Epidemiology of Infectious Keratitis(II): A Multi-center Study

To identify risk factors and causative organisms, and to evaluate clinical manifestations, methods and results of treatment in infectious keratitis, an epidemiological study was performed prospectively under the identical protocol from April 1995 to March 2000.Logistic regression analysis was used to evaluate possible risk factors. The 1474 cases of infectious keratitis reported from 22 hospitals were studied. Five hundred forty-four organisms(442 bacteria, 82 fungi, 20 A c a n t h a m o e b a)were detected in 1320 eyes with infectious keratitis excluding 154 herpetic keratitis. The Pseudomonas aeruginosa was the most common organism in bacterial keratitis, and Fusariumspp. was the major isolate in fungal keratitis. Contact lens wear and occupation(industry, forester, miner, fisherman)were the risk factors for bacterial keratitis. Risk factors in fungal keratitis were fifth decade of age, farmer, and systemic diseases(diabetes mellitus etc.). Risk factors in herpetic keratitis were male and occupation(office worker, service, student, housewife). Risk factors in Acanthamoeba keratitis was contact lens wear.

A Case of Spontaneous Regression of Schnyder's Crystalline Corneal Dystrophy

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.

Traumatic Wound Dehiscence after Penetrating Keratoplasty

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.

Difference of Corneal Thickness in Enucleated Eye

The maintenance of corneal endothelial cells is essential for success of corneal transplantation. Endothelial cell count by specular microscope and measurement of donor corneal thickness is useful in measuring the function of cornea. We studied difference of corneal thickness in central and peripheral corneal region in enucleated eye. We measured corneal thickness of 48 eyes(48 persons) with ultrasound pachymetry that were presented to The Eye Bank of Catholic University Medical College. Average age was 61.42+/-16.12 years and average time was 163.02+/-102.52 minutes until measurement of corneal thickness after death. Increased amount of corneal thickness was 136.73+/-101.44micrometer in center and 61.37+/135.46micrometer in periphery compared with normal average corneal thickness. According to these results, corneal edema due to functional loss of endothelial cells after death lead to increased corneal thickness, especially in central region being more statistically significant than peripheral region (p=0.002).

A Case of Bacterial Endophthalmitis Following Penetrating Keratoplasty

Endophthalmitis is an intraocular inflammation caused by bacteria or fungus. Although endophthalmitis may result from an endogenous source elsewhere in the body, it most commonly occurs following intraocular surgery or penetrating ocular injury. But endophthalmitis following penetrating keratoplasty reveals the significantly lower incidence than by other causes. We have experienced one case of bacterial endophthalmitis following penetrating keratoplasty which was proved to be Pseudomonas aeruginosa by bacterial culture. In spite of two intravitreal injection of proper antibiotics, his clinical symptoms and signs did not improve and his visual acuity decreased to hand movement. So, we performed pars plana vitrectomy and third intravitreal injection of antibiotic and achieved a successful results with final visual acuity of 6/20. We report a case of endophthalmitis following penetrating keratoplasty and with the review of literature.

Keratometry and Computerized Videokeratography in Determining Intraocular Lens Calculation

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 Amyloidosis Developed after Penetratioin Keratoplasty

Amyloidosis is a disorder of protein metabolism in which amyloid can be accumulated in various tissues of the body. Primary localized amyloidosis can affect the bulbar or palpebral conjuctiva, Tenon`s capsule, tarsus, limbus, lacrimal gland, or orbit. Especially secondary localized amyloidosis of the cornea can occur after trauma. scar, and corneal opacity or can be associated with a chronic ocular inflammatory disorder. The authors diagnosed the secondary localized amyloidosis that developed in a 53-years-old female patient who had undergone penetrating keratoplasty. The diagnosis was confirmed by hematoxylin-eosin and Congo red staining, and transmission electron microscopic examination.

