1.Usefulness of Refractive Measurement by Wavefront Aberrometer in Children
Si Eun OH ; Woong Joo WHANG ; Mi Ra PARK
Journal of the Korean Ophthalmological Society 2021;62(5):680-687
Purpose:
To compare the refractive measurements from a wavefront aberrometer, autorefractor, and retinoscopy after cycloplegia in evaluating the usefulness and validity of refractive measurements by a wavefront aberrometer in children.
Methods:
A total of 130 eyes of 65 children, aged from 3 to 16 years, were examined using retinoscopy, a wavefront aberrometer (OPD-Scan III), and an autorefractor (KR-1) after cycloplegia. Refractive measurements were converted to power vectors (M, J0, and J45) and cylindrical absolute values for statistical analysis. The agreement between instruments was assessed and the correlations of measurements were evaluated. Subgroup analysis was performed on two subgroups: one representing less refractive error (|M| < 2 D on cycloplegic retinoscopy) and the other with larger refractive error (|M| ≥ 2 D on cycloplegic retinoscopy).
Results:
Compared with retinoscopy readings, the aberrometer and autorefractor yielded more myopic values (p = 0.007, p < 0.001). In the less refractive error group, the autorefractor results showed statistically significant differences from retinoscopy readings for M, J0, and J45 and the cylindrical absolute value (all p < 0.05); there were no statistically significant differences between M, J0, and J45 vectors of the aberrometer and those obtained using retinoscopy (p = 0.674, p = 0.699, p = 0.766). With the larger refractive error group, the M vectors of the aberrometer and autorefractor showed more myopic values than the M vector retinoscopy readings; the differences were statistically significant (all p < 0.001).
Conclusions
The wavefront aberrometer yielded refraction readings closer to those obtained with retinoscopy than the automated refraction in the less refractive error group. With a larger refractive error, statistically significant differences (all p < 0.001) were found among the aberrometer, autorefractor, and retinoscopy readings.
2.Usefulness of Refractive Measurement by Wavefront Aberrometer in Children
Si Eun OH ; Woong Joo WHANG ; Mi Ra PARK
Journal of the Korean Ophthalmological Society 2021;62(5):680-687
Purpose:
To compare the refractive measurements from a wavefront aberrometer, autorefractor, and retinoscopy after cycloplegia in evaluating the usefulness and validity of refractive measurements by a wavefront aberrometer in children.
Methods:
A total of 130 eyes of 65 children, aged from 3 to 16 years, were examined using retinoscopy, a wavefront aberrometer (OPD-Scan III), and an autorefractor (KR-1) after cycloplegia. Refractive measurements were converted to power vectors (M, J0, and J45) and cylindrical absolute values for statistical analysis. The agreement between instruments was assessed and the correlations of measurements were evaluated. Subgroup analysis was performed on two subgroups: one representing less refractive error (|M| < 2 D on cycloplegic retinoscopy) and the other with larger refractive error (|M| ≥ 2 D on cycloplegic retinoscopy).
Results:
Compared with retinoscopy readings, the aberrometer and autorefractor yielded more myopic values (p = 0.007, p < 0.001). In the less refractive error group, the autorefractor results showed statistically significant differences from retinoscopy readings for M, J0, and J45 and the cylindrical absolute value (all p < 0.05); there were no statistically significant differences between M, J0, and J45 vectors of the aberrometer and those obtained using retinoscopy (p = 0.674, p = 0.699, p = 0.766). With the larger refractive error group, the M vectors of the aberrometer and autorefractor showed more myopic values than the M vector retinoscopy readings; the differences were statistically significant (all p < 0.001).
Conclusions
The wavefront aberrometer yielded refraction readings closer to those obtained with retinoscopy than the automated refraction in the less refractive error group. With a larger refractive error, statistically significant differences (all p < 0.001) were found among the aberrometer, autorefractor, and retinoscopy readings.
3.Comparison of Accuracy of Six Modern Intraocular Lens Power Calculation Formulas
Ji Hyun YOON ; Woong-Joo WHANG
Korean Journal of Ophthalmology 2023;37(5):380-386
Purpose:
To compare the accuracy of modern intraocular lens (IOL) power calculation formulas in predicting refractive outcomes after standard cataract surgery.
Methods:
The medical records of 203 eyes from 203 patients that received phacoemulsification and IOL implantation were retrospectively reviewed. Partial coherence interferometry was used to obtain the biometric values. The refractive outcomes of Barrett Universal II (BUII), Emmetropia Verifying Optical (EVO) 2.0, Hill-RBF 3.0, Hoffer QST, Kane, and PEARL-DGS formulas were evaluated. Axial length (AL) subgroup analysis was done separately. The correlations between the prediction error calculated by each formula and AL and corneal power were also analyzed.
