Tommy C Y Chan1,2, Jason C K Chan1,2, Yu Meng Wang2, Christopher J Rapuano3. 1. Hong Kong Eye Hospital, Kowloon, Hong Kong, China. 2. Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China. 3. Cornea Service, Wills Eye Hospital, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA.
Abstract
PURPOSE: To evaluate the history of densitometric data in patients with keratoconus undergoing corneal cross-linking. METHODS: Twenty-two eyes of 22 patients with keratoconus were included. Corneal tomography and densitometry measurements were performed before and after accelerated corneal cross-linking. The duration of corneal haze was defined as the time between cross-linking and densitometry measurements returning to the preoperative value. Survival analysis of corneal haze after cross-linking was performed. Preoperative and postoperative corneal densitometry, maximum keratometry (Kmax), and central corneal thickness were compared. RESULTS: The duration of corneal haze was 18.2 ± 3.8 months at the first zone of 0 to 2 mm and 10.9 ± 2.5 months at the second zone of 2 to 6 mm. There was no change in Kmax between the preoperative period and the time at which corneal haze resolved (P = 0.394 at the first zone; P = 0.658 at the second zone). Compared with the measurement taken at resolution of corneal haze, Kmax at 1 year after haze resolution was lower (62.0 ± 9.9 D to 61.2 ± 9.9 D, P = 0.008 at the first zone; 63.6 ± 10.9 D to 62.5 ± 10.1 D, P = 0.016 at the second zone). There was a decrease of central corneal thickness between the preoperative period and the time at which corneal haze resolved (470.8 ± 34.1 μm to 464.8 ± 34.5 μm, P = 0.047 at the first zone; 465.0 ± 35.3 μm to 454.7 ± 37.2 μm, P = 0.001 at the second zone), but it remained unchanged after haze resolution (P = 0.146 at the first zone; P = 0.067 at the second zone). CONCLUSIONS: Corneal cross-linking halted keratoconus progression when detectable haze was present. There was continuous corneal flattening measured at 1 year after haze resolution. Thinning of the cornea was seen only when haze was detectable after cross-linking.
PURPOSE: To evaluate the history of densitometric data in patients with keratoconus undergoing corneal cross-linking. METHODS: Twenty-two eyes of 22 patients with keratoconus were included. Corneal tomography and densitometry measurements were performed before and after accelerated corneal cross-linking. The duration of corneal haze was defined as the time between cross-linking and densitometry measurements returning to the preoperative value. Survival analysis of corneal haze after cross-linking was performed. Preoperative and postoperative corneal densitometry, maximum keratometry (Kmax), and central corneal thickness were compared. RESULTS: The duration of corneal haze was 18.2 ± 3.8 months at the first zone of 0 to 2 mm and 10.9 ± 2.5 months at the second zone of 2 to 6 mm. There was no change in Kmax between the preoperative period and the time at which corneal haze resolved (P = 0.394 at the first zone; P = 0.658 at the second zone). Compared with the measurement taken at resolution of corneal haze, Kmax at 1 year after haze resolution was lower (62.0 ± 9.9 D to 61.2 ± 9.9 D, P = 0.008 at the first zone; 63.6 ± 10.9 D to 62.5 ± 10.1 D, P = 0.016 at the second zone). There was a decrease of central corneal thickness between the preoperative period and the time at which corneal haze resolved (470.8 ± 34.1 μm to 464.8 ± 34.5 μm, P = 0.047 at the first zone; 465.0 ± 35.3 μm to 454.7 ± 37.2 μm, P = 0.001 at the second zone), but it remained unchanged after haze resolution (P = 0.146 at the first zone; P = 0.067 at the second zone). CONCLUSIONS: Corneal cross-linking halted keratoconus progression when detectable haze was present. There was continuous corneal flattening measured at 1 year after haze resolution. Thinning of the cornea was seen only when haze was detectable after cross-linking.
Authors: Kristin E Hirabayashi; Winston Chamberlain; Jennifer Rose-Nussbaumer; Ariana Austin; Laurel Stell; Charles C Lin Journal: Cornea Date: 2020-06 Impact factor: 2.651
Authors: Katja C Iselin; Philipp B Baenninger; Lucas M Bachmann; Frank Bochmann; Michael A Thiel; Claude Kaufmann Journal: Eye Vis (Lond) Date: 2020-03-03