Do Hyung Lee

Han HC, et al. J Korean Ophthalmol Soc. 2013 Dec;54(12):1939-1944. http://dx.doi.org/10.3341/jkos.2013.54.12.1939

Hwang SJ, et al. J Korean Ophthalmol Soc. 2008 Oct;49(10):1597-1602. http://dx.doi.org/10.3341/jkos.2008.49.10.1597

To determine whether corneal tissue can be conserved with wavefront-guided ablation compared to conventional surgery with a larger ablation zone for attempted prevention of glare and halo. Department of Ophthalmology, Ilsan Paik Hospital, Inje University, Korea. This prospective study was composed of 2 parts: First, 40 eyes of 20 patients were studied to determine whether a larger optical ablation could be beneficial in prevention of glare after conventional laser in situ keratomileusis (LASIK) surgery. One eye in each patient was treated with a 6.00 mm optical zone, and the other with a 6.25 mm optical zone. Second, 20 eyes of 10 patients with a higher-order root mean square (RMS) value of 0.3 or greater were evaluated to learn whether a wavefront-guided ablation could be as effective as a larger conventional optical ablation. One eye in each patient was treated by conventional LASIK surgery with a 6.25 mm optical zone, and the other eye was treated by wavefront-guided LASIK surgery with a 6.00 mm optical zone. All patients were analyzed with a WASCA analyzer (Carl Zeiss Meditec) preoperatively, and 1 month and 3 months after surgery. Higher-order aberrations including coma, spherical aberration, and higher-order RMS were statistically significantly increased after conventional surgery with both a 6.00 mm and 6.25 mm optical zone. High-order aberrations including comaer-and spherical aberration after conventional surgery with 6.25 mm zone were statistically significantly increased. However, coma and higher-order RMS did not show a statistically significant increase between pre-LASIK and post-LASIK in wavefront-ablated eyes with a 6.00 mm optical zone. Wavefront ablation showed less increase of coma and higher-order RMS regardless of a smaller optical zone. This finding might provide a clinical clue for an advantage of wavefront-guided ablation from the standpoint of corneal tissue conservation.

Purpose: This study was performed to elucidate the role of nuclear factor-ĸB (NF-ĸB) in the death of corneal epithelial cells after ultraviolet (UV) irradiation. Methods: Simian virus 40-transfected human corneal epithelial cells (T-HCECs) were used in this study. Cell cultures were irradiated with a UVB (312 nm) source located 10 cm from the bottom of the slides for 10, 20, 30, or 40 s. Cytotoxicity was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Translocation of NF-ĸB was examined by immunocytochemistry using anti-NF-ĸB p65 antibody and electrophoretic mobility shift assay (EMSA). Sulfasalazine and SN-50, specific NF-ĸB inhibitors, were used to confirm the role of NF-ĸB by pretreating samples for 30 min before UV irradiation, after which cytotoxicity and NF-ĸB translocation were evaluated. Results: When T-HCECs were irradiated with UVB, translocation of NF-ĸB was observed with immunocytochemistry. These translocations peaked 2 h after UV irradiation during EMSA. When pretreated with sulfasalazine or SN-50, the translocation of NF-ĸB was blocked. Cellular death after UV irradiation was also markedly blocked by sulfasalazine. Conclusion: These findings suggest that NF-ĸB plays an important role in cellular death after UV irradiation.

To determine the role of nuclear factor kappa B (NF-κB) in the death of lens epithelial cells (LECs) after ultraviolet (UV) irradiation. Department of Ophthalmology, Ilsan Paik Hospital, Inje University, Korea. Cultures of simian virus 40 transfected human LECs (HLE B-3 cells) were were irradiated with a UVB source (312 nm) located 10 cm from the bottom of the slides for 1, 2, 3, or 4 minutes. Cytotoxicity was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide method. Translocation of NF-κB was examined by immunocytochemistry using anti-NF-κB p65 antibody and electrophoretic mobility shift assay (EMSA). Sulfasalazine, a specific NF-κB inhibitor, was used to confirm the role of NF-κB by pretreating samples for 30 minutes before UV irradiation, after which cytotoxicity and NF-κB translocation were evaluated. When HLE B-3 cells were irradiated with UVB, translocation of NF-κB was observed with immunocytochemistry. These translocations peaked during EMSA 6 hours after UV irradiation. In HLE B-3 cells pretreated with sulfasalazine, the translocation of NF-κB was blocked. Cellular death after UV irradiation was also markedly reduced by sulfasalazine pretreatment. Ultraviolet irradiation can translocate NF-κB, and sulfasalazine is a useful blocking agent in this pathway. In this experimental model, sulfasalazine prevented cellular death after UV irradiation. The findings suggest that NF-κB plays an important role in cellular death after UV irradiation.

