Boo Sup Oum

Toxicity of indocyanine green injected into the subretinal space: subretinal toxicity of indocyanine green.

Purpose To evaluate the toxicity of indocyanine green (ICG) injected into the subretinal space. Indocyanine green may come in contact with photoreceptors and retinal pigment epithelium through a macular hole during ICG-assisted peeling of the internal limiting membrane. Methods Balanced salt solution or ICG of various concentrations (0.6, 1.25, 2.5, or 5.0 mg/mL) was injected into the subretinal space of rabbit eyes and removed after 1 minute. After 3 days, 1 week, and 4 weeks, the eyes were enucleated and evaluated by light microscopy and electron microscopy. Results When the ICG of 1.25 mg/mL or higher concentration was injected into the subretinal space, degenerative changes of the photoreceptors and the retinal pigment epithelial cells were found after 3 days with light and electron microscopy. After 1 week, the outer retina was disintegrated and the photoreceptors were not found. After 4 weeks in the eyes with 1.25 mg/mL ICG, short photoreceptors and a thin outer nuclear layer were seen. In the eyes with 2.5 mg/mL or higher ICG, the photoreceptors and the outer nuclear layer were destroyed completely. Conclusion The results of this study suggest that the ICG of 1.25 mg/mL or higher concentration has toxicity to the outer retina of the rabbit and may cause adverse effects on the functional outcome after macular hole surgery.

Relationship between intraocular pressure and systemic health parameters in a Korean population

Purpose: This study aimed to evaluate the relationship between intraocular pressure (IOP) and age and obesity, adjusted for systemic health parameters such as sex and mean blood pressure, in a Korean population.

A comparative study of corneal endothelial changes induced by different durations of soft contact lens wear.

Abstract Purpose: To analyze the effect on the morphologic characteristics of the corneal endothelium of the duration of soft contact lens wearing periods. Methods: Ninety soft contact lens wearers were divided into three groups: short-term users, for less than 5 years (n=60 eyes); intermediate-term users, from 6 years to 10 years (n=60); long-term users, for more than 10 years (n=60). Thirty non-contact lens wearers (60 eyes) were included as controls. All eyes were examined with a specular microscope. Analysis of covariance was used to detect any differences among the controls and the various soft contact lens subgroups. Results: There was a significant correlation between duration of soft contact lens use and morphologic changes of corneal endothelium. All soft contact lens subgroups had a significantly greater coefficient of variation in cell size than non-contact lens users . The proportion of hexagonal cells and the mean corneal endothelial cell density in those using soft contact lenses for more than 6 years were significantly lower than in the control group . Soft contact lens wear was significantly correlated with decreasing corneal endothelial cell densities with time. Conclusion: The coefficient of variation in cell size may be a sensitive indicator of early morphologic changes of the corneal endothelium. As the decrease in cell density among the contact lens subgroups was significantly associated with the duration of soft contact lens wearing periods, it will be useful to investigate endothelial cell density for evaluation of corneal endothelial function concerned with contact lens wearing.

Cysticidal effect on acanthamoeba and toxicity on human keratocytes by polyhexamethylene biguanide and chlorhexidine.

Purpose: To evaluate the cysticidal effect of polyhexamethylene biguanide (PHMB) and chlorhexidine on Acanthamoeba and its toxic effect on cultured human keratocytes. Methods: Each well of a twofold-diluted Acanthamoeba cyst-containing suspension of 5 × 104 cysts/mL was treated with PHMB and chlorhexidine for 8, 24, and 48 hours to determine the minimal cysticidal concentration (MCC) of each disinfectant. Human corneal keratocytes (5 × 104cells/mL) were exposed to PHMB and chlorhexidine for the same time to determine the survival rate of keratocytes. Inverted phase-contrast and electron microscopy were used to observe the morphologic changes. Results: The mean MCC of PHMB for 8, 24, and 48 hours was 9.42, 5.62, and 2.37 μg/mL, respectively. The mean MCC of chlorhexidine for 8, 24, and 48 hours was 24.32, 10.02, and 7.02 μg/mL, respectively. The respective survival rate of keratocytes at the MCC was 91.7%, 64.6%, and 49.7% for PHMB and 95.7%, 90.6%, and 78.1% for chlorhexidine, respectively. The cysts and keratocytes showed more damaged appearances after treatment with PHMB than chlorhexidine. Conclusions: PHMB and chlorhexidine showed a similar amoebicidal efficacy. However, PHMB seemed to be more toxic to keratocytes than chlorhexidine.

