Factors Affecting ISNT Rule Satisfaction in Normal and Glaucomatous Eyes

PURPOSE: To determine the factors that influence the satisfaction of the ‘ISNT rule’ (neural rim width: inferior ≥ superior ≥ nasal ≥ temporal) in normal and glaucomatous eyes. METHODS: The medical records of patients that visited Boramae Medical Center, Seoul, Korea, were reviewed. Each group of normal and glaucomatous eyes was divided into subgroups based on whether or not they satisfied the ISNT rule. ISNT rule assessment was performed by measuring the rim width with stereoscopic optic disc photographs using ImageJ software. Logistic regression analysis was performed to determine the factors that affect ISNT rule satisfaction. RESULTS: Seventy-seven normal eyes and 97 glaucomatous eyes were included in the study. The ISNT rule was intact in 59 (76.6%) of the normal eyes and was violated in 71 (73.2%) of the glaucomatous eyes. Logistic regression analysis revealed a significant influence of axial length in violation of the ISNT rule in the normal eye group, while the mean deviation value was a significant factor for violation of the ISNT rule in the glaucomatous eye group. CONCLUSIONS: The ISNT rule should be cautiously applied when evaluating normal eyes with long axial lengths. In addition, the ISNT rule might not be as effective for detecting early glaucoma.

Amniotic Membrane Transplantation for Repair of a Large Intraoperative Conjunctival Defect during Trabeculectomy

No abstract available.

Patterns of Subsequent Progression of Localized Retinal Nerve Fiber Layer Defects on Red-free Fundus Photographs in Normal-tension Glaucoma

PURPOSE: To investigate patterns of subsequent progression of localized retinal nerve fiber layer (RNFL) defects and to quantify the extent of progression in normal-tension glaucoma (NTG) patients. METHODS: Thirty-three eyes of 33 consecutive NTG patients who had shown continuous progression of localized RNFL defect on serial red-free fundus photographs were selected for the study. Patterns of subsequent progression of localized RNFL defects were categorized, and extents of progression were quantified. Serial evaluations of disc stereophotographs and visual fields were also performed to detect progression. RESULTS: The most common pattern was continuous widening of the defect towards the macula (n = 11, 33.3%) followed by sharpening of the defect border after widening of the defect towards the macula (n = 5, 15.2%), continuous widening of the defect away from the macula (n = 2, 6.1%), and deepening of the defect after appearance of a new defect (n = 2, 6.1%). Four eyes (12.1%) simultaneously showed two patterns of subsequent progression. In 13 eyes that showed continuous widening of the defect, subsequent angular widening towards the macula and away from the macula were 9.2 ± 6.0degrees (range, 1.1degrees to 24.4degrees; n = 11) and 5.2 ± 4.9degrees (range, 0.3degrees to 11.3degrees; n = 2), respectively. Thirty-two eyes showed no progression of optic disc cupping. Out of the 21 eyes in which Humphrey central 30-2 threshold visual field tests were performed after progression of RNFL defects, 15 eyes showed no deterioration in the visual field. CONCLUSIONS: There were nine patterns of subsequent progression of localized RNFL defects. Among them, continuous RNFL loss proceeding temporally was the most common one. Initial progression of the defect proceeded temporally, especially in the defect located at the inferior fundus, might be at a risk of further RNFL loss temporally.

