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Abstract #26674 Published in IGR 12-3
Determination of corneal elasticity coefficient using the ORA database
Avetisov SE; Novikov IA; Bubnova IA; Antonov AA; Siplivyi VIJournal of Refractive Surgery 2010; 26: 520-524
PURPOSE: To propose a new approach for the study of corneal biomechanics using the Reichert Ocular Response Analyzer (ORA) database, which is based on changes in velocity retardation in the central cornea at the peak of flattening. METHODS: The ORA applanation curve was analyzed using a mathematical technique, which allowed calculation of the elasticity coefficient (Ke), which is primarily characteristic of the elastic properties of the cornea. Elasticity coefficient values were obtained in patients with presumably different biomechanical properties of the cornea: "normal" cornea (71 eyes, normal group), keratoconus (34 eyes, keratoconus group), LASIK (36 eyes, LASIK group), and glaucoma with elevated and compensated intraocular pressure (IOP) (38 eyes, glaucoma group). RESULTS: The mean Ke value in the normal group was 11.05(plus or minus)1.6, and the corneal thickness correlation coefficient r (2) was 0.48. In the keratoconus group, the mean Ke value was 4.91(plus or minus)1.87 and the corneal thickness correlation coefficient r(2) was 0.47. In the LASIK group, Ke and r(2) were 5.99(plus or minus)1.18 and 0.39, respectively. In the glaucoma group, the same eyes that experienced a two-fold reduction in IOP developed a statistically significant reduction in the Ke (1.06 times lower), whereas their corneal hysteresis value increased 1.25 times. CONCLUSIONS: The elasticity coefficient calculated using the ORA applanation curve can be used in the evaluation of corneal biomechanical properties.
I. A. Bubnova. 11-a Rossolimo St, Moscow, 119021, Russian Federation. bubnovai@mail.ru
Classification:
6.1.1 Devices, techniques (Part of: 6 Clinical examination methods > 6.1 Intraocular pressure measurement; factors affecting IOP)
2.2 Cornea (Part of: 2 Anatomical structures in glaucoma)
