Keratokonus Tanısında Optik Koherens Tomografi ile Pakimetrik Haritalama

Purpose: To evaluate abnormal corneal thinning using optical coherence tomography (OCT) pachymetry mapping in keratoconus patients.\udMaterial and Method: In this prospective study, 57 eyes of 33 keratoconus patients and 50 eyes of 25 control subjects without ocular\udpathology were compared. After routine ophthalmologic examination, corneal topography and corneal pachymetry mapping by OCT with\udanterior segment module were performed in all subjects. Central corneal thickness (CCT), minimum corneal thickness (Min), superior-inferior\ud(S-I), minimum-median (Min-Med), superonasal-inferotemporal (SN-IT), superotemporal-inferonasal (ST-IN), minimum-maximum (MinMax)\udand minimum corneal vertical localization(MCVL) parameters were evaluated from the OCT pachymetric maps. Measurements were\udperformed three times in all patients, and the means of these data were used for statistical analysis and comparisons. Cut-off values were\uddetermined for all OCT-derived parameters. Sensitivity, specificity, and area under the receiver operating characteristic (AROC) curve were\udalso calculated for these parameters.\udResults: Keratoconic corneas were thinner. Minimum corneal thickness was 425±63 µm in the keratoconus group, and 513.7±3 µm in the\udcontrol group (p<0.001). The thinnest corneal location was inferiorly displaced in the keratoconus group. MCVL value was -845.6±427.9\udµm in the keratoconus group and -419.6±240.1 µm in the control group (p<0.001). Min-med was -46.3±23.8 µm and 18.4±16.3 µm in\udkeratoconus and control groups, respectively. Corneal thinning was more asymmetric in the keratoconus group ( S-I, SN-IT, ST-IN parameters\udwere statistically different between the groups, p<0.001). Sensitivity, specificity, and AROC values of the OCT pachymetric parameters were\udwithin the range of 82-92%, 54-89%, and 0.674-0.922, respectively.\udDiscussion: OCT pachymetry maps have high sensitivity and specificity for keratoconus diagnosis. OCT provides additional information\udin patients whose corneal topography was inconsistent with clinical signs and interpretation of both devices together would be more valuable\udin the diagnosis of keratoconus. (Turk J Ophthalmol 2013; 43: 236-4