Jong-uk Hwang

Changes in the clinical features and prognostic factors of endogenous endophthalmitis: fifteen years of clinical experience in Korea.

Purpose: To identify changes in the clinical features, management, and prognostic factors of endogenous endophthalmitis in Korea from 1996 through 2010. Methods: We conducted a retrospective review of medical records of patients diagnosed with endogenous endophthalmitis from January 1996 to December 2010, which was divided into 3 periods: 1996 to 2000, 2001 to 2005, and 2006 to 2010. Variables included age, source of infection, systemic conditions, initial and final visual acuities, causative organisms, and treatment. Results: Endophthalmitis was identified in 80 patients (97 eyes). Diabetes (42.5%) and liver cirrhosis (20%) were the common systemic problems in these patients. Liver abscess (25%) was the most common infection focus of the endophthalmitis. Klebsiella pneumoniae (48.4%) was the common causative agent, although more recently, endophthalmitis caused by gram-positive cocci has increased in frequency. The use of vitrectomy as an initial treatment has increased during the past 5 years. Good initial visual acuity greater than counting fingers (P < 0.001), early vitrectomy in patients with initially good visual presentation (P = 0.035), and gram-positive cocci (P = 0.033) as a causative agent were significantly related to a successful visual outcome. Conclusion: Although the prognosis of endogenous endophthalmitis is generally poor in most patients, some eyes can have relatively good visual outcomes if treated appropriately and early enough.

Optical coherence tomography in the diagnosis and monitoring of cystoid macular edema in patients with retinitis pigmentosa.

Purpose: To identify cystoid macular edema (CME) in patients with retinitis pigmentosa (RP) using optical coherence tomography (OCT) and to evaluate response to acetazolamide by serial OCT. Methods: Twenty-nine consecutive RP patients were included in the study. Patients with CME were treated with acetazolamide (125 or 250 mg/d for 4–12 months). OCT, fluorescein angiography, and determination of best-corrected visual acuity (BCVA) were performed initially and throughout the follow-up period. Results: Ten of the 29 patients had CME by OCT. Of these 10 patients, 5 had various degrees of fluorescein leakage by fluorescein angiography. After acetazolamide treatment, six patients had significant decreases in macular edema in at least one eye by follow-up OCT. In six patients, visual acuity improved by ≥1 line in at least one eye. The change of central foveal thickness shown by OCT was significantly correlated with the change of logMAR of BCVA (Pearson correlation coefficient [r] = 0.576; P = 0.008). We observed no differences in the change of central foveal thickness by OCT (Mann–Whitney test; P = 1.000) and in the change of logMAR of BCVA (Mann–Whitney test; P = 0.106) between patients treated with 125 mg/d acetazolamide and those treated with 250 mg/d acetazolamide. Conclusions: These results indicate that OCT is a valuable tool in the detection and follow-up of CME in RP patients. Treatment with acetazolamide resulted in marked improvement in OCT-diagnosed CME in RP, but visual improvement was variable.

Combined phacoemulsification, foldable intraocular lens implantation, and 25-gauge transconjunctival sutureless vitrectomy

&NA; We describe a technique for combined cataract and vitreoretinal surgery using a 25‐gauge transconjunctival sutureless vitrectomy system. This technique was successfully performed in 20 consecutive cases. Outcomes were assessed in terms of visual acuity, intraocular pressure, postoperative refractive error, and incidence of complications. The technical feasibility, rationale, and advantages and disadvantages of this technique are discussed.

Assessment of Macular Function for Idiopathic Epiretinal Membranes Classified by Spectral-Domain Optical Coherence Tomography

