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العنوان
Assessment of corneal higher order aberrations before and after corneal collagen cross-linking in patients with keratoconus /
المؤلف
Awad-Allah,Mo’mena Ahmad Abd-elRazeik.
هيئة الاعداد
باحث / Mo’mena Ahmad Abd-elRazeik Awad-Allah
مشرف / Rafeek Mohamed Fouad El-Ghazawy
مشرف / Tamer Mohamed Fathi El-Mekkawi
مشرف / Ahmed Hasan Samir Assaf
تاريخ النشر
2018
عدد الصفحات
132p.:
اللغة
الإنجليزية
الدرجة
الدكتوراه
التخصص
طب العيون
تاريخ الإجازة
1/1/2018
مكان الإجازة
جامعة عين شمس - كلية الطب - طب و جراحة العيون
الفهرس
Only 14 pages are availabe for public view

from 132

from 132

Abstract

Keratoconus is a progressive ectatic disorder that leads to collagen network organization disruption. Irregularities in the collagen network leads to distortion of refractive function resulting in high myopia and irregular astigmatism.
Keratoconus alter the cornea causing an area of increased corneal power surrounded by concentric areas of decreasing power, inferior-superior power asymmetry, and skewing of the steepest radial axes above and below the horizontal meridian. These topographic alterations are mainly responsible for the significant induction of higher order aberrations and consequently, the visual quality degradation.
Corneal collagen cross-linking (CXL) is regarded as a standard technique in keratoconus management, being the only clinically available intervention that has demonstrated a potential to slow down or halt the progression of the disease.
The aim of this work was to study the short term effect of corneal collagen crosslinking on higher order aberrations of cornea in patients with keratoconus using corneal topography.
The study was a prospective cohort study that was conducted in a private specialized eye hospital on 40 eyes of 28 keratoconus patients. Each patient was fully assessed preoperatively including doing corneal topography using Pentacam® HR. Transepithelial accelerated CXL was done to all patients. Postoperative corneal topography was done at six months and data was retrieved and analyzed.
This study reached the following results:
1. RMS HOA recorded a higher mean value preoperatively, with an extremely statistically significant difference (p=0.00).
2. All elements of HOAs showed lower postoperative values except for trefoil 30º, which had insignificant higher value (p=0.466). Trefoil 0º, fifth order trefoil 0º, fifth order trefoil 30º and fifth order comma 0º had insignificant improvement (p=0.373, p=0.331, p=0.055 and p=0.149 respectively). The difference was statistically significant in comma 0º, comma 90º, spherical aberrations and fifth order comma 90° (p=0.026, p= 0.003, p=0.005, and p=0.001 respectively).
3. Regarding K1, K2 and K max, higher values were recorded preoperatively, the difference between pre- and postoperative mean values was insignificant in K1 and K2 (p=0.616; p=0.425), but was extremely statistically significant in K max (p=0.000). Pachymetry apex and thinnest location recorded a higher value preoperatively, with no significant difference between the pre- and postoperative mean values (p=0.128, p=0.093).
4. A weak positive insignificant correlation was noted between K1 and HOA (p=0.176), while a moderate positive statistically significant correlation was noted between RMS and K2 & Kmax (p=0.011 and 0.005 respectively). A weak negative insignificant correlation was noted between RMS and pachymetry apex & thinnest location (p=0.226 and 0.218 respectively).
This study reached its primary goal, which was studying the effect of transepithelial CXL on corneal HOAs and achieved secondary goal, which was correlating the HOAs improvement with other topographical parameters.