Articoli Scientifici di Oftalmologia
Argomento : 2
Anterior Segment Characteristics of Keratoconus Eyes Using ScheimpflugPlacido Topograph
Abstract
Purpose: To assess anterior segment parameters of keratoconus (KC) eyes at different stages
of the disease using Scheimpflug-placido topography (Sirius, CSO, Italy) in a sample of the southern
Egyptian population.
Methods: retrospective study of 400eyes of different grades of keratoconus along with 50 normal
eyes as a control group were assessed for the following parameters: corneal thickness at apex (CCT),
thinnest corneal thickness (TCT), anterior chamber depth (ACD), corneal volume (CV), corneal
keratometry, corneal asphericity (Q), corneal elevation (both anterior and posterior) with aspherotoric
surface as a reference, total root mean square (RMS), RMS Coma, RMS spherical aberration (SA),
RMS Astigmatism, , Baiocchi Calossi Versaci front index (BCVf
) and BCV back index (BCVb
). They
underwent Sirius Schemipflug placid topographer evaluation.
Results: eyes were subdivided into: normal group (50 eyes), suspect KC (82eyes), grade 1 KC
(80eyes), grade 2 KC (142eyes), and grade 3 KC (96eyes). The thinnest corneal thickness corneal
thickness at apex and posterior corneal elevation were significantly different in all comparison groups.
ACD values showed inconsistent differences between groups. Corneal volume was proved to be
significant in comparing normal vs suspect KC group as well as in normal vs mild KC and normal vs
moderate KC. Total RMS, RMS coma and BCV f and BCV b were significant for most groups
Conclusion: Corneal thickness and high order aberrations proved to be able to diagnose different
grades of keratoconus while corneal volume did not prove to have a significant role.