Importance of Hemoglobin A1c Levels for the Detection of Post-Surgical Infection Following Single-Level Lumbar Posterior Fusion in Patients with Diabetes.

OBJECTIVE: Several studies have reported that patients with diabetes mellitus (DM) are vulnerable to infection. However, the mechanism underlying this remains unclear. We hypothesized that preoperative blood glucose levels in patients with DM may be a risk factor for surgical site infection (SSI). We aimed to investigate the relationship between hemoglobin A1c (HbA1c) level and SSI incidence following single-level spinal fusion surgery. METHODS: Patients with DM who underwent single-level lumbar posterior fusion surgery were retrospectively reviewed. Ninety-two patients were included and classified into the SSI and SSI-free groups. Clinical data with demographic findings were obtained and compared. The HbA1c cut-off value was defined using receiver operating characteristic (ROC) and area under the curve (AUC) analyses, which showed a significantly increased SSI risk. Potential variables were verified using multiple logistic regression analysis. RESULTS: Among the enrolled patients, 24 had SSI and 68 did not within 1 year. The preoperative HbA1c level was higher in patients with SSI (6.8%) than in the non-infected patients (6.0%; p=0.008). ROC analysis showed that if the HbA1c level is higher than 6.9%, the risk of SSI significantly increases (p=0.003; AUC, 0.708; sensitivity, 62.5%; specificity, 70.6%). The preoperative HbA1c level was significantly correlated with SSI incidence, after adjusting for potential variables (p=0.008; odds ratio, 4.500; 95% confidence interval, 1.486-13.624). CONCLUSION: The HbA1c level, indicating glycemic control, in patients with DM may be a risk factor for SSI in single-level lumbar spine posterior fusion.

Effect of Modic Changes in Cervical Degenerative Disease.

OBJECTIVE: Modic changes are signal intensity changes in adjacent vertebral bone marrow on magnetic resonance imaging. Few studies have investigated these changes with regard to the cervical spine. In this study, we investigated the associations between cervical degenerative disease and Modic changes. METHODS: We conducted a retrospective collection of radiological data in patients with neck pain at Pusan National University Yangsan Hospital from January 2010 to December 2014. A total of 169 patients were included in this study. Disc herniation grade, disc space height and global cervical lordosis (C2-C7 Cobb angle) were measured and analyzed. If Modic changes were present, we recorded the Modic change type based on the literature, vertebral level, age, sex, and surgical requirement. RESULTS: Sixty-six patients exhibited Modic changes in the cervical spine. Out of these 66 patients, Modic change type II (56 patients, 84.8%) and C5-6 vertebral level (23 patients, 34.8%) were the most predominant categories. Patients with Modic change showed worse outcomes in regard to disc herniation grade, disc space height and global cervical lordosis than patients without (p<0.01). Among 169 patients, 18 patients had undergone anterior cervical discectomy with fusion (ACDF). Patients with Modic changes (10 of 66 patients, 15.1%) had a greater probability of undergoing ACDF than those without (8 of 103 patients, 7.8%; p<0.01). CONCLUSION: Modic changes refer cervical degenerative changes, and incidence of ACDF is higher when the Modic changes are occurred.

Methallothionein-3 contributes to vascular endothelial growth factor induction in a mouse model of choroidal neovascularization.

In the present study, we investigated possible roles of the zinc (Zn)-binding protein metallothionein-3 (MT3) and cellular Zn in a mouse model of laser-induced choroidal neovascularization (CNV) using wild-type (WT) and MT3-knockout (KO) mice. Quantitative RT-PCR was used for the detection of MT3 mRNA. CNV was induced in mice between 8 and 12 weeks of age by disrupting the Bruch's membrane using an argon laser. Fundus photography and fluorescein angiography (FA) were performed 2 weeks following laser photocoagulation. The possible connection between MT3 and vascular endothelial growth factor (VEGF) expression was explored by quantifying VEGF levels in WT and MT3-KO mouse retinas by enzyme-linked immunosorbent assay. The role of Zn in VEGF expression was tested in WT and MT3-KO cells treated with pyrithione, with or without additional Zn, using immunoblotting and fluorescence photomicrography. Following laser-treatment, MT3-KO mice exhibited substantially smaller areas of CNV compared to WT mice. In addition, retinal angiograms revealed less severe fluorescein leakage in MT3-KO mice than in WT mice. On day 14 following the induction of CNV, VEGF expression was markedly increased in WT mice, but remained unchanged in MT3-KO mice. Consistent with the possible involvement of Zn released from MT3, raising intracellular Zn levels increased VEGF levels and activated its receptor, Flk-1, in both WT and MT3-KO retinal cells. Present results demonstrated that neural retinal cells express high levels of MT3, which might play a role in the process of CNV development. Moreover, Zn released from MT3 may contribute to VEGF induction.

Microincision vitrectomy surgery for myopic foveoschisis.

OBJECTIVE: To evaluate the technical feasibility and surgical outcome of microincision vitrectomy surgery (MIVS) in patients with myopic foveoschisis (MF). METHODS: In total, 33 eyes of 29 patients who underwent surgical intervention due to MF were included. The patients were diagnosed with MF by spectral-domain optical coherence tomography (SD-OCT) and followed up for 6 months after MIVS that included internal limiting membrane (ILM) peeling with or without intraocular gas tamponade. To identify factors affecting visual outcome, the best-corrected visual acuity, axial length, and SD-OCT findings were analysed. RESULTS: After surgery, the mean BCVA improved from 1.01 ± 0.46 logMAR to 0.76 ± 0.64 logMAR (p=0.004). Central subfield thickness in SD-OCT decreased from 431 ± 256 µm to 231 ± 72 µm after surgery (p<0.001). SD-OCT showed complete resolution of MF with complete foveal reattachment in 96% of patients (27/28). The accompanying macular hole was successfully closed in all four cases. Hypotony <6 mm Hg was seen in one eye only. At the end of surgery, eight of 24 eyes (33.3%) undergoing 25-gauge MIVS and four of nine eyes (44.4%) undergoing 23-gauge MIVS required sutures to close at least one sclerotomy site. Postoperative development of a macular hole was seen in one patient. It was successfully treated by reoperation using silicone oil tamponade. CONCLUSIONS: MIVS with ILM peeling appeared to yield favourable visual and anatomical outcomes for MF in highly myopic eyes.