Results:
Overall, there was no significant difference between the absolute prediction errors predicted by the six formulas after adjusting the mean prediction error (p = 0.058). AL subgroup analysis of absolute error also showed that there is no significant difference between the formulas. The BUII and Hill-RBF 3.0 formulas showed a higher percentage of eyes with prediction error within ±0.50 diopters compared to the Hoffer QST formula (p = 0.022 and p = 0.035, respectively). However, there was no significant difference after Bonferroni correction was applied. The BUII formula showed the highest IOL Formula Performance Index and therefore the highest accuracy, followed by PEARL-DGS, EVO 2.0, Kane, Hill-RBF 3.0, and Hoffer QST formulas. Out of the six formulas, the prediction error calculated by the Hoffer QST was significantly correlated with the AL (p = 0.011). None of the prediction errors calculated by the six formulas showed correlation to the corneal power.
Conclusions
Analysis of the prediction error showed that the six modern IOL power calculation formulas have comparable accuracy overall and across different ranges of AL.
4.Steep Axis Incision Versus Temporal Incision in Microcoaxial Cataract Surgery.
Woong Joo WHANG ; Yong Soo BYUN ; Choun Ki JOO
Journal of the Korean Ophthalmological Society 2011;52(1):29-33
PURPOSE: To determine if a difference exists in surgically-induced astigmatism (SIA) and the mean change in keratometric astigmatism in patients who underwent microcoaxial cataract surgery (MCCS). METHODS: A prospective study including 193 eyes with astigmatism of greater than 0.5 diopters was performed. The eyes were randomized into two groups: (1) 95 eyes with steep axis incision, and (2) 98 eyes with temporal incision. A 2.2-mm microcoaxial phacoemulsification was performed. The UCVA, BCVA and corneal topography (Orbscan II, Bausch & Lomb) were measured preoperatively and three months postoperatively. Surgically induced astigmatism was calculated via vector analysis, and the mean change in keratometric astigmatism was also calculated. RESULTS: There were no significant differences in UCVA or BCVA between the two groups three months postoperative. The mean SIA was 0.45 +/- 0.27 diopters in the steep axis incision group and 0.30 +/- 0.17 diopters in the temporal incision group. In the steep axis incision group, the mean keratometric astigmatism showed a mean reduction of 0.31 +/- 0.37 diopter (WTR: 0.37 D; oblique: 0.35D; ATR: 0.16 D), while the mean keratometric astigmatism showed a mean increase of 0.06 +/- 0.29 diopters (WTR: 0.15 D increased; oblique: 0.11 D increased; ATR: 0.13 D reduced) in the temporal incision group. There were statistically significant differences in SIA and change in astigmatism between the two groups (p = 0.002, p = 0.000). CONCLUSIONS: In MCCS, steep axis incision achieved superior astigmatism correction in patients having with-the-rule or oblique astigmatism of greater than 0.5 diopters.
Astigmatism
;
Cataract
;
Corneal Topography
;
Eye
;
Humans
;
Phacoemulsification
;
Prospective Studies
5.Corneal Collagen Crosslinking in Progressive Keratoconus.
Kyung Euy HONG ; Woong Joo WHANG ; So Hyang CHUNG ; Choun Ki JOO
Journal of the Korean Ophthalmological Society 2016;57(11):1714-1722
PURPOSE: To report the clinical efficacy and safety of progressive keratoconic eyes in Korean patients treated with accelerated corneal cross-linking. METHODS: This retrospective study focused on progressive keratoconic eyes in Korean patients that underwent accelerated corneal cross-linking from February 2015 to October 2015. Keratoconus was diagnosed in 45 eyes in 30 patients. After accelerated corneal cross-linking with VibeX rapid solution, best corrected visual acuity, maximum keratometry, mean keratometry, corneal thickness, corneal astigmatism, and endothelial cell count were measured at the preoperative visit and post operation 1 week, 1 month, 3 months, and 6 months. RESULTS: Best corrected visual acuity (log MAR) was 0.51 ± 0.23 at pre operation and 0.51 ± 0.26 at post operation 6 months, showing no improvement. The maximum keratometry measured with Auto K, Pentacam, and Orbscan II at pre operation was 49.11 ± 4.5 D, 48.37 ± 3.31 D, and 48.98 ± 4.88 D and changed to 49.29 ± 4.34 D, 46.99 ± 3.63 D, and 47.01 ± 3.62 D postoperatively, respectively. Only Pentacam and Orbscan II measurements showed a statistically significant decrease (p < 0.05). Corneal thickness (at the thinnest area) was measured with Pentacam and Orbscan II; pre-operative and post-operative 6 month data showed changes from 485 ± 26.27 and 479.24 ± 27.89 to 471.64 ± 27.12 and 472.52 ± 25.36, respectively. Only the Pentacam method resulted in a statistically significant decrease. Endothelial cell count was measured with confocal microscopy and showed a statistically significant difference between pre-operative 2,857 ± 390.49/mm² and post-operative 6 month 2,639.21 ± 249.92/mm². CONCLUSIONS: This 6-month follow-up study of Korean keratoconus patients who underwent accelerated corneal cross-linking indicates that the method is effective in stabilizing the progression of keratoconus, according to maximum keratometry change. With regard to endothelial cell count change, further long-term evaluation is required. Other than endothelial cell count change, this procedure is expected to show long-term safety comparable to that of conventional corneal cross-linking.
