No abstract available.
Myopia* ; Refractive Surgical Procedures*

Objectives: This study evaluated the efficacy and safety of an angle-supported phakic intraocular lens (PIOL) for the treatment of moderate to high myopia. Methods : This is a case series of 13 eyes of 8 patients with moderate to high myopia that underwent implantation of an acrylic, angle-supported PIOL. The main outcome measures were manifest refraction, uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), endothelial-cell count (ECC), intraocular pressure (IOP), and adverse events. Results: The mean spherical equivalent (SE) improved from –11.79 ± 4.12 diopters (D) preoperatively to –0.08 ± 0.58 D postoperatively (p = 0.000), UCVA from 0.016 ± 0.015 to 0.79 ± 0.29 postoperatively (p = 0.000), and BCVA from 0.76 ± 0.33 to 0.86 ± 0.27 (p = 0.017). The ECC slightly decreased from 3033.57 ± 367.71 cells/mm2 preoperatively to 2947 ± 279.86 cells/mm2 (2.8% loss) postoperatively (p = 0.400). The mean preoperative IOP was 16.36 ± 3.53 mm Hg while the mean three-month postoperative IOP was 15.72 ± 4.15 mm Hg (p = 0.659). Two (15%) eyes experienced transient postoperative IOP rise on the day of the surgery, which resolved by postoperative day 1 using topical timolol maleate. The mean follow-up was 2.54 ± 1.39 months (range, 1 to 5 months). Conclusion Acrylic angle-supported phakic intraocular lens (PIOL) implantation is an effective and safe method of correcting moderate to high myopia.
Refractive Surgical Procedures

PURPOSE: To report the evaluation and comparison of true corneal power after corneal refractive surgery through ARK, Orbscan II(R), Pentacam and IOL master. METHODS: Target IOL (Intraocular lens) power calculated with the SRK/T formula using SMK (Sungmo Eye Hospital keratometry), which is a new method for measuring corneal refractive power, was compared with the back-calculated ideal IOL power after cataract surgery for 30 eyes that required cataract surgery and had previously undergone refractive surgery. Target IOL powers calculated using 4 systems were compared with IOL power calculated using the clinical history method for 64 eyes that had undergone refractive surgery. RESULTS: Using SMK with the SRK/T formula, the actual refraction was within +/-0.5 diopter (D) of the intended refraction for 63.8% of eyes and within +/-1.0 D for 90.9% of eyes. Compared with target IOL power calculated with the clinical history method, target IOL power calculated by SMK with the SRK/T formula had a difference of 1.95 +/- 0.86 D, which was similar to the results calculated by the Haigis-L formula and by TNP with Haigis. CONCLUSIONS: The method of IOL calculation using SMK with the SRK/T formula showed the best predictability in patients after corneal refractive surgery. Comparatively accurate results were produced in IOL power calculations using the Haigis-L formula, and the TNP with Haigis method.
Cataract* ; Humans ; Refractive Surgical Procedures

Purpose: To connect didactic learning to clinical application is a challenging task both for the teachers and students. Target-Oriented Clinical Skill Enhancement (TOCSE) is a teaching and learning tool that integrates basic medical sciences at the clinical level. The authors sought to determine if TOCSE is effective in bridging didactic knowledge to clinical skill and enhancing the clinical performance of fourth year medical students.

Method: Between March 2021 and June 2021, in an online platform, the authors randomly allocated 141 fourth year medical students into the experimental (n=12 groups; n=63) and control groups (n=12 groups; n=78). Participants in the experimental group underwent the TOCSE module workshop while the control group utilized the standard method of teaching. The actively teaching faculty staff blinded of group allocation were invited to assess case presentations using a standardized rubric. A survey was done by the students (experimental and control) to evaluate how they perceived TOCSE to their performance and learning. Independent parametric t-test was performed to compare the clinical skill scores between the two groups.