Location of the Tube Tip in the Anterior Chamber and Change in Corneal Endothelium after Ahmed Valve Implantation

PURPOSE: To evaluate the impact of location of a silicone tube tip in the anterior chamber on corneal endothelium after Ahmed glaucoma valve implantation. METHODS: We measured the distance from the tip of a silicone tube in the anterior chamber to the posterior surface of the cornea by anterior segment optical coherence tomography (OCT) in 24 eyes of 21 patients who underwent Ahmed glaucoma valve implantation. All surgeries were performed by a single surgeon. The corneal endothelial cells of central, superior, superotemporal, and superonasal area of the cornea were examined by specular microscope before and after surgery. RESULTS: The distance from the tip of the silicone tube in the anterior chamber to the posterior surface of the cornea and the corneal endothelium were measured at 19.2 +/- 11.8 months (2.8-41.2 months) after surgery. At the central corneal area, a statistically significant decrease in the number of corneal endothelial cells (2278 +/- 565/mm2 vs. 2177 +/- 529/mm2, p = 0.043) after surgery was observed, but no relationship was found between the amount of decrease and distance from the tip to the posterior surface of the cornea. At the superotemporal corneal area where the tip of the silicone tube was located in the anterior chamber, there was more significant loss of corneal endothelial cells than in the other areas after surgery (p = 0.006). Moreover, the amount of endothelial cell loss at the superotemporal area was negatively correlated to the distance from the tip to the posterior surface of the cornea (partial correlation coefficient by time -0.558, p = 0.031). CONCLUSIONS: To minimize the loss of corneal endothelial cells after Ahmed glaucoma valve implantation, ensuring a sufficient distance from the tip of the silicone tube to the posterior surface of the cornea is important.

Anterior Chamber Configuration Changes after Cataract Surgery in Eyes with Glaucoma

PURPOSE: To evaluate changes in anterior chamber depth (ACD) and angle width induced by phacoemulsification and intraocular lens (IOL) implantation in eyes with glaucoma, using anterior segment optical coherence tomography (AS-OCT). METHODS: Eleven eyes of 11 patients with angle-closure glaucoma (ACG) and 12 eyes of 12 patients with open-angle glaucoma (OAG) underwent phacoemulsification and IOL implantation. Using AS-OCT, ACD and angle parameters were measured before and 2 days after surgery. Change in intraocular pressure (IOP) and number of ocular hypotensive drugs were evaluated. RESULTS: After surgery, central ACD and angle parameters increased significantly in eyes with glaucoma (p < 0.05). Prior to surgery, mean central ACD in the ACG group was approximately 1.0 mm smaller than that in the OAG group (p < 0.001). Post surgery, mean ACD of the ACG group was still significantly smaller than that of the OAG group. No significant differences were found in angle parameters between the ACG and OAG groups. In the ACG group, postoperative IOP at the final visit was significantly lower than preoperative IOP (p = 0.018) and there was no significant change in the number of ocular hypotensive medications used, although clinically, patients required fewer medications. In the OAG group, the IOP and number of ocular hypotensive drugs were almost unchanged after surgery. CONCLUSIONS: The ACD and angle width in eyes with glaucoma increased significantly after phacoemulsification and IOL implantation. Postoperative ACD significantly differed between the ACG and OAG groups, whereas angle parameters did not differ.

Changes in Anterior Chamber Configuration after Cataract Surgery as Measured by Anterior Segment Optical Coherence Tomography

PURPOSE: To evaluate the changes in anterior chamber depth (ACD) and angle width induced by phacoemulsification and intraocular lens (IOL) implantation in normal eyes using anterior segment optical coherence tomography (AS-OCT). METHODS: Forty-five eyes (45 patients) underwent AS-OCT imaging to evaluate anterior chamber configuration before and 2 days after phacoemulsification and IOL implantation. We analyzed the central ACD and angle width using different methods: anterior chamber angle (ACA), trabecular-iris angle (TIA), angle opening distance (AOD), and trabecular iris surface area (TISA) in the nasal and temporal quadrants. Comparison between preoperative and postoperative measurement was done using paired t-tests and each of the angle parameters was analyzed with Pearson correlation testing. Subgroup analyses according to the IOL and axial length were performed with a general multivariate linear model adjusted for age. RESULTS: Before surgery, the mean anterior chamber angle widths were 23.21 +/- 6.70degrees in the nasal quadrant and 24.89 +/- 7.66degrees in the temporal quadrant. The mean central ACD was 2.75 +/- 0.43 mm. After phacoemulsification and IOL implantation, the anterior chamber angle width increased significantly to 35.16 +/- 4.65degrees in the nasal quadrant (p = 0.001) and 36.03 +/- 4.86degrees in the temporal quadrant (p = 0.001). Also, central ACD increased to 4.14 +/- 0.31 mm (p = 0.001). AOD, TISA, and TIA increased significantly after cataract surgery and showed positive correlation with ACA. CONCLUSIONS: After cataract surgery, the ACD and angle width significantly increased in eyes with cataract. AS-OCT is a good method for obtaining quantitative data regarding anterior chamber configuration.

