1.Long-term Effects and Prognostic Factors of Accelerated Cross-Linking with Retention Ring-assisted Riboflavin Application on Keratoconus Progression
Seonghwan KIM ; Won Jong CHOI ; Chang Ho YOON ; Mee Kum KIM
Korean Journal of Ophthalmology 2025;39(2):145-156
Purpose:
To evaluate the long-term efficacy, safety, and prognostic factors of pulsed-light accelerated corneal collagen cross-linking (A-CXL) with continuous riboflavin application to halt keratoconus progression
Methods:
A-CXL with retention ring-assisted continuous riboflavin application for either 10 or 5 minutes was performed in 37 eyes of 33 patients with progressive keratoconus between 2016 and 2020. Successful halting rates and prognostic factors of time-dependent changes in keratometric values, visual acuity, refractive errors, topographic indices, central corneal thickness, thinnest corneal thickness, irregularity at 3- and 5-mm zone, and endothelial cell density were evaluated.
Results:
Survival analysis showed successful halting rates of 71% and 89% in A-CXL with 5- and 10-minute–applied riboflavin, respectively. Best-corrected visual acuity significantly improved after A-CXL in both groups. Maximum keratometry decreased significantly from 52.52 to 50.39 diopters (p < 0.001) in the 10-minute group, while there was no significant decrease in the 5-minute group (52.77–51.80 diopters, p = 0.146). irregularity in 3- and 5-mm zone decreased significantly in the 10-minute group, while there was no difference in 5-minute group. Central corneal thickness and thinnest corneal thickness did not differ, and endothelial cell density changes were within acceptable ranges in both groups before and after the surgery. Among keratometric values, keratometric astigmatism was significantly related to posttreatment corneal flattening effect in multivariate regression analysis.
Conclusions
A-CXL with continuous riboflavin application for 10 minutes is an effective and safe treatment for preventing keratoconus progression. In addition, higher corneal astigmatism showed greater posttreatment corneal flattening effect in successfully treated patients.
2.Comparison of Toric Intraocular Lens Axis Accuracy between Optical Biometry and Dual Scheimpflug Topography
Seonghwan KIM ; Yengwoo SON ; Joon Young HYON
Korean Journal of Ophthalmology 2025;39(1):64-70
Purpose:
To evaluate the accuracy of toric intraocular lens (IOL) axis prediction between two preoperative measurement devices: the optical biometry (IOLMaster 500 or IOLMaster 700) and the dual Scheimpflug topography (Galilei G4)
Methods:
Medical records of 64 eyes from 44 patients who underwent phacoemulsification and posterior chamber toric IOL (Zeiss AT TORBI 709M) implantation between July 2017 and January 2022 were reviewed. All patients underwent preoperative evaluation by optical biometry (IOLMaster 500 or IOLMaster 700) and Galilei G4. The gold-standard axis that minimizes astigmatism was calculated by the online Toric Results Analyzer postoperatively and compared to the preoperative toric IOL axis calculated by the Z CALC Online IOL Calculator using parameters from either IOLMaster or Galilei G4. The axis error (AE) and the absolute AE (AAE) between the gold-standard axis and the preoperative calculated axis were analyzed to assess the accuracy of each device.
Results:
The mean flat keratometry and steep keratometry were 42.99 diopters (D) and 45.61 D, respectively, in IOLMaster, and 43.04 D and 45.51 D, respectively, in Galilei G4, which did not show any significant difference. The mean keratometric astigmatism was 2.62 D in IOLMaster and 2.46 D in Galilei G4, which also did not show any statistical difference. The keratometric astigmatism axis did not show any significant difference between IOLMaster and Galilei G4. The mean AE and AAE were 0.19° and 6.84°, respectively, by IOLMaster, and –0.80° and 7.98°, respectively, by Galilei G4. The AE and AAE by IOLMaster did not show any significant difference compared to those of Galilei G4 (p = 0.583, and p = 0.346, respectively).
Conclusions
This study suggests that the Galilei G4 demonstrated a similar level of accuracy to the IOLMaster in predicting the toric IOL axis, based on the gold-standard axis provided by the Toric Results Analyzer.