Results: The experimental group had a mean clinical skill score of 35.29 (SD=2.64, excellent) while the control group had a mean clinical skill score of 31.96 (SD=4.04, satisfactory). The between-group comparisons using independent t-test indicated that the mean difference of -3.33 clinical skills scores between the experimental and control groups was statistically significant (t=-2.39, p=0.026, 95% CI=-6.22 to -0.45). Moreover, the perceived usefulness score (scale 10 as highest) among the TOCSE presenters (experimental groups) was 8.43 (SD=0.84) and scores among the TOCSE audience (control groups) was comparable at 8.36 (SD=0.71), both of which were interpreted as very helpful.

Conclusion: TOCSE is effective in bridging didactic knowledge to clinical skill and enhancing clinical performance of fourth year medical students.

PURPOSE: To report the distribution of ocular higher-order aberrations in candidates for refractive surgery measured by Zywave(R) II aberrometer. METHODS: The present study included 232 eyes of 116 subjects. Ocular aberration data were obtained by measurements per eye using Zywave(R) II aberrometer. The mean Zywave spherical equivalent (SE) and higher order aberrations (HOAs) calculated in the central 6-mm zone and expressed as root mean square (RMS) values were analyzed. Correlation analysis was performed to assess the association between ocular HOAs and gender, age, SE refractive error, or central corneal thickness (CCT) and investigate the aberration symmetry between right and left eyes. RESULTS: The average SE was-4.67 +/- 1.83 diopters (D). The mean RMS values of total HOA, 3rd, 4th or 5th summated HOAs, coma, trefoil and spherical aberration (SA) were 0.421 +/- 0.201 microm, 0.346 +/-0.206 microm, 0.202 +/- 0.105 microm, 0.087 +/- 0.048 microm, 0.241 +/- 0.172 microm, 0.225 +/- 0.154 microm and 0.136 +/- 0.102 microm, respectively. There was no significant differences of the mean total HOA, summated HOAs, coma, trefoil and SA between genders, age and refractive errors, but the 3rd order trefoil was strongly related with myopia (r = -0.900, p = 0.008). There was symmetry of ocular aberrations between both eyes and the ocular aberrations were not correlated with CCT. CONCLUSIONS: Herein, we report the normative distribution of ocular aberrations in the myopic Korean population measured by Zywave(R) II aberrometer. The 3rd order trefoil and myopia were correlated and mirror symmetry was observed between right and left eyes.
Aniline Compounds ; Coma ; Lotus ; Myopia ; Refractive Errors ; Refractive Surgical Procedures*

Corneal thickness is not only a major indicator of corneal diseases but an important parameter for the safety and the prevention of complications in various refractive surgeries widely performed nowadays.Therefore, we tried to acquire the basic data of corneal thickness in normal Koreans through this study. Central corneal thickness was measured using ultrasonic pachymeter in 460 eyes of 238 normal Koreans and analyzed according to the difference in age, sex, left &right, refractive error, and mean keratometry.Mean CCT was 529.67+/-32.18 micrometer.There is no statistically significant difference in CCT according to the difference in age, sex, left and right, refractive error, and mean keratometry in normal Koreans.
Corneal Diseases ; Refractive Errors ; Refractive Surgical Procedures ; Ultrasonics*

PURPOSE: To investigate the accuracy of Orbscan system in measuring corneal thickness before refractive surgery, the authors conducted a comparative study of Orbscan system and ultrasonic pachymeter in their agreement and repeatability. METHODS: 84 patients (168 eyes) who were examined between December, 2000 and March, 2001 were divided into two groups: those who exceeded -6.00 D, and those who did not. Orbscan and ultrasonic pachymeter were employed. Correlation and regression were analyzed to assess their agreement. The repeatability was measured by analyzing mean, standard deviation, and 95% confidence interval of each method. RESULTS: The average central corneal thickness was 542.3+/-34.2micro meter by Orbscan system, and 528.6+/-29.7micro meter by ultrasonic pachymeter. Correlation coefficient was nearly 1 between them, and therefore we obtained statistically significant linear regression equation. In the analysis of repeatability, 95% confidence interval of Orbscan system was -17.2micro meter~+11.8micro meter which was superior to the interval of ultrasonic pachymeter (-23.2micro meter~+14.4micro meter). CONCLUSION: Orbscan system measurements of corneal thickness was greater than ultrasonic pachymeter measurements by 9 to 19 m. Because Orbscan system also showed superiority in repeatability, it may be a useful method in the clinical field.
Humans ; Linear Models ; Refractive Surgical Procedures ; Ultrasonics