Circadian Blood Pressure and Intraocular Pressure Patterns in Normal Tension Glaucoma Patients with Undisturbed Sleep

PURPOSE: To investigate and compare the circadian pattern of blood pressure (BP), intraocular pressure (IOP) and mean ocular perfusion pressure (MOPP) while experiencing undisturbed sleep in normal-tension glaucoma (NTG) and non-glaucoma control patient groups. METHODS: Twenty-four eyes from 24 patients diagnosed with NTG and 22 eyes from 22 control group patients were enrolled. Systolic BP, diastolic BP and IOP were measured every two hours except for the period of time from 1 AM to 7 AM in the NTG group and from 11 PM to 7 AM in the control group over a one-day period. IOP and hemodynamic parameters were then compared between the two groups. NTG patients were subdivided according to the degree of morning BP dip and IOP, and hemodynamic parameters and visual field indices (mean deviation and pattern standard deviation) were also compared among these subgroups. RESULTS: There were no significant differences in mean systolic BP, mean diastolic BP and mean arterial pressure (MAP) between the NTG and the control groups. The NTG group showed a significantly large morning BP dip compared to the control group (7.1+/-4.2% vs. 3.8+/-3.4%, p=0.022). However, there were no significant differences in mean or fluctuation of MOPP between the two groups. Morning over-dippers showed significantly large MAP and MOPP fluctuations compared to non-dippers and dippers, while there were no significant differences in visual field indices among the three subgroups. CONCLUSIONS: NTG patients showed significant morning BP dips compared to the control group. The marked morning BP dip was associated with significantly large MAP or MOPP fluctuations but was not associated with visual field indices.

Clinical Outcomes of Ahmed Glaucoma Valve Implantation Using Tube Ligation and Removable External Stents

PURPOSE: To investigate the immediate and long-term outcomes of Ahmed glaucoma valve (AGV) implantation with silicone tube ligation and removable external stents. METHODS: This retrospective non-comparative study investigated the outcomes of AGV implantation with silicone tube ligation and removable external stents in 95 eyes (90 patients) with at least 12 months of postoperative follow-up. Qualified success was defined as an intraocular pressure (IOP) of or =6 mmHg regardless of anti-glaucoma medication. Those who required additional glaucoma surgery, implant removal or who had phthisis bulbi were considered failures. Hypotony was defined as an IOP of <6 mmHg. RESULTS: Mean IOP reduced from 37.1+/-9.7 mmHg preoperatively to 15.2+/-5.6 mmHg at 12 months postoperatively (p<0.001). Qualified success was achieved in 84.2% at 1 year. Hypotony with an IOP of <6 mmHg was seen in 8.4% and an IOP of <5 mmHg in 3.2% on the first postoperative day. No case of hypotony required surgical intervention. Suprachoroidal hemorrhage did not occur in this study. When stents were removed on the first postoperative day because of an insufficient IOP decrease, the mean IOP decreased significantly from 42.0 mmHg to 14.1 mmHg (p<0.001) after 1 hour. The most common complication was hyphema, which occurred in 17.9%. CONCLUSIONS: Hypotony-related early complications requiring surgical intervention were reduced by ligation and external stents in the tube. In addition, early postoperative high IOPs were managed by removing external stents. The described method can prevent postoperative hypotony after AGV implantation and showed long-term success rates comparable to those reported previously.