3.Long-term Effects and Prognostic Factors of Accelerated Cross-Linking with Retention Ring-assisted Riboflavin Application on Keratoconus Progression
Seonghwan KIM ; Won Jong CHOI ; Chang Ho YOON ; Mee Kum KIM
Korean Journal of Ophthalmology 2025;39(2):145-156
Purpose:
To evaluate the long-term efficacy, safety, and prognostic factors of pulsed-light accelerated corneal collagen cross-linking (A-CXL) with continuous riboflavin application to halt keratoconus progression
Methods:
A-CXL with retention ring-assisted continuous riboflavin application for either 10 or 5 minutes was performed in 37 eyes of 33 patients with progressive keratoconus between 2016 and 2020. Successful halting rates and prognostic factors of time-dependent changes in keratometric values, visual acuity, refractive errors, topographic indices, central corneal thickness, thinnest corneal thickness, irregularity at 3- and 5-mm zone, and endothelial cell density were evaluated.
Results:
Survival analysis showed successful halting rates of 71% and 89% in A-CXL with 5- and 10-minute–applied riboflavin, respectively. Best-corrected visual acuity significantly improved after A-CXL in both groups. Maximum keratometry decreased significantly from 52.52 to 50.39 diopters (p < 0.001) in the 10-minute group, while there was no significant decrease in the 5-minute group (52.77–51.80 diopters, p = 0.146). irregularity in 3- and 5-mm zone decreased significantly in the 10-minute group, while there was no difference in 5-minute group. Central corneal thickness and thinnest corneal thickness did not differ, and endothelial cell density changes were within acceptable ranges in both groups before and after the surgery. Among keratometric values, keratometric astigmatism was significantly related to posttreatment corneal flattening effect in multivariate regression analysis.
Conclusions
A-CXL with continuous riboflavin application for 10 minutes is an effective and safe treatment for preventing keratoconus progression. In addition, higher corneal astigmatism showed greater posttreatment corneal flattening effect in successfully treated patients.
4.Comparison of Toric Intraocular Lens Axis Accuracy between Optical Biometry and Dual Scheimpflug Topography
Seonghwan KIM ; Yengwoo SON ; Joon Young HYON
Korean Journal of Ophthalmology 2025;39(1):64-70
Purpose:
To evaluate the accuracy of toric intraocular lens (IOL) axis prediction between two preoperative measurement devices: the optical biometry (IOLMaster 500 or IOLMaster 700) and the dual Scheimpflug topography (Galilei G4)
Methods:
Medical records of 64 eyes from 44 patients who underwent phacoemulsification and posterior chamber toric IOL (Zeiss AT TORBI 709M) implantation between July 2017 and January 2022 were reviewed. All patients underwent preoperative evaluation by optical biometry (IOLMaster 500 or IOLMaster 700) and Galilei G4. The gold-standard axis that minimizes astigmatism was calculated by the online Toric Results Analyzer postoperatively and compared to the preoperative toric IOL axis calculated by the Z CALC Online IOL Calculator using parameters from either IOLMaster or Galilei G4. The axis error (AE) and the absolute AE (AAE) between the gold-standard axis and the preoperative calculated axis were analyzed to assess the accuracy of each device.
Results:
The mean flat keratometry and steep keratometry were 42.99 diopters (D) and 45.61 D, respectively, in IOLMaster, and 43.04 D and 45.51 D, respectively, in Galilei G4, which did not show any significant difference. The mean keratometric astigmatism was 2.62 D in IOLMaster and 2.46 D in Galilei G4, which also did not show any statistical difference. The keratometric astigmatism axis did not show any significant difference between IOLMaster and Galilei G4. The mean AE and AAE were 0.19° and 6.84°, respectively, by IOLMaster, and –0.80° and 7.98°, respectively, by Galilei G4. The AE and AAE by IOLMaster did not show any significant difference compared to those of Galilei G4 (p = 0.583, and p = 0.346, respectively).