Triamcinolone-Induced Intraocular Pressure Elevation: Intravitreal Injection for Macular Edema and Posterior Subtenon Injection for Uveitis

Purpose To assess the effect of intravitreal and posterior subtenon injections of triamcinolone acetonide (TA) on intraocular pressure (IOP). Methods we reviewed 42 consecutive eyes after intravitreal TA injection (IVTA) and 43 eyes following posterior subtenon TA injection (PSTA). All cases had a minimum follow-up time of three months. After injection, the value and time of the maximal IOP, the amount of IOP elevation and the needs of the medication were assessed. Results The IOP increased significantly (p<0.001) from 16.3±2.5 mmHg preoperatively to a mean maximum of 21.7±5.3 mmHg in the IVTA group, and from 15.3±4.5 mmHg to 20.6±3.0 mmHg in the PSTA group. An elevation in the IOP of more than 5 mmHg from the baseline IOP was seen in 52.4% of the IVTA group at a mean time of 3.1 weeks postoperatively, and 44.2% of the PSTA group displayed an IOP elevation at 5.9 weeks. Conclusions Both developed significant elevations of IOP, but this appeared at a later date in the PSTA group. Careful follow-up after local injection of steroids is necessary.

Clinical efficacy of the polyurethane stent without fluoroscopic guidance in the treatment of nasolacrimal duct obstruction

PURPOSE To evaluate the clinical efficacy of the polyurethane (Song) stent in the treatment of nasolacrimal duct obstruction without fluoroscopic guidance, especially at the junction between the lacrimal sac and nasolacrimal duct or at the nasolacrimal duct. DESIGN Retrospective noncomparative case series. PARTICIPANTS This study evaluated 59 cases of nasolacrimal duct obstruction in 53 patients, with mean epiphora of 36 months (range, 2 months-17 years). METHODS Without the assistance of a radiologist, a polyurethane nasolacrimal stent was placed by introducing a guidewire through the superior or inferior punctum into the canaliculus and advancing it across the obstruction into the opening of the inferior meatus of the nasal cavity. The mean follow-up period was 22 months (range, 12 months-48 months). MAIN OUTCOME MEASURES Patency of the lacrimal passage to irrigation and the duration of this procedure. RESULTS Complete resolution of epiphora was accomplished in 55 (93.2%) of the 59 eyes. There was recurrence of epiphora in four cases because of obstruction of the stent in three cases and obstruction of the common canaliculus by recurrent dacryocystitis in one case. CONCLUSIONS Polyurethane stenting without fluoroscopic guidance seems to be a valuable technique for primary management of nasolacrimal duct obstruction before dacryocystorhinostomy.

The treatment of lacrimal apparatus obstruction with the use of an inner canthal Jones tube insertion via a transcaruncular route.

BACKGROUND AND OBJECTIVE To evaluate the clinical utility of the lacrimal bypass surgery using Bowmans probe in treatment of obstruction of the lacrimal apparatus. PATIENTS AND METHODS This study evaluated 124 cases of obstruction of the lacrimal passage systems with mean epiphora of 2.7 years. An incision was made on the side of the caruncle, and the lacrimal bone was penetrated between the lacrimal sac and the nasal mucosa by Bowman #0. Insertion of a Jones tube was made at the new lacrimal pathway, a puctum dilator or scissors was introduced through the caruncle and dilated across the lacrimal bone into the nasal cavity. The Jones tube was introduced over the probe into the nasal cavity, and fixed at the caruncle with nonabsorbable suture material. RESULTS Complete resolution of epiphora was accomplished in 120 (96.8%) of 124 eyes; only 4 (3.2%) eyes failed during a mean of 17.1 months of follow-up. CONCLUSION This procedure is simple and safe with no facial scarring, short operation time, high success rate, and can be performed under local anesthesia. Therefore, the clinical utility of this procedure seems to be of value in treatment of complicated obstruction of the lacrimal apparatus.

