Accuracy of Different Topographic Instruments in Calculating Corneal Power after Myopic Photorefractive Keratectomy

نویسندگان

  • Alireza Baradaran-Rafii
  • Sahba Fekri
  • Mohammad Rezaie
  • Shahram Salehi-Rad
  • Ali Moradi
  • Tahmineh Motevasseli
  • Masumeh Kalantarion
چکیده

PURPOSE To compare the corneal power measurements obtained using different topographic instruments after myopic photorefractive keratectomy (PRK). METHODS Patients with myopia who were candidates for corneal refractive surgery were sequentially included. Pre-PRK and six months post-PRK corneal powers were measured using Javal manual keratometer, Orbscan II, Galilei, Tomey TMS4, and EyeSys 2000 topographers. Measured values were compared with those obtained using the clinical history method (CHM). RESULTS This study included 66 eyes of 33 patients. The lowest keratometric measurements were obtained using the Galilei topographer (42.98 ± 1.69 diopters, D) and the highest measurements were obtained using the Javal manual keratometer (43.96 ± 1.54 D) preoperatively. The same order was observed postoperatively. Effective refractive power (EffRP) measured using EyeSys was most similar to the values obtained using CHM (ICC, intraclass correlation coefficient = 0.951), followed by the total corneal power measured using the Galilei system (ICC = 0.943). The values obtained using the adjusted EffRP formula (EffRP - 0.015*Δ Refraction - 0.05) were more consistent with the values obtained using CHM (ICC = 0.954) compared to those obtained with the adjusted average central corneal power formula measured using the Tomey system (ICC = 0.919). CONCLUSION Post-PRK corneal powers measured using the adjusted EffRP formula were the most similar to values obtained using CHM.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

نتایج عمل Photorefractive keratectomy برای درمان نزدیک بینی زیاد در کلینیک نور تهران

Many studies have shown the effectiveness of photorefractive keratectomy (PRK) in correction of vision in low and moderate Myopia. To evaluate the results of 193-nm exeimer laser photorefractive keratectomy for highly Myopic eyes, we reviewed refractive outcome of 43 eyes of 30 patients. Most eyes were treated with 1-step operation, using a 6 mm optical zone. 43 eyes were treated for Myopia, wh...

متن کامل

تغییرات برآمدگی سطح خلفی قرنیه پس از جراحی فتورفرکتیوکراتکتومی

  Background : Posterior corneal elevation changes are keys to early diagnosis of corneal ectasia after keratorefractive surgery, so it is important to use an accurate method for measuring posterior corneal elevation. The purpose of this study is investigating posterior corneal elevation changes with Pentacam(HR) on patients underwent photorefractive keratectomy.   Methods: In this clinical tri...

متن کامل

Effects of optimized photorefractive keratectomy (PRK) operation on the asphericity and high-order aberration changes

Background: Optimized is a common and important method in which aberrations are created by the device and the surgeon, but high-grade aberrations are out of the surgeon's control and are induced by the device in the patient. The aim of this study was the evaluation of out-of-control high-order aberration changes before and after PRK surgery and these impact on vision outcome. Materials and meth...

متن کامل

Photorefractive keratectomy in patients with suspected keratoconus: five-year follow-up.

PURPOSE To assess the long-range outcomes of photorefractive keratectomy (PRK) using functional and topographic criteria in myopic eyes with suspected keratoconus. SETTING Rothschild Foundation, Paris, France. DESIGN Retrospective interventional case series. METHODS Eyes of patients classified as keratoconus suspects or keratoconus by the Corneal Navigator software of the OPD-Scan II devi...

متن کامل

Long-term changes of the anterior corneal topography after photorefractive keratectomy for myopia and myopic astigmatism.

PURPOSE To analyze the anterior corneal topography changes after 8 years after photorefractive keratectomy (PRK) for the correction of myopia and myopic astigmatism. METHODS Sixty-six eyes (33 patients) underwent PRK using an excimer laser platform. Patients were subdivided into three groups: the low myopia (13 patients; range, -1.25 to -4.40 diopters [D]), the high myopia (13 patients; -4.50...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره 12  شماره 

صفحات  -

تاریخ انتشار 2017