Differences in the Histopathology and Matrix Metalloproteinase Expression in Tenon's Tissue of Primary Open-Angle Glaucoma and Primary Angle-Closure Glaucoma

PURPOSE: To investigate the differences in the histopathology and matrix metalloproteinase (MMP) expression in the Tenon's tissue of primary open-angle glaucoma (POAG) patients, primary angle-closure glaucoma (PACG) patients, and non-glaucomatous patients. METHODS: POAG and PACG patients, who underwent a trabeculectomy and had no history of ocular disease except glaucoma, were enrolled. The number and instillation period of topical eye drops were reviewed. For the controls, which were patients without glaucoma or a history of ocular surgery, the Tenon's tissue was obtained in the course of retinal detachment surgery. For glaucoma patients, the Tenon's tissue was obtained during the trabeculectomy. H&E and Masson's trichrome staining and immunohistochemistry for MMP-1, MMP-2, and MMP-9 were performed. A total of six eyes of POAG, six eyes of PACG, and four control eyes were evaluated. RESULTS: The duration of topical anti-glaucoma medication and the mean number of anti-glaucoma medications were similar in the POAG and PACG groups. The levels of MMP-1 and 2 were elevated in the POAG and PACG groups compared to the control group (p=0.03, 0.01, respectively). Compared with the control group, the MMP-2 level was higher in the POAG patients (p=0.01), whereas the MMP-1 was higher in the PACG patients (p=0.04). The levels of MMP-9 in the POAG and PACG patients were not significantly different from that of the control patients (p=0.48, 0.26). The levels of MMP-2 were significantly lower in the PACG patients than in the POAG patients (p=0.02). CONCLUSIONS: The MMP expression was altered in the Tenon's tissue of glaucoma patients compared to the control group. The levels of MMP-2 were lower in the PACG patients than in the POAG patients. These results suggest that there may be histopathological differences in the Tenon's tissue of POAG and PACG patients.

Differences in the Histopathology and Matrix Metalloproteinase Expression in Tenon's Tissue of Primary Open-Angle Glaucoma and Primary Angle-Closure Glaucoma

PURPOSE: To investigate the differences in the histopathology and matrix metalloproteinase (MMP) expression in the Tenon's tissue of primary open-angle glaucoma (POAG) patients, primary angle-closure glaucoma (PACG) patients, and non-glaucomatous patients. METHODS: POAG and PACG patients, who underwent a trabeculectomy and had no history of ocular disease except glaucoma, were enrolled. The number and instillation period of topical eye drops were reviewed. For the controls, which were patients without glaucoma or a history of ocular surgery, the Tenon's tissue was obtained in the course of retinal detachment surgery. For glaucoma patients, the Tenon's tissue was obtained during the trabeculectomy. H&E and Masson's trichrome staining and immunohistochemistry for MMP-1, MMP-2, and MMP-9 were performed. A total of six eyes of POAG, six eyes of PACG, and four control eyes were evaluated. RESULTS: The duration of topical anti-glaucoma medication and the mean number of anti-glaucoma medications were similar in the POAG and PACG groups. The levels of MMP-1 and 2 were elevated in the POAG and PACG groups compared to the control group (p=0.03, 0.01, respectively). Compared with the control group, the MMP-2 level was higher in the POAG patients (p=0.01), whereas the MMP-1 was higher in the PACG patients (p=0.04). The levels of MMP-9 in the POAG and PACG patients were not significantly different from that of the control patients (p=0.48, 0.26). The levels of MMP-2 were significantly lower in the PACG patients than in the POAG patients (p=0.02). CONCLUSIONS: The MMP expression was altered in the Tenon's tissue of glaucoma patients compared to the control group. The levels of MMP-2 were lower in the PACG patients than in the POAG patients. These results suggest that there may be histopathological differences in the Tenon's tissue of POAG and PACG patients.

