Recognition and Using Status of Carbon Disulfide (CS₂) as Fumigant for Controlling Chestnut Weevil, Curculio sikkimensis among Chestnut Farmers / 農村醫學 地域保健

OBJECTIVES: We surveyed the awareness and current status of using fumigant carbon disulfide for exterminate Curculio sikkimensis among chestnut farmers in Chungnam Province to suggest directions for health education and public relations. METHODS: We designed questionnaires to evaluate recognition of fumigant carbon disulfide. We conducted a questionnaire survey to assess recognition and recognition level of fumigant carbon disulfide by the study variables. RESULTS: The recognition status for fumigant carbon disulfide was 74.5%, but the recognition level was low (know well 27.5%). The path of recognition was 45.1% and 15.7% for neighbor and rural technology center, respectively. The recognition status for warning label of fumigant carbon disulfide was 52.9%. Recognition for warning label of fumigant carbon disulfide was tended to increase with high educational attainment, bigger owning land area. Recognition on the content of warning label were 29.4%, 27.5%, 21.6%, and 21.6% for inflammability, toxicity, hazard, and explosiveness, respectively. Using personal protection equipment was tended to increase with the high status of awareness on fumigant carbon disulfide. CONCLUSIONS: Health education programs for using fumigant carbon disulfide are needed for chestnut farmers. In addition, publicity information activities about prevention and protection of carbon disulfide poisoning are needed for high risk farmers.

Efficient Cultivation Conditions for Human Limbal Epithelial Cells

To compare the stem niche in different culture conditions of limbal epithelial cells, the suspended human limbal epithelial cells (HLECs) were seeded on the 3T3-pretreated plates and the other suspended cells were plated on amniotic membranes (AMs) which were either cryo-preserved or freeze-dried. All were cultured for 10 to 12 days. Reverse transcription-polymerase chain reaction (RT-PCR) for ATP-binding casette, subfamily G, member 2 (ABCG2), p63, cytokeratin 12, and connexin 43 were performed in cultivated HLECs and their expression levels were compared. The mRNA expression of all markers examined showed no statistically significant differences between the cells on cryo-preserved and on freeze-dried AM. The expression of p63 and cytokeratin 12 in cultivated cells on AMs were significantly lower than those in 3T3-cocultured cells on RT-PCR and immunofluorescent staining. Cultivated HLECs on AMs showed reduced proliferation and differentiation while maintaining stem-property regardless of the preservative method of AM.

Short-term Efficacy of Topical Immunosuppressive Agents on the Survival of Cultivated Allo-Conjunctival Equivalents

PURPOSE: To investigate the short-term efficacy of topical immunosuppressive agents on the survival of cultivated allo-conjunctival equivalents. METHODS: Twenty-five eyes of New Zealand white rabbits were included. Temporal conjunctivae were trephined to a diameter of 7.5 mm, and then cultured allo-conjunctival epithelial cells on amniotic membrane were transplanted onto them. Various immunosuppressants including steroid, cyclosporine, and rapamycin were applied topically four times a day for a week. Epithelial defects and graft edema were graded daily. Numbers of inflammatory cells were measured in H&E. PKH26 and cytokeratin 4 and 7 were immunostained. RESULTS: Earlier epithelialization was observed in 1% steroid-treated eyes and defects persisted significantly in 0.5% CsA applied eyes. In histology, PKH26 positive cells considered as donor cells were only found in 1% steroid or 0.01% rapamycin applied eyes. 1% steroid- or 0.01% rapamycin-applied eyes both showed positive staining for keratin-4 and -7. Inflammatory cells were less found in 1% steroid or 0.01% rapamycin treated eyes. CONCLUSIONS: Topical steroid or rapamycin can help to suppress acute inflammation and enhance the acute survival of transplanted conjunctival cells.

Experience of Comamonas Acidovorans Keratitis with Delayed Onset and Treatment Response in Immunocompromised Cornea

PURPOSE: To report 2 cases of Comamonas acidovorans keratitis in immunocompromised cornea. METHODS: A complete review of the medical records of the two cases of Comamonas acidovorans keratitis. RESULTS: We found some similarities in clinical courses of two cases. Both of them showed development of keratitis during the management with corticosteroids, delayed onset, slow response to antibiotics, and relatively less affected corneal epithelium. CONCLUSIONS: Comamonas acidovorans is known as a less virulent organism. However it can cause an indolent infection that responds slowly even to adequate antibiotics therapy in immunocompromised corneas.

