Predictive model for early diagnosis of keratoconus

Mapping Intimacies ◽

10.21203/rs.2.21162/v1 ◽

2020 ◽

Author(s):

GRACIA CASTRO-LUNA ◽

ANTONIO PÉREZ-RUEDA

Keyword(s):

Early Diagnosis ◽

Central Corneal Thickness ◽

Corneal Thickness ◽

Cross Sectional Study ◽

Bivariate Analysis ◽

Diagnostic Model ◽

Sectional Study ◽

Cross Sectional ◽

Recorded Data ◽

Topographic Parameters

Abstract Background To describe the topographic, pachymetric and aberrometry characteristics in patients with keratoconus, subclinical keratoconus/forme fruste and normal corneas. Calculate a diagnostic model of subclinical keratoconus/forme fruste. Methods The design was a cross-sectional study. It included 205 eyes from 188 patients distributed in 82 normal corneas, 40 subclinical keratoconus/forme fruste and 83 established keratoconus The topographic, pachymetric and aberrometry variables obtained by rotary Scheimpflug camera (Pentacam® type) were analyzed. A descriptive and bivariate analysis of the recorded data was performed. A diagnostic model of subclinical keratoconus/forme fruste was calculated. Results Statistically significant differences were obtained when comparing normal corneas with subclinical keratoconus/forme fruste in variables of vertical asymmetry and corneal thickness.The regression model was calculated with the minimum corneal thickness and the anterior coma to 90º and posterior coma to 90º. Conclusions The diagnosis of subclinical keratoconus/forme fruste depends on the central corneal thickness, and two aberrometric topographic parameters the anterior coma to 90º and posterior coma to 90º.

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A predictive model for early diagnosis of keratoconus

10.21203/rs.2.21162/v3 ◽

2020 ◽

Author(s):

GRACIA CASTRO-LUNA ◽

ANTONIO PÉREZ-RUEDA

Keyword(s):

Logistic Regression ◽

Predictive Model ◽

Early Stage ◽

Corneal Thickness ◽

Binary Logistic Regression ◽

Cross Sectional Study ◽

Bivariate Analysis ◽

Diagnostic Model ◽

Binary Logistic Regression Model ◽

Cross Sectional

Abstract Background: The diagnosis of keratoconus in the early stages of the disease is necessary to initiate an early treatment of keratoconus. Furthermore, to avoid possible refractive surgery that could produce ectasias. This study aims to describe the topographic, pachymetric and aberrometry characteristics in patients with keratoconus, subclinical keratoconus and normal corneas. Additionally to propose a diagnostic model of subclinical keratoconus based in binary logistic regression models Methods: The design was a cross-sectional study. It included 205 eyes from 205 patients distributed in 82 normal corneas, 40 early-stage keratoconus and 83 established keratoconus. The rotary Scheimpflug camera (Pentacam® type) analyzed the topographic, pachymetric and aberrometry variables. It performed a descriptive and bivariate analysis of the recorded data. A diagnostic and predictive model of early-stage keratoconus was calculated with the statistically significant variables Results: Statistically significant differences were observed when comparing normal corneas with early-stage keratoconus/ in variables of the vertical asymmetry to 90º and the central corneal thickness. The binary logistic regression model included the minimal corneal thickness, the anterior coma to 90º and posterior coma to 90º. The model properly diagnosed 92% of cases with a sensitivity of 97.59%, specificity 98.78%, accuracy 98.18% and precision 98.78%Conclusions: The differential diagnosis between normal cases and subclinical keratoconus depends on the mínimum corneal thickness, the anterior coma to 90º and the posterior coma to 90º.