Astigmatism
;
Collagen*
;
Endothelial Cells
;
Follow-Up Studies
;
Humans
;
Keratoconus*
;
Methods
;
Microscopy, Confocal
;
Retrospective Studies
;
Treatment Outcome
;
Visual Acuity
6.Cerebral Basilar Artery Mycotic Aneurysm Associated With Aspergillus Endogenous Endophthalmitis.
Mee Yon LEE ; Woong Joo WHANG ; Won Ki LEE
Journal of the Korean Ophthalmological Society 2010;51(12):1671-1675
PURPOSE: To report a case of mycotic aneurysm of the cerebral basilar artery associated with bilateral endogenous aspergillus endophthalmitis. CASE SUMMARY: A 41-year-old man with no underlying disease presented with decreased vision in both eyes. The patient was diagnosed with bilateral endogenous endophthalmitis, and the authors performed a vitrectomy and lensectomy on the right eye. Hyphae were detected in the vitreous sample, and systemic amphotericin was administered. Three days after the operation, the patient became comatose due to a subarachnoid hemorrhage. Aspergillus antigen was detected in the vitreous sample and in the cerebrospinal fluid. Subarachnoid hemorrhage was due to the rupture of a mycotic aneurysm of the cranial basilar artery, complicated by aspergillus infection of the central nervous system.
Adult
;
Amphotericin B
;
Aneurysm, Infected
;
Aspergillus
;
Basilar Artery
;
Central Nervous System
;
Coma
;
Endophthalmitis
;
Eye
;
Humans
;
Hyphae
;
Rupture
;
Subarachnoid Hemorrhage
;
Vision, Ocular
;
Vitrectomy
7.Astigmatic Analysis before and after Surgical Excision of Limbal Dermoid: Functional Outcome.
Ji Hyun KIM ; Ye Jin AHN ; Woong Joo WHANG ; Shin Hae PARK
Journal of the Korean Ophthalmological Society 2017;58(9):1092-1098
PURPOSE: To analyze the length and area of limbal dermoid invading the cornea and to evaluate the effects on visual acuity and astigmatism before and after surgery. METHODS: This retrospective study included 20 eyes of 20 patients who underwent surgical removal of limbal dermoid. The preoperative and postoperative visual acuity and astigmatism level were measured. In addition, we evaluated the correlations of astigmatism with the length ratio (length of limbal dermoid invading the cornea/total corneal diameter), width ratio (width of limbal dermoid invading the cornea/total corneal diameter), and area ratio (area of limbal dermoid invading the cornea/total corneal area) using preoperative anterior segment photographs. RESULTS: The mean preoperative astigmatism was 0.85 ± 0.71 D in the sound eye and 3.00 ± 3.14 D in the affected eye (p = 0.004). Length, width, and area ratio of limbal dermoid have positive correlation with astigmatism (p < 0.010 for all variables), with a larger length ratio of limbal dermoid invading the cornea producing greater reduction in postoperative astigmatism (p = 0.010, r = 0.816). The amount of astigmatism was significantly higher in patients with amblyopia in the affected eye (p = 0.030). Visual acuity gain more than 2 lines was achieved in 8 among 10 patients with amblyopia under the age of 7 years through the appropriate refractive correction and occlusion 1 year after surgery. CONCLUSIONS: Astigmatism is a major cause of amblyopia in pediatric patients with limbal dermoid. The degree of astigmatism can be predicted by the size factors of the limbal dermoid. In particular, the relative length of limbal dermoid invading the cornea has a stronger correlation with preoperative astigmatism than other factors and has correlation with postoperative reduction of astigmatism. It should be emphasized that children with limbal dermoid need appropriate refractive correction and occlusion in addition to surgical excision.
Amblyopia
;
Astigmatism
;
Child
;
Cornea
;
Dermoid Cyst*
;
Humans
;
Retrospective Studies
;
Visual Acuity
8.Prediction of Effective Lens Position by Reference to the Preoperative Axial Length
Gee-Hyun KIM ; Woong-Joo WHANG ; Hyun-Seung KIM
Journal of the Korean Ophthalmological Society 2021;62(3):308-314
Purpose:
We derived optimal formulae permitting effective lens position (ELP) for patients differing in terms of their preoperative axial lengths as revealed by partial coherence interferometry.