PURPOSE: To investigate clinical availability of AL-Scan(TM) (Nidek, Gamagori, Japan) by comparing corneal refractive power with AL-Scan(TM), Autokeratometer(TM) (Topcon KR-1, Tokyo, Japan) and Pentacam(TM) (Oculus, Wetzlar, Germany) devices. METHODS: Seventy-one patients (142 eyes) who visited our hospital for refractive surgery were tested using AL-Scan(R), Autokeratometer and Pentacam(R) and corneal refractive power was compared among devices. RESULTS: When comparing measurements with AL-Scan(R), Autokeratometer and Pentacam(R), the mean corneal refractive power was 43.37 +/- 1.32 D (2.4 mm zone), 43.35 +/- 1.32 D (3.3 mm zone), 43.36 +/- 1.35 D, and 43.35 +/- 1.36 D respectively and showed no significant differences. Corneal refractive power had strongly positive linear correlation (p < 0.001) and Bland-Altman plots showed high degree of agreement among AL-Scan(R), Autokeratometer and Pentacam(R) devices. CONCLUSIONS: Because measuring ocular biometry with AL-Scan(R) including axial length, intraocular lens power calculation and topography simultaneously is possible, clinical use is convenient. Corneal refractive power was not different when compared with autokeratometer and Pentacam(R) devices, thus, AL-Scan(R) can be used in the clinical environment.
Biometry ; Humans ; Lenses, Intraocular ; Refractive Surgical Procedures

PURPOSE: To evaluate the reproducibility and repeatibility of biometry in cataractous eyes, pseudophakic eyes and eyes having undergone refractive surgery. The OcuScan(R)RxP, LENSTAR(R) and IOL Master(R) instruments were compared, as were. The accuracies of the refractive results after cataract surgery. METHODS: The biometries of 45 cataractous eyes, 31 pseudophakic eyes, and 32 eyes having undergone refractive surgery were measured by two practitioners using OcuScan(R)RxP, LENSTAR(R) and IOL Master(R) instruments. The paired t-test was used to compare the reproducibilities in the three groups. RESULTS: There were no differences in axial length among the groups when using any of the instruments. There was no significant difference in the repeatibility regardless of the instrument used, although. In the cataractous eyes, pseudophakic eyes and eyes with refractive surgery, OcuScan(R)RxP showed the highest repeatability. However, we knew that all three instruments were excellent in the repeatability because the difference was less than 1.5%. The Prediction error of the instruments with regard to refractive results could not be determined after cataract surgery. In some patients with severe cataract, measurement was impossible for both the LENSTAR(R) and IOL Master(R) instruments. CONCLUSIONS: In all groups, OcuScan(R)RxP, LENSTAR(R) and IOL Master(R) showed no significant differences with regard to reproducibility or prediction of refractive power after surgery. Among three groups, the repeatability was rather high in the existing ultrasound method than in the partial coherence interferometers. In some patients with severe cataract, measurement was impossible for both the LENSTAR(R) and IOL Master(R) instruments.
Biometry ; Cataract ; Eye ; Humans ; Refractive Surgical Procedures

PURPOSE: To evaluate differences in intraocular pressure change after three different methods of corneal refractive surgery. METHODS: The medical records of 296 eyes of 150 patients who underwent corneal refractive surgery were reviewed. Spherical equivalent, central corneal thickness (CCT), and intraocular pressure before surgery, and one month, three months and six months after surgery were analyzed. RESULTS: The patients included those having undergone laser-assisted in situ keratomileusis (LASIK; 96 eyes), IntraLASIK (98 eyes), laser assisted sub-epithelial keratomileusis (LASEK; 102 eyes). Post operative intraocular pressure in ablated corneal depth and in CCT showed a meaningful correlation. Intraocular pressure decreased significantly after refractive surgery; however, there were no differences among the three groups. CONCLUSIONS: Post operative intraocular pressure after corneal refractive surgery is influenced by CCT. There were no differences in intraocular pressure change among the three groups.
Eye ; Humans ; Intraocular Pressure ; Medical Records ; Refractive Surgical Procedures