Experience of Comamonas Acidovorans Keratitis with Delayed Onset and Treatment Response in Immunocompromised Cornea

PURPOSE: To report 2 cases of Comamonas acidovorans keratitis in immunocompromised cornea. METHODS: A complete review of the medical records of the two cases of Comamonas acidovorans keratitis. RESULTS: We found some similarities in clinical courses of two cases. Both of them showed development of keratitis during the management with corticosteroids, delayed onset, slow response to antibiotics, and relatively less affected corneal epithelium. CONCLUSIONS: Comamonas acidovorans is known as a less virulent organism. However it can cause an indolent infection that responds slowly even to adequate antibiotics therapy in immunocompromised corneas.

The Efficacy of Amniotic Membrane Graft in the Treatment of Symptomatic Bullous Keratopathy

PURPOSE: To evaluate the efficacy of amniotic membrane (AM) transplantation in symptomatic bullous keratopathy using cryo-preserved or lyophilized AM. METHODS: Eight bullous keratopathic patients, who experienced intractable pain despite medication and the application of a therapeutic lens, underwent permanent AM transplantation with 5 cryo-preserved and 3 lyophilized AMs following removal of epithelium using a trephine. The time to re-epithelization and the subsidence of pain were evaluated retrospectively. RESULTS: Mean follow-up was 252+/-171.0 days. Pain relief and re-epithelization were obtained in all eight patients. The times to complete relief of pain was 32.2+/-22.7 days in patients with cryo-preserved AM transplantations (n=5) and 22.0+/-18.0 days in those with lyophilized AM transplantations (n=3) (p=0.549, Mann-Whitney U test). Respective times to re-epithelization were 25.4+/-20.7 days and 23.0+/-25.2 days (p=0.297). There were no significant differences in the diameter of transplanted AMs between the two groups (7.6+/-0.2 vs. 7.3+/-0.3 mm, p=0.172). CONCLUSIONS: Permanent AM transplantation effectively reduced the intractable pain caused by epithelial bulla. Whether the AM was cryo-preserved or lyophilized did not affect the efficacy of the treatment.

Isolation of Putative Corneal Epithelial Stem Cells from Cultured Limbal Tissue

PURPOSE: To investigate methods of isolating putative corneal epithelial stem cells from cultured limbal tissue. METHODS: Three extraction techniques were compared to identify an efficient method of obtaining a large number of viable corneal epithelial stem cells from the limbus. Limbal tissues were extracted by incubation at 37 degrees C or 4 degrees C for 1 or 16 hours, respectively, with 1.2U/ml dispase/trypsin or by treatment with 0.05% trypsin and 0.01% ethyldiaminetetraacetic acid (EDTA) at 37 degrees C in single procedure. Collected cells were cultured on NIH/3T3-seeded plates, and colony forming efficiency (CFE) was evaluated. Fluorescence activated cell sorting (FACS) was performed with a Coulter EPICS 753 after incubation with Hoechst 33342 and propidium iodide (PI). Hoechst negative cells were obtained using gates exhibiting low Hoechst blue with a 424/44 nm BP filter. Gated cells of each fraction were re-cultured to assess the capability of colony formation. RESULTS: The mean numbers of viable cells obtained from treatment with dispase and trypsin was 3x10(4) cell/ml and 8.06x10(5) cell/ml at 37 degrees C and 4 degrees C incubations; the number increased to 1.21x10(6) cell/ml with a trypsin/EDTA treatment (p<0.05). CFE was 9.67+/-2.13% and 6.63+/-2.35% in rabbit and human cells, respectively. Likewise, the Hoechst negative fraction was 3.61+/-0.42% and 5.21+/-4.91% in rabbit and human cells, respectively. The sorted Hoechst negative cells were cultured through four passages, forming small round colonies. In rabbit cells, the CFEs of Hoechst negative and positive fractions after FACS, were 12.67+/-2.24% and 1.17+/-6.13%, respectively (p<0.05). CONCLUSIONS: Putative corneal epithelial stem cells were efficiently isolated from limbal tissue using a trypsin/EDTA extraction and FACS. This technique may be very useful in tissue engineered stem cell therapy.

Change of Corneal Parameters after Removing Reverse Geometry Lens in Moderate Degree Myopia

PURPOSE: To investigate the recovery time associated with refractive and corneal topographic changes after discontinuing short term wear of reverse-geometry contact lenses in low and moderate myopic patients. METHODS: Twenty-four eyes of 12 patients who were fitted with Ortho-K LK(TM) lenses for a mean duration of 7.9 months were divided into two groups based on the mean manifest refraction (MR) of -3.50D. In groups I (mean MR -2.83D) and II (mean MR -4.00D), uncorrected visual acuity, refractive correction, and topographic changes were evaluated at 3 