Conclusions
This study suggests that the Galilei G4 demonstrated a similar level of accuracy to the IOLMaster in predicting the toric IOL axis, based on the gold-standard axis provided by the Toric Results Analyzer.
5.Long-term Effects and Prognostic Factors of Accelerated Cross-Linking with Retention Ring-assisted Riboflavin Application on Keratoconus Progression
Seonghwan KIM ; Won Jong CHOI ; Chang Ho YOON ; Mee Kum KIM
Korean Journal of Ophthalmology 2025;39(2):145-156
Purpose:
To evaluate the long-term efficacy, safety, and prognostic factors of pulsed-light accelerated corneal collagen cross-linking (A-CXL) with continuous riboflavin application to halt keratoconus progression
Methods:
A-CXL with retention ring-assisted continuous riboflavin application for either 10 or 5 minutes was performed in 37 eyes of 33 patients with progressive keratoconus between 2016 and 2020. Successful halting rates and prognostic factors of time-dependent changes in keratometric values, visual acuity, refractive errors, topographic indices, central corneal thickness, thinnest corneal thickness, irregularity at 3- and 5-mm zone, and endothelial cell density were evaluated.
Results:
Survival analysis showed successful halting rates of 71% and 89% in A-CXL with 5- and 10-minute–applied riboflavin, respectively. Best-corrected visual acuity significantly improved after A-CXL in both groups. Maximum keratometry decreased significantly from 52.52 to 50.39 diopters (p < 0.001) in the 10-minute group, while there was no significant decrease in the 5-minute group (52.77–51.80 diopters, p = 0.146). irregularity in 3- and 5-mm zone decreased significantly in the 10-minute group, while there was no difference in 5-minute group. Central corneal thickness and thinnest corneal thickness did not differ, and endothelial cell density changes were within acceptable ranges in both groups before and after the surgery. Among keratometric values, keratometric astigmatism was significantly related to posttreatment corneal flattening effect in multivariate regression analysis.
Conclusions
A-CXL with continuous riboflavin application for 10 minutes is an effective and safe treatment for preventing keratoconus progression. In addition, higher corneal astigmatism showed greater posttreatment corneal flattening effect in successfully treated patients.
6.Comparison of Toric Intraocular Lens Axis Accuracy between Optical Biometry and Dual Scheimpflug Topography
Seonghwan KIM ; Yengwoo SON ; Joon Young HYON
Korean Journal of Ophthalmology 2025;39(1):64-70
Purpose:
To evaluate the accuracy of toric intraocular lens (IOL) axis prediction between two preoperative measurement devices: the optical biometry (IOLMaster 500 or IOLMaster 700) and the dual Scheimpflug topography (Galilei G4)
Methods:
Medical records of 64 eyes from 44 patients who underwent phacoemulsification and posterior chamber toric IOL (Zeiss AT TORBI 709M) implantation between July 2017 and January 2022 were reviewed. All patients underwent preoperative evaluation by optical biometry (IOLMaster 500 or IOLMaster 700) and Galilei G4. The gold-standard axis that minimizes astigmatism was calculated by the online Toric Results Analyzer postoperatively and compared to the preoperative toric IOL axis calculated by the Z CALC Online IOL Calculator using parameters from either IOLMaster or Galilei G4. The axis error (AE) and the absolute AE (AAE) between the gold-standard axis and the preoperative calculated axis were analyzed to assess the accuracy of each device.
Results:
The mean flat keratometry and steep keratometry were 42.99 diopters (D) and 45.61 D, respectively, in IOLMaster, and 43.04 D and 45.51 D, respectively, in Galilei G4, which did not show any significant difference. The mean keratometric astigmatism was 2.62 D in IOLMaster and 2.46 D in Galilei G4, which also did not show any statistical difference. The keratometric astigmatism axis did not show any significant difference between IOLMaster and Galilei G4. The mean AE and AAE were 0.19° and 6.84°, respectively, by IOLMaster, and –0.80° and 7.98°, respectively, by Galilei G4. The AE and AAE by IOLMaster did not show any significant difference compared to those of Galilei G4 (p = 0.583, and p = 0.346, respectively).