Epidemiology of infectious KeratitisI A Multi-center Study

Infectious keratitis is the most common serious ocular infection, and may be caused by various bacteria, fungi, viruses and parasites. The authors performed prospectively an epidemiological study to identify risk factors and causative organisms, and to evaluate clinical manifestations, methods and results of treatment in infectious keratitis under the identical protocol from April 1995 to September 1997. Logistic regression analysis [univariate analysis and multivariate analysis] was used to evaluate possible risk factors. Six hundred sixty cases of infectious keratitis reported from 19 hospitals were studied. Two hundred eighty-three organisms[247 bacteria, 32 fungi, 4 acanthamoeba] were detected in 626 eyes with infectious keratitis excluding 34 pherpetic keratitis. The Pseudomonas aeruginosa, coagulase negative staphylococcus, Staphylococcus aureus and Serratia marcescens were the major orgnisms in bacterial keratitis. Aspergillus, Fusarium and Candida were the major isolates in fungal keratitis. Contact lens wear was a risk factor for bacterial keratitis. Female, age[less than 40 years] and occupation[student, house-wife, office worker, servise] were associated with bacterial keratitis. Risk factors in herpetic keratitis were age[between 40 and 59 years] and ocular adnexal diseases. Male was associated factor with herpetic keratitis.

A Clinical Study of Risk Factors of Graft Rejection for Penetrating Keratoplasty

Penetrating keratoplasty was performed on 185 eyes. We analyzed the relative risk about the high and low risk groups, sex, age, complication, neovascularization, and graft size. In 185 grafts, graft rejection was developed in 60 eyes(32.4%). In the low risk group, there was the most graft rejection in 17 keratoconus eyes(62.9%) and in the high risk group, in 18 eyes with vascularized corneal scar. Graft rejection was developed in 33 eyes(47.8%) of the high risk group and developed in 27 eyes(23.3%) of the low risk group. The high risk group increased the risk of graft rejection(Relative risk=3.022, P value=0.001). Graft rejection developed in 33 eyes(25%) with non-vascularization and in 27 eyes(52%) with neovascularization. Neovascularization increased the risk of graft rejection (Relative risk=3.273, P value0.5). Mean preoperative visual acuity was 0.048 and mean postoperative visual acuity was 0.4. In the high risk group the mean postoperative corrected visual acuity was 0.25 and in the low risk group it was 0.5.

Clinical Results of Graft Rejection Related to Graft Size after Keratoplasty in Keratoconus

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).

Broken Suture after Keratoplasty

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(p0.05).

Cases of Macular Corneal Dystrophy with a Family History

Macular corneal dystrophy is a heredo-familial disease inherited as an autosomal recessive trait and characterized by corneal opacities due to localized mucopolysaccharidosis. One case of macular corneal dystrophy was reported by Cho et al in Korea in 1976, but it was a case without a family history. We report 3 cases of macular corneal dystrophy with a family history including more specific histopathologic findings and the review of available literatures.

Analysis of The Test Results about The Disease Possibly Transmitted by Donor Eye

We analyzed the result of the tests about HBs Ag, HCv Ag, HIV Ag and VDRL in the blood of the donor and evaluated sex and age distribution, cause of death of the donor, which were obtained from Central Eye Bank at St. Mary's Hospital from January 1, 1993 to December 31, 1994. 1. Hepatitis B surface Ag in the blood was positive in 13 donors(4.80%) and Hepatitis C Ag was in 4 donors(1.48%). 2. VDRL test in the blood was positive in 11 donors(4.06%) and HIV Ag was in 1 donor(0.37%). 3. In sex and age distribution, 128 donors(47.23%) were male and 3 donors(52.77%) were from 71 to 80 years was the major group of donors(67 donors: 24.72%). 4. The most common cause of death was respiratory disease(94 donors: 34.69%) and then tumor(76 donors: 28.04%), circulatory disease(66 donors: 24.35%), metabolic disease (19 donors: 7.01%), infection(9 donors: 3.32%) and trauma(7 donors: 2.58%).

Histopathological Findings of Schnyder's Crystalline Corneal Dystrophy

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.

Clinical Results of Graft Rejection after Unilateral and Bilateral Keratoplasty in Keratoconus

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.