Methods:
We included 736 eyes from 736 patients who underwent conventional cataract surgery at Yeouido St. Mary’s Hospital. The preoperative axial length (AL), corneal power (CP), and anterior chamber depth (ACD) measured via partial coherence interferometry served as independent variables for ELP prediction. The 736 eyes were divided into seven groups differing by 1.0-mm intervals in terms of the preoperative axial length. We sought correlations between the independent variables and the ELP, and defined the combinations that best predicted the ELPs of the seven groups.
Results:
The CP correlated significantly with the ELP for eyes with AL between 22.0 and 25.0 mm (all p < 0.01) and the ACD correlated significantly with the ELP for eyes with AL between 23.0 and 26.0 mm (all p < 0.01). Although a regression equation featuring all of the AL, ACD, and CP best predicted the ELP for the total of 736 eyes (p < 0.001), the optimal combination varied by the preoperative AL.
Conclusions
The effects of CP, ACD, and AL on ELP vary by the preoperative AL. The optimal combination of preoperative variables predicting ELP thus varies as that parameter changes.
9.Prediction of Effective Lens Position by Reference to the Preoperative Axial Length
Gee-Hyun KIM ; Woong-Joo WHANG ; Hyun-Seung KIM
Journal of the Korean Ophthalmological Society 2021;62(3):308-314
Purpose:
We derived optimal formulae permitting effective lens position (ELP) for patients differing in terms of their preoperative axial lengths as revealed by partial coherence interferometry.
Methods:
We included 736 eyes from 736 patients who underwent conventional cataract surgery at Yeouido St. Mary’s Hospital. The preoperative axial length (AL), corneal power (CP), and anterior chamber depth (ACD) measured via partial coherence interferometry served as independent variables for ELP prediction. The 736 eyes were divided into seven groups differing by 1.0-mm intervals in terms of the preoperative axial length. We sought correlations between the independent variables and the ELP, and defined the combinations that best predicted the ELPs of the seven groups.
Results:
The CP correlated significantly with the ELP for eyes with AL between 22.0 and 25.0 mm (all p < 0.01) and the ACD correlated significantly with the ELP for eyes with AL between 23.0 and 26.0 mm (all p < 0.01). Although a regression equation featuring all of the AL, ACD, and CP best predicted the ELP for the total of 736 eyes (p < 0.001), the optimal combination varied by the preoperative AL.
Conclusions
The effects of CP, ACD, and AL on ELP vary by the preoperative AL. The optimal combination of preoperative variables predicting ELP thus varies as that parameter changes.
10.Comparison of Short Term Clinical Results Between Epi-LASIK and Femtosecond LASIK.
Sung Il KIM ; Woong Joo WHANG ; Yong Soo BYUN ; Ji Hye SONG ; Kyung Sun NA ; Choun Ki JOO
Journal of the Korean Ophthalmological Society 2010;51(12):1573-1578
PURPOSE: To compare short-term clinical results of femtosecond LASIK with those of epi-LASIK. METHODS: Twenty subjects (40 eyes) underwent femtosecond LASIK and 20 subjects (40 eyes) underwent epi-LASIK for myopia with astigmatism. The results of each surgery were compared with regard to visual acuity, spherical equivalent, safety, efficacy, stability, predictability and high order aberration. RESULTS: Postoperative uncorrected visual acuities were 0.51 +/- 0.11, 0.95 +/- 0.08, and 0.97 +/- 0.08 for epi-LASIK and 0.76 +/- 0.19, 0.97 +/- 0.07, and 0.98 +/- 0.06 for femtosecond LASIK at one week, one month, and two months after surgery, respectively. Femtosecond LASIK showed faster improvement in visual acuity. Postoperative spherical equivalents were -0.83 +/- 0.24, -0.31 +/- 0.19, and -0.27 +/- 0.09 for epi-LASIK and -0.47 +/- 0.21, -0.28 +/- 0.15, and -0.25 +/- 0.12 for femtosecond LASIK. Safety, efficacy, stability, and predictability showed no differences between the two groups. High order aberrations were increased significantly; however, no significant difference between the two groups was found. CONCLUSIONS: Both epi-LASIK and femtosecond LASIK are effective for surgical correction of myopia with fast visual rehabilitation. In addition, epi-LASIK and femtosecond LASIK showed good safeties, efficacies, predictabilities, and stabilities.
Astigmatism
;
Keratomileusis, Laser In Situ
;
Myopia
;
Safety
;
Visual Acuity