Chang-Sik Kim

Prevalence of Primary Open-Angle Glaucoma in Central South Korea: The Namil Study

PURPOSE To assess the prevalence of primary open-angle glaucoma (POAG) in the Namil-myon area in central South Korea. DESIGN A cross-sectional, epidemiologic study in a defined population. PARTICIPANTS Residents aged ≥ 40 years in Namil-myon, a rural agricultural area in central South Korea. METHODS Each subject underwent a screening that consisted of an interview and ophthalmic examinations, including visual acuity measurement, autorefraction, anterior segment evaluation by optical biometry, slit-lamp examination, Goldmann applanation tonometry, binocular optic disc evaluation, fundus photography, pachymetry, gonioscopy, and screening visual field test using frequency doubling technology. Subjects with suspected glaucoma were referred for definitive examinations. Standard automated field tests and retinal nerve fiber layer analysis using optical coherence tomography (Stratus OCT) or scanning laser polarimetry (GDx VCC) were performed. A diagnosis of glaucoma was made based on the optic disc shape, retinal nerve fiber layer appearance, perimetric results, and other ocular findings. MAIN OUTCOME MEASURES Prevalence of POAG, mean intraocular pressure (IOP), and mean central corneal thickness (CCT). RESULTS Of 1928 eligible residents in the area, 1532 (79.5%) participated in this study. The estimated prevalence of POAG in the population aged ≥ 40 years was 3.5% (95% confidence interval [CI], 2.7%-4.3%). The prevalence of POAG with an IOP of ≤ 21 mmHg was 2.7% (95% CI, 2.1%-3.3%), and the prevalence of POAG with an IOP of ≥ 22 mmHg was 0.8% (95% CI, 0.4%-1.2%). The mean IOP for POAG eyes (16.3 ± 4.6 mmHg) was significantly higher than nonglaucomatous eyes (13.3 ± 2.7 mmHg; P = .001). The mean CCT of POAG eyes with an IOP of ≤ 21 mmHg was 528 ± 26 μm, and that of POAG eyes with an IOP ≥ 22 mmHg was 531 ± 37 μm; these values were not significantly different from that of nonglaucomatous eyes (530 ± 31 μm; P = .943 and .996, respectively). CONCLUSIONS The prevalences of POAG and POAG with an IOP ≤ 21 mmHg in the Namil-myon region of central South Korea were higher than that in most previous reports worldwide, but were similar to the reported rates in black and Japanese populations. The mean IOP of POAG eyes was higher than nonglaucomatous eyes, but the mean CCTs were not different. FINANCIAL DISCLOSURE(S) The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Changes in Corneal Endothelial Cells after Ahmed Glaucoma Valve Implantation: 2-Year Follow-up

PURPOSE To evaluate changes in corneal endothelial cells after Ahmed glaucoma valve (AGV) implantation for the treatment of refractory glaucoma. DESIGN Observational case series. METHODS We prospectively evaluated the change in density and shape of the corneal endothelium in 41 patients (41 eyes) who had undergone AGV implantation for the treatment of refractory glaucoma. Corneal specular microscopy was performed on the superior, supratemporal, supranasal, and central areas with a noncontact specular microscope before surgery and 1, 6, 12, 18, and 24 months after surgery. The changes at each time point were compared with those at baseline and with those of the control group, which consisted of 20 contralateral glaucomatous eyes receiving antiglaucoma medications. RESULTS The mean follow-up was 19.1 months. The average percentage decrease in corneal endothelial cell count was 5.8% at 1 month, 11.5% at 6 months, 15.3% at 12 months, 16.6% at 18 months, and 18.6% at 24 months after surgery. The changes were statistically significant compared with those at baseline and those of the control eye at all time points during the study period (P < .05). The supratemporal area, the closest site to the tube, showed the greatest decrease in endothelial cell density, by 22.6%, whereas the central cornea showed the smallest decrease, by 15.4%, at 24 months after surgery. CONCLUSIONS There was statistically significant corneal endothelial cell loss in the operated eye after AGV implant surgery. The corneal endothelial cell loss increased with time: 15.3% at 12 months and 18.6% at 24 months after surgery, on average, in all measured areas.

