Optic Nerve Head Morphology is Associated with the Initial Location of Structural Progression in Early Open Angle Glaucoma.

PRCIS: Glaucoma eyes with a small cup-to-disk ratio (CDR) tend to show retinal nerve fiber layer progression earlier than ganglion cell-inner plexiform layer progression. PURPOSE: To investigate the effects of clinical variables on the temporal relationship between macular ganglion cell-inner plexiform layer (mGCIPL) loss and peripapillary retinal nerve fiber layer (pRNFL) loss in glaucoma. METHODS: This retrospective observational study used medical records of patients diagnosed with open angle glaucoma. Structural change was determined using guided progression analysis software of Cirrus optical coherence tomography. Based on the time of detection of pRNFL and mGCIPL changes, eyes showing progressive layer loss were categorized into the pRNFL-first and mGCIPL-first groups. The association between sites of layer thinning and clinical variables such as major retinal arterial angles and several optic disk measurements, including disk area, average CDR, and vertical CDR, were analyzed. RESULTS: A total of 282 eyes were included in the study, of which 104 showed structural progression either in the mGCIPL or pRNFL. Out of these, 49 eyes showed the first progression in pRNFL, while 37 eyes showed the first progression in mGCIPL. The minimum mGCIPL thickness, pRNFL thickness, average CDR, vertical CDR, and location of progression were significantly different between the 2 groups ( P =0.041, P =0.034, P =0.015, P <0.001, and P <0.001, respectively). In multivariate analysis, average CDR and vertical CDR were significantly associated with the progression site ( P =0.033 and P =0.006, respectively). The structural changes in the inferoinferior area and the superior vulnerability zone were significantly associated with RNFL-first progression ( P <0.001 for both). CONCLUSION: The location of layer loss and CDR are related to the layer where loss is first detected (either pRNFL or mGCIPL) in open angle glaucoma.

Risk factors for undergoing surgery in patients with newly diagnosed open-angle glaucoma.

Despite the clinical importance of glaucoma surgery, studies on its prevalence and risk factors are limited. We analyzed a database comprising approximately 1,000,000 Korean residents to investigate the prevalence and risk factors for undergoing glaucoma surgery within 5 years of diagnosis with open-angle glaucoma. Of the 4,303 patients evaluated, 226 (5.3%) underwent glaucoma surgery. Factors associated with the likelihood of glaucoma surgery included the use of two or more eye drops (odds ratio [OR], 30.30; 95% confidence interval [CI], 10.95-83.84), intake of oral carbonic anhydrase inhibitor (OR, 1.79; 95% CI, 1.23-2.61), age > 55 years (55-65 years: OR, 1.71; 95% CI, 1.06-2.76; > 65 years: OR 1.72; 95% CI, 1.10-2.70), female sex (OR, 1.46; 95% CI, 1.10-1.94), middle- and high-income (OR, 2.36; 95% CI, 1.30-4.28, OR, 1.86; 95% CI, 1.03-3.35, respectively), and metropolitan residence (OR, 1.61; 95% CI, 1.14-2.26). Our nomogram for predicting the likelihood of glaucoma surgery showed an acceptable result. In conclusion, older age, female sex, and the intensity of intraocular pressure lowering treatment increased the likelihood of undergoing glaucoma surgery. Our findings indicated that a lower socioeconomic status may forestall receiving this necessary surgery, which requires further attention.

Efficacy and Safety of Preservative-free Latanoprost Eyedrops Compared with Preserved Prostaglandin Analogues in Patients with Open-angle Glaucoma.