PURPOSE To evaluate the functional changes in various morphologic types of idiopathic epiretinal membrane (ERM) by multifocal electroretinography (mfERG) and spectral-domain optical coherence tomography (SD-OCT). METHODS All patients (n = 71) with unilateral idiopathic ERM underwent complete ophthalmologic examination, including measurements of best-corrected visual acuity (BCVA), SD-OCT, and mfERG for both eyes. To classify idiopathic ERM by subtype, the morphologic characteristics of the foveal area on representative scanned images were assessed. The five subtypes by foveal SD-OCT morphology included fovea-attached ERM with outer retinal thickening and minimal inner retinal change (Group 1A), outer retinal inward projection and inner retinal thickening (Group 1B), and prominent thickening of inner retinal layer (Group 1C) and foveal sparing ERM with formation of macular pseudohole (Group 2A) and with schisislike, intraretinal splitting (Group 2B). RESULTS On mfERG, P1 amplitude density in the central ring (R1) and inter-eye (affected eye/fellow eye) response ratio of P1 amplitude density in R1 differed significantly among five groups (P = 0.032 and P = 0.022, respectively). In Group 1 patients, central subfield thickness (CST) and inner retinal layer thickness (IRT) on SD-OCT were strongly correlated with BCVA and P1 amplitude density in R1. A receiver operating characteristic (ROC) curve analysis showed that IRT had high predictive accuracy in distinguishing Groups 1A and 1B (area under the ROC curve [AUROC] = 0.966) and Groups 1B and 1C (AUROC = 1.000). CONCLUSIONS Multifocal electroretinography can be used to investigate the pathophysiology of ERM and to evaluate the degree of functional demise in the fovea on SD-OCT.

Inner retinal layer thickness is the major determinant of visual acuity in patients with idiopathic epiretinal membrane

Editor, I diopathic epiretinal membrane (ERM) may be asymptomatic until the tangential tractional forces on the retina cause significant thickening and intraretinal structural distortion at the macula (Pournaras et al. 2000). In clinical practice, we often witness asymptomatic patients with prominent ERM. It is unclear whether central subfield thickness (CST), inner retinal layer thickness (IRLT), outer retinal layer thickness (ORLT) or photoreceptor inner segment ⁄outer segment (IS ⁄OS) disruption is the major contributing factor to reduced visual acuity in ERM (Michalewski et al. 2007; Arichika et al. 2010). Medical records for 123 patients (134 eyes: 107 phakic eyes and 27 pseudophakic eyes) with idiopathic ERM were reviewed. Cases of ERM secondary to other diseases or accompanied by lens opacity of N3, C3, P3 or greater (LOCS III) (Chylack et al. 1993) were excluded. Fluorescein angiography was performed in all eyes to exclude associated vascular occlusive disease. Best-corrected visual acuity (BCVA) was converted to the logMAR scale. SD-OCT examinations were performed using a Cirrus SD-OCT system (Carl Zeiss Meditec Inc., Dublin, CA, USA) with software version 4.0. CST was measured automatically. Inner retinal layer thickness (length from the vitreoretinal interface to the outer border of the inner nuclear layer) and ORLT (length from the inner border of the outer plexiform layer to the photoreceptor IS ⁄OS junction) were measured manually on the horizontal raster image passing through the foveal centre. The mean age was 65.1 ± 8.5 years. The CST values ranged from 189 to 661 lm, and BCVA in

Prevalence and Risk Factors of Early-Stage Age-Related Macular Degeneration in Patients Examined at a Health Promotion Center in Korea

We evaluated the prevalence and risk factors for early age-related macular degeneration (AMD) in Koreans 50 yr of age or older who were examined at a single health promotion center. We retrospectively reviewed the records of 10,449 subjects who visited the center over a 6-month period. Fundus photography was performed on all subjects, and systematic risk factor analysis was conducted using a structured questionnaire. All patients (n = 322) were initially diagnosed with drusen or early AMD using fundoscopy; the control group (n = 10,127) were those yielding normal fundoscopy findings. The age- and gender-adjusted prevalence of early AMD was 3.08%. Advanced age, male gender, smoking status, hyperlipidemia, working outdoors, and residence in rural areas were all significantly associated with an increased risk for development of early AMD. Higher-level ingestion of fruit or herbal medication and an increased amount of exercise were associated with a lower risk of early AMD development. In our Korean cohort, consisting principally of relatively healthy, middle-class urban adults, the prevalence of early AMD was 3.08% that is similar to that reported in earlier epidemiological studies. Several modifiable risk factors such as smoking and hyperlipidemia are associated with the prevalence of early AMD in our cohort.

Recurrent submacular hemorrhage in patients with neovascular age-related macular degeneration.

