Hyuk Jin Choi

Clinical comparison of ciliary sulcus and pars plana locations for posterior chamber intraocular lens transscleral fixation

PURPOSE: To compare the clinical outcomes of transscleral fixation of a posterior chamber intraocular lens (PC IOL) in the ciliary sulcus or pars plana. SETTING: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, South Korea. DESIGN: Comparative case series. METHODS: This retrospective chart review comprised eyes having ciliary sulcus or pars plana fixation of a 3‐piece foldable acrylic PC IOL between January 2003 and August 2010. The postoperative corrected distance visual acuity (CDVA), efficacy index, safety index, endothelial cell count (ECC), and complication rates in the 2 groups were compared. RESULTS: The ciliary sulcus group comprised 38 eyes and the pars plana group, 56 eyes. There was no significant between‐group difference in the postoperative CDVA, efficacy index, safety index, or ECC. The mean spherical equivalent difference was larger in the ciliary sulcus group. Intraocular lens dislocation and pupillary capture of the IOL optic occurred more frequently in the ciliary sulcus group (P=.001 and P=.041, respectively). However, retinal detachment, IOL decentration or tilt, cystoid macular edema, secondary glaucoma, and vitreous hemorrhage did not differ significantly between the 2 groups. CONCLUSION: The pars plana location for PC IOL transscleral fixation was as safe and effective as the ciliary sulcus location. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Effect of αGal on corneal xenotransplantation in a mouse model

Choi HJ, Kim MK, Lee HJ, Jeong SH, Kang HJ, Park C‐S, Park C‐G, Kim SJ, Wee WR. Effect of αGal on corneal xenotransplantation in a mouse model. Xenotransplantation 2011; 18: 176–182.

Comparative Cross-sectional Analysis of the Effects of Topical Antiglaucoma Drugs on the Ocular Surface

IntroductionThe aim of this study was to comparatively analyze the effects of topical intraocular pressure (IOP)-lowering drugs on the ocular surface and to elucidate whether the main causative factor of toxicity is associated with benzalkonium chloride (BAK) or an active compound.MethodsThe medical records of 300 eyes in 187 glaucoma patients that had instilled IOP-lowering drugs were cross-sectionally reviewed. Corneal epithelial punctuate erosion and tear break-up time (BUT) were quantitatively assessed. Durations of glaucoma, sums of concentrations of BAK in current medication (BAK%sum), and the presence of beta-blockers were investigated as risk factors (Institutional Review Board of Seoul National University Hospital, Seoul - IRB number: H-1007-103-324).ResultsAge-adjusted BAK%sum was found to be significantly and positively correlated with corneal epithelial punctate erosion (P = 0.001, r = 0.208) and negatively correlated with BUT (P = 0.042, r = 0.131). BAK%sum adjusted corneal epithelial erosion was found to be significantly greater in beta-blocker containing eyedrop-instilled eyes (P = 0.016). No difference in ocular toxicity was found between carbonic anhydrase inhibitor and prostaglandin analog or between latanoprost- and travoprost-treated eyes.ConclusionLong-term treatment with BAK-containing antiglaucoma medication appears to be the main contributor to corneal toxicity and to do so in a dose-dependent manner. Formulations containing beta-blockers also appear to contribute to corneal toxicity.

Effect of Toll-like receptor 2 and 4 of corneal fibroblasts on cytokine expression with co-cultured antigen presenting cells

