Purpose:To study variation in central corneal thickness (CCT) during corneal collagen cross-linking(CXL) using ultrasound pachymetry. Methods:Twenty patients (26 eyes) with progressing keratoconus undergoing riboflavi...Purpose:To study variation in central corneal thickness (CCT) during corneal collagen cross-linking(CXL) using ultrasound pachymetry. Methods:Twenty patients (26 eyes) with progressing keratoconus undergoing riboflavin-UVA-induced CXL were involved in this study. Intraoperative CCT measurement using ultrasonic pachymetry was performed during the procedure.Measurements were obtained before operation, after epithelial removal, after riboflavin drop instillation, and after UVA irradiation. Results:Mean CCT was 495±56 and 450±52 μm before and after epithelial removal, respectively. Mean CCT was 443±42 and 411±39 μm after riboflavin drop instillation and after UVA irradiation, respectively. Statistically significant decreases in CCT occurred between the preoperative period and after epithelial removal, after riboflavin drop instillation and after UVA irradiation. Twenty-six eyes from 20 patients undergoing CXL were divided into 2 groups (I with CCT≥400 μm after UVA irradiation and II with CCT<400 μm after UVA irradiation). No statistically significant difference was noted between I and II in preoperative endothelial cell count, but a statistically greater postoperative endothelial cell count was noted in I compared to II. A statistically significant difference was evident between preoperative and postoperative endothelial cell counts in Group II (P<0.05). Conclusion:Performing CXL with the use of riboflavin and UVA irradiation resulted in a statistically significant decrease in CCT, to a level where the corneal endothelium may be damaged.(Eye Science 2013; 28:15-19)展开更多
Purpose:To assess the effect of having an open or closed eye on the variation in central corneal thickness during riboflavin instillation for corneal collagen cross-linking (CXL).Methods:.Thirty eyes of 15 New Zealand...Purpose:To assess the effect of having an open or closed eye on the variation in central corneal thickness during riboflavin instillation for corneal collagen cross-linking (CXL).Methods:.Thirty eyes of 15 New Zealand White rabbits underwent an in vivo anterior segment optical coherence tomography (OCT) examination at 0,10,20,and 30 min after riboflavin instillation on the de-epithelialized corneal surface.Each eye of every rabbit was randomly placed into one of two different treatment groups(open-eye or closed-eye)during the instillation;.the examinations were performed one after the other.After instillation for 30 min,the changes in the corneal stroma and anterior chamber were observed by slit lamp.Results:.A significant decrease in the central corneal thickness(CCT).was demonstrated during riboflavin instillation;.the variations were smaller in the measurements performed with the eye closed than with the eye open.(81.36±15.13μm and129.20±12.05μm respectively)..Both methods turned the corneal stroma and anterior chamber yellow.Conclusion:Keeping the eye closed during riboflavin instillation reduced the decrease in the CCT..The same yellow change in the corneal stroma and anterior chamber occurred,but the exposure time of the ocular surface was shorter.Therefore,.keeping the eye closed was a more effective and safer method than keeping the eye open.展开更多
文摘Purpose:To study variation in central corneal thickness (CCT) during corneal collagen cross-linking(CXL) using ultrasound pachymetry. Methods:Twenty patients (26 eyes) with progressing keratoconus undergoing riboflavin-UVA-induced CXL were involved in this study. Intraoperative CCT measurement using ultrasonic pachymetry was performed during the procedure.Measurements were obtained before operation, after epithelial removal, after riboflavin drop instillation, and after UVA irradiation. Results:Mean CCT was 495±56 and 450±52 μm before and after epithelial removal, respectively. Mean CCT was 443±42 and 411±39 μm after riboflavin drop instillation and after UVA irradiation, respectively. Statistically significant decreases in CCT occurred between the preoperative period and after epithelial removal, after riboflavin drop instillation and after UVA irradiation. Twenty-six eyes from 20 patients undergoing CXL were divided into 2 groups (I with CCT≥400 μm after UVA irradiation and II with CCT<400 μm after UVA irradiation). No statistically significant difference was noted between I and II in preoperative endothelial cell count, but a statistically greater postoperative endothelial cell count was noted in I compared to II. A statistically significant difference was evident between preoperative and postoperative endothelial cell counts in Group II (P<0.05). Conclusion:Performing CXL with the use of riboflavin and UVA irradiation resulted in a statistically significant decrease in CCT, to a level where the corneal endothelium may be damaged.(Eye Science 2013; 28:15-19)
文摘Purpose:To assess the effect of having an open or closed eye on the variation in central corneal thickness during riboflavin instillation for corneal collagen cross-linking (CXL).Methods:.Thirty eyes of 15 New Zealand White rabbits underwent an in vivo anterior segment optical coherence tomography (OCT) examination at 0,10,20,and 30 min after riboflavin instillation on the de-epithelialized corneal surface.Each eye of every rabbit was randomly placed into one of two different treatment groups(open-eye or closed-eye)during the instillation;.the examinations were performed one after the other.After instillation for 30 min,the changes in the corneal stroma and anterior chamber were observed by slit lamp.Results:.A significant decrease in the central corneal thickness(CCT).was demonstrated during riboflavin instillation;.the variations were smaller in the measurements performed with the eye closed than with the eye open.(81.36±15.13μm and129.20±12.05μm respectively)..Both methods turned the corneal stroma and anterior chamber yellow.Conclusion:Keeping the eye closed during riboflavin instillation reduced the decrease in the CCT..The same yellow change in the corneal stroma and anterior chamber occurred,but the exposure time of the ocular surface was shorter.Therefore,.keeping the eye closed was a more effective and safer method than keeping the eye open.
