatus dry eye severity level 4 (severe and/or disabling constant discomfort and visual symptoms, marked conjunctival injection, filamentary keratitis, mucus clumping, tear debris, ulceration, trichiasis, keratinization, symblepharon) lid deformities Preceding ocular surgery or trauma Pregnancy Lactation Uncontrolled systemic or ocular disease

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 95 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
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Biometry will be performed in individuals with age related cataract. Patients will be classified as dry eye or normal eye. Two different artificial tears will be instilled at two time points in a randomized order with a time-lag of at least 24 hours.
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: High viscous artificial tears<br>First, a native measurement at the IOL Master will be performed. Following which, high viscous artificial tears are installed and the biometry will be repeated within 30 seconds, as well as after 2 and 5 minutes | Device: High viscous artificial tears<br>* Instillation of one drop high viscous artificial tears<br>|
| Active Comparator: Low viscous artificial tears<br>First, a native measurement at the IOL Master will be performed. Following which, low viscous artificial tears are installed and the biometry will be repeated within 30 seconds, as well as after 2 and 5 minutes | Device: Low viscous artificial tears<br>* Instillation of one drop low viscous artificial tears<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The primary objective is to determine whether application of highly viscid eye drops in normal eyes leads to a change in keratometry measurements after 30 seconds. | The change in measured k-values (k, k1, k2 in mm) before and after instillation of artificial eye drops will be calculated | 30 seconds | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To determine whether application of highly viscid eye drops in normal eyes leads to a change keratometry measurements after 2 minutes or 5 minutes. These objectives will be assessed analogously to the primary objective. | The change in measured k-values (k, k1, k2 in mm)before and after instillation of artificial eye drops will be calculated | 2, 5minutes | 
| To determine whether application of slightly viscid eye drops in normal and in dry eyes leads to a change in keratometry measurements after 30 seconds, 2 minutes or 5 minutes. These objectives will be assessed analogously to the primary objective | The change in measured k-values (k, k1, k2 in mm) before and after instillation of artificial eye drops will be calculated | 30 seconds, 2 minutes or 5 minutes | 
| To determine whether application of highly viscid eye drops in dry eyes leads to a change in keratometry measurements after 30 seconds, 2 minutes or 5 minutes. These objectives will be assessed analogously to the primary objective | The change in measured k-values (k, k1, k2 in mm) before and after instillation of artificial eye drops will be calculated | 30 seconds, 2 minutes or 5 minutes |