SURGICAL OUTCOME OF SIMULTANEOUS INTRAOCULAR LENS RESCUE AND SUTURELESS INTRASCLERAL TUNNEL FIXATION OF DISLOCATED INTRAOCULAR LENSES.

PURPOSE: To report short-term surgical outcomes of single-stage simultaneous rescue and sutureless intrascleral fixation of dislocated intraocular lens (IOLs). METHODS: Sixteen eyes of 16 patients who underwent simultaneous rescue and intrascleral fixation of dislocated 3-piece IOLs were retrospectively evaluated. Partial thickness limbal-based scleral flaps (2.0 × 2.0 mm) were created, and a 22-gauge round needle was used to create a sclerotomy at 1.5 mm from the limbus under the previously created scleral flap, and a 23-gauge trans pars plana vitrectomy was performed. Bimanual maneuvers using two 23-gauge end-grasping forceps under chandelier illumination and a wide-angle viewing system enabled 1 step rescue of IOLs from the posterior vitreous cavity with 1 hand and simultaneous haptic externalization through sclerotomy with the other hand. An externalized haptic was placed into the 3-mm intrascleral tunnel created using a bent 26-gauge needle. Fibrin glue was used to fixate haptics and close the scleral flaps. RESULTS: Intraocular lenses were successfully rescued and sclera-fixated through intrascleral tunnels in all 16 eyes (mean age, 56.56 ± 19.89 years). The mean preoperative logarithm of the minimum angle of resolution best-corrected visual acuity was 0.92 ± 0.68, and this significantly improved at 6 months to 0.289 ± 0.36 (P = 0.003). During the follow-up period (10.1 ± 3.21 months), no significant change of endothelial cell count or central foveal thickness was noted postoperatively (P = 0.203 and P = 0.979, respectively). There were no significant postoperative complications such as IOL dislocation, IOL decentration, retinal detachment, endophthalmitis, or postoperative hypotony. CONCLUSION: Simultaneous rescue and sutureless intrascleral haptic fixation of dislocated 3-piece IOLs using bimanual maneuvers is an effective, safe, and minimally invasive surgical method to rescue and fixate the dislocated IOL without further explant.

Regression of uveal melanoma after ru-106 brachytherapy and thermotherapy based on metabolic activity measured by positron emission tomography/computed tomography.

PURPOSE: To evaluate regression rates of uveal melanoma after combined Ru-106 plaque radiotherapy and thermotherapy according to metabolic activity measured by positron emission tomography/computed tomography imaging. METHODS: A retrospective medical chart review was conducted on 26 patients with uveal melanoma who underwent pretreatment whole-body positron emission tomography/computed tomography and received combined plaque radiotherapy and thermotherapy between 2006 and 2011. Tumors were classified as metabolically active and inactive based on the positron emission tomography/computed tomography imaging and compared with tumor height regression rates after treatment. RESULTS: Before treatment, the median tumor thickness was 8.8 mm for metabolically active tumors (7 eyes) and 5.0 mm for metabolically inactive tumors (19 eyes). The median tumor thicknesses with respect to the original thickness at 3, 6, and 12 months after treatment were 88%, 78%, and 64% for metabolically active tumors and 95%, 89%, and 81% for metabolically inactive tumors, respectively. The monthly tumor regression rates during the first 3 months (4.2% vs. 1.7%, P = 0.022) and the overall monthly tumor regression rates (3.0% vs. 1.5%, P = 0.041) were significantly higher for metabolically active tumors versus inactive tumors. Two patients with positive metabolic activity developed metastatic diseases 2 years after treatment, whereas no patient with negative metabolic activity developed metastatic disease during the study period. CONCLUSION: Positive metabolic activity of uveal melanoma based on the positron emission tomography/computed tomography was significantly associated with rapid initial tumor regression after combined plaque radiotherapy and thermotherapy, suggesting a prognostic value for this diagnostic approach.

Therapeutic outcomes of retinal hemangioblastomas.

PURPOSE: To report the results of treatments and therapeutic complications of retinal hemangioblastomas (RH). METHODS: Retrospective consecutive case series. Data from 32 patients (37 eyes) with RH were reviewed for characteristics of RH and treatment outcomes. RESULTS: Among 32 patients, we identified 73 RHs in 37 eyes. At baseline, 24 of 37 eyes (65%) had 20/50 visual acuity or better, 8 eyes (22%) had intermediate vision (20/400-20/50), and 5 eyes (13%) had poor vision (≤20/400). Seven RHs (9.6%) were located in the juxtapapillary area, and 66 RHs (90.4%) were located in peripheral area. Small RHs (54.8%; <0.5 mm in size) were treated with laser photocoagulation, moderate-sized RHs (24.7%; 0.5-3.0 mm in size) were treated with transpupillary thermotherapy, and large RHs (20.5%; >3.0 mm in size) were treated with a combination of transpupillary thermotherapy and cryotherapy. After treatment, 90% of small RHs regressed, whereas only 67% of large RHs regressed (P = 0.044). Peripheral RHs showed better response to treatment than juxtapapillary RHs (P = 0.010). Treatment-related complications occurred in 5 eyes (14%), and 1-step combination therapy was applied more frequently in the complication group (P = 0.048). CONCLUSION: Small RHs in peripheral areas may require aggressive treatment because they respond well to treatment. In larger RHs, staged treatment could reduce treatment-related complications. Transpupillary thermotherapy could be an effective method in tumor regression for moderate-to-large-sized RHs showing tumor regression rate of 70%.

