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First Author: A.Kanellopoulos GREECE
Co Author(s): G. Asimellis
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To compare the efficacy of two alternative corneal topography data sources employed in the topography - guided part of the clinical keratoconus management with the Athens Protocol (AP) procedure, namely a Placido-disk imaging device and a Scheimpflug imaging device, by analysis of one-year refractive, topometric and visual rehabilitation changes.
Laservision.gr Eye Institute, Athens, Greece
One hundred eighty-one (181) consecutive keratoconic patients subjected to the Athens Protocol procedure, between 2008 and 2011, from which one eye was randomly selected, were studied pre-operatively and 1, 3, 6, and 12-months postoperatively for visual acuity, keratometry, and anterior segment corneal indices. Two groups were formed, depending on the primary source for the topo-guided photoablation, namely a Placido disc, for group A (Topo), and a Scheimpflug rotating camera, for group B (Ocu). The one-year changes in visual acuity, keratometric, and anterior-segment topometric indices were studied for both groups.
The visual acuity changes, expressed as difference between post minus the pre-operative corrected distance visual acuity were, for group A (Topo), +0.12 ±0.20 (range +0.60 to -0.45), and for group B (Ocu), +0.15 ±0.20 (range +0.75 to 0.30), respectively. For group A, (Topo), K1 (flat keratometry) changed from 45.202 ±3.782 diopters (D) to 43.022 ±3.819, or a change of -2.18 D, and K2 (steep keratometry) changed from 48.670 ±4.066 D to 45.865 ±4.794 D, or a change of -2.805 D. Respectively, for group B (Ocu), K1 (flat keratometry) changed from 46.213 ±4.082 D to 43.190 ±4.398 D, or a change of -3.023 D, and K2 (steep keratometry) changed from 50.774 ±5.210 to 46.380 ±5.006 D, or a change of -4.394 D. For group A (Topo), the index of surface variance was reduced to -5.07% and the index of height decentration to -26.81%, and for group B (Ocu), the index of surface variance was reduced to -18.35% and the index of height decentration to -39.03%, respectively. This negative change is indicative of corneal surface becoming less irregular (ISV) and the cone becoming more central (IHD) in the post-operative assessment.
Of the two sources of primary topography-guided corneal data, the Scheimpflug rotating camera (Oculyzer II) appears to provide statistically significant better improvement when compared to the Placido disk topographer (Vario Topolyzer). Overally, the Athens Protocol procedure, aiming to both arrest the keratoconus ectasia progression, as well as to improve corneal topometry and visual performance, demonstrates impressive refractive, keratometric and topometric results.
... travel has been funded, fully or partially, by a company producing, developing or supplying the product or procedure presented