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Featured researches published by Seung Ah Chung.


Investigative Ophthalmology & Visual Science | 2014

Pirfenidone attenuates the IL-1β-induced hyaluronic acid increase in orbital fibroblasts from patients with thyroid-associated ophthalmopathy.

Seung Ah Chung; Bo Kyung Jeon; Youn-Hee Choi; Keum Ok Back; Jong Bok Lee; Koung Hoon Kook

PURPOSE This study aimed to investigate the effect of pirfenidone on the IL-1β-induced hyaluronic acid (HA) increase in orbital fibroblasts from patients with thyroid-associated ophthalmopathy (TAO). METHODS Primary cultured orbital fibroblasts were obtained from patients with TAO, and the excreted levels of HA from IL-1β-treated cells with or without pirfenidone were measured. The effect of pirfenidone on IL-1β-induced hyaluronic acid synthase (HAS) expression was evaluated. The relevance of the mitogen-activated protein kinase (MAPK)-mediated signaling pathway in IL-1β-induced HAS expression was assessed using specific inhibitors to p38, extracellular signal-regulated kinase (ERK), or c-Jun N-terminal kinase (JNK). The phosphorylation level of each MAPK in IL-1β-treated cells with or without pirfenidone and the level of AP-1 DNA binding were measured. The inhibitory potency of pirfenidone on HA production was evaluated using dexamethasone as a reference agent. RESULTS Pirfenidone strongly attenuated the IL-1β-induced HA release in a dose-dependent manner. The IL-1β-induced HAS expression was decreased significantly following cotreatment with pirfenidone at the mRNA and protein levels. The production of mRNAs was halted by cotreatment with inhibitors of ERK and p38, but not by inhibitors of JNK. The IL-1β-induced ERK and p38 phosphorylation, and AP-1 DNA binding were attenuated in the presence of pirfenidone. Pirfenidone showed greater potency than dexamethasone in inhibiting increases in IL-1β-induced HA. CONCLUSIONS Pirfenidone attenuates the IL-1β-induced HA production in orbital fibroblasts from patients with TAO, at least in part, through suppression of the MAPK-mediated HAS expression. These results support the potential use of pirfenidone for treatment of patients with TAO.


Journal of Pediatric Ophthalmology & Strabismus | 2011

Practical aspects and efficacy of intraoperative adjustment in concomitant horizontal strabismus surgery.

Jeong Ho Yi; Seung Ah Chung; Yoon Hee Chang; Jong Bok Lee

PURPOSE To analyze the practical aspects and advantages of one-stage adjustable surgery under topical anesthesia in concomitant horizontal strabismus. METHODS A retrospective review of 363 patients was completed to assess (1) the frequency of need to perform adjustment, (2) the amount and pattern of adjustment, and (3) the final alignment at least 6 months after surgery. Intraoperative adjustment was performed strictly toward the aim of orthophoria or slight overcorrection (heterophoria < 6 prism diopters [PD]) while avoiding diplopia. RESULTS Of the 363 patients, 261 (72%) required intraoperative adjustment. Of these, 85% of exotropes underwent a decreased amount of surgery compared with the standard amount, whereas 58% of esotropes underwent an increased amount of surgery. Forty-two patients underwent a one-muscle surgery instead of the scheduled two-muscle surgery, and all had less than 35 PD preoperative angle of deviation. Success rates were 83% in all patients with one-stage adjustable sutures and 87% in patients who underwent adjustment. In 42 patients with one-muscle surgery instead of two-muscle surgery, 32 (76%) obtained successful results. CONCLUSION Intraoperative adjustment was effective in concomitant horizontal strabismus surgery and can provide the opportunity to avoid a large overcorrection, especially in cases with moderate angle horizontal muscle surgery.


