Anterior Chamber Depth Measurement before and after Photorefractive Keratectomy : Comparison between IOL Master and Orbscan II

PurposeTo measure the anterior chamber depth (ACD) with 2 different devices before and after photorefractive keratectomy (PRK).DesignNoncomparative case series.ParticipantsOne hundred forty-three eyes of 143 patients who had undergone PRK with refractive errors ranging from −13.13 diopters (D) to +7 D (mean, −3.67±3.58) were analyzed.MethodsThe ACD values preoperatively and at 1, 3, and 6 months postoperatively were measured with the Orbscan II and IOL Master. The results were analyzed using the Pearson correlation.Main Outcome MeasureAnterior chamber depth.ResultsThe instruments showed good agreement between the measurements before and after surgery. A significant decrease between the preoperative and 1-month postoperative measurements was found in the ACD measured from the epithelium with Orbscan II (P<0.01) and IOL Master (P<0.01). A nonsignificant decrease with both IOL Master (P>0.01) and Orbscan II (P>0.01) was found between 3 and 6 months after surgery. The ACD measured from the endothelium using the Orbscan II showed a significant difference only between the 3- and 6-month follow-up data (P<0.01).ConclusionsThe 2 devices showed good agreement, and the changes detected postoperatively seem to be related not only to corneal thinning but also to anterior segment remodeling.