Mohammed Ziaei1, Akilesh Gokul2, Hans Vellara2, Dipika Patel2, Charles N J McGhee2. 1. Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand. Electronic address: m.ziaei@auckland.ac.nz. 2. Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
Abstract
PURPOSE: To compare the corneal densitometry changes after transepithelial pulsed (t-ACXL), epithelium-off continuous (c-ACXL) and epithelium-off pulsed (p-ACXL), accelerated corneal crosslinking for patients with progressive keratoconus. METHODS: Prospective, interventional case series at a university hospital tertiary referral center. Forty eyes received t-ACXL, 40 eyes received c-ACXL, and 40 eyes received p-ACXL. Corneal tomography, densitometry and visual acuity were evaluated preoperatively and at 1, 3, 6, 12 and 24 months postoperatively. RESULTS: Total densitometry values of the total layer over the annular diameters 0-12 mm expressed in grayscale units (GSU) showed no significant change after t-ACXL and p-ACXL but increased significantly after c-ACXL at 1 month (16.76 ± 2.38, P value < 0.01) and 3 months (16.12 ± 2.22, P value 0.04), returning to baseline levels at month 6 (14.97 ± 2.13, P value 0.99) and remained stable until final follow-up. At 1 month, the mean change in total densitometry value of the t-ACXL group (-0.53 ± 2.08) was significantly lower than the p-ACXL (0.70 ± 1.96 P value 0.04) and c-ACXL (1.97 ± 2.65 P value < 0.01). There was no statistical difference in the mean change in total densitometry between the three groups from 6 to 24 months. In the c-ACXL group, a higher degree of CXL-induced corneal haze at 1 month was observed in patients with steeper preoperative keratometry readings and in individuals where a greater flattening effect was achieved at 24 months. CONCLUSIONS: Continuous epithelium-off accelerated cornea crosslinking appears to induce more corneal haze than pulsed epithelium-off and transepithelial pulsed cornea crosslinking in the early postoperative period. Differences resolve by six-months.
PURPOSE: To compare the corneal densitometry changes after transepithelial pulsed (t-ACXL), epithelium-off continuous (c-ACXL) and epithelium-off pulsed (p-ACXL), accelerated corneal crosslinking for patients with progressive keratoconus. METHODS: Prospective, interventional case series at a university hospital tertiary referral center. Forty eyes received t-ACXL, 40 eyes received c-ACXL, and 40 eyes received p-ACXL. Corneal tomography, densitometry and visual acuity were evaluated preoperatively and at 1, 3, 6, 12 and 24 months postoperatively. RESULTS: Total densitometry values of the total layer over the annular diameters 0-12 mm expressed in grayscale units (GSU) showed no significant change after t-ACXL and p-ACXL but increased significantly after c-ACXL at 1 month (16.76 ± 2.38, P value < 0.01) and 3 months (16.12 ± 2.22, P value 0.04), returning to baseline levels at month 6 (14.97 ± 2.13, P value 0.99) and remained stable until final follow-up. At 1 month, the mean change in total densitometry value of the t-ACXL group (-0.53 ± 2.08) was significantly lower than the p-ACXL (0.70 ± 1.96 P value 0.04) and c-ACXL (1.97 ± 2.65 P value < 0.01). There was no statistical difference in the mean change in total densitometry between the three groups from 6 to 24 months. In the c-ACXL group, a higher degree of CXL-induced corneal haze at 1 month was observed in patients with steeper preoperative keratometry readings and in individuals where a greater flattening effect was achieved at 24 months. CONCLUSIONS: Continuous epithelium-off accelerated cornea crosslinking appears to induce more corneal haze than pulsed epithelium-off and transepithelial pulsed cornea crosslinking in the early postoperative period. Differences resolve by six-months.