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Biomedical subjects

N H Baek

Publications and source records attributed to N H Baek.

7 recordsLinked to original sources
PubMed2001

Corneal opacity after repeated photorefractive keratectomy.

Corneal opacity developed in an eye that had photorefractive keratectomy (PRK) with a 193 nm excimer laser 5 times over 3 years. Six months after the last PRK, a partial penetrating keratoplasty was performed. The cornea was stained and immunohistochemically evaluated for collagen types. Light microscopy showed thickening of epithelial layers, proliferation of subepithelial fibroblasts, and the absence of Bowman's membrane. Transmission electron microscopy showed irregular collagen lamellae and electron-dense deposits adjacent to keratocytes. The staining was positive for Alcian blue, and immunohistochemistry was positive for type IV and VI collagen. This case suggests that corneal opacity after repeated PRK is the result of deposits of type IV and VI collagen and acidic mucoprotein in the extracellular matrix.

Collagen↗
PubMed2000

Decentration and tilt: silicone multifocal versus acrylic soft intraocular lenses.

PURPOSE: To compare differences in decentration and tilt between a silicone multifocal and an acrylic intraocular lens (IOL) by evaluating postoperative changes. SETTING: Department of Ophthalmology, College of Medicine, The Catholic University of Korea, Seoul, Korea. METHODS: Forty eyes of 20 patients with IOL implantation were randomized into 2 groups according to IOL type: 3-piece silicone multifocal IOL or 3-piece acrylic IOL. All lenses were implanted in the capsular bag through a clear corneal incision after continuous curvilinear capsulorhexis and phacoemulsification. The amount of the decentration and the degree of the tilt of each IOL were measured using the EAS-1000 anterior eye segment analysis system 1 day and 1 and 2 months after surgery. RESULTS: No significant difference in decentration and tilt was found among the 3 follow-ups or between lens types. CONCLUSION: Neither IOL decentration nor tilt showed significant progression up to 2 months in eyes with a silicone multifocal or acrylic IOL when the IOLs were placed properly in the capsular bag. The amount of decentration and tilt was similar between lens types.

Acrylic Resins↗
PubMed2000

Decentration, tilt, and near vision of the array multifocal intraocular lens.

PURPOSE: To study the periodic changes in decentration, tilt, and near vision in eyes with the Array(R) multifocal intraocular lens (IOL). SETTING: Department of Ophthalmology, St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea. METHOD: This study comprised 20 eyes of 10 patients older than 60 years who had binocular cataract and bilateral implantation of the Array multifocal IOL. Mean patient age was 66.0 years (range 60 to 75 years). After a clear corneal incision and continuous curvilinear capsulorhexis were made, each eye had phacoemulsification and in-the-bag IOL implantation. The amount of IOL decentration and degree of tilt were evaluated using the EAS-1000 anterior eye segment analysis system 1 day and 1 and 2 months postoperatively. Near and far visual acuities were measured at the same examinations. RESULTS: No statistically significant differences were observed in decentration (P =.13) or tilt (P =.32) throughout the follow-up. Mean uncorrected distance visual acuity was 0.68 +/- 0.27 (SD), and mean uncorrected near acuity was 0.49 +/- 0.15 2 months postoperatively. Uncorrected distance acuity better than 0.5 was achieved in 14 eyes (77.8%), in which the mean uncorrected distance acuity was 0.80 +/- 0.18 and the mean uncorrected near acuity was 0. 53 +/- 0.14 2 months postoperatively. CONCLUSIONS: Tilt and decentration of the Array multifocal IOL showed no significant progression up to 2 months after implantation. For near acuity, the Array IOL may be an effective aid.

Aged↗
PubMed1999

The additive effect of latanoprost to maximum-tolerated medications with low-dose, high-dose, or no pilocarpine therapy.