Edema of the Photoreceptor Layer in Vogt-Koyanagi-Harada Disease Observed Using High-Resolution Optical Coherence Tomography

Purpose To evaluate the characteristics of fluid accumulation in the uveitic stage of Vogt-Koyanagi-Harada (VKH) disease using high resolution optical coherence tomography (OCT3). Methods Twenty-eight eyes in 14 patients with VKH disease were reviewed retrospectively. These 28 eyes were divided into 19 eyes with intraretinal fluid (C group) and 9 eyes without intraretinal fluid (N group). Changes in visual acuity and fluid accumulation observed using OCT were compared between the two groups. Results Visual acuity at the time of presentation was significantly worse in the C group than in the N group (p=0.005). The photoreceptor layer appeared to be double-layered due to a cystoid space in the C group. Layered structures and strands found in the cystoid space. Expanding sponge-form edema led to the development of a cystoid space in the photoreceptor layer. Intraretinal fluid resolved earlier than subretinal fluid. There were no observed differences in visual acuity between the two groups after four days of treatment. Conclusions Accumulation of intraretinal fluid was related to poor initial visual acuity, but not to final visual acuity. High resolution OCT findings indicate that edema of the photoreceptor layer participates in the development of a cystoid space.

Mitomycin c influence on inhibition of cellular proliferation and subsequent synthesis of type I collagen and laminin in primary and recurrent pterygia.

The purpose was to investigate the biological effects of mitomycin C (MMC) on the inhibition of cellular proliferation and the subsequent synthesis of extracellular matrix like type I collagen (PIP) and laminin on primary and recurrent pterygia. The 3H-thymidine assay for cellular proliferation was consistent with the MMC dose and time response of both pterygia. The cellular inhibitory effect of MMC was greater on recurrent pterygial cells than primary ones. The inhibition of laminin by MMC followed the dose and time-response curves, with a stronger effect found in recurrent pterygial cells, but no significant difference between the two types concerning type I collagen synthesis. The inhibition of fibroblast proliferation and subsequent synthesis of laminin by MMC was more marked in recurrent pterygium than the primary one.

Results Of Vitrectomy For Breakthrough Vitreous Hemorrhage Associated With Age-related Macular Degeneration And Polypoidal Choroidal Vasculopathy

Purpose:The purpose of this study was to evaluate the results of vitrectomy in patients with vitreous hemorrhage associated with age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV). Methods:A retrospective review was conducted of consecutive cases of patients undergoing pars plana vitrectomy for nonclearing vitreous hemorrhage associated with neovascular AMD or PCV. Results:Twenty-four eyes of 23 patients were included. The mean length of time from the onset of vitreous hemorrhage to operation was 4.3 months. Twelve eyes had AMD, and 12 eyes of 11 patients had PCV. Additional treatments for active choroidal neovascular-ization or PCV were required in 12 eyes during follow-up. The mean visual acuity improved significantly from a logarithm of the minimum angle of resolution of 2.79 ± 0.85 before operation to 1.61 ± 0.98 at 2 months after operation (P < 0.001). Visual acuity was ≥20/200 in 9 eyes (37.5%) at 2 months after operation; 1 eye was in the AMD group, and the other eyes were in the PCV group. Improvement was more frequently observed in the PCV group (P = 0.005). Conclusion:In this series, the functional outcomes of vitrectomy for vitreous hemorrhage associated with AMD were inferior to outcomes of the PCV group. Vitrectomy is beneficial for improving visual function in select cases of breakthrough vitreous hemorrhage.