Alberto López-Miguel1, María Sanchidrián1,2, Itziar Fernández1,3, Alfredo Holgueras1, Miguel J Maldonado4. 1. IOBA, Institute of Applied Ophthalmobiology, Universidad de Valladolid, Valladolid, Spain. 2. Rio Hortega University Hospital, Valladolid, Spain. 3. Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Valladolid, Spain. 4. IOBA, Institute of Applied Ophthalmobiology, Universidad de Valladolid, Valladolid, Spain. maldonado@ioba.med.uva.es.
Abstract
PURPOSE: To compare specular microscopy (Topcon SP-3000P, Topcon Corporation, Tokyo, Japan) and ultrasound (US) technology when evaluating central corneal thickness (CCT) prior to and after phacoemulsification. METHODS: Corneal edema was assessed in phacoemulsification patients due to senile cataract by measuring CCT preoperatively and 1 day, 1 month, and 3 months postoperatively. Bland-Altman analysis was performed to assess interchangeability between pachymetry techniques for each visit. Repeated measures analysis of variance was performed to evaluate variation in CCT agreement depending on the degree of corneal edema. RESULTS: One hundred and eighteen patients aged 73.9 ± 10.1 years were recruited. Topcon SP-3000P provided significant (p < 0.0001) lower CCT values than US with and without induced corneal edema. Mean differences between CCT techniques for baseline, 1 day, 1 month and 3 months after cataract surgery were -28.9 ± 22.6, -30.5 ± 41.4, -32.3 ± 16.2 and -33.0 ± 16.9 μm, respectively. The systematic bias observed was not significantly different among the 4 visits (p = 0.59). The estimated limits of agreement (based on 1.96 standard deviation) were substantial, being 90.5, 165.8, 64.9 and 67.5 um at baseline, 1 day and 1 and 3 months. CONCLUSIONS: Topcon SP-3000P provides similar systematic bias in comparison with US technique for CCT measurements regardless of the degree of corneal edema after phacoemulsification, which should be reduced after applying a constant calibration adjustment of ∼30 μm. However, interchangeability between techniques may be still limited by the notable random measurement error.
PURPOSE: To compare specular microscopy (Topcon SP-3000P, Topcon Corporation, Tokyo, Japan) and ultrasound (US) technology when evaluating central corneal thickness (CCT) prior to and after phacoemulsification. METHODS:Corneal edema was assessed in phacoemulsification patients due to senile cataract by measuring CCT preoperatively and 1 day, 1 month, and 3 months postoperatively. Bland-Altman analysis was performed to assess interchangeability between pachymetry techniques for each visit. Repeated measures analysis of variance was performed to evaluate variation in CCT agreement depending on the degree of corneal edema. RESULTS: One hundred and eighteen patients aged 73.9 ± 10.1 years were recruited. Topcon SP-3000P provided significant (p < 0.0001) lower CCT values than US with and without induced corneal edema. Mean differences between CCT techniques for baseline, 1 day, 1 month and 3 months after cataract surgery were -28.9 ± 22.6, -30.5 ± 41.4, -32.3 ± 16.2 and -33.0 ± 16.9 μm, respectively. The systematic bias observed was not significantly different among the 4 visits (p = 0.59). The estimated limits of agreement (based on 1.96 standard deviation) were substantial, being 90.5, 165.8, 64.9 and 67.5 um at baseline, 1 day and 1 and 3 months. CONCLUSIONS: Topcon SP-3000P provides similar systematic bias in comparison with US technique for CCT measurements regardless of the degree of corneal edema after phacoemulsification, which should be reduced after applying a constant calibration adjustment of ∼30 μm. However, interchangeability between techniques may be still limited by the notable random measurement error.
Authors: Alberto López-Miguel; Loreto Martínez-Almeída; María B Coco-Martín; María del Val; María Pichel; Miguel J Maldonado Journal: Cornea Date: 2014-03 Impact factor: 2.651
Authors: Laura J Kopplin; Katie Przepyszny; Brian Schmotzer; Karen Rudo; Denise C Babineau; Sanjay V Patel; David D Verdier; Ula Jurkunas; Sudha K Iyengar; Jonathan H Lass Journal: Arch Ophthalmol Date: 2012-04