Authors: Bader Alqahtani¹,  Khalid Alburayk ².  ¹Ophthalmology Department, King Faisal Specialist Hospital, Riyadh, Saudi Arabia Cornea and Anterior Segment Department, The Eye Institute, University of Ottawa, Ottawa, Canada, ²PGY4, Chief Ophthalmology Resident, Ministry of Health, Saudi Arabia.

Author Disclosures: B. Alqahtani:  None.  K. Alburayk:  None 

Abstract Body: 

Purpose:  This study aims to provide a better understanding of the long-term effect of CXL in keratoconus. Cone location considered to be a debatable subject in the literature whether it has any effect on outcome of CXL and to evaluate the effectiveness of CXL in enhancing visual performance in keratoconus. Moreover, To investigate the effect of CXL on corneal parameter, mainly curvatures, astigmatism and thickness. moreover, to explore the extent to which the severity of keratoconus prior to CXL treatment affects CXL outcomes. This could ultimately lead to increased successful outcomes 

Study Design:  retrospective chart review study  

Methods:  In this retrospective single center study, after reviewing more than 600 eYes,  160 eyes treated with accelerated CXL were included. Preoperative measurements of visual acuity, corneal astigmatism, keratometric reading including K1,K2 and Kmax and corneal thickness were collected in addtion to cone location whether central or paracentral. these meausremnts were evluated and complared to 6 months,1 and 2 years interval post CXL. Central and paracentral cones were defined as cones within the central 3 mm and those between 3 and 5 mm, respectively. Eyes with history of ocular surgery or any other procedural related intervention were excluded. The primary outcome measures K max and corneal thickness.  

Results:  Total of 160 eyes were included in the study. Table 1 shows the sociodemographic profile. As for the age of the patients, the minimum was 13, the maximum was 37, and the mean was 23.65  +  5.26. As for the gender, (58.2%) of the patients were males, while (41.8%) were females. Figure 1 displays the eyes included in the study. (49.2%) were right sided eYes,  while (50.8%) were left sided eyes. Figure 2 presents the cone location and if was significantly related to the progression or not. In (45.1%) of the eYes,  the cone was central, while in 67 (54.9%) of the eyes the cone was paracentral. Table 3 demonstrates comparison of keratometry parameters pre-treatment and post-treatment measurement. There was a significant reduction in the following parameters at both 1-year interval, and at 2-year interval: K1, K2, K max, astigmatism, and pachy, except for K1 at 1-year interval, and astigmatism at 1-year interval.  

Conclusions:  This is a relatively fair data showing the significance and insignificance of some of corneal parameters pre-CXL in predicting the CXL outcome in 2 years follow up enhancing the patient management plan in keratconus population.