A Novel Congenital Cataract Category System

Study Overview
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Brief Summary
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Congenital cataracts (CC) are the leading cause of childhood visual disabilities and treatable childhood blindness worldwide1. CC patients have a wide range of presentations of lens opacities and are generally categorized into several groups based on the etiologies, anatomical positions, or shapes of lens opacities. Cataractous eyes of CC patients are also frequently complicated with other anterior segment abnormalities due to their close anatomical relationships and similar developmental origins. Lens opacities in different positions may be related to specific anterior segment abnormalities; for example, anterior polar cataracts are associated with greater corneal astigmatism (CA). However, no studies have systematically related the position of lens opacities to specific anterior segment abnormities, mainly due to the small number of CC patients, a lack of proper equipment, and a lack of awareness of these important relationships.

Detailed Description
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Congenital cataracts (CC) are the leading cause of childhood visual disabilities and treatable childhood blindness worldwide1. CC patients have a wide range of presentations of lens opacities and are generally categorized into several groups based on the etiologies, anatomical positions, or shapes of lens opacities. Cataractous eyes of CC patients are also frequently complicated with other anterior segment abnormalities due to their close anatomical relationships and similar developmental origins. Lens opacities in different positions may be related to specific anterior segment abnormalities; for example, anterior polar cataracts are associated with greater corneal astigmatism (CA). However, no studies have systematically related the position of lens opacities to specific anterior segment abnormities, mainly due to the small number of CC patients, a lack of proper equipment, and a lack of awareness of these important relationships. Using the largest CC database in the Zhongshan Ophthalmic Center (ZOC), the current study compared the anterior segment characteristics of CC patients with lens opacities in different positions and further proposed a modified CC category system based on the specific relationships between the position of lens opacities and anterior segment characteristics. Knowledge of these relationships is beneficial for further understanding of CC occurrence and development and has clinical significance for CC diagnosis and treatment.

Official Title
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A Novel Congenital Cataract Category System Based on Lens Opacity Positions and Their Relevant Anterior Segment Characteristics

Conditions
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Cataract

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of congenital cataract less than 18 years old Exclusion Criteria: With other ocular abnormalities including severe corneal diseases, lens luxation, glaucoma, retinal diseases, nystagmus, nanophthalmos, and strabismus.

Ages Eligible for Study
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Maximum Age: 18 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Total cataract group<br>All selected eyes were categorized into four groups: total cataracts, anterior cataracts, interior cataracts and posterior cataracts, based on the position of lens opacities shown by both a slit lamp (BX900, HAAG-STREIT AG, Bern, Switzerland) examination and a 3-dimensional anterior segment imaging and analysis system (Pentacam HR, Oculus Inc., Wetzlar, Germany) after mydriasis. | |
| Anterior cataract group<br>All selected eyes were categorized into four groups: total cataracts, anterior cataracts, interior cataracts and posterior cataracts, based on the position of lens opacities shown by both a slit lamp (BX900, HAAG-STREIT AG, Bern, Switzerland) examination and a 3-dimensional anterior segment imaging and analysis system (Pentacam HR, Oculus Inc., Wetzlar, Germany) after mydriasis. | |
| Interior cataracts group<br>All selected eyes were categorized into four groups: total cataracts, anterior cataracts, interior cataracts and posterior cataracts, based on the position of lens opacities shown by both a slit lamp (BX900, HAAG-STREIT AG, Bern, Switzerland) examination and a 3-dimensional anterior segment imaging and analysis system (Pentacam HR, Oculus Inc., Wetzlar, Germany) after mydriasis. | |
| Posterior cataract group<br>All selected eyes were categorized into four groups: total cataracts, anterior cataracts, interior cataracts and posterior cataracts, based on the position of lens opacities shown by both a slit lamp (BX900, HAAG-STREIT AG, Bern, Switzerland) examination and a 3-dimensional anterior segment imaging and analysis system (Pentacam HR, Oculus Inc., Wetzlar, Germany) after mydriasis. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The mean keratometry value | The anterior segment parametersthe mean keratometry value of CC patients were measured by the 3-dimensional anterior segment imaging analysis system. | Baseline | 
| The central corneal thickness | The anterior segment parametersthe central corneal thickness of CC patients were measured by the 3-dimensional anterior segment imaging analysis system. | Baseline | 
| The anterior chamber depth | The anterior segment parametersthe anterior chamber depth of CC patients were measured by the 3-dimensional anterior segment imaging analysis system. | Baseline | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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congenital cataract;anterior segment characteristics