The role of hyperthyroidism as the predisposing factor for superior sagittal sinus thrombosis.

Superior sagittal sinus thrombosis (SSST) is an uncommon cause of stroke, whose symptoms and clinical course are highly variable. It is frequently associated with a variety of hypercoagulable states. Coagulation abnormalities are commonly seen in patients with hyperthyroidism. To the best of our knowledge, there are few reports on the association between hyperthyroidism and cerebral venous thrombosis. We report on a 31-year-old male patient with a six-year history of hyperthyroidism who developed seizure and mental deterioration. Findings on brain computed tomography (CT) showed multiple hemorrhages in the subcortical area of both middle frontal gyrus and cerebral digital subtraction angiography (DSA) showed irregular intra-luminal filling defects of the superior sagittal sinus. These findings were consistent with hemorrhagic transformation of SSST. Findings on clinical laboratory tests were consistent with hyperthyroidism. In addition, our patient also showed high activity of factors IX and XI. The patient received treatment with oral anticoagulant and prophylthiouracil. His symptoms showed complete improvement. A follow-up cerebral angiography four weeks after treatment showed a recanalization of the SSS. In conclusion, findings of our case indicate that hypercoagulability may contribute to development of SSST in a patient with hyperthyroidism.

Comparison of posterior fixation alone and supplementation with posterolateral fusion in thoracolumbar burst fractures.

OBJECTIVE: We compared the radiological and clinical outcomes between patients who underwent posterior fixation alone and supplemented with fusion following the onset of thoracolumbar burst fractures. In addition, we also evaluated the necessity of posterolateral fusion for patients treated with posterior pedicle screw fixation. METHODS: From January 2007 to December 2009, 46 consecutive patients with thoracolumbar burst fracture were included in this study. On the basis of posterolateral fusion, we divided our patients into the non-fusion group and the fusion group. The radiological assessment was performed according to the Cobb's method, and results were obtained at immediately, 3, 6, 12 months after surgery. The clinical outcomes were evaluated using the modified Mcnab criteria at the final follow-up. RESULTS: The demographic data and the mean follow-up period were similar between the two groups. Patients of both groups achieved satisfactory clinical outcomes. The mean loss of kyphosis correction showed that patients of both groups experienced loss of correction with no respect to whether they underwent the posterolateral fusion. There was no significant difference in the degree of loss of correction at any time points of the follow-up between the two groups. In addition, we also compared the effect of fixed levels (i.e., short versus long segment) on loss of correction between the two groups and there was no significant difference. There were no major complications postoperatively and during follow-up period. CONCLUSION: We suggest that posterolateral fusion may be unnecessary for patients with thoracolumbar burst fractures who underwent posterior pedicle screw fixation.

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.

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.

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.

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.

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.

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 > or =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.

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.

Sutureless vitreoretinal surgery using a new 25-gauge transconjunctival system.

BACKGROUND AND OBJECTIVE: To evaluate the efficacy of vitreoretinal surgery using a new 25-gauge transconjunctival sutureless vitrectomy system. PATIENTS AND METHODS: Forty-one eyes of 41 consecutive patients were treated from July 2003 to October 2003. Diagnoses included diabetic vitreous hemorrhage (n = 19), diabetic tractional retinal detachment (n = 4), diabetic macular edema (n = 2), macular hole (n = 3), epiretinal membrane (n = 2), branch retinal vein occlusion (n = 3), central retinal vein occlusion (n = 1), vitreous opacity (n = 4), retinal detachment (n = 1), capsular block syndrome (n = 1), and submacular hemorrhage (n = 1). The procedure was combined with phacoemulsification in 14 eyes. RESULTS: All except 3 patients were operated on under retrobulbar anesthesia only. Four cases required the superior sclerotomy to be converted to a 20-gauge procedure. The mean operation time was 33 minutes and the mean balanced salt solution used was 59 cc. The mean visual acuity improved rapidly during 3 to 4 weeks following 25-gauge transconjunctival sutureless vitrectomy from 20/275 to 20/125, and then to 20/100 during the subsequent 5 months. Transient hypotony occurred in only 1 eye. Neither wound leakage nor infection was identified. CONCLUSION: Despite some limitations in surgical indications, 25-gauge transconjunctival sutureless vitrectomy appeared to increase the efficiency of vitrectomy and to facilitate postoperative visual recovery in various vitreoretinal diseases.

Acquired simulated brown syndrome following surgical repair of medial orbital wall fracture.

Simulated Brown syndrome is a term applied to a myriad of disorders that cause a Brown syndrome-like motility. We encountered a case of acquired simulated Brown syndrome in a 41-year-old man following surgical repair of fractures of both medial orbital walls. He suffered from diplopia in primary gaze, associated with hypotropia of the affected eye. We performed an ipsilateral recession of the left inferior rectus muscle as a single-stage intraoperative adjustment procedure under topical anesthesia, rather than the direct approach to the superior oblique tendon. Postoperatively, the patient was asymptomatic in all diagnostic gaze positions.