| Abstrakt: |
Introduction: Keratoconus (KC) is the most common corneal ectatic disorder with a prevalence of about 1 in 2,000 people. KC is a progressive, non-inflammatory, almost bilateral and asymmetric of corneal. Corneal collagen cross-linking (CXL) with riboflavin and ultraviolet- A (UVA) is a new technique of mechanical stability of the cornea and prevention of keratoconus progression. Purpose: Determining the relationship between changes in corneal density before and after collagen cross-linking surgery in patients with keratoconus Materials and Methods This prospective study was performed on 45 eyes of 23 patients with keratoconus undergoing corneal collagen cross-linking treatment at Imam Khomeini Hospital in Ahvaz in 2019. Corneal densitometry (CD) and pachymetry were measured using Pentacam before CXL and at 3, 6 and 12 months after CXL. Also, all of the patients were evaluated in terms of best corrected visual acuity (BCVA), during follow-up. Results: In this study, 23 people including 12 men (54.2%) and 11 women (45.8%) with a mean age of 25.2 ± 4.64 years in the age range of 18-34 years participated. The mean value of corneal density in total layer over the annular diameters 0-2 mm was 19.10±5.58, 22.31±5.64, 24.28±6.37 and 20.89±5.73 for before, 3 months, 6 months and 12 months after CXL, respectively (P = 0.001). The mean value of corneal density in ant layer over the annular diameters 0-2 mm was 22.38±8.38, 27.46±9.63, 28.07±11.28 and 24.53±9.21for before, 3 months, 6 months and 12 months after CXL, respectively (P = 0.001). The mean value of corneal pachymetry in thinnest location was 426.2±34.7 µm, 412.5±42.6 µm, 419.2±37.3 µm and 428.3±36.9 µm for before, 3 months, 6 months and 12 months after CXL, respectively (P = 0.392). The pre-CXL value of BCVA was significantly lower than the post-CXL values in 12 months (0.10 ± 0.19, 0.15 ± 0.10 and 0.019 ± 0.15, respectively, P<0.0001). In general, Densitometry values increases and corneal thinnest location decreses during the 3-6 months after CXL and then return to baseline preoperative values in 12 months. There was a significant improvement in best corrected visual acuity (BCVA) before and 12 months after surgery (P<0.0001). Conclusions: CXL can increase corneal densitometry and decrease corneal thinnest location during the postoperative 6 months period. Densitometric values and corneal thickness return to baseline preoperative values to a large extent during 6-12 months postoperatively. The patient's BCVA increased over 12 months but no correlation was observed between this increase and densitometric changes. [ABSTRACT FROM AUTHOR] |
