We compared the incidence of graft rejection and the rejection time after penetrating keratoplasty on the 72 keratoconus patients retrospectively between the range of 5.5 mm to 7.0 mm diameter in graft size(Group 1) and the range of 7.25 mm to 8.0 mm diameter(Group 2). The graft rejection was developed in 25 eyes(28.09%) among 89 penetrating keratoplasty patients with keratoconus. In group 1, there was graft rejection in 6 eyes(23.08%) among 26 eyes and in group 2, 19 eyes(30.16%) among 63 eyes. The rejection time of 21 eyes(84.00%) was within the first postoperative year. In group 1, graft rejections in 5 eyes(83.33%) were noted within the first postoperative year among 6 rejected eyes, and in group 2, rejections in 16 eyes(84.21%) among 19 rejected eyes. The statistical analysis showed no significant differences between the two groups in the incidence of graft rejection and rejection time(p>0.05).
Corneal Transplantation* ; Graft Rejection* ; Humans ; Incidence ; Keratoconus* ; Keratoplasty, Penetrating ; Retrospective Studies ; Transplants*

In order to evaluate the clinical application of the Nd:YAG laser(Coherent model 9900(R)) to correct the astigmatism, we observed the change in corneal curvature, thickness and endothelium after laser radiation to the rabbit cornea. The experiment composed of 14 rabbit eyes divided into two groups according to the power setting; 7 eyes of 2.5mJ group, and 7 eyes of 5mJ group. Lader pulse was focused at corneal epithelium and an average of 25-30 applications were required to make the single pair of transverse line like conventional lineal corneal transverse incision for one eye. Changes ir keratometry and pachymetry were measured postlaser application for 3 months. Seven days after radiation, two rabbit eyes(2.5mJ and 5mJ) were enucleated for scanning electron microscopy. The results were as follows: 1. The mean flattening induced at 900 meridian was 1.91 diopter in 2.5mJ group and 1.98 diopter in 5mJ group 3 months after laser radiation, and the difference between the two groups was not statistically significant(p>0.5). 2. The steepening at 1800 meridian induced only one week after laser radiation in both groups, thereafter the flattening was shown. 3. The significant mean corneal thickness increase of 30.72pm in 2.5mJ group and 33.47 micrometer in 5mJ group was noted at postlaser 7 days and returned to normal range at postlaser 2 months, but the corneal thickness showed no significant statistical difference between two group(p>0.5). 4. Scanning electron microscopy findings showed changes of the ultrastructure of the endothelial cell: edematous changes of the endothelial cell and cell membrane destruction were much less in 2.5mJ group than 5mJ group.
Astigmatism ; Cell Membrane ; Cornea ; Endothelial Cells ; Endothelium* ; Epithelium, Corneal ; Microscopy, Electron, Scanning ; Rabbits* ; Reference Values

In order to evaluate the clinical application of the Nd:YAG laser(Coherent model 9900(R)) to correct the astigmatism, we observed the change in corneal curvature, thickness and endothelium after laser radiation to the rabbit cornea. The experiment composed of 14 rabbit eyes divided into two groups according to the power setting; 7 eyes of 2.5mJ group, and 7 eyes of 5mJ group. Lader pulse was focused at corneal epithelium and an average of 25-30 applications were required to make the single pair of transverse line like conventional lineal corneal transverse incision for one eye. Changes ir keratometry and pachymetry were measured postlaser application for 3 months. Seven days after radiation, two rabbit eyes(2.5mJ and 5mJ) were enucleated for scanning electron microscopy. The results were as follows: 1. The mean flattening induced at 900 meridian was 1.91 diopter in 2.5mJ group and 1.98 diopter in 5mJ group 3 months after laser radiation, and the difference between the two groups was not statistically significant(p>0.5). 2. The steepening at 1800 meridian induced only one week after laser radiation in both groups, thereafter the flattening was shown. 3. The significant mean corneal thickness increase of 30.72pm in 2.5mJ group and 33.47 micrometer in 5mJ group was noted at postlaser 7 days and returned to normal range at postlaser 2 months, but the corneal thickness showed no significant statistical difference between two group(p>0.5). 4. Scanning electron microscopy findings showed changes of the ultrastructure of the endothelial cell: edematous changes of the endothelial cell and cell membrane destruction were much less in 2.5mJ group than 5mJ group.
Astigmatism ; Cell Membrane ; Cornea ; Endothelial Cells ; Endothelium* ; Epithelium, Corneal ; Microscopy, Electron, Scanning ; Rabbits* ; Reference Values

