Correlation Analysis of Lens Nucleus Density and Surgical Parameters Based on Ss-oct and Scheimpflug Technology

Study Overview
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Brief Summary
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To study the correlation between three different lens nuclear opacity classification methods and intraoperative phacoemulsification parameters .

Detailed Description
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Slit-lamp lens images, Pentacam and IOL-Master 700 images were collected in patients with dilated pupil before cataract surgery, and phacoemulsification parameters on the Centurion phacoemulsification machine (Alcon) screen were recorded. Spearman correlation analysis was used to analyze the correlation between lens nuclear density and phacoemulsification parameters based on SS-OCT and Scheimpflug techniques.

Official Title
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Correlation Analysis of Lens Nucleus Density and Surgical Parameters Based on Long-range Swept-source Optical Coherence Tomography and Scheimpflug Technology

Conditions
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Age-related Cataract

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age-related cataracts performed by the same surgeon in our hospital; Pupil diameter can be enlarged more than 6 millimetre. Exclusion Criteria: The pupil diameter cannot be dilated greater than 6mm; previously ocular surgery or laser treatment; history of ocular trauma; other ocular diseases such as keratoconus, glaucoma and retinal detachment; corneal opacities caused by leucoma, pterygium and other diseases; lens dislocation or complicated cataract surgery (any complications during/after the operations); poor fixation leading to low image quality or inability to cooperate with examinations.
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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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lens nuclear opalescence(NO) and nuclear colour (NC) | After the maximumly pupil dilation, the same experienced ophthalmologist examined all the eyes with slit-lamp digital cameras in dark conditions and scored the lens nuclear opalescence(NO) and nuclear colour (NC) on a scale of 0.1-6.9 according to LOCS III criteria. | 2021.12.30 | 
| Pentacam mean nuclear density (PND) | After the maximumly pupil dilation, Pentacam HR was used to acquire the Scheimpflug images of the lens, and the average density reading for the entire nucleus provided by PNS function was defined as Pentacam mean nuclear density (PND), ranging from 0% to 100%. | 2021.12.30 | 
| Mean nucleus density (MND) of the lens presented by IOL-Master 700 | After the maximumly pupil dilation, the inspected eyes are asked to focus on the indicator light to obtain a high-definition image of the lens. The image is derived to the ImageJ software, and the contour of the lens nucleus is manually drawn. The pixel density of the image within the contour is measured, with a value range of 0-255.The mean pixel density within the region was used to represent the mean nucleus density (MND) of the lens presented by IOL-Master 700.For each eye, the SS-OCT nucleus density is defined as the average of six readings from the corresponding image. | 2021.12.30 | 
| Intraoperative phacoemulsification parameters | The intraoperative phacoemulsification parameters on the Centurion phacoemulsification machine (Alcon) screen were recorded after surgery. | 2021.12.30 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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cataract, nucleus density, phacoemulsification parameters, ss-oct, scheimpflug