Purpose: To describe the incidence, risk factors for, and long-term visual outcomes of recurrent submacular hemorrhage in the context of age-related macular degeneration. Methods: Medical records of patients with neovascular age-related macular degeneration with or without polypoidal choroidal vasculopathy showing submacular hemorrhage at their first visit to our institution were reviewed. The required minimum follow-up period was 24 months, and any newly developed submacular hemorrhage larger than 1 disk area after near-complete resolution of initial hemorrhage was defined as recurrence. Results: A total of 47 eyes of 47 patients were eligible for inclusion. Twenty-four patients showed recurrent submacular hemorrhage during the follow-up period (Group I). Patients without recurrent submacular hemorrhage were included in Group II. The time to recurrent submacular hemorrhage in Group I patients was 21.4 ± 9.2 months. Polypoidal choroidal vasculopathy was present in 50% of Group I patients (n = 12) and 13% of Group II patients (n = 3) (P = 0.025). Intravitreal anti–vascular endothelial growth factor injection was performed during the follow-up period in 70.8% of Group I patients (n = 17) and 95.7% of Group II patients (n = 22) (P = 0.048). Visual acuity change during the follow-up period did not significantly differ between the two groups. Conclusion: In patients with neovascular age-related macular degeneration presenting with submacular hemorrhage at their first visit, the incidence of recurrent submacular hemorrhage was 51.1% in our retrospective long-term follow-up study. The presence of polypoidal choroidal vasculopathy was associated with an increased risk of recurrent submacular hemorrhage. Use of anti–vascular endothelial growth factor agents was correlated with a reduced risk of such hemorrhage. Visual acuity was stably maintained over 2 years regardless of hemorrhage recurrence.

Insights Into Epiretinal Membranes: Presence of Ectopic Inner Foveal Layers and a New Optical Coherence Tomography Staging Scheme

WE READWITH GREAT INTEREST THE ARTICLE BY GOVETTO and associates. In their retrospective study, the authors concluded that the presence of continuous ectopic inner foveal layers in epiretinal membranes (ERMs) is a newly described optical coherence tomography (OCT) finding associated with significant vision loss and is an essential element of a novel OCT-based grading scheme of ERMs that may influence visual prognosis. We have a few comments on the authors’ observations and would like to make some contributions with respect to the pathologic mechanisms of ERM. First, the current study seemed to confirm the conclusions of our previous publications. In our study including 134 eyes with idiopathic ERMs, we have shown that the inner retinal layer (IRL) thickness is the main determinant of visual acuity in patients with ERM. Our classification of types Ia, Ib, and Ic is very similar to the authors’ classification of stages 1, 2, and 3. Unlike our series, the current study separated a small proportion (6.2%) of long-standing complicated cases as stage 4 ERMs. In addition, we reported on ‘‘postoperative restoration of foveal inner retinal configuration in patients with ERM and abnormally thick inner retina,’’ after reviewing the surgical results of patients with type 1c ERM (stage 3 or 4 according to the current study). In that article, our hypothesis of foveal IRL thickening was that when the contractile forces induced by ERM are strong, the inward peak of the outer nuclear layer is exaggerated, resulting in attachment of the adjacent parafoveal IRLs. To be consistent with our hypothesis, when such tangential traction was released by surgical removal of ERM, the attached parafoveal IRL reopened and the degree of IRL restoration correlated well with the extent of visual recovery. OCT angiography findings of displacement of foveal vessels toward the foveal center in this current study also seemed to support our hypothesis of the attachment of parafoveal IRLs. In the Discussion section, the authors suggested that ‘‘ectopic’’ inner foveal layers might persist even after surgical removal of ERM, as shown by 1 case of stage 4 ERM. However, in our surgical series, approximately 40% of

Noninvasive identification of different intraocular lenses using Raman spectroscopy in porcine eyes

PURPOSE: To develop a noninvasive technique for identifying the specific type of intraocular lens (IOL) implanted in porcine eyes. SETTING: Department of Ophthalmology, University of Ulsan College of Medicine, Asan Medical Center, and Department of Chemistry Education, Seoul National University, Seoul, Korea. METHODS: A confocal Raman spectroscopy system was used to identify various acrylic (AcrySof SA60AT [Alcon], Sensar AR40e [Advanced Medical Optics], I‐Flex [I‐Medical Intraocular Lenses]) and silicone (ClariFlex, [Advanced Medical Optics]) IOLs implanted in enucleated pig eyes. Confocal Raman spectra of IOLs were obtained by photoexcitation using the 514.5 nm line from an argon‐ion laser, with a power of 1 mW at the sample and an acquisition time of 10 to 100 seconds. RESULTS: All IOLs, including those composed of acrylic optic material from different manufacturers, exhibited distinct spectral peaks before and after implantation in pig eyes. CONCLUSION: Confocal Raman spectroscopy may represent a novel method for obtaining specific information about implanted IOLs through direct and noninvasive confocal observation of spectral characteristics.