We performed keratoplasty and did not remove suture material in 189 patients (189 eyes) after operation. Among them, 48 eyes which had clear grafts with spontaneous suture breakage had been analyzed retrospectively for the age, the sex distribution, the time and the site of broken suture, the preoperative diagnosis and the relationship between the suture breakage and the presence of vasculized recipient bed or suture method. The time when suture was broken after keratoplasty ranged from 3 months to 80 months(average 30 months). Leukoma cornea, 25 eyes(52.1%) and keratoconus, 13 eyes(27.1%) were the most common cause of keratoplasty and the others were corneal dystrophy, Fuchs dystrophy and re-keratoplasty. The most common site of broken suture was at superior quadrant(30 eyes, 62.5%), The vasculized recipient bed was found in 16 eyes, 13 eyes of leukoma cornea and 3 eyes of fe-keratoplasty in preoperative state. The statistical analysis showed significant relationship between the presence of vasculized recipient bed and the suture breakage(p<0.05). Suture was broken in 28 eyes(26.7%) of 105 eyes with single continuous suture, 6 eyes(21.9%) of 20 eyes with combined interupted suture and 14 eyes(21.9%) of 64 eyes with combined interupted and continuous suture. The statistical analysis showed no significant relationship between the suture method and the suture breakage(p>0.05).
Cornea ; Corneal Opacity ; Corneal Transplantation* ; Diagnosis ; Fuchs' Endothelial Dystrophy ; Humans ; Keratoconus ; Retrospective Studies ; Sex Distribution ; Sutures* ; Transplants

Posterior polymorphous dystrophy is a bilateral, dominantly inherited (rarely recessively inherited) disorder of corneal endothelium, characterized by a spectrum of changes in posterior cornea and less commonly in the iris and angle structures. We have experienced a 39-year-old male patient complaining of visual disturbance in the right eye. On examination, we found characteristics of postenor polymorphous dystrophy which were Descemet's membrane thickening. peripheral anterior synechiae, iridocorneal adhesion. abnormal corneal endothelial cells in both eyes, and corneal epithelial and stromal edema in the right eye and after penetrating keratoplasty, the result was good. Therefore, we report a case of posterior polymorphous dystrophy with review of literatures.
Adult ; Cornea ; Descemet Membrane ; Edema ; Endothelial Cells ; Endothelium, Corneal ; Humans ; Iris ; Keratoplasty, Penetrating ; Male

Penetrating keratoplasty was performed on 72 eyes with keratoconus (60 patients) including 12 bilateral cases. We analyzed the difference of unilateral and bilateral grafts about incidence of graft rejection, age and sex dlstribution, and visual acuity change after keratoplasty. In 48 unilatferal grafts, graft rejection was developed in ll eyes (22.9%). in 12 bilateral grafts, there was graft rejection in 3 eyes (25%) of first eyes and 4 eyes (33.3%) of second eyes. The statlstical analysis showed no signifiant difference between the groups (P>0.05). The rejectlOn tlme of 16 eyes (88.8%) was within the first postoperative year. The mean interval between grafts performed on the first and second eyes was 8.8 months. When the interval was Within 1 year, 7 cases of graft rejectlon was developed. In 65 out of 72 grafts (90.3%), the best corrected visual acuity was 0.4 or better. In 18 eyes with graft rejection episode. 15 (83.3%) achieved 0.4 or better.
Corneal Transplantation* ; Graft Rejection* ; Incidence ; Keratoconus* ; Keratoplasty, Penetrating ; Transplants* ; Visual Acuity