OBJECTIVE: To assess the efficacy of latanoprost additive therapy in patients with intraocular pressure (IOP) out of control while taking maximum-tolerated medications and to determine whether pilocarpine therapy has a dose-dependent adverse effect on the efficacy of latanoprost therapy. DESIGN: Noncomparative case series. PARTICIPANTS: Sixty-one eyes of 61 patients with chronic glaucoma with IOP out of control while receiving maximum-tolerated medications were treated with latanoprost additive therapy on a compassionate basis. MAIN OUTCOME MEASURES: Follow-up was up to 22 months with a mean of 13.9 +/- 5.7 months. Kaplan-Meier survival analysis with Mantel-Cox log-rank test was performed to determine the overall success of latanoprost additive therapy and to compare the success rates of high-dose pilocarpine, low-dose pilocarpine, and no pilocarpine therapies. The criterion for success was avoiding glaucoma surgery with IOP decrease of 20% or greater and final IOP less than 22 mmHg. The IOP change and its significance for patients satisfying and failing the criterion for success also were determined to assess the latanoprost additive therapy. In addition, a number of pretreatment variables, including pilocarpine therapy, were analyzed for a significant effect on the efficacy of latanoprost additive therapy using Cox proportional hazards regression analysis. RESULTS: Latanoprost additive therapy significantly lowered mean IOP by 3.9 +/- 5.5 mmHg at 3 months and by 3.5 +/- 5.8 mmHg at 12 months. The cumulative success rate of the latanoprost additive therapy was 70% at 1 month, 42% at 3 months, 40% at 6 months, and 30% at 12 months. Of the variables studied, only increased number of previous incisional glaucoma surgeries and IOP greater than 24 mmHg before latanoprost additive therapy were significant prognostic factors for failure of latanoprost additive therapy. Pilocarpine therapy in any dose had no significant effect. CONCLUSION: This study supports a trial of latanoprost additive therapy before glaucoma surgery in patients with IOP out of control while receiving maximum-tolerated medications irrespective of pilocarpine therapy and the pilocarpine dosage, especially when the number of previous incisional glaucoma surgery is less than three and the IOP is less than 25 mmHg.

Adult↗
PubMed1991

Visual field defects in diabetic patients with primary open-angle glaucoma.

We reviewed the automated visual field tests of 110 nondiabetic and 87 diabetic patients with primary open-angle glaucoma randomly selected from a large glaucoma practice to investigate a possible qualitative difference in the pattern of visual field defects between nondiabetic and diabetic patients with primary open-angle glaucoma. A single reviewer analyzed, in masked fashion, the visual field tests of each patient and decided whether or not visual field defects were present mainly in the inferior half of the visual field. Of the 110 nondiabetic patients, 40 (36.4%) had visual field defects located mainly in the inferior half of the visual field in one or both eyes, whereas 56 of the 87 (64.4%) diabetic patients had such defects. This difference was statistically significant (P = .0001). We believe that a vascular factor, such as that attributable to diabetes mellitus, may influence glaucomatous optic nerve damage, thus causing a difference in the pattern of visual field loss in patients with primary open-angle glaucoma.

Adult↗
PubMed1991

Effect of gamma-interferon on fibroblast proliferation and collagen synthesis after glaucoma filtering surgery in white rabbits.

Failure of a glaucoma filtering operation mainly results from scarring at the filtering wound, and postoperative proliferation and migration of fibroblasts play an important role histologically in the formation of scar tissue. As an inhibitory agent for fibroblast proliferation, gamma-interferon has been introduced, and the application of gamma-interferon following filtering surgery is now being made on a trial basis. We studied the effect of gamma-interferon histologically on the fibroblast proliferation and collagen synthesis occurring at the filtering site by comparing the effect of gamma-interferon on the experimental group with that of 5-fluorouracil on the control group, using 10 rabbits (20 eyes) after posterior lip sclerectomy. Both groups showed similar flat and diffused bleb grossly and also showed a similar inhibitory effect on fibroblast proliferation and collagen fiber synthesis histologically. Our findings seem to justify the clinical use of gamma-interferon. Further studies on adequate dosage, method of administration, and local and systemic complications would be desired.

Animals↗