To evaluate the forward shift of the posterior corneal surface after myopic laser in situ keratomileusis (LASIK) relative to the residual stromal bed thickness and the ablation percentage of the total corneal thickness. Department of Ophthalmology, Ilsan Paik Hospital, Inje University, Ilsan, Korea. Three hundred sixty-three eyes of 182 consecutive patients who had LASIK were examined retrospectively. The range of the refractive errors was -1.5 to -12.0 diopters. Corneal topography using Orbscan II (Bausch & Lomb) and pachymetry were obtained preoperatively and 1 week and 1, 2, and 3 months postoperatively. The patients were divided into 4 groups based on the residual stromal bed thickness: Group 1, 145 eyes with less than 250 microm; Group 2, 129 eyes with 250 to 300 microm; Group 3, 76 eyes with 300 to 350 microm; and Group 4, 13 eyes with more than 350 microm. They were also grouped by the ablation percentage per total corneal thickness: Group A, 16 eyes with less than 10%; Group B, 166 eyes with 10% to 20%; Group C, 146 eyes with 20% to 30%; and Group D, 35 eyes with more than 30%. The increase in the forward shift of the posterior corneal surface postoperatively correlated with the residual corneal bed thickness and the ablation ratio per total corneal thickness. There were no statistically significant changes in the postsurgical forward shift of the posterior corneal surface if the residual corneal thickness remained greater than 350 microm or the ablation percentage was less than 10%. Increased forward shift of the posterior corneal surface is common after myopic LASIK and correlates with the residual corneal thickness and the ablation percentage per total corneal thickness. An excessively thin residual corneal bed or a large ablation percentage may increase the risk of iatrogenic complications.

To evaluate the effect of a capsular tension ring (CTR) on the tilting and decentration of intraocular lenses (IOLs) after cataract surgery. Department of Ophthalmology, Ilsan Paik Hospital, Inje University, Kyunggyi-do, Korea. Cataract surgery was performed in both eyes of 20 patients ranging in age from 57 to 75 years. The 40 eyes were divided into 2 groups based on whether a CTR (Lucid Korea) was implanted. Each patient received a CTR in 1 eye only. All IOLs (AcrySof MA60BM, Alcon) were implanted in the capsular bag after a continuous curvilinear capsulorhexis smaller than the IOL optic was created and phacoemulsification performed. The extent of IOL tilting and decentration was measured with the EAS-1000 anterior eye segment analysis system 7, 30, and 60 days after surgery. The extent of IOL decentration was statistically significantly less in eyes with both an IOL and CTR than in those with an IOL only. The mean decentration in the CTR-IOL group was 0.38 mm +/- 0.16 (SD) at 7 days, 0.43 +/- 0.15 mm at 30 days, and 0.42 +/- 0.17 mm at 60 days. The mean values in the IOL-only group were 0.49 +/- 0.11 mm, 0.53 +/- 0.14 mm, and 0.57 +/- 0.16 mm, respectively. The amount of IOL tilting was also significantly less in the CTR-IOL group. The mean tilting in the CTR-IOL group was 2.22 +/- 0.46 degrees at 7 days, 2.36 +/- 0.50 degrees at 30 days, and 2.47 +/- 0.40 degrees at 60 days. The mean values in the IOL-only group were 3.14 +/- 0.65 degrees, 2.91 +/- 0.67 degrees, and 3.06 +/- 0.56 degrees, respectively. These results indicate that the CTR reduces undesirable postsurgical IOL movement for at least 60 days.