Keratocytes are the first component to contact ocular pathogens when the epithelial barrier breaks down and the emerging evidences indicated keratocytes appeared to be one of the corneal cellular immune components. Little is known about the role of Toll-like receptors (TLRs) in keratocytes, although it has been well documented that keratocytes constitutively express various TLRs including TLR2 and TLR4. In this in vitro study, the authors focused on the role of keratocytes in corneal innate immune system and cross-talk of keratocytes with resident antigen presenting cells (APCs), especially through TLR2 and TLR4. Primary cultivated keratocytes (corneal fibroblasts) from C57BL/6 mice per se actively secreted pro-inflammatory cytokines, especially interleukin (IL)-6, with a dose-dependent manner in response to Pam3CSK4 or lipopolysaccharide (LPS) challenge. With co-culture of corneal fibroblasts with APCs per se, secretion of IL-6 and tumor necrosis factor (TNF)-α was markedly increased and it was counterbalanced by concurrent increase in IL-10 and tumor growth factor-β1. After Pam3CSK4 or LPS stimulation, this cytokine balance was completely broken down by overwhelming amplification of IL-6 and TNF-α secretion, especially in co-culture of corneal fibroblasts with macrophages, rather than with dendritic cells. Using corneal fibroblasts from TLR2 or TLR4 knockout mice, we could find the reversal of Pam3CSK4 or LPS-responsive dose-dependent increment in IL-6 and TNF-α. These results implied that corneal fibroblasts and their TLRs could be key components for the ocular homeostasis and pathogen-associated ocular innate immunity.

Anti-CD40 antibody-mediated costimulation blockade promotes long-term survival of deep-lamellar porcine corneal grafts in non-human primates.

Corneal xenotransplantation is an effective solution for the shortage of human donor corneas, and the porcine cornea may be a suitable candidate for the donor cornea because of its optical similarity with humans. However, it is necessary to administer additional immunosuppressants to overcome antigenic differences. We aimed to investigate the feasibility of porcine corneas with anti‐CD40 antibody‐mediated costimulation blockade in a clinically applicable pig‐to‐non‐human primate corneal xenotransplantation model.

Estimation of axial curvature of anterior sclera: correlation between axial length and anterior scleral curvature as affected by angle kappa

AbstractufeffBackgroundThough the development and fitting of scleral contact lenses are expanding steadily, there is ufeffno simple method to provide scleral metrics for scleral contact lens fitting yet. The aim of this study was to establish formulae for estimation of the axial radius of curvature (ARC) of the anterior sclera using ocular biometric parameters that can be easily obtained with conventional devices.MethodsA semi-automated stitching method and a computational analysis tool for calculating ARC were developed by using the ImageJ and MATLAB software. The ARC of all the ocular surface points were analyzed from the composite horizontal cross-sectional images of the right eyes of 24 volunteers; these measurements were obtained using anterior segment optical coherence tomography for a previous study (AS-OCT; Visante). Ocular biometric parameters were obtained from the same volunteers with slit-scanning topography and partial coherence interferometry. Correlation analysis was performed between the ARC at 8xa0mm to the axis line (ARC[8]) and other ocular parameters (including age). With ARC obtained on several nasal and temporal points (7.0, 7.5, 8.0, 8.5, and 9.0xa0mm from the axis line), univariate and multivariate linear regression analyses were performed to develop a model for estimating ARC with the help of ocular biometric parameters.ResultsAxial length, spherical equivalent, and angle kappa showed correlations with temporal ARC[8] (tARC[8]; Pearson’s ru2009=u20090.653, −0.579, and −0.341; Pu2009=u20090.001, 0.015, and 0.015, respectively). White-to-white corneal diameter (WTW) and anterior chamber depth (ACD) showed correlation with nasal ARC[8] (nARC[8]; Pearson’s ru2009=u2009−0.492 and −0.461; Pu2009=u20090.015 and 0.023, respectively). The formulae for estimating scleral curvatures (tARC, nARC, and average ARC) were developed as a function of axial length, ACD, WTW, and distance from the axis line, with good determinant power (72u2009−u200980xa0%; SPSS ver. 22.0). Angle kappa showed strong correlation with axial length (Pearson’s ru2009=u2009−0.813, P <0.001), and the different correlation patterns of nasal and temporal ARC with axial length can be explained by the ocular surface deviation represented by angle kappa.ConclusionsAxial length, ACD, and WTW are useful parameters for estimating the ARC of the anterior sclera, which is important for the haptic design of scleral contact lenses. Angle kappa affects the discrepancies between the nasal and temporal scleral curvature.

Frequency of symptoms and signs of primary vascular dysregulation in Swiss and Korean populations.