Connexin 43 hemichannels mediate the Ca2+ influx induced by extracellular alkalinization.

Although alkaline pH is known to trigger Ca(2+) influx in diverse cells, no pH-sensitive Ca(2+) channel has been identified. Here, we report that extracellular alkalinization induces opening of connexin 43 hemichannels (Cx43 HCs). Increasing extracellular pH from 7.4 to 8.5, in the presence of physiological Ca(2+)/Mg(2+) concentrations, rapidly increased the ethidium uptake rate and open probability of HCs in Cx43 and Cx43EGFP HeLa transfectants (HeLa-Cx3 and HeLa-Cx43EGFP, respectively) but not in parental HeLa cells (HeLa-parental) lacking Cx43 HCs. The increase in ethidium uptake induced by pH 8.5 was not affected by raising the extracellular Ca(2+) concentration from 1.8 to 10 mM but was inhibited by a connexin HC inhibitor (La(3+)). Probenecid, a pannexin HC blocker, had no effect. Extracellular alkalinization increased the intracellular Ca(2+) levels only in cells expressing HCs. The above changes induced by extracellular alkalinization did not change the cellular distribution of Cx43, suggesting that HC activation occurs through a gating mechanism. Experiments on cells expressing a COOH-terminal truncated Cx43 mutant indicated that the effects of alkalinization on intracellular Ca(2+) and ethidium uptake did not depend on the Cx43 C terminus. Moreover, purified dephosphorylated Cx43 HCs reconstituted in liposomes were Ca(2+) permeable, suggesting that Ca(2+) influx through Cx43 HCs could account for the elevation in intracellular Ca(2+) elicited by extracellular alkalinization. These studies identify a membrane pathway for Ca(2+) influx and provide a potential explanation for the activation of cellular events induced by extracellular alkalinization.

Melanocytoma of the optic disk in the Korean population.

PURPOSE: To report on the clinical features and the natural course of optic disk melanocytoma in the Korean population. METHODS: A retrospective review of medical records was performed on 27 consecutive patients with optic disk melanocytoma. In cases with tumor enlargement, surface area and diameter of tumors were measured from fundus images using computer software. RESULTS: The median age at diagnosis was 46 years with a slight female predominance (63%). The median tumor diameter and height were 3.1 mm and 1.9 mm, respectively. There were no cases with tumor-related visual loss for a median follow-up of 2 years. Tumor enlargement was observed in 4 of 21 patients (19%) that had follow-up of 1 year or more with no malignant transformation. The mean change of tumor surface area was 2.4 mm (52% increase), and the mean change of tumor diameter was 1.8 mm over a mean follow-up of 53 months in 4 cases with tumor growth. Only tumor vascularization on fluorescent angiography correlated with tumor growth (Log-rank test; P = 0.049). Kaplan-Meier survival estimated that the tumor growth was 0% at 1 year, 14% at 5 years, and 57% at 8 years. CONCLUSION: Optic disk melanocytoma in the Korean population tends to be superiorly located in the optic disk, and visual prognosis was excellent. Periodic ocular examination is warranted because 57% of patients were estimated to show tumor enlargement by 8 years of follow-up.

Retinal toxicity of commercial tissue plasminogen activator is mediated by the induction of nitric oxide in the mouse retinal primary cells.

PURPOSE: Tissue plasminogen activator (tPA) is an efficient thrombolytic agent, but the dose-dependent retinal toxicity of intravitreal injection of commercial tPA (containing L-arginine) has been reported. Here, we sought to investigate the mechanism of tPA-induced cell death in mouse retinal cell cultures and the role of nitric oxide (NO). METHODS: Primary retinal cell cultures were maintained using glial conditioned medium (GCM) solution. Mouse retinal cell death was observed by using Hoechst-propidium iodide staining. Mouse retinal cell death was also measured by lactate dehydrogenase (LDH) assay. The formation of NO was measured using Griess reagent. RESULTS: tPA-induced cell death was detected in mouse retinal cell cultures by Hoechst-propidium iodide staining or LDH assay. L-arginine seems to be the major factor in retinal toxicity of commercial tPA (containing L-arginine). The formation of NO was markedly increased in mouse retinal cell cultures treated with tPA (containing L-arginine) or L-arginine. NO inhibitor reduced the cell death induced by commercially available tPA or L-arginine. CONCLUSIONS: This study suggests that l-arginine from commercial tPA (containing L-arginine) induces the majority of cell death in mouse retinal cell cultures and that its cytotoxicity may depend on the induction of NO.