PURPOSE: To evaluate the safety and efficacy of preservative-free (PF) latanoprost in glaucoma patients. METHODS: In this prospective, open-label, observational study, a total of 27 primary open-angle glaucoma patients who used benzalkonium chloride-preserved prostaglandin analogues for at least 6 months were enrolled. After changing the eye drops to PF lataprost, the intraocular pressure (IOP) and ocular surface symptoms and signs were evaluated in all patients on days 0 (first visit, D0), 45 (D45), and 90 (D90). RESULTS: Mean IOP remained stable during the study period (14.0 ± 2.4 mmHg at D0, 13.9 ± 2.0 mmHg at D45, 13.7 ± 2.2 mmHg at D90; p = 0.603). Mean deviation, pattern standard deviation, and best-corrected visual acuity were similar before and after eye drops replacement. Bulbar conjunctival hyperemia, corneal staining, and conjunctival staining were significantly decreased over 90 days (p = 0.025, p < 0.001, p = 0.020, respectively). The ocular surface disease index score showed a statistically significant improvement from 26.4 ± 18.5 at D0 to 19.8 ± 17.0 at D45 and 15.7 ± 15.6 at D90 (p < 0.001). In the evaluation of ocular tolerability, burning symptoms and dryness were significantly decreased (p = 0.001, p = 0.040). CONCLUSIONS: The effects of PF latanoprost on reducing IOP were comparable with those of benzalkonium chloride-preserved prostaglandin analogues, but side effects on the ocular surface were much less pronounced when PF latanoprost was used. With this efficacy, PF latanoprost could slow the progression of glaucoma by increasing patient compliance.

Incidence, Comorbidity, and Mortality of Primary Congenital Glaucoma in Korea from 2001 to 2015: A Nationwide Population-based Study.

PURPOSE: To report incidence rates of primary congenital glaucoma in Korea and evaluate comorbidity and mortality from 2001 to 2015. METHODS: This study is a nationwide and retrospective population-based study. We used claims data from the Korean National Health Insurance Service database between 2001 and 2015. Data for all patients diagnosed with primary congenital glaucoma were retrieved using the Korean Electronic Data Interchange and Korean Standard Classification of Diseases-6 codes. RESULTS: The number of patients with primary congenital glaucoma between 2001 and 2015 was 776, of which 437 were male (56.31%) and 339 were female (43.69%). The annual prevalence demonstrated a general decreasing trend since 2011, but this was not significant. Over the total survey period, the incidence rate was 11.0 per 100,000 births, with 12.0 cases among males and 10.0 among females. The incidence according to age was 518 (68.78%) patients at age 0, 112 (13.66%) at 1 year, 70 (8.39%) at 2 years, and 76 (9.17%) at 3 years. Of the 776 patients diagnosed with primary congenital glaucoma in the study population, 27 died. The observed mortality per 100,000 people is about 10 times higher than that of the general infant and child population under the age of 4 years. Visual impairment was the most common accompanying disability, followed by brain lesion. CONCLUSIONS: Our study's estimates of the nationwide population-based incidence of primary congenital glaucoma in a Korean population will expand our understanding of the disease and allow healthcare systems to plan for primary congenital glaucoma.

The Association between Symptoms of Dry Eye Syndrome and Metabolic Outcome in a General Population in Korea.

Dry eye syndrome (DES) is recognized as a public health concern. One of the pathophysiologies in the development of DES is inflammation, and metabolic syndrome (MetS), which is highly prevalent in the general population, is a well-known chronic and systemic inflammatory condition. Despite the increasing interest regarding a relationship between DES and MetS, information is lacking on the association between DES and MetS and its individual components. We investigated the association between DES symptoms and MetS and its components among adults aged ≥ 19 years using population-based data from the Korea National Health and Nutrition Examination Survey V. A sample group of 15,294 adults (42.67% men and 57.33% women) completed household interviews in which they provided blood (for high-density lipoprotein cholesterol, triglyceride, and glucose) and anthropometric measurements (including waist circumference, weight, and height) to define MetS. We also collected information regarding sociodemographic and behavioral risk factors. The survey results showed that 11.50% of men and 22.35% of women experienced DES and 5.30% of patients had both DES and diagnosis of MetS, including 204 men and 606 women. Thus, no significant difference was observed between DES and the diagnosis of MetS according to sex (P = 0.4008 in men; P = 0.0804 in women); however, a significant association was observed between DES and hypertriglyceridemia in women (OR, 1.13; 95% CI, 1.01-1.29). Therefore, hypertriglyceridemia might be an important factor in the association between DES and MetS. Further longitudinal research is needed to evaluate this relationship.

Short-term effects of Ginkgo biloba extract on peripapillary retinal blood flow in normal tension glaucoma.

