| Abstract |
Purpose: To evaluate visual performance in keratoconic patients undergoing simultaneous conventional photorefractive keratectomy (PRK) followed by corneal crosslinking (CXL)
Patients and Methods: Prospective, interventional, case series. 15 patients (18 eyes) with progressive keratoconus were included. There was performed preoperative and postoperative evaluation of retinal straylight (C-Quant, Oculus GmbH) for two eccentricities (7o and 3,5o), cycloplegic manifest refraction with 6 mm artificial pupil, monocular and binocular cycloplegic corrected ETDRS visual acuity with 3 and 6 mm artificial pupil, cycloplegic contrast sensitivity assessment in a dark room (FΑCT, Vision Sciences Research Corp.) using an 6 mm artificial pupil and cycloplegic wavefront analysis for 3 and 6 mm pupil (iTrace; Tracey Tech, Houston, Texas, USA)
Results: Preoperatively mean retinal straylight value at 7ο was 1.06 ± 0.26 log units and at 3.5ο 1.198 ± 0.15 log units. Postoperatively mean retinal straylight value increased to 1.13 ± 0.11 log units at 7ο (p=0.26) and at 1.338 ± 0.12 log units at 3.5ο (p=0.04). Visual acuity improved at the statistical significant level of 5% by using the artificial pupil of 6 mm (p=0,042 monocularly και p=0,035 binocularly) from the preoperative value of 0.14 ± 0.18 to 0.07 ± 0.15 monocularly to 0.06 ± 0.18 σε -0.04 ± 0.11 binocularly. Contrast sensitivity improved postoperatively at all spatial frequencies in mesopic and photopic conditions. The difference is statistical significant in all spatial frequencies in mesopic conditions and at 3, 6, και 18 c/deg in photopic conditions. RMS values of total, low and high order aberrations as well as 3rd order aberrations, coma, defocus and astigmatism show statistical significant reduction at the level of 1% for 3 mm pupil diameter. RMS values differ statistical significantly at the level of 1% for 6 mm pupil diameter in total, low and high order aberrations as well as in 3rd order aberrations and defocus. Improvement is statistically significant at the level of 5% in coma whereas astigmatism did not differ significantly. Introduction of positive spherical aberration was statistical significant for both 3 and 6 mm pupil. Aberrations of 4th, 5th and 6th order did not differ significantly postoperatively.
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ΔΙΑΤΜΗΜΑΤΙΚΟ ΜΕΤΑΠΤΥΧΙΑΚΟ ΠΡΟΓΡΑΜΜΑ ΣΠΟΥΔΩΝ
«ΟΠΤΙΚΗ ΚΑΙ ΟΡΑΣΗ»
Conclusion: Combined photorefractive keratectomy and corneal crosslinking seem to result in better visual performance by improving corrected visual acuity and contrast sensitivity as well as by reducing visual impairment caused by aberrations. Retinal straylight is increased due to corneal structural changes and posterior haze formation. Further follow-up and additional cases are needed in order to obtain final conclusions regarding visual performance of keratoconic patients after combined treatment.
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Αξιολόγηση της ποιότητας όρασης σε ασθενείς με κερατόκωνο πριν και μετά το συνδυασμό φωτοδιαθλαστικής κερατεκτομής με επέμβαση διασύνδεσης πλαγίων συνδέσμων κερατοειδικού κολλαγόνου