BACKGROUNDnPrimary vascular dysregulation syndrome (also called Flammer syndrome) is related to certain eye diseases, particularly normal tension glaucoma. Primary vascular dysregulation is characterized by a number of symptoms and signs (e.g., cold hands and/or feet, low blood pressure), that occur more frequently in subjects with primary vascular dysregulation compared to the general population. The aim of the present study was to test and compare the relative frequency of symptoms and signs related to primary vascular dysregulation in unselected populations in Switzerland and Korea.nnnSUBJECTS AND METHODSnSwiss (n=259) and Korean (n=1116) subjects filled out our questionnaire containing 15 questions related to symptoms and signs of primary vascular dysregulation.nnnRESULTSnIn the populations studied, seven of 15 symptoms and signs of primary vascular dysregulation (increased smell perception, increased pain sensation, increased response to certain drugs, low body mass index, feeling cold, cold hands and/or feet, and headaches) occurred significantly more often in the Swiss population than in the Korean population, whereas five symptoms and signs (reversible skin blotches, tendency toward perfectionism, long sleep onset time, tinnitus, and dizziness) occurred significantly more often in the Korean population.nnnCONCLUSIONnThe relative frequency of these symptoms and signs of primary vascular dysregulation in an unselected average population differs between Switzerland and Korea. Therefore, if a diagnosis of primary vascular dysregulation is based on the self-reported symptoms and signs of the patient, they must be compared with the frequency of symptoms and signs in the corresponding local population.

Relationship between normal tension glaucoma and Flammer syndrome

BackgroundBesides intraocular pressure, vascular factors play a role in the pathogenesis of glaucomatous optic neuropathy. One of these potential vascular factors is Flammer syndrome. The purpose of the present study was to determine in a Korean population whether signs and symptoms of Flammer syndrome occur more often in normal tension glaucoma patients than in control subjects.MethodsTwo hundred forty-six normal tension glaucoma patients and 1116 control subjects responded to a multiple-choice questionnaire asking about 15 signs and symptoms of Flammer syndrome.ResultsSeven of the 15 signs and symptoms of Flammer syndrome (increased drug sensitivity, good smell perception, reversible skin blotches, tinnitus, long sleep onset time, tendency to perfectionism, and cold hands/feet) were significantly more often positive in normal tension glaucoma patients than in controls. Six additional signs and symptoms (migraines, low blood pressure, headaches, dizziness, increased pain sensation, and feeling cold) also occurred more often, but did not reach statistical significance. Only two items (low body weight and reduced feeling of thirst) were more frequently (not significant) positive in the controls.ConclusionThere is an association between normal tension glaucoma and Flammer syndrome. If future studies confirm this relationship, treatment of Flammer syndrome may help to prevent normal tension glaucoma or to slow down its progression.

Corneal keloid: four case reports of clinicopathological features and surgical outcome

BackgroundSurgical outcome of corneal keloid is largely variable depending on reports, although surgical management is inevitable in visually significant cases. We here report clinical features, histopathological findings, and surgical outcome of four cases of corneal keloid.Case presentationFour Korean male patients without a history of corneal trauma or disease were clinically and histologically evaluated for a slowly-growing, white opacity in the cornea. On slit lamp examination, corneal lesions appeared as a solitary, pearly white, well-circumscribed nodule with a smooth and glistening surface. Because the lesions involved the visual axis deteriorating the visual acuity, the nodules were surgically removed by superficial keratectomy in all patients. Amniotic membrane transplantation was combined in three patients, and an intraoperative mitomycin C application in two patients. Hematoxylin-eosin staining of the excised nodules revealed epithelial hyperplasia, Bowman’s layer disruption, thick and irregularly-arranged collagen fibers in the stroma, and accumulation of prominent fibroblasts, which are consistent with the diagnosis of corneal keloid. The corneal keloids recurred in all patients within 10xa0months of surgical excision and outgrew the boundary of the excised area.ConclusionA diagnosis of corneal keloid should be suspected in patients presenting with an enlarging, white, glistening corneal nodule, even in the absence of a history of corneal trauma or disease. The recurrence is common after surgical excision, and the lesion can be exacerbated by surgery.