Results of different refractive error measurement methods/ Farkli yontemlerle kirma kusuru olcum sonuclari

• Published in: Turk oftalmoloji gazetesi Vol. 41; no. 2; p. 84
• Main Authors: Ceyhan, Dogan, Bozca, Tarik, Konca, Reyhan, Keskin, Siddik
• Format: Journal Article
• Language: English
• Published: Galenos Yayinevi Tic. Ltd 01.06.2011
• Subjects: Analysis; Eye; Mathematical statistics; Measurement; Measuring instruments; Medical examination; Refractive errors; Turkey
• ISSN: 1300-0659
• DOI: 10.4274/tjo.41.17

Purpose: The aim of this study was to compare the reliability of different methods of objective refractive error measurement. Material and Method: Cycloplegic refractive errors of sixty-seven eyes of thirty-six male patients were measured. Subjects were chosen between the patients who had refractive errors more than 2.00 diopters of myopia, hyperopia or astigmatism. Spherical and cylindrical errors as well as spherical equivalents were measured with two different autore-fractors and a retinoscope. Repeated measures analysis of variance and Tukey's multiple comparison test were used for the statistical analysis of refractive error measurements. Results: The mean and standard deviation values of spherical refractive error were 6.94 ± 3.43 with retinoscopy, 7.21 ± 3.29 for autorefractor 1, and 7.94 ± 3.44 for autorefractor 2. The spherical equivalents were 7.50 ± 3.43 for retinoscopy, 7.93 ± 3.38 for autorefractor 1, and 8.83 ± 3.64 for autorefractor 2. These values show that statistically and clinically significant differences existed between autorefractors 1 and 2 as well as between autorefractor 1 and retinoscope (p<0.05). Discussion: The results of this study demonstrate that different measurement methods and instruments may yield different values of refractive errors, which may cause wrong decisions about the value of objective refraction. Standardization of measurement methods should be established to obtain valid, accurate and reliable results and, especially for occupational requirements, subjective refraction should gain wider acceptance as "gold standard" method. (Turk J Ophthalmol 2011; 41: 849) Key Words: Refractive error, measurement, validity, reliability, accuracy Amac: Bu calismada farkli kirma kusuru olcum yontemleri ile elde edilen sonuclarin karsilastirilmasi amaclanmistir. Gerec ve Yontem: Otuz alti erkek hastanin 76 gozunde siklopleji sonrasi kirma (refraksiyon) kusuru degerleri olculmustur. Calisma grubu 2.00 diyoptri uzerinde miyopi, hipermetropi ve astigmatizmasi olan kisilerden olusturulmustur. Iki farkli otorefraktometre ve retinoskopi ile kuresel (sferik), silindirik ve sferik esdeger olcumleri yapilmistir. Elde edilen kirma kusuru degerlerinin istatistiksel degerlendirmesi icin "tekrarlanan olcumlu varyans analizi" ve Tukey coklu karsilastirma testi uygulanarak olcumler arasi uyum varligi belirlenmistir. Sonuclar: Kuresel (sferik) kirma kusurlarinin ortalama ve standart sapma degerleri; retinoskopi icin 6,94 ± 3,43; 1 no'lu otorefraktometre icin 7,21 ± 3,29; iki no'lu otorefraktometre icin 7,94 ± 3,44 olarak olculmustur. Kuresel esdegerler ise retinoskopi icin 7,50 ± 3,43; 1 no'lu otorefraktometre icin 7,93 ± 3,38 ve 2 no'lu otorefraktometre icin 8.83 ± 3.64 olarak belirlenmistir. Bu sonuclar, 1 ve 2 no'lu otorefraktometre ile 1 no'lu otorefraktometre ile retinoskopi olcumleri arasinda istatistiksel ve klinik olarak onemli fark olabildigini gostermektedir (p<0,05). Tartisma: Bu calisma, farkli cihaz ve yontemlerle yapilan kirma kusuru objektif muayenesinin, hekimin hatali kararina neden olabilecek farkli kirma kusuru degerleri verebildigini gostermektedir. Gecerli, dogru ve guvenilir sonuclarin alinabilmesi icin olcum yontemlerinin standardizasyonu yaninda; ozellikle meslek muayenelerine yonelik kirma kusuru subjektif olcumlerini "altin standart" olarak kabul eden yaklasima agirlik verilmelidir. (Turk J Ophthalmol 2011; 41: 84-9) Anahtar Kelimeler: Kirma kusuru, olcum, gecerlilik, guvenilirlik, dogruluk