The Effect of Indomethacin Pretreatment Before Nd:YAG Laser Anterior Capsulotomy on Intraoular Pressure of Rabbits

To evaluate the cause of intraocular pressure elevation and the effect of indomethacin after Nd:YAG laser anterior capsulotomy in rabbit authors measured the intraocular pressure, prostaglandin E2 and thromboxane B2 concentrations of aquous humor, and observed the morphological change of trabecular meshwork using scanning electron microscope in indomethacin pretreatment (group I) and non-treatment (group II) group. The intraocular pressure and the concentrations of prostaglanding E2 and thromboxane B2 in group II were higher than in group I. And the scanning electron microscopy showed inflammatory reaction in group II. These results support that the causes of intraocular pressure elevation are elevation of prostaglandin E2. thromboxane B2 concentrations in aqueous humor and intraocular inflammation secondary to it.

The Effect of Indomethacin Pretreatment Before Nd:YAG Laser Anterior Capsulotomy on Intraoular Pressure of Rabbits

To evaluate the cause of intraocular pressure elevation and the effect of indomethacin after Nd:YAG laser anterior capsulotomy in rabbit authors measured the intraocular pressure, prostaglandin E2 and thromboxane B2 concentrations of aquous humor, and observed the morphological change of trabecular meshwork using scanning electron microscope in indomethacin pretreatment (group I) and non-treatment (group II) group. The intraocular pressure and the concentrations of prostaglanding E2 and thromboxane B2 in group II were higher than in group I. And the scanning electron microscopy showed inflammatory reaction in group II. These results support that the causes of intraocular pressure elevation are elevation of prostaglandin E2. thromboxane B2 concentrations in aqueous humor and intraocular inflammation secondary to it.

Clinical Evaluations of Dermoid in External Eye

We conducted a retrospective study of 19 patients(21 eyes) that were confirmed as dermoid by pathologic study, from July, 1987 to June. 1992 at St. Mary's Hospital. Catholic University Medical College. The follow-up period was at least over 6 months We studied on age and sex distribution of the patients, site and portion of involvement and postoperative complications. The most frequent involved age was below 9 years of age(8 patients, 42.0%). The most common site of involvement was the conjunctiva(10 eyes, 47.6%). The most frequent involvement portion was inferiotemporal portion(15 eyes, 71.4%) We did not find any recurrence or remarkable postoperative complications.

Clinical Evaluations of Recurrence after Keratoplasty in Herpes Simplex Keratitis

We conducted a retrospective study of 30 penetrating keratoplasties (30 patients) for corneal opacity due to herpes simplex keratitis from Jan. 1980 to Dec. 1989 at St. Mary's Hospital. The follow-up periods ranged from 1.3 years to 11 years (mean; 4.8 years). Overall, 23 out of the 30 transplants (76.7%) remained clear grafted cornea and 18 eyes (60%) achieved good to excellent visual acuities (0.3 or better). Herpes simplex keratitis was inactive at the time of corneal transplantation in 27 eyes (90%) and the recurrent rate after surgery was 18.5%. Patients with active ulceration or perforation, had particularly poor success rates. The overall rate of recurrent herpetic keratitis after transplantation for herpes was 26.6% Preoperative corneal neovascularization was not a statistically significant prognostic factor with regard to final visual outcome, graft clarity, graft rejection or recurrent herpetic keratitis.

Clinical Evaluations of Recurrence after Keratoplasty in Herpes Simplex Keratitis

We conducted a retrospective study of 30 penetrating keratoplasties (30 patients) for corneal opacity due to herpes simplex keratitis from Jan. 1980 to Dec. 1989 at St. Mary's Hospital. The follow-up periods ranged from 1.3 years to 11 years (mean; 4.8 years). Overall, 23 out of the 30 transplants (76.7%) remained clear grafted cornea and 18 eyes (60%) achieved good to excellent visual acuities (0.3 or better). Herpes simplex keratitis was inactive at the time of corneal transplantation in 27 eyes (90%) and the recurrent rate after surgery was 18.5%. Patients with active ulceration or perforation, had particularly poor success rates. The overall rate of recurrent herpetic keratitis after transplantation for herpes was 26.6% Preoperative corneal neovascularization was not a statistically significant prognostic factor with regard to final visual outcome, graft clarity, graft rejection or recurrent herpetic keratitis.