| Abstrakt: |
Purpose To compare Keratoconus Match Index (KMI) and Keratoconus Match Probability (KMP) of the Ocular Response Analyser (ORA) between forme fruste keratoconus and normal corneas and estimate the sensitivity and the specificity of KMI in discriminating forme fruste keratoconus from healthy corneas. Methods The study population of this retrospective comparative case series was divided into 2 groups: 8 forme fruste keratoconic eyes (FFKCN) and 36 healthy eyes. Every patient underwent a corneal topography, and a biomechanical evaluation with the Ocular Response Analyser. KMI and KMP were compared between the 2 groups. KMI and KMP results from an individual eye are compared to average values from 5 clinically classified populations in a normative database: Normal, Suspect KCN, Mild KCN, Moderate KCN, and Severe KCN. The software determines which population the measurement result best fits. Results The mean KMI 0.67 for FFKCN and 0.928 for control eyes. There was a statistically significant difference between the 2 groups (P = 0.05). For a threshold of 0,8, KMI had a sensitivity of 63% with a specificity of 72%. For a threshold of 10,7mmHg, the CH had a sensitivity of 75% and a specificity of 66,7%. According to the KMP, corneas of the control group match best with the normal group in 64% of the cases. According to the KMP, corneas of the FFKCN group match best with the normal group in 34% of the cases, with the suspect group in 35% of the cases, with the mild, moderate or severe group in 31% of the cases. Conclusion Sensitivity and specificity of the KMI is not greater than those of CH and CRF. The classification proposed by the KMP is not accurate and does not allows the screening of FFKCN. [ABSTRACT FROM AUTHOR] |
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