Yonsei Medical Journal | 2012

Parent-Reported Symptoms of Attention Deficit Hyperactivity Disorder in Children with Intermittent Exotropia before and after Strabismus Surgery

Seung Ah Chung; Yoon Hee Chang; Soolienah Rhiu; Helen Lew; Jong Bok Lee

Purpose To investigate the symptoms of attention deficit hyperactivity disorder (ADHD) as reported by parents in children with intermittent exotropia [X(T)] and to determine whether strabismus surgery for X(T) affects ADHD symptoms. Materials and Methods Fifty-one consecutive children undergoing muscle surgery for X(T) were prospectively recruited. One parent of each child completed the ADHD rating scale IV (ADHD RS-IV) assessment consecutively before and one year after surgery. Patients whose preoperative scores were above the cut-off point, the 90th percentile based on a Korean sample, were regarded as demonstrating the ADHD trait. The impact of muscle surgery on ADHD symptoms was assessed by comparing the preoperative scores with the post-operative scores. Results Eight (15.7%) of the 51 patients demonstrated the ADHD trait. ADHD RS-IV scores following strabismus surgery significantly decreased in patients with the ADHD trait (p=0.014), while they did not differ in patients without the ADHD trait. Seven (87.5%) of the 8 patients with the ADHD trait showed improvement in their ADHD RS-IV scores after surgery. There was no difference in surgical success rates between X(T) patients with and without the ADHD trait. Conclusion The ADHD trait was relatively common in children with X(T), and the parent-reported symptoms of the children with the ADHD trait improved after strabismus surgery. These results suggest that childhood X(T) may be one contributing factor to ADHD-related symptoms.


Journal of Pediatric Ophthalmology & Strabismus | 2011

Changes in exodeviation following hyperopic correction in patients with intermittent exotropia.

Seung Ah Chung; In Sik Kim; Wook Kyum Kim; Jong Bok Lee

PURPOSE To evaluate changes in the angle of deviation after spectacle correction in patients who had hyperopia and intermittent exotropia (X(T)) and to determine whether the changes and surgical outcomes differ when compared with those of myopic and emmetropic X(T). METHODS One hundred fourteen patients with X(T) were recruited and allocated into three groups: X(T) with hyperopia (group I; 38 patients), X(T) with emmetropia (group II; 35 patients), and X(T) with myopia (group III; 41 patients). After at least 6 months wearing spectacles, changes in exodeviation were compared. The results of surgery based on the spectacle-corrected distance angle and the ratios of accommodative convergence over accommodation (AC/A) were also assessed. RESULTS With spectacle correction, the mean exodeviation increased significantly in group I, but did not change in groups II or III. Thirteen patients in group I (34%) showed a more than 10 prism diopters (PD) exotropic shift after wearing spectacles. The mean AC/A ratio in group I was 2.63 (PD/D), whereas in groups II and III the ratios were 4.03 and 4.06, respectively. There was no difference in surgical results among the three groups. CONCLUSION Although hyperopic correction in patients with X(T) resulted in a limited increase in exodeviation with a subnormal AC/A ratio, one-third of the patients experienced a significant increase in exodeviation. A spectacle correction trial should be considered before surgery in patients with hyperopia and X(T).


Korean Journal of Ophthalmology | 2012

The Analysis of AC/A Ratio in Nonrefractive Accommodative Esotropia Treated with Bifocal Glasses