Visual field defect caused by nerve fiber layer damage associated with an internal limiting lamina defect after uneventful epiretinal membrane surgery.

PURPOSE: To report a case of visual field defect caused by damage of the nerve fiber layer associated with an internal limiting lamina defect after uneventful epiretinal membrane peeling. DESIGN: Interventional case report. METHODS: In the right eye, a 43-year-old male patient developed a nasal step and mild inferior arcuate scotoma after uneventful epiretinal membrane surgery without any associated glaucoma. Transmission electron microscopy was performed on the epiretinal membrane specimens. RESULTS: An epiretinal membrane specimen showed adhesion between epiretinal membrane and axons of nerve fiber layer in the area of the internal limiting lamina defect. CONCLUSION: Adhesion between epiretinal membrane and retinal tissue in the area of the internal limiting lamina defect may cause damage of the nerve fiber layer and visual field defect after epiretinal membrane peeling.

Prevalence and risk factors of visual impairment and blindness in Korea: the Fourth Korea National Health and Nutrition Examination Survey in 2008-2010.

PURPOSE: To describe the age, gender specific prevalence and risk factors of visual impairment and blindness in Korea. METHODS: From 2008 to 2010, a total 14 924 randomly selected national representative participants of the Korea National Health and Nutrition Examination Survey underwent additional ophthalmologic examinations by the Korean Ophthalmologic Society. Best Corrected Distance Visual Acuity was measured using an international standard vision chart based on Snellen scale (Jin's vision chart). Independent risk factors for visual impairment were investigated using multivariate logistic regression analysis. RESULTS: The overall prevalence of visual impairment (≤20/40) of adults 40 years and older was 4.1% (95% CI, 3.6-4.6) based on the better seeing eye. The overall prevalence of blindness (≤20/200) for adults 40 years and older was 0.2% (95% CI, 0.1-0.3). Risk indicators of visual impairment were increasing age, low education status, living in rural area, being unemployed, being without spouse and the absence of private health insurance. The visually impaired were more likely to have eye diseases compared with the normal subjects, and they were less likely to utilize eye care. CONCLUSION: The prevalence of visual impairment was demonstrated to be higher while that of blindness was similar to previous population studies in Asia or U.S. Sociodemographic disparities are present in the prevalence of visual impairment and more targeted efforts are needed to promote vision screening in high risk groups.

Prognostic factors in vitrectomy for lamellar macular hole assessed by spectral-domain optical coherence tomography.

PURPOSE: To evaluate the association between the macular structure on spectral-domain optical coherence tomography (SD-CT) and visual outcome after vitrectomy for lamellar macular hole (LMH). METHODS: Best-corrected visual acuity (VA) and SD-OCT images of the macula were assessed before and after surgery in 30 eyes of 30 patients with a LMH. Preoperative VA and SD-OCT features were investigated as predictors of surgical outcome. RESULTS: Mean patient age was 65 years with female predominance (77%). Visual acuity improved in 19 eyes (63%) with an overall mean improvement of 1 Snellen line (from 20/65 to 20/50; p = 0.002) at a mean of 18 months after vitrectomy. Subgroup analysis showed that statistically significant visual benefit was only observed in patients with an intact photoreceptor inner segment/outer segment (IS/OS) junction (p = 0.003), with foveal thickness bigger than 100 µm (p = 0.004) and with initial VA better than 20/100 (p = 0.003). The most efficient model to predict final VA was the combination of preoperative VA and the presence or absence of IS/OS disruption (r(2) = 0.77, p < 0.001). CONCLUSIONS: Poor initial VA, the presence of a disrupted IS/OS junction or a thin fovea on preoperative SD-OCT predicted poor vision outcome after LMH surgery.

The effect of photodynamic therapy with rose bengal on posterior capsule opacification in rabbit eyes.

We investigated the in vivo effect of photodynamic therapy (PDT) using rose bengal on the development of posterior capsule opacification (PCO). Endocapsular phacoemulsification was performed on white rabbits, which were divided into 4 groups: control group; group 1, treated with visible light only; group 2, treated with rose bengal only, and group 3, treated with PDT. In the case of the PDT group, rose bengal dissolved in sodium hyaluronate was injected into the empty capsular bag and treated with visible light. Three months after surgery, the rabbits were sacrificed and the eyeballs enucleated. The obstruction rate of visible light caused by PCO was measured with an optical powermeter. The mean obstruction rate was 30.6% in the control group, 28.3% in group 1, 19.3% in group 2, and 14.3% in group 3. Group 3 showed a statistically significant decrease in PCO compared with the control group and group 1 (p = 0.0014). Our results suggest that PDT using rose bengal effectively decreased PCO in rabbit eyes.