Conclusions
This study suggests that the Galilei G4 demonstrated a similar level of accuracy to the IOLMaster in predicting the toric IOL axis, based on the gold-standard axis provided by the Toric Results Analyzer.
7.The SIRT6 Activator MDL-800 Inhibits PPARα and Fatty acid Oxidation-Related Gene Expression in Hepatocytes
Yeonsoo KIM ; Hyeokjin LIM ; Ye Eun CHO ; Seonghwan HWANG
Biomolecules & Therapeutics 2025;33(3):438-446
A histone deacetylase SIRT6 regulates the transcription of various genes involved in lipid metabolism. Fatty acid (FA) oxidation plays a pivotal role in maintaining hepatic lipid homeostasis, and its dysregulation significantly contributes to lipotoxicity and inflammation, driving the progression of steatotic liver disease. While SIRT6 is known to activate peroxisome proliferator-activated receptor-alpha (PPARα), a central regulator of FA oxidation, the development of SIRT6 activators capable of enhancing FA oxidation and mitigating steatotic liver disease has yet to be achieved. This study evaluated the effect of MDL-800, a selective SIRT6 activator, on the expression of PPARα and genes related to FA oxidation. In AML12 mouse hepatocytes, MDL-800 treatment activated SIRT6 but unexpectedly decreased the expression of PPARα and its FA oxidation-associated target genes. Furthermore, OSS128167, a selective SIRT6 inhibitor, did not reverse the suppressive effects of MDL-800 on PPARα, suggesting that MDL-800 downregulates PPARα and FA oxidation-related genes through a mechanism independent of SIRT6 activation. Mechanistic investigations revealed that MDL-800 increased the production of reactive oxygen species and activated stress kinases. The inhibition of PPARα by MDL-800 was reversed by co-treatment with the antioxidant N-acetylcysteine or the JNK inhibitor SP600125.In summary, MDL-800 suppresses PPARα and FA oxidation-related genes primarily through the induction of oxidative stress in hepatocytes, independent of its role as a SIRT6 activator.
8.Long-term Effects and Prognostic Factors of Accelerated Cross-Linking with Retention Ring-assisted Riboflavin Application on Keratoconus Progression
Seonghwan KIM ; Won Jong CHOI ; Chang Ho YOON ; Mee Kum KIM
Korean Journal of Ophthalmology 2025;39(2):145-156
Purpose:
To evaluate the long-term efficacy, safety, and prognostic factors of pulsed-light accelerated corneal collagen cross-linking (A-CXL) with continuous riboflavin application to halt keratoconus progression
Methods:
A-CXL with retention ring-assisted continuous riboflavin application for either 10 or 5 minutes was performed in 37 eyes of 33 patients with progressive keratoconus between 2016 and 2020. Successful halting rates and prognostic factors of time-dependent changes in keratometric values, visual acuity, refractive errors, topographic indices, central corneal thickness, thinnest corneal thickness, irregularity at 3- and 5-mm zone, and endothelial cell density were evaluated.
Results:
Survival analysis showed successful halting rates of 71% and 89% in A-CXL with 5- and 10-minute–applied riboflavin, respectively. Best-corrected visual acuity significantly improved after A-CXL in both groups. Maximum keratometry decreased significantly from 52.52 to 50.39 diopters (p < 0.001) in the 10-minute group, while there was no significant decrease in the 5-minute group (52.77–51.80 diopters, p = 0.146). irregularity in 3- and 5-mm zone decreased significantly in the 10-minute group, while there was no difference in 5-minute group. Central corneal thickness and thinnest corneal thickness did not differ, and endothelial cell density changes were within acceptable ranges in both groups before and after the surgery. Among keratometric values, keratometric astigmatism was significantly related to posttreatment corneal flattening effect in multivariate regression analysis.
Conclusions
A-CXL with continuous riboflavin application for 10 minutes is an effective and safe treatment for preventing keratoconus progression. In addition, higher corneal astigmatism showed greater posttreatment corneal flattening effect in successfully treated patients.