The association between conjunctival MALT lymphoma and Helicobacter pylori.

Background/aims: Helicobacter pylori is well known to be responsible for gastric mucosa-associated lymphoid tissue (MALT) lymphoma. This study evaluates whether H pylori is also responsible for conjunctival MALT lymphoma and which strain of H pylori is associated with conjunctival MALT lymphoma. Methods: Fifteen cases of conjunctival MALT lymphoma were investigated. Eight biopsies of normal conjunctiva were also investigated as controls. The specimens were investigated for the presence of H pylori DNA with polymerase chain reaction (PCR) using 16S rDNA primer. When the PCR using 16S rDNA was positive for H pylori, the specimens were analysed for the virulent gene with PCR using vacA s1/2 primer and vacA m1/2 primer. Results: H pylori DNA was identified in all 15 specimens of conjunctival MALT lymphomas and none of the controls. Of these 15 H pylori positive lymphoma specimens, the vacA s1 and vacA m2 alleles were detected in two, and only vacA s1 allele was detected in 11. Conclusions: H pylori is thought to play a role in the pathogenesis of conjunctival MALT lymphoma, and H pylori with vacA s1 allele appears to be a virulent strain for conjunctival MALT lymphoma.

Sectoral Retinal Nerve Fiber Layer Thinning In Branch Retinal Vein Occlusion

Purpose: To analyze longitudinal changes in the retinal nerve fiber layer (RNFL) thickness in branch retinal vein occlusion (BRVO) using optical coherence tomography. Methods: The authors prospectively analyzed 20 eyes in 20 patients diagnosed with branch retinal vein occlusion (BRVO) and followed for more than 1 year. The RNFL thickness of the normal and occluded eyes was measured at the time of diagnosis and at 1, 3, 6, and 12 months. The authors compared the changes in the occluded eye over the follow-up and the differences between two eyes at each time. They also analyzed the area opposite the occluded area. Results: The thickness of the RNFL in BRVO was significantly reduced at 1, 3, 6, and 12 months (P = 0.005 at 1 month and P = 0.001 at 3, 6, and 12 months) compared with initial thickness. The RNFL thickness at 3 months did not differ significantly between 2 eyes, whereas at 6 months and 12 months, significant (P = 0.032, P = 0.002, respectively.) thinning was observed in the occluded eye. Analysis of the area opposite that of BRVO revealed no significant (P > 0.05) change during the follow-up and no difference between the 2 eyes. Conclusion: There was a significant decrease in RNFL thickness over time in BRVO and significant thinning at 6 months compared with the normal eye. Retinal nerve fiber layer thinning needs to be differentiated from glaucoma or systemic disease, but it should be considered the natural course after BRVO.

Comparison of experimental porous silicone implants and porous silicone implants

BackgroundTo investigate the extent and pattern of fibrovascular ingrowth of porous silicone sphere implants compared to porous polyethylene implants.MethodsExperimental porous silicone sphere implants and porous polyethylene implants were implanted in the left socket of 20 New Zealand white rabbits after enucleation. Fibrovascular ingrowth and maturation was evaluated at 4 weeks and 8 weeks after implantation by histopathologic examination and scanning electron microscope.ResultsAt 4 weeks after surgery, porous polyethylene implants showed deeper fibrovascular ingrowth than porous silicone sphere implants; 42.4% versus 34.2% of radius of the implants respectively (p = 0.047). However there was no significant difference in the depth of fibrovascular ingrowth between the two groups at 8 weeks after implantation, although porous polyethylene implants showed deeper fibrovascular ingrowth than porous silicone sphere implants; 71.6% versus 63.6% (p = 0.102).ConclusionsPorous silicone orbital implants demonstrated a comparable extent of fibrovascular ingrowth to that for porous polyethylene implants. Therefore, this new porous silicone sphere implant may be a good candidate to substitute for current porous implants at a lower cost.

