Academic Journal
Placido disk-based topography versus high-resolution rotating Scheimpflug camera for corneal power measurements in keratoconic and post-LASIK eyes: reliability and agreement
| العنوان: | Placido disk-based topography versus high-resolution rotating Scheimpflug camera for corneal power measurements in keratoconic and post-LASIK eyes: reliability and agreement |
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| المؤلفون: | Rachele R. Penna, Ugo de Sanctis, Martina Catalano, Luca Brusasco, Federico M. Grignolo |
| المصدر: | International Journal of Ophthalmology, Vol 10, Iss 3, Pp 453-460 (2017) |
| بيانات النشر: | Press of International Journal of Ophthalmology (IJO PRESS), 2017. |
| سنة النشر: | 2017 |
| المجموعة: | LCC:Ophthalmology |
| مصطلحات موضوعية: | keratoconus, post-LASIK, corneal power measurement, Placido disk-based topography, Scheimpflug camera, Ophthalmology, RE1-994 |
| الوصف: | AIM: To compare the repeatability/reproducibility of measurement by high-resolution Placido disk-based topography with that of a high-resolution rotating Scheimpflug camera and assess the agreement between the two instruments in measuring corneal power in eyes with keratoconus and post-laser in situ keratomileusis (LASIK). METHODS: One eye each of 36 keratoconic patients and 20 subjects who had undergone LASIK was included in this prospective observational study. Two independent examiners worked in a random order to take three measurements of each eye with both instruments. Four parameters were measured on the anterior cornea: steep keratometry (Ks), flat keratometry (Kf), mean keratometry (Km), and astigmatism (Ks-Kf). Intra-examiner repeatability and inter-examiner reproducibility were evaluated by calculating the within-subject standard deviation (Sw) the coefficient of repeatability (R), the coefficient of variation (CoV), and the intraclass correlation coefficient (ICC). Agreement between instruments was tested with the Bland-Altman method by calculating the 95% limits of agreement (95% LoA). RESULTS: In keratoconic eyes, the intra-examiner and inter-examiner ICC were >0.95. As compared with measurement by high-resolution Placido disk-based topography, the intra-examiner R of the high-resolution rotating Scheimpflug camera was lower for Kf (0.32 vs 0.88), Ks (0.61 vs 0.88), and Km (0.32 vs 0.84) but higher for Ks-Kf (0.70 vs 0.57). Inter-examiner R values were lower for all parameters measured using the high-resolution rotating Scheimpflug camera. The 95% LoA were -1.28 to +0.55 for Kf, -1.36 to +0.99 for Ks, -1.08 to +0.50 for Km, and -1.11 to +1.48 for Ks-Kf. In the post-LASIK eyes, the intra-examiner and inter-examiner ICC were >0.87 for all parameters. The intra-examiner and inter-examiner R were lower for all parameters measured using the high-resolution rotating Scheimpflug camera. The intra-examiner R was 0.17 vs 0.88 for Kf, 0.21 vs 0.88 for Ks, 0.17 vs 0.86 for Km, and 0.28 vs 0.33 for Ks-Kf. The inter-examiner R was 0.09 vs 0.64 for Kf, 0.15 vs 0.56 for Ks, 0.09 vs 0.59 for Km, and 0.18 vs 0.23 for Ks-Kf. The 95% LoA were -0.54 to +0.58 for Kf, -0.51 to +0.53 for Ks and Km, and -0.28 to +0.27 for Ks-Kf. CONCLUSION: As compared with Placido disk-based topography, the high-resolution rotating Scheimpflug camera provides more repeatable and reproducible measurements of Ks, Kf and Ks in keratoconic and post-LASIK eyes. Agreement between instruments is fair in keratoconus and very good in post-LASIK eyes. |
| نوع الوثيقة: | article |
| وصف الملف: | electronic resource |
| اللغة: | English |
| تدمد: | 2222-3959 2227-4898 |
| Relation: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5360783/; https://doaj.org/toc/2222-3959; https://doaj.org/toc/2227-4898 |
| DOI: | 10.18240/ijo.2017.03.20 |
| URL الوصول: | https://doaj.org/article/8e565d9229a34b23968fdf91e6b06cbd |
| رقم الانضمام: | edsdoj.8e565d9229a34b23968fdf91e6b06cbd |
| قاعدة البيانات: | Directory of Open Access Journals |
Full Text Finder | تدمد: | 22223959 22274898 |
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| DOI: | 10.18240/ijo.2017.03.20 |