Enhanced Ectasia Susceptibility Screening Based on Clinical Data and Scheimpflug Corneal Topographer

Ramos, Isaac

Enhanced Ectasia Susceptibility Screening Based on Clinical Data and Scheimpflug Corneal Topographer

Friday, April 25, 2014

KIOSKS (Boston Convention and Exhibition Center)

Isaac C. Ramos, MD, Hospital de Olhos Santa Luzia, Maceió-AL, Brazil

Bernardo T. Lopes, MD, Rio de Janeiro Corneal Tomography and Biomechanical Study Group, Rio de Janeiro, Brazil

Allan Luz, MD, Hospital de Olhos de Sergipe, Aracaju, Brazil

Marcella Salomão, MD, Barra Vision Center, Rio de Janeiro, Brazil

Rosane Correa, MD, Rio de Janeiro Corneal Tomography and Biomechanical Study Group, Rio de Janeiro, Brazil

Renato Ambrósio Jr., MD, PhD, Inst. Olhos R. Ambrósio, Rio de Janeiro, Brazil

Lívia F. Jordão, MD, Instituto de Olhos Renato Ambrosio, Rio de Janeiro, Brazil

Narrative Responses:

Purpose
To test a previously described criteria based on clinical and Pentacam corneal tomography data to identify pre-operative risk (susceptibility) for ectasia.

Methods
The pre-operative clinical and tomographic data from forty-six eyes from 38 patients that developed ectasia after LASIK (Group 1), and 266 control eyes from 141 patients with stable LASIK (Group 2) were analyzed. The “Enhanced Ectasia Susceptibility Screening” (EESS), a combined parameter based logistic regression analysis of clinical and corneal tomography data was previously described to identify pre-operative risk for ectasia. The EESS was used to distinguish the groups. The Mann-Whitney U test and the area under the ROC curve (AUC) were used to verify the diferences between the groups, and test the performance of this criteria in this series.

Results
Statistically significant difference was found among the groups for EESS (p<0.0001, Mann-Whitney test). EESS obtained 90.5% of sensitivity and 92.1% of specificity, with AUC = 0.936 (95% Confidence Interval = 0.902 to 0.960; Standard Error = 0.0318; Cut-off = -2.31; Z statistic = 13.722; Significance level p < 0.001) to distinguish ectasia susceptibility after LASIK from stable LASIK cases.

Conclusion
The “Enhanced Ectasia Susceptibility Screening” is a valid and effective method for detecting eyes at risk for ectasia after LASIK. This combined parameter represents a significant improvement over previously utilized screening strategies. Corneal biomechanical parameters should be considered to further improve this diagnostic criteria.