Factors that influence intraocular pressure after cataract surgery in primary glaucoma.

OBJECTIVE We sought to find predictive factors for favourable postoperative intraocular pressure (IOP) after cataract surgery in patients with primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG). STUDY DESIGN Retrospective evaluation of patients who had undergone cataract surgery. PARTICIPANTS Forty-eight patients with POAG and 48 patients with PACG. METHODS Various clinical factors were evaluated retrospectively in 96 patients. All patients had undergone standard 2.75-3.5 mm limbal incision cataract surgery. Clinical parameters in patients with successful postoperative IOP courses were compared with those in unsuccessful patients. Success was defined as an IOP between 6 and 21 mm Hg, with fewer antiglaucoma medications needed compared with before surgery, and no need of additional glaucoma surgery. RESULTS In POAG, eyes with a highest preoperative IOP of <31 mm Hg or those being treated with <3 antiglaucoma medications before surgery had a significantly higher probability of success. In PACG, the probability of success was significantly higher if the highest preoperative IOP was <42 mm Hg, the number of antiglaucoma medications before surgery was <3, or the areas of peripheral anterior synechiae were <4 clock hours. CONCLUSIONS Primary small-incision cataract surgery using phacoemulsification and foldable intraocular lens implantation may be the procedure of choice in patients with medically controlled glaucoma and coexisting visually significant cataracts, considering the highest preoperative IOP and number of antiglaucoma medications in POAG and PACG, and the area of peripheral anterior synechiae in PACG.

Changes in Corneal Endothelial Cell after Ahmed Glaucoma Valve Implantation and Trabeculectomy: 1-Year Follow-up

Purpose To compare changes in corneal endothelial cell density (CECD) after Ahmed glaucoma valve (AGV) implantation and trabeculectomy. Methods Changes in corneal endothelium in patients that underwent AGV implantation or trabeculectomy were prospectively evaluated. Corneal specular microscopy was performed at the central cornea using a non-contact specular microscope before surgery and 6 months and 12 months after surgery. The CECD, hexagonality of the endothelial cells, and the coefficient of variation of the cell areas were compared between the two groups. Results Forty eyes of 40 patients with AGV implantation and 28 eyes of 28 patients with trabeculectomy were studied. Intraocular pressure in the AGV implantation group was significantly higher than that in the trabeculectomy group (p < 0.001), but there was no significant difference in other clinical variables between the two groups. In the AGV implantation group, the mean CECD significantly decreased by 9.4% at 6 months and 12.3% at 12 months compared with baseline values (both, p < 0.001), while it decreased by 1.9% at 6 months and 3.2% at 12 months in the trabeculectomy group (p = 0.027 and p = 0.015, respectively). The changes at 6 months and 12 months in the AGV implantation group were significantly higher than those in the trabeculectomy group (p = 0.030 and p = 0.027, respectively). In the AGV implantation group, there was a significant decrease in the CECD between baseline and 6 months and between 6 months and 12 months (p < 0.001 and p = 0.005, respectively). However, in the trabeculectomy group, a significant decrease was observed only between baseline and 6 months (p = 0.027). Conclusions Both the AGV implantation group and the trabeculectomy group showed statistically significant decreases in the CECD 1 year after surgery. The decrease in CECD in the AVG implantation group was greater and persisted longer than that in the trabeculectomy group.

Changes in corneal endothelial cell density and the cumulative risk of corneal decompensation after Ahmed glaucoma valve implantation