Personal Privacy Protection of Electronic Medical Record in Health Information System / 대한의료정보학회지

OBJECTIVE: The consolidation of health information has led to the creation of a national network of medical institutions. In this wireless and hard-line communication web, patients' medical information, which is extremely private and must be kept in secret, may leak out, and the risk of dangers such as privacy infringement and misuse of information has increased. METHODS: For this dissertation, a patient information protection algorithm was designed for a hospital information system in order to improve the untraceability and anonymity of patients' individual information in a ubiquitous computing environment. RESULTS: Additionally, analyzing the computing load showed that the computing load of the entire system did not increase, and since 57 percent of the sensor node's computing load was transferred to the secure server, the sensor node's load was minimized. Thus, the system can also be applied to low performance sensor networks. CONCLUSION: In conclusion, improving the security level of identification information transmissions while minimizing the computing and communication load of sensor nodes in a ubiquitous computing environment did not lead to an increase in the system's overall computing or communication load. Thus, a system with improved security features for identification information and communication information was developed and established.

Investigation of the Association between Normal-tension Glaucoma and Single Nucleotide Polymorphisms in Natriuretic Peptide Gene

PURPOSE: The expression of natriuretic peptides in the neural bundles of the anterior portion of the optic nerves and their functions in regulating vessel tone and blood flow may suggest a possible role in the pathogenesis of glaucoma. The purpose of this study was to investigate the association between normal-tension glaucoma and the genetic variations of atrial natriuretic peptide (Nppa) and natriuretic peptide receptor A (Npr1) gene. METHODS: Sixty-seven Korean normal-tension glaucoma (NTG) patients and 100 healthy subjects (as normal controls) were enrolled. DNA from peripheral blood leukocytes was extracted, and the genotypes of five polymorphisms (c.94G>A, c.454T>C, IVS1+16C>T, IVS2+701G>A, and c.-764C>G) in the Nppa gene and one polymorphism (c.1023G>C) in the Npr1 gene were determined using the restriction fragment length polymorphism and the SNaPshot methods. The genotype and allele frequencies of these polymorphisms in patients with NTG and normal controls were compared using the Fisher's exact test and the chi-square test. RESULTS: In both groups, the genotype distributions were in accordance with the Hardy-Weinberg equilibrium. There was no significant difference in the frequency of the Nppa and Npr1 alleles or genotypes in the normal-tension glaucoma group as compared to the control group. CONCLUSIONS: Nppa and Npr1 gene polymorphisms are not associated with normal-tension glaucoma, suggesting that this gene does not have an important role in the pathogenesis of optic neuropathy in this disease.

Comparison of the Results between Heidelberg Retina Tomography II and Stratus Optical Coherence Tomography in Glaucoma

PURPOSE: To evaluate the ability of Stratus OCT and HRT II with Moorfields' analysis to detect localized RNFL defects and to evaluate the accordance of Stratus OCT and HRT II results in glaucoma patients. METHODS: A total of 60 patients (119 eyes) who had localized RNFL defects of either eye in red-free fundus photographs unserwent evaluation by Stratus OCT and HRT II. For the results of Stratus OCT and HRT II with Moorfields' analysis, normal distribution percentiles less than 5% were considered a significant RNFL defect. For each disc, superotemporal and inferotemporal portions were evaluated. The diagnostic abilities of Stratus OCT and HRT II to detect localized RNFL defects were calculated. The results of HRT II were compared with those of Stratus OCT. RESULTS: The overall sensitivity, specificity, positive predictive value and negative predictive value to detect localized RNFL defects were 67.9%, 88.9%, 84.3% and 76.5% in Stratus OCT and 67.3%, 64.8%, 62.2% and 69.6% in HRT II, respectively. Compared with Stratus OCT, 67.2% of HRT II results were in accord in the superotemporal portion and 68.9% in the inferotemporal portion. The accordance of detection of RNFL defects between the two instruments in the inferotemoral portion was higher (79.2%) than others. CONCLUSIONS: Stratus OCT with a normative database is a useful aid to detect localized RNFL defects in early glaucoma. If observation of topographic changes of the optic disc with HRT II is added, results will be even better.