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Central corneal thickness and normal tension glaucoma: A cross-sectional study

Optometry - Journal of the American Optometric Association ◽

10.1016/j.optm.2006.04.106 ◽

2006 ◽

Vol 77 (7) ◽

pp. 325

Author(s):

Steven Givner

Keyword(s):

Central Corneal Thickness ◽

Corneal Thickness ◽

Normal Tension Glaucoma ◽

Cross Sectional Study ◽

Sectional Study ◽

Cross Sectional

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A predictive model for early diagnosis of keratoconus

10.21203/rs.2.21162/v2 ◽

2020 ◽

Author(s):

GRACIA CASTRO-LUNA ◽

ANTONIO PÉREZ-RUEDA

Keyword(s):

Logistic Regression ◽

Predictive Model ◽

Corneal Thickness ◽

Binary Logistic Regression ◽

Cross Sectional Study ◽

Bivariate Analysis ◽

Diagnostic Model ◽

Binary Logistic Regression Model ◽

Cross Sectional ◽

Logistic Regression Models

Abstract Background: The diagnosis of keratoconus in the early stages of the disease is necessary to initiate an early treatment of keratoconus. Furthermore to avoid possible refractive surgery that could produce ectasias. This study aims to describe the topographic, pachymetric and aberrometry characteristics in patients with keratoconus, subclinical keratoconus and normal corneas. Additionally to propose a diagnostic model of subclinical keratoconus based in binary logistic regression models Methods: The design was a cross-sectional study. It included 205 eyes from 205 patients distributed in 82 normal corneas, 40 subclinical keratoconus and 83 established keratoconus The rotary Scheimpflug camera (Pentacam® type) analyzed the topographic, pachymetric and aberrometry variables. It performed a descriptive and bivariate analysis of the recorded data. A diagnostic and predictive model of subclinical keratoconus was calculated with the statistically significant variables Results: Statistically significant differences were observed when comparing normal corneas with subclinical keratoconus/ in variables of the vertical asymmetry to 90º and the central corneal thickness. The binary logistic regression model included the minimal corneal thickness, the anterior coma to 90º and posterior coma to 90º. The model properly diagnosed 92% of cases Conclusions: The differential diagnosis between normal cases and subclinical keratoconus depends on the mínimum corneal thickness, the anterior coma to 90º and the posterior coma to 90º.

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Reference values of the central corneal thickness with different refractive errors for the adult Egyptian population

10.21203/rs.3.rs-29153/v1 ◽

2020 ◽

Author(s):

Amr A. Gab-Alla

Keyword(s):

Reference Values ◽

Central Corneal Thickness ◽

Corneal Thickness ◽

Cross Sectional Study ◽

Refractive Errors ◽

Spherical Equivalent ◽

Sectional Study ◽

Cross Sectional ◽

Egyptian Population ◽

The Mean

Abstract Background: To generate reference values of the central corneal thickness (CCT) with different refractive errors for the adult Egyptian population. Methods: A retrospective, observational, and cross-sectional study of 2200 eyes in 1166 subjects scheduled for LASIK, who came to private refractive eye center, Ismailia, Egypt. The study period was from January 2018 to January 2020. The subjects were divided into a broad range of myopia with spherical equivalent (SE) <-0.5D and hyperopia SE> +0.5D. Then, the myopic eyes divided into low (SE>-3.0D), moderate (SE-3.0D to >-6.0D), and high (SE<-6.0D). Similarly, the hyperopic eyes were divided into low (SE<+3.0 D) and moderate (SE+3.0D to <+6.0D) and high >+6.0D. The refractive error was measured by an auto-refractometer (Topcon, Tokyo Optical Co., Ltd., Japan), and CCT was measured using Sirius (CSO, Florence, Italy). Results: The data of 1100 myopic eyes in 556 subjects (30.5% males and 69.5% females) and 1100 hyperopic eyes in 610 subjects (33.6% males and 66.4% females). The mean+SD of CCT for the total myopic subjects was 531.98+32.92μm, range (406 to 636μm). The mean+SD of SE was -4.1±2.5D, range (-0.5 to -12.0D). The mean+SD of CCT for the total hyperopic subjects was 529±38.8μm, range (448 to 619 μm). The mean+SD of SE was +3.65+1.97D, range (+0.5 to +8.5D).Conclusion: In this study, the mean of CCT of the Egyptian population was 531.9 μm for myopic and 529μm for hyperopic subjects respectively. The myopic and hyperopic subjects show a reduction in CCT with age. Females have a thinner cornea than males, 23.6% of the myopic eyes, and 16.5% of the hyperopic eyes have CCT less than 500μm.

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