Aims To evaluate changes in the corneal endothelial cell density (ECD) and corneal decompensation following Ahmed glaucoma valve (AGV) implantation. Methods This study was retrospective and observational case series. Patients with refractory glaucoma who underwent AGV implantation and were followed >5 years were consecutively enrolled. We reviewed the medical records, including the results of central corneal specular microscopy. Of the 127 enrolled patients, the annual change in ECD (%) was determined using linear regression for 72 eyes evaluated at least four times using serial specular microscopic examination and compared with 31 control eyes (fellow glaucomatous eyes under medical treatment). The main outcome measures were cumulative risk of corneal decompensation and differences in the ECD loss rates between subjects and controls. Results The mean follow-up after AGV implantation was 43.1 months. There were no cases of postoperative tube–corneal touch. The cumulative risk of corneal decompensation was 3.3%, 5 years after AGV implantation. There was a more rapid loss of ECD in the 72 subject eyes compared with the 31 controls (−7.0% and −0.1%/year, respectively; p<0.001). However, the rate of loss decreased over time and statistical significance compared with control eyes disappeared after 2 years postoperatively: −10.7% from baseline to 1 year (p<0.01), −7.0% from 1 year to 2 years (p=0.037), −4.2% from 2 years to 3 years (p=0.230) and −2.7% from 3 years to the final follow-up (p=0.111). Conclusions In case of uncomplicated AGV implantation, the cumulative risk of corneal decompensation was 3.3%, 5 years after the operation. The ECD loss was statistically greater in eyes with AGV than in control eyes without AGV, but the difference was significant only up to 2 years post surgery.

Properties of pattern standard deviation in open-angle glaucoma patients with hemi-optic neuropathy and bi-optic neuropathy

Purpose To evaluate the properties of pattern standard deviation (PSD) according to localization of the glaucomatous optic neuropathy. Methods We enrolled 242 eyes of 242 patients with primary open-angle glaucoma, with a best-corrected visual acuity ≥ 20/25, and no media opacity. Patients were examined via dilated fundus photography, spectral-domain optical coherence tomography, and Humphrey visual field examination, and divided into those with hemi-optic neuropathy (superior or inferior) and bi-optic neuropathy (both superior and inferior). We assessed the relationship between mean deviation (MD) and PSD. Using broken stick regression analysis, the tipping point was identified, i.e., the point at which MD became significantly associated with a paradoxical reversal of PSD. Results In 91 patients with hemi-optic neuropathy, PSD showed a strong correlation with MD (r = −0.973, β = −0.965, p < 0.001). The difference between MD and PSD (“−MD−PSD”) was constant (mean, −0.32 dB; 95% confidence interval, −2.48~1.84 dB) regardless of visual field defect severity. However, in 151 patients with bi-optic neuropathy, a negative correlation was evident between “−MD−PSD” and MD (r2 = 0.907, p < 0.001). Overall, the MD tipping point was −14.0 dB, which was close to approximately 50% damage of the entire visual field (p < 0.001). Conclusions Although a false decrease of PSD usually begins at approximately 50% visual field damage, in patients with hemi-optic neuropathy, the PSD shows no paradoxical decrease and shows a linear correlation with MD.

Intraoperative endolaser retinopexy around the sclerotomy site for prevention of retinal detachment after pars plana vitrectomy.

Purpose: To investigate whether intraoperative endolaser retinopexy around the sclerotomy site during pars plana vitrectomy can prevent the postoperative complication of retinal detachment (RD). Methods: Two hundred and seventy-eight patients who had undergone 20-gauge pars plana vitrectomy for various vitreoretinal disorders were investigated retrospectively. Patients who had rhegmatogenous RD and who underwent panretinal photocoagulation for diabetic retinopathy were excluded. In Group 1, 152 patients had not undergone laser retinopexy around the sclerotomy site, and in Group 2, 126 patients had undergone laser retinopexy around the sclerotomy site. The incidence rates of postoperative RD were compared. Results: In Group 1, 7 cases (4.6%) of RD developed: 6 cases (3.9%) of sclerotomy-related retinal breaks, and 1 of a sclerotomy-unrelated retinal break. In Group 2, superior RD developed in 1 case (0.8%), but no sclerotomy-related retinal break was observed. Conclusion: Endolaser retinopexy around the sclerotomy site is relatively simple to perform, without inducing particular complications. It is expected to reduce the development of postoperative RD (4.6% vs. 0.8%; P = 0.08) and especially sclerotomy-related RD (3.9% vs. 0%; P = 0.03).