9.Comparison of Toric Intraocular Lens Axis Accuracy between Optical Biometry and Dual Scheimpflug Topography
Seonghwan KIM ; Yengwoo SON ; Joon Young HYON
Korean Journal of Ophthalmology 2025;39(1):64-70
Purpose:
To evaluate the accuracy of toric intraocular lens (IOL) axis prediction between two preoperative measurement devices: the optical biometry (IOLMaster 500 or IOLMaster 700) and the dual Scheimpflug topography (Galilei G4)
Methods:
Medical records of 64 eyes from 44 patients who underwent phacoemulsification and posterior chamber toric IOL (Zeiss AT TORBI 709M) implantation between July 2017 and January 2022 were reviewed. All patients underwent preoperative evaluation by optical biometry (IOLMaster 500 or IOLMaster 700) and Galilei G4. The gold-standard axis that minimizes astigmatism was calculated by the online Toric Results Analyzer postoperatively and compared to the preoperative toric IOL axis calculated by the Z CALC Online IOL Calculator using parameters from either IOLMaster or Galilei G4. The axis error (AE) and the absolute AE (AAE) between the gold-standard axis and the preoperative calculated axis were analyzed to assess the accuracy of each device.
Results:
The mean flat keratometry and steep keratometry were 42.99 diopters (D) and 45.61 D, respectively, in IOLMaster, and 43.04 D and 45.51 D, respectively, in Galilei G4, which did not show any significant difference. The mean keratometric astigmatism was 2.62 D in IOLMaster and 2.46 D in Galilei G4, which also did not show any statistical difference. The keratometric astigmatism axis did not show any significant difference between IOLMaster and Galilei G4. The mean AE and AAE were 0.19° and 6.84°, respectively, by IOLMaster, and –0.80° and 7.98°, respectively, by Galilei G4. The AE and AAE by IOLMaster did not show any significant difference compared to those of Galilei G4 (p = 0.583, and p = 0.346, respectively).
Conclusions
This study suggests that the Galilei G4 demonstrated a similar level of accuracy to the IOLMaster in predicting the toric IOL axis, based on the gold-standard axis provided by the Toric Results Analyzer.
10.The SIRT6 Activator MDL-800 Inhibits PPARα and Fatty acid Oxidation-Related Gene Expression in Hepatocytes
Yeonsoo KIM ; Hyeokjin LIM ; Ye Eun CHO ; Seonghwan HWANG
Biomolecules & Therapeutics 2025;33(3):438-446
A histone deacetylase SIRT6 regulates the transcription of various genes involved in lipid metabolism. Fatty acid (FA) oxidation plays a pivotal role in maintaining hepatic lipid homeostasis, and its dysregulation significantly contributes to lipotoxicity and inflammation, driving the progression of steatotic liver disease. While SIRT6 is known to activate peroxisome proliferator-activated receptor-alpha (PPARα), a central regulator of FA oxidation, the development of SIRT6 activators capable of enhancing FA oxidation and mitigating steatotic liver disease has yet to be achieved. This study evaluated the effect of MDL-800, a selective SIRT6 activator, on the expression of PPARα and genes related to FA oxidation. In AML12 mouse hepatocytes, MDL-800 treatment activated SIRT6 but unexpectedly decreased the expression of PPARα and its FA oxidation-associated target genes. Furthermore, OSS128167, a selective SIRT6 inhibitor, did not reverse the suppressive effects of MDL-800 on PPARα, suggesting that MDL-800 downregulates PPARα and FA oxidation-related genes through a mechanism independent of SIRT6 activation. Mechanistic investigations revealed that MDL-800 increased the production of reactive oxygen species and activated stress kinases. The inhibition of PPARα by MDL-800 was reversed by co-treatment with the antioxidant N-acetylcysteine or the JNK inhibitor SP600125.In summary, MDL-800 suppresses PPARα and FA oxidation-related genes primarily through the induction of oxidative stress in hepatocytes, independent of its role as a SIRT6 activator.

Result Analysis
Print
Save
E-mail