Case of traumatic wound dehiscence after penetrating keratoplsty were evaluated. Six eyes of six patients which had sustained traumatic wound dehiscence after penetrating keratoplasty done between 1994 and 1997 were included in the study. Among the six patients, four were men,two were women and age ranged from 13 to 62 years (average, 36 years). Penetrating keratoplasty was performed due to visual loss from keratoconus (n=3), herpes keratitis (n=2), leukoma cornea (n=1). The mean duration between penetrating keratoplasty and traumatic wound dehiscence was 10.83 months. Direct hit in the eyes by fist, elbow, bumping against iron post and door handle were the cause leading to wound dehiscence. Corneal donor-recipient junction is known to be vulnerable to trauma and all the wound dehiscence in the six eyes developed at donor-recipient junction, especially at inferior portion. Vision recovered after primary closure of the wound but was worse than before the traum due to the development of corneal opacity and astigmatism.
Astigmatism ; Cornea ; Corneal Opacity ; Elbow ; Female ; Humans ; Iron ; Keratitis ; Keratoconus ; Keratoplasty, Penetrating* ; Wounds and Injuries*

The most important factor in intraocular lens power calculation is the axial length, followed by the corneal power measurement. In measuring corneal power, conventionally used keratometry evaluates only four indivisual points on the central 3mm of the corneal surface. But coinputerized videokeratography (CVK) is a new technology which maps inside and outside of the central 3mm zone using twenty or seventy hundred data maps. We studied 27 eyes of 26 patients having phacoemulsification and posterior chamber lens implantation. We calculated corneal power using keratometry and CVK. Using the SRK II and Holladay, we obtained intraocular lens power with keratometric value and five values derived. from CVK. 6 weeks later, we evaluated actual postoperative refractive errors and predictive values for each pararneters. Keratometric datas were lower than CVK datas in mean absolute error and standard deviation between actual and predicted postoperative refractive errors and were higher in percentages of cases with power prediction errors < OR =l.0, < OR =2.0 and < OR =3.0 diopters for each formula. And the average keratornetric datas were 0.25mm flatter than CVK. Conventional keratometry may provide more accurate corneal curvature value than the CVK in intraocular lens power calculation.
Corneal Topography* ; Humans ; Lenses, Intraocular* ; Phacoemulsification ; Refractive Errors

Schnyder's crystalline corneal dystrophy is a hereditary disease of unknown etiology and characterized by bilateral subepithelial corneal opacity with diffuse crystalline deposits of cholesterol or other lipid. The authors experienced a case of Schnyder's crystalline corneal dystrophy whose corneal opacity of left eye regressed gradually without treatment. This 40-year-old man had undergone keratoplasty on the right eye and adiagnosis of Schnyder's crystalline corneal dystrophy was made histopatho-logically. In this report, the authors describe a case of regression of Schnyder's crystalline corneal dystrophy without treatment.
Adult ; Cholesterol ; Corneal Opacity ; Corneal Transplantation ; Crystallins* ; Genetic Diseases, Inborn ; Humans

Schnyder's crystalline corneal dystrophy is a hereditary disease of unknown etiology, and characterized by bilateral subepithelial corneal opacification with crystalline or diffuse deposits of cholesterol or other lipid. It is rare and has never been reported in Korea. The authors experienced a case of Schnyder's crystallin corneal dystrophy examined in a 36-year-old man who had bilateral corneal crystalline deposits since 15 years old and significant reduction in vision for two years. Light microscopic examination of patient's keratoplasty specimen showed lipid deposits in the superficial stroma, and electron microscopy disclosed multiple lipid vacuoles in basal epithelium, Bowman slayer, superficial stroma and keratocytes. In this report, we describe the histopathological findings of Schnyder's crystalline corneal dystrophy.
Adolescent ; Adult ; Cholesterol ; Corneal Opacity ; Corneal Transplantation ; Crystallins* ; Epithelium ; Genetic Diseases, Inborn ; Humans ; Korea ; Microscopy, Electron ; Vacuoles