Wook Kyum Kim; Sung Yong Kang; Soolienah Rhiu; Seung Ah Chung; Jong Bok Lee

Purpose To report the long term results of bifocal treatment in nonrefractive accommodative esotropia and to analyze the changes of accommodative convergence to accommodation (AC/A) ratio. Methods Sixteen patients treated with bifocal glasses for at least 5 years were evaluated retrospectively. Angle of deviation at near and distance, refractive error, and AC/A ratio by the lens gradient method were analyzed. The changes of AC/A ratios were also compared after dividing the patients according to continuation or cessation of bifocal therapy. Results Six patients (38%; bifocal stop group, BSG) were able to stop using bifocal glasses at an average age of 10.8 years (range, 6.5 to 15.4 years) during their follow-up. However, the other ten patients (62%; bifocal continue group, BCG) had to continue using bifocal glasses until the final visit, which was 13.8 years on average (range, 11.3 to 18.5 years). The AC/A ratio decreased from time of bifocal prescription to the last visit in both groups, from 4.4 to 2.7 in the BSG and from 5.9 to 4.5 in the BCG. AC/A ratios were significantly higher (p = 0.03) in the BCG than that of the BSG from the beginning of bifocal treatment and this difference was persistent until the final visit (p = 0.03). Conclusions The AC/A ratio decreased with age in both groups but was significantly higher throughout the entire follow-up period in the BCG. AC/A ratio at bifocal prescription could be an important factor in predicting response to bifocal treatment.


Journal of Pediatric Ophthalmology & Strabismus | 2012

Changes in the Interpupillary Distance Following General Anesthesia in Children With Intermittent Exotropia: A Predictor of Surgical Outcomes

Hyoung Won Bae; Seung Ah Chung; Jin Sook Yoon; Jong Bok Lee

PURPOSE To determine whether changes in ocular alignment following general anesthesia, as measured by interpupillary distance, can be used as a predictor for surgical outcomes in children with intermittent exotropia. METHODS The authors obtained digital photographs of 40 children with exotropia and 20 children with epiblepharon (control group) before and immediately after induction of general anesthesia in the primary supine position. Differences in the anatomic interpupillary distance (aIPD) for each patient were measured and compared with the preoperative angles of deviation. They were also correlated with surgical outcomes on the first day and 1 year after surgery. RESULTS All 60 patients demonstrated an increase in aIPD following general anesthesia. The mean change in aIPD in patients with exotropia was similar to that in patients with epiblepharon (3.78% ± 2.53% and 3.15% ± 1.05%, respectively). In patients with exotropia, there was a significant positive linear correlation between the preoperative distance deviation (P) and the change in eye position (A): A = 0.362 P - 4.488, r(2) = 0.476 (P < .001). Five (71%) of seven patients whose changes were outside the 80% confidence interval for expected values had poor surgical outcomes on the first postoperative day and four had unsatisfactory results 1 year after surgery. CONCLUSIONS Changes in aIPD following general anesthesia were strongly correlated with preoperative angle of deviation. Therefore, they may be a useful predictor of surgical outcomes in children with exotropia.


Yonsei Medical Journal | 2010

The Prismatic Effect on Stereoacuity in Intermittent Exotropia

Kyoung Sub Choi; Seung Ah Chung; Kyu-Sung Lee; Jong Bok Lee

Purpose To evaluate the effect of acrylic refractive prism and Fresnel membrane prism on stereoacuity in intermittent exotropia. Materials and Methods Stereoacuities of fifty-two patients (mean age, 12.4 years; range 6 to 45 years) with intermittent exotropia were measured using the Titmus and TNO stereotests, while they wore prisms of varying power on nonfixating eye or evenly on each eye. Results Stereoacuities were significantly reduced with increasing prism power for both prisms, ranging from 8 to 25 prism dipotres. The effects on stereoacuity in single acrylic prism and single Fresnel prism were similar, whereas spilt Fresnel prisms reduced stereoacuity more than spilt acrylic prisms. Spilt prisms were found to have much less effect on stereoacuity than single prisms for both acrylic and Fresnel prisms. Conclusion The use of acrylic refractive prism shared evenly on each eye would be optimal method to minimize the reduction of stereoacuity during the prismatic therapy for intermittent exotropia.


