Evaluation of the TRK-2P Instrument Reliability in Normal and Keratoconus Eyes: A Preliminary Observation

Öz

To compare keratometry and corneal thickness measurements by the TRK-2P instrument (Topcon Medical Systems Inc., Oakland NJ) with the anterior cornea keratometry and pachymetry values obtained by the Pentacam-HR instrument (Oculus; Optikgeräte GmbH, Wetzlar, Germany). Patients who had full records of two both instruments in our databases were included in the observational study. Keratoconus diagnosed twenty-three eyes of twelve patients and thirty-two eyes of sixteen patients with no eye problem (controls) were included. The keratometry and the central corneal thickness (CCT) outputs were collected by TRK-2P and Pentacam-HR. The consistency of the mean anterior cornea keratometry and pachymetry data were correlated using the intraclass correlation coefficient (ICC). Means were statistically correlated using a Paired t-test seeking significant correlations (α=0.05). Mean keratometry of TRK-2P and Pentacam-HR were 42.64D±2.02 and 42.79D±1.95 in controls whereas, these were 47.64D±5.24 and 47.16D±4.65 in keratoconus, respectively. The mean differences in keratometry data were 0.14D for controls and 0.48D for keratoconus(p<0.001). Mean CCT of TRK-2P and Pentacam-HR were 560.27±42.18µm and 537.63±36µm in controls whereas, these were 489.67±45.13µm and 470.22±38.14µm in keratoconus, respectively. The mean differences in CCT data were 22.63µm for controls and 19.44µm for keratoconus(p<0.001). ICC values between two instruments for controls and keratoconus, respectively were as follows: 0.987 and 0.983 for keratometry, 0.998 and 0.994 for CCT (p<0.001). TRK-2P produces consistent result outputs in normal and pathological corneas. Also, TRK-2P is a reliable instrument when correlated with a reference high-reliable instrument. However, in terms of monitoring the progression of keratoconus, these instruments cannot be interchangeable alternatives

Anahtar Kelimeler

• Central corneal thickness
• Keratoconus
• Pentacam HR
• TRK-2P

Normal ve Keratokonuslu Gözlerde TRK-2P Cihazının Güvenilirliğinin Değerlendirilmesi: Bir Ön Gözlem

Öz

Bu çalışmanın amacı TRK-2P cihazı (Topcon Medical Systems Inc., Oakland NJ) ile elde edilen keratometri ve kornea kalınlık değerlerini, Pentacam-HR cihazı (Oculus; Optikgeräte GmbH, Wetzlar, Almanya) ile elde edilen ön kornea keratometrisi ve pakimetri değerleri ile karşılaştırmaktır. Veri tabanlarımızda her iki cihazın tam kayıtlarına sahip olan hastalar bu gözlemsel çalışmaya dahil edildi. On iki hastanın keratokonus tanılı yirmi üç gözü ve herhangi bir göz sorunu olmayan on altı hastanın otuz iki gözü çalışmaya dahil edildi (kontrol). Keratometri ve santral kornea kalınlığı (SKK) çıktıları TRK-2P ve Pentacam-HR ile elde edilmiştir. Ortalama ön kornea keratometrisi ve pakimetri verilerinin tutarlılığı, sınıf içi korelasyon katsayısı (ICC) kullanılarak ilişkilendirildi. Ortalamalar paired t-testi kullanılarak istatistiksel olarak analiz edildi (α=0.05). Ortalama keratometri TRK-2P ve Pentacam-HR kontrollerde 42.64 D±2.02 ve 42.79 D±1.95 iken keratokonusta 47.64 D±5.24 ve 47.16 D±4.65 idi. Keratometri verilerindeki ortalama farklılıklar kontroller için 0.14 D ve keratokonus için 0.48 D idi (p<0.001). TRK-2P ve Pentacam-HR ortalama SKK değerleri sırasıyla kontrollerde 560,27±42,18 µm ve 537,63±36 µm iken keratokonus hastaları için sırasıyla 489,67±45,13 µm ve 470,22±38,14 µm idi. SKK verilerindeki ortalama farklar kontroller için 22.63 µm ve keratokonus için 19.44 µm idi (p<0.001). Kontrol ve keratokonus grupları için iki cihaz arasındaki ICC değerleri sırasıyla keratometri için 0,987 ve 0,983, SKK için 0,998 ve 0.994 idi (p<0.001). Çalışmamızın sonuçları, TRK-2P, normal ve patolojik kornealarda tutarlı sonuç çıktıları üretir. Ayrıca, TRK-2P, yüksek güvenilirliğe sahip referans bir cihazla ilişkilendirildiğinde güvenilir bir araçtır. Ancak keratokonus progresyonunun izlenmesi açısından bu enstrümanlar birbirinin yerine geçebilecek alternatifler olamaz.

Anahtar Kelimeler

• Santral kornea kalınlığı
• Keratokonus
• Pentacam HC
• TRK-2P

Kaynakça

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