The Detection of Retinal Never Fiber Layer Defect by Modification of Non-mydriatic Digital Fundus Photograph

PURPOSE: To evaluate the efficiency of digital retinal nerve fiber layer (RNFL) photographs converted from a non-mydriatic digital fundus camera for detecting RNFL defects. METHODS: Ninety-five eyes were evaluated with both a non-mydriatic digital fundus photograph and a digital RNFL photograph by two glaucoma specialists independently. The red-free, monochrome modified digital fundus photograph was acquired from non-mydriatic digital fundus photographs using Photoshop 7.0. Whether a localized wedge-shaped or diffuse RNFL defect existed or not was evaluated on a non-mydriatic digital fundus photograph and a modified digital fundus photograph, and inter- and intraobserver agreement were also evaluated. Regarding the use of digital RNFL photographs as a standard method, we calculated the sensitivity, specificity, and positive and negative predictive values of the two types of photographs. RESULTS Interobserver agreement (Cohen's kappa values) about localized RNFL defects observable on digital RNFL photographs, non-mydriatic digital fundus photographs, and modified digital fundus photographs were 0.749, 0.634, and 0.793, respectively, but all were 0.417 or less with regard to diffuse RNFL defects. Regarding localized RNFL defects, the sensitivity, specificity, and positive and negative predictive values of modified digital fundus photographs were 85.7%, 95.5%, 85.7% and 94.1%, respectively, showing superiority to those of non-mydriatic digital fundus photographs. But, in cases of diffuse RNFL defect, the sensitivity and specificity of modified digital fundus photographs were 60.0% and 97.8%, respectively, indicating no superiority to non-mydriatic digital fundus photographs. CONCLUSIONS: The localized RNFL defect can be detected more efficiently with modified digital fundus photographs than non-mydriatic digital fundus photographs, but the diffuse RNFL defect cannot.

The Detection of Retinal Never Fiber Layer Defect by Modification of Non-mydriatic Digital Fundus Photograph

PURPOSE: To evaluate the efficiency of digital retinal nerve fiber layer (RNFL) photographs converted from a non-mydriatic digital fundus camera for detecting RNFL defects. METHODS: Ninety-five eyes were evaluated with both a non-mydriatic digital fundus photograph and a digital RNFL photograph by two glaucoma specialists independently. The red-free, monochrome modified digital fundus photograph was acquired from non-mydriatic digital fundus photographs using Photoshop 7.0. Whether a localized wedge-shaped or diffuse RNFL defect existed or not was evaluated on a non-mydriatic digital fundus photograph and a modified digital fundus photograph, and inter- and intraobserver agreement were also evaluated. Regarding the use of digital RNFL photographs as a standard method, we calculated the sensitivity, specificity, and positive and negative predictive values of the two types of photographs. RESULTS Interobserver agreement (Cohen's kappa values) about localized RNFL defects observable on digital RNFL photographs, non-mydriatic digital fundus photographs, and modified digital fundus photographs were 0.749, 0.634, and 0.793, respectively, but all were 0.417 or less with regard to diffuse RNFL defects. Regarding localized RNFL defects, the sensitivity, specificity, and positive and negative predictive values of modified digital fundus photographs were 85.7%, 95.5%, 85.7% and 94.1%, respectively, showing superiority to those of non-mydriatic digital fundus photographs. But, in cases of diffuse RNFL defect, the sensitivity and specificity of modified digital fundus photographs were 60.0% and 97.8%, respectively, indicating no superiority to non-mydriatic digital fundus photographs. CONCLUSIONS: The localized RNFL defect can be detected more efficiently with modified digital fundus photographs than non-mydriatic digital fundus photographs, but the diffuse RNFL defect cannot.