Korean Journal of Ophthalmology | 2010

Two Cases of Mirror-Image Eye Anomalies in Monozygotic Twins

Wook Kyum Kim; Seung Ah Chung; Jong Bok Lee

We report two cases of mirror image anomalies in two different pairs of monozygotic twins. In case 1, the twins exhibited mirroring of strabismus and refractive errors. Twin 1 had 35 prism diopters (PD) right intermittent exotropia at distant fixation and myopic anisometropia that was spherical 2.00 diopters more myopic in the right eye. Twin 2 had 35 PD left intermittent exotropia at distant fixation and her left eye was more myopic by - spherical 1.00 diopters. In case 2, the twins were diagnosed with infantile nystagmus with upbeat jerk. Twin 1 exhibited a habitual head turn of 30° to the left with dampening of her nystagmus in dextroversion. Twin 2 also exhibited abnormal head position, but in his case the habitual turn was 30° to the right. We believe that this is the first report describing mirror imaged intermittent exotropia with anisometropia and infantile nystagmus with opposite abnormal head positions in pairs of monozygotic twins.


Eye | 2011

The efficacy of intravenous ketorolac for pain relief in single-stage adjustable strabismus surgery: a prospective, randomized, placebo-controlled trial

Soolienah Rhiu; Seung Ah Chung; Wook Kyum Kim; Jee-Ho Chang; S J Bae; Jong Bok Lee

PurposeTo determine the efficacy of preoperative intravenous ketorolac in reducing intraoperative and postoperative pain and improving patient satisfaction in patients undergoing single-stage adjustable strabismus surgery.MethodsA prospective, randomized, placebo-controlled clinical trial was performed with 67 patients who underwent horizontal recti muscle surgery with adjustable sutures. The test group received intravenous ketorolac (60 mg) before surgery, and the control group received intravenous normal saline. Topical 0.5% proparacaine was administered to both groups during surgery. Vital signs including heart rate and blood pressure were recorded every 10 min throughout the surgery. The patients were asked to rate their maximum intraoperative and postoperative pain scores using a numerical pain rating scale. Patient satisfaction was also assessed using a five-point analogue scale.ResultsThe ketorolac-premedicated patients had less pain both during and after surgery (P=0.033 and P=0.024, respectively). There were no differences in vital signs during surgery and patient satisfaction between the two groups.ConclusionsIntravenous ketorolac, when administered preoperatively for single-stage adjustable strabismus surgery under topical anaesthesia, was effective in reducing pain during and after surgery.


Journal of Craniofacial Surgery | 2015

Ophthalmic findings in children with nonsyndromic craniosynostosis treated by expansion cranioplasty.

Seung Ah Chung; Il Suk Yun; Jong Wook Moon; Jong Bok Lee

AbstractThe ocular and systemic abnormalities of nonsyndromic craniosynostosis are often considered to be less severe than those of syndromic craniosynostosis and are less well described. The purpose of this article was to describe the frequency and nature of ophthalmic abnormalities in children treated for nonsyndromic craniosynostosis by expansion cranioplasty. A retrospective review identified 88 consecutive children with nonsyndromic craniosynostosis who underwent expansion cranioplasty with distraction osteogenesis. Assessment of presence and type of strabismus, refractive error, and amblyopia before and 6 months after surgery was recorded. Children with a mean age of 24.4 months were treated for nonsyndromic craniosynostosis (27 with coronal and 61 with sagittal and/or lambdoid). One-fourth of the patients had a fixation preference. Significant refractive errors were found in 45 (51%) of the 88 patients: hyperopia in 27%, myopia in 5%, and astigmatism in 35%. Anisometropia was present in 20%. Of the 85 patients who completed orthoptic examination, 48 (56%) had strabismus: exodeviation in 26%, esodeviation in 14%, and vertical deviation in 5%. Fourteen patients (16%) had abnormal head posture. Significant refractive error and strabismus were more likely to occur in cases with coronal synostosis. The procedures used for cranial vault expansion improved the abnormal head posture but did not affect the refractive error or ocular misalignment. Of children with nonsyndromic craniosynostosis who need neurosurgical correction, more than half were found to have significant refractive error and strabismus. Our findings support the importance of ophthalmic evaluation in these children.

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