Epidemiologic Studies of Keratoplasty in Korea

PURPOSE: To report an epidemiologic study of keratoplasty in which we analyze basic data of corneal transplants and corneal donations in Korea. METHODS: From June 2004 through October 2004, questionnaires were distributed to 25 hospitals. The questionnaires were about the characteristics of patients registered in eye banks for keratoplasty from May 2001 to April 2003, and about the results of keratoplasties performed from May 2002 to April 2003. RESULTS: The leading corneal diseases in patients registered for keratoplasty were infectious keratitis (22.0%), trauma (21.0%), and pseudophakic and aphakic bullous keratopathy (13.8%), in that order. The leading indications in corneal recipients were: trauma (15.5%), pseudophakic and aphakic bullous keratopathy (13.7%), and infectious keratitis (10.7%), in that order. In 233 cases of keratoplasties, penetrating keratoplasty was performed in 229 cases (98.3%) and lamellar keratoplasty was performed in 4 cases (1.7%). The most common combined surgery was cataract extraction. Common causes of graft failure were rejection of donor cornea and infection. Imported donor corneas were used in sixty-one cases (26.2%) among the 233 total keratoplasties. CONCLUSIONS: We constructed an epidemiologic data base of patients registered for keratoplasty, corneal donation, and the results of keratoplasties throughout Korea.

Epidemiologic Studies of Keratoplasty in Korea

PURPOSE: To report an epidemiologic study of keratoplasty in which we analyze basic data of corneal transplants and corneal donations in Korea. METHODS: From June 2004 through October 2004, questionnaires were distributed to 25 hospitals. The questionnaires were about the characteristics of patients registered in eye banks for keratoplasty from May 2001 to April 2003, and about the results of keratoplasties performed from May 2002 to April 2003. RESULTS: The leading corneal diseases in patients registered for keratoplasty were infectious keratitis (22.0%), trauma (21.0%), and pseudophakic and aphakic bullous keratopathy (13.8%), in that order. The leading indications in corneal recipients were: trauma (15.5%), pseudophakic and aphakic bullous keratopathy (13.7%), and infectious keratitis (10.7%), in that order. In 233 cases of keratoplasties, penetrating keratoplasty was performed in 229 cases (98.3%) and lamellar keratoplasty was performed in 4 cases (1.7%). The most common combined surgery was cataract extraction. Common causes of graft failure were rejection of donor cornea and infection. Imported donor corneas were used in sixty-one cases (26.2%) among the 233 total keratoplasties. CONCLUSIONS: We constructed an epidemiologic data base of patients registered for keratoplasty, corneal donation, and the results of keratoplasties throughout Korea.

Effect of Excimer Laser Radial Kentotomy on the Correction of Myopia and Astigmatism: Report 2

The term Excimer is a contraction of "Excited dimer", and it is emitting light produced in the far-ultraviolet portion of the spectrum and has a wave length of 193 nm produced by an argon fluoride. It ablate corneal tissue through photochemical Iaser tissue interaction without thermal damage. We performed the radial keratotomy with argon fluoride excimer laser (MEL50, MEDITEC,W.GERMANY) and treated 71 eyes of myopia and myopic astigmatism from February 1989 to February 1990. All eyes were followed up about six months to 1 yr or over 1 yr and the results were as follows: 1) The mean flattening by skiascopy was 2.32 diopters(D), that is 1.42 D of low myopia, 2.07 D of moderate myopia, 2.54 D of high myopia. By Keratometry, the mean flattening was 1.67 D, that is 2.0 D of low myopia, 1.9 D of moderate myopia, 1.52 D of high myopia. In the correction for the best visual acuity, spectacle diopter was decreased average 2.19 D, that is 1.75 D of low myopia, 2.32 D of moderate myopia, 2.15 D of high myopia respectively. After Ruiz operation, the astigmatic flattening in 4 cases were 2.0, 3.0, 2.0 and 1.0 D respectively. 2) The uncorrected visual acuity after surgery was 20/40 or better in 32% of the entire eye group, that is, 60% of low myopia, 60% of moderate myopia and 12% of high myopia.

Variability and application of VEP components in Transient VEP and Steady VEP

Before VEP use in clinics, we studied in statistical significance between borh eyes, intrasubject varciabilty intersubject variability (between incdividul) and changes of VEP cmponents between ignorance and attention in losujects (20eyes). There was no statistically significant difference between both eyes in each component of VEP and the variability of intersubjects was larger than that of intrasubjects. The smallest variability of intersubject was N1, P1 latency and that of intrasubject was PI latency in each component of VEP. When subjects were ignored, N1-P1, P1-N2 and steady VEP amplitude decreased significantly but N1, P1 and N2 latency were no significant difference.

Excimer laser Radial Keratotomy for Correction of Myopia and Astigmatism: Preliminary Report

Ultraviolet light(193nm) produced by an Excimer laser has a photochemical effect upon organic structures, which breaks molecular bonds without producing thermal damage. We performed argon fluoride Excimer laser radial keratotomy and treated 32 eyes of myopia and myopic-astigmatism from Febraury to september, 1989. All eyes were followed up over 3 months, and the results were as follows: 1. Mean reduction by skiascopy was 2.47 diopters, that is, 1.9 diopters of moderate myopia, 2.75 diopters of high myopia. By keratometry, mean reduction was 1.45 diopters, that is, 1.68 diopters of moderate myopia, 1.33 diopters in high myopia. In correction for best visual acuity, spectacle diopters were decreased average 2.40 diopters, that is, 2.35 diopters of moderate myopia, 2.45 diopters of high myopia. The astigmatic reduction in 2 cases were 2.0 diopters and 3.0 diopters respectively after Ruiz operation. 2. Uncorrected visual acuity after surgery was 20/50 or better in 41% of entire eye group, that is, 67% of moderate myopia, 25% of high myopia.