PURPOSE: Based on the vascular theory of glaucoma pathogenesis, we wanted to evaluate the effect of Ginkgo biloba extract (GBE) on peripapillary blood flow in patients with normal tension glaucoma (NTG). METHODS: Thirty patients with NTG were randomly placed in the GBE-treated or control groups. The GBE-treated group received 80 mg GBE orally, twice a day for four weeks, and the control group received a placebo twice a day for four weeks. Complete ocular examinations including visual field, Heidelberg retina flowmeter, and systemic examinations were performed on the first study day and on the day treatment was completed. RESULTS: After GBE treatment, the mean blood flow, volume, and velocity increased at almost all points, and there was a statistically significant increase in blood flow at almost all points, in comparison to the placebo. Blood volume significantly increased only in the superior nasal and superior temporal neuroretinal rim areas. GBE also significantly increased blood velocity in areas of the inferior temporal neuroretinal rim and superior temporal peripapillary area. CONCLUSIONS: GBE administration appears to have desirable effect on ocular blood flow in NTG patients.

Intraocular pressure reduction in normal-tension glaucoma patients in South Korea.

To evaluate the potential benefit of intraocular pressure (IOP) reduction in normal-tension glaucoma (NTG) patients in South Korea. A retrospective, multi-center analysis of Korean NTG patients with 5-years follow-up, typical glaucomatous optic disc and/or visual field changes and no recorded IOP >21 mmHg. Progression was identified by Advanced Glaucoma Intervention Study visual field scoring. There were 90 (42%) progressed patients and 127 (58%) stable patients included in the study. Mean IOP measured higher in the progressed (14.3 ± 2.2 mmHg) than stable patients (14.0 ± 1.9 mmHg), but was not statistically different between the groups (P = 0.29). The mean IOP that best discriminated stable patients was ≤15 mmHg, but no statistical difference existed in the numbers of progressed versus stable patients at ≤15 mmHg compared to >15 mmHg (P = 0.07). Multivariate regression analysis showed that the baseline number of glaucoma medicines and visual field as well as mean, peak and fluctuation of IOP were significant risk factors for glaucomatous progression (P < 0.01). This study suggests that in Korean NTG patients, despite relatively similar IOPs between progressed and stable patients, and based on multivariate regression analysis, IOP may be a risk factor for glaucomatous progression.

Out-coupling efficiency enhancement of organic light emitting diode device by SiO2-UV hardener composite layer.

The enhancement of out-coupling efficiency of organic light emitting diode (OLED) using SiO2-polymer composite layers was investigated. The SiO2-polymer composite was made from a SiO2 nanopowder and commercial UV-hardeners. The composite layer was coated on glass by dip-coating method in a SiO2 suspension, followed by spin-coating of 1 microm thick UV-hardener of was found that the optical properties were depend on the quantity of SiO2 nanopowder in the composite layer and dispersion of SiO2 suspension. 194/440 nm size of SiO2 nanopowders were added to the composite layer to enhance the light scattering effect. The OLED device which the SiO2-polymer composite layer was applied showed enhanced out-coupling efficiency around 30%.

A retained lens fragment induced anterior uveitis and corneal edema 15 years after cataract surgery.

A 60-year-old male was referred to the ophthalmologic clinic with aggravated anterior uveitis and corneal edema despite the use of topical and systemic steroids. He had undergone cataract surgery in both eyes 15 years previous. Slit lamp examinations revealed a retained lens fragment in the inferior angle of the anterior chamber, with severe corneal edema and mild anterior uveitis. The corneal edema and uveitis subsided following surgical extraction of the lens fragment. That a retained lens fragment caused symptomatic anterior uveitis with corneal edema 15 years after an uneventful cataract surgery is unique. A retained lens fragment should be considered as one of the causes of anterior uveitis in a pseudophakic patient.

Stability of the posterior corneal surface after laser surface ablation for myopia.

PURPOSE: The purpose of this study was to evaluate changes in the posterior corneal surface before and after laser surface ablation using the Pentacam. METHODS: Thirty consecutive myopic eyes having laser surface ablation (14 photorefractive keratectomies, 16 laser-assisted subepithelial keratectomies) were evaluated preoperatively and postoperatively with the Pentacam. Changes in the posterior corneal curvature, posterior elevation, and anterior chamber depth were measured. RESULTS: The 30 eyes had a mean correction of -4.50 D (range, -2.12 to -8.0) and a mean ablation depth of 58.4 microm (range, 21-106 microm). The change in mean posterior corneal curvature was -0.02 +/- 0.07 mm in the central 4-mm zone (P = 0.106) and the mean posterior displacement was 0.47 +/- 4.23 microm (P = 0.551). The mean change in the anterior chamber depth was -0.06 +/- 0.08 mm (P < 0.001). The amount of forward shift of the posterior corneal surface had no correlation with the residual corneal thickness and ablation depth. CONCLUSIONS: There was no significant change in the posterior corneal surface after laser surface ablation.

