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K. Yu, T. Swartz, M. Wang; Higher Order Aberrations Attributable to the Cornea and Internal Ocular Components in Myopic, Keratoconus and Cataractous Eyes . Invest. Ophthalmol. Vis. Sci. 2005;46(13):865.
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© ARVO (1962-2015); The Authors (2016-present)
Purpose: To compare higher order aberration (HOA) attributable to cornea versus internal ocular components in myopic eyes and in eyes with keratoconus and cataract. Methods: 122 eyes of 65 patients were divided into 3 groups: myopic with normal cornea and clear lens (N = 71), keratoconic (N = 21) and cataractous (N =30). In each patient, HOA Root Mean Square (RMS) values derived from the whole eye, from cornea, and from internal ocular components (lens, vitreous, retina), respectively, were obtained using a combined wavefront sensor (iTracey) and corneal topography (EyeSys) system. In each group, the average HOA RMS values from the whole eye, cornea and internal ocular components were determined and compared both from within the group and in–between groups. Results: Within the first group (myopic eyes), the average HOA RMS value from the cornea (0.65±0.41µm) is comparable to that from internal ocular components (0.66±0.34µm); comparing the second group (keratoconic eyes) with the first (myopic eyes with normal corneas), the average whole–eye HOA RMS value of the keratoconic eyes (3.75±2.51µm) is statistically higher than that from the normal myopic eyes (0.65+0.41µm ) (p<0.001); within the second group (keratoconic eyes), corneal contribution to HOA (4.07±3.02µm) is statistically significantly higher than that from the internal ocular component (1.83±1.41µm) (p<0.01); comparing the third group (cataractous eyes) with the first (myopic eyes with clear lens), the average whole–eye HOA RMS value from the cataract eyes (1.13±0.82µm) is statistically significantly higher than of the myopic eyes with clear lens (0.65+0.41µm) (P<0.01). Conclusions: In myopic eyes with normal cornea and clear lens, cornea and lens have equal contribution to the whole–eye HOA; in keratoconic eyes, not only the whole–eye HOA RMS value is increased (when compared with that of myopic eyes with normal cornea), but also the cornea is the largest contributor to whole–eye HOA in these keratoconic eyes; in the cataractous eyes, whole–eye HOA is also higher than that of myopic eyes with clear lens.
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