Postural Change of Intraocular Pressure in Normal Persons and in Patients with Hypertension and Diabetes

This paper describes the results of the investigation of the intraocular pressure response upon postural change in 56 healthy adults and in 20 hypertensive patients, with a short study of 9 diabetic patients. Both hypertensive and diabetic groups showed abnormal response. In the hypertensive and diabetic groups the mean rise at immediately after lying was significantly higher than that occuring during 15 min in lying, that is, 1.9 mmHg compared to 0.8 mmHg in hypertensive group and 2.4 mmHg compared to 0.5 mmHg in diabetic group(p<0.05).

5-Fluorouracil and Glaucoma Filtering Surgery: I. Delayed administration

As fibroblasts proliferation at the sclerectomy wound is known to be vigorous after the fifth or sixth postoperative day, this study was performed to know if a delay in the administration of 5-fluorouracil until this time can still interfere with fibroblasts proliferation. The delayed onset of administration was seem to be efficacious. If this is more confirmed at further study, a decreased dose of postoperative 5-fluorouracil may interfere less with corneal wound healing.

5-Fluorouracil in a Collagen Sponge and Glaucoma Filtering Surgery

A histologic study was performed if fibroblast proliferation could be inhibited and filtering bleb longevity could be enhanced in rabbits by delivery of 5-fluorouracil(0.5 mg) in a collagen sponge implant. Results showed that fibroblast proliferation was inhibited and bleb longevity was prolonged when compared to controls. And it is theorized that if an antitumor agents can be delivered in small and sustained amounts after filtering agents can be delivered in small and sustained amounts after filtering surgery, this may enhance bleb longevity and unnecessary drug toxicity.

The Acute Effects of N-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine on the Inner Plexiform Layer of Rabbits

The electrophysiological effects of N-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine(NMPTP), a chemical inducer of Parkinsonism in man and monkey, on the pigmented rabbit retina were determined under acute condition. The amplitude of the b-wave of the rabbit electroretinogram was affected, but both the implicit time and half-amplitude duration of it were not. The amplitude of the photopic b-wave was increased by 72.9 +/- 32.1% 5 hours after NMPTP administration(P[t]<0.05), Whereas the scotopic b-wave was decreased by 31.2 +/- 6.4% 4 hours after injection(P[t]<0.05). The above results suggest or support that: (1) the dopaminergic amacrine cells are related to the modulation of the b-wave of the rabbit electroretinogram. (2) during light adaptation, the dopaminergic amacrine cells uncouple the rod and cone systems in the inner plexiform layer and are involved in functions of the rod system. (3) the hypothesis that the function of tyrosine hydroxylase may be affected by NMPTP.

Fibrous Capsule Surrounding Silicone Encircling Band and Gore Tex(TM) Surgical Membrane: A Histological Study

As the anterior chamber tube shunt to an encircling band(ACTSEB) is a complicated procedure, extended polytetafluoroethylene(e-PTFE)-silicone tube implant is being attempated as a new glaucoma drainage implant in Korea. Anterior chamber tube shunt to a two-fold e-PTFE surgical membrane(ACTSSM) has better intraocular pressure(IOP) control than ACTSEB and kept the postoperative anterior chamber depth deep. ACTSEB and ACTSSM procedures were done in normal, colored rabbit eyes in order to compare the tissue response to each shunt. The rabbits were sacrificed 3 and 6 weeks later and the eyes were prepared for light microscopy. In general, foreign body responses were similar. Fibrous capsules lining the e-PTFE were thicker, less dense fibroblast, and less collagen than that lining the silicone encircling band. These findings seem to be related to the difference of the IOP lowering effect between ACTSEB and ACTSSM.