Decrease in work function of transparent conducting ZnO tin films by phosphorus ion implantation.

To confirm the possibility of engineering the work function of ZnO thin films, we have implanted phosphorus ions into ZnO thin films deposited by radio-frequency magnetron sputtering. The fabricated films show n-type characteristics. It is shown that the electrical and optical properties of those thin films vary depending sensitively on the ion dose and rapid thermal annealing time. Compared to as-deposited ZnO films, the work-function of phosphorus ion-implanted ZnO thin films is observed to be lower and decreases with increasing ion doses. It is likely that the zinc or oxygen vacancies are firstly filled with the implanted phosphorus ions. With further increased ions, free electrons are generated as Zn2+ sites are replaced by those ions or interstitial phosphorus ions increase at the lattice sites, the fermi level by which approaches the conduction band and thus the work function decreases. Those films exhibit the optical transmittance higher than 85% within the visible wavelength range (up to 800 nm).

Investigation on growth behavior of CNTs synthesized by atmospheric pressure plasma enhanced chemical vapor deposition system on Fe catalyzed substrate.

We have studied growth behavior of carbon nanotubes (CNTs) on iron (Fe) catalyzed substrate using newly developed atmospheric pressure plasma enhanced chemical vapor deposition (AP-PECVD) system. To investigate the improved growth performance with simple equipment and process on large scale, a new AP-PECVD system containing different concept on downstream gas was designed and manufactured. As a catalyst, either sputtered or evaporated Fe thin film on SiO2/Si substrate was used and acetylene gas was used as a carbon source. We observed growth behavior of CNTs such as height, rate and density were strongly affected by plasma power. The maximum height of 427 microm and 267 microm was synthesized under RF plasma power of 30 W for 30 min and 40 W for 3 min, respectively. The growth rate dramatically increased to 6.27 times as plasma power increased from 30 to 40 W which opens the possibility the mass production of CNTs. By SEM and TEM observation, it was verified the grown CNTs was consists of mixture of single-wall and multi-wall CNTs. The graphitization ratio was measured to be 0.93, indicating that the graphitized CNTs forest was formed and relatively high purity of CNTs was synthesized, being useful for nano-composite materials to reinforce the strength. From our experiments, we can observe that the height and growth rate of CNTs is strong function of plasma power.

Decrease in work function of boron ion-implanted ZnO thin films.

We have fabricated boron ion-implanted ZnO thin films by ion implantation into sputtered ZnO thin films on a glass substrate. An investigation of the effects of ion doses and activation time on the electrical and optical properties of the films has been made. The electrical sheet resistance and resistivity of the implanted films are observed to increase with increasing rapid thermal annealing (RTA) time, while decreasing as the ion dose increases. Without any RTA process, the variation of the carrier density is insensitive to the ion dose. With the RTA process, however, the carrier density of the implanted films increases and approaches that of the un-implanted ZnO film as the ion dose increases. On the other hand, the carrier mobility is shown to decrease with increasing ion doses when no RTA process is applied. With the RTA process, however, there is almost no change in the mobility. We have achieved the optical transmittance as high as 87% within the visible wavelength range up to 800 nm. It is also demonstrated that the work function can be engineered by changing the ion dose during the ion implantation process. We have found that the work function decreases as the ion dose increases.

Work function increase of Al-doped ZnO thin films by B+ ion implantation.

The work function of an Al-doped ZnO (AZO) thin film can be increased via B+ ion implantation from 3.92 eV up to 4.22 eV. The ion implantation has been carried out with the ion dose of 1 x 10(16) cm(-2) and ion energy of 5 keV. The resistance of the B+ implanted AZO films has been a bit raised, while their transmittance is slightly lowered, compared to those of un-implanted AZO films. These behaviors can be explained by the doping profile and the resultant band diagram. It is concluded that the coupling between the B+ ions and oxygen vacancies would be the main reason for an increase in the work function and a change in the other properties. We also address that the work function is more effectively alterable if the defect density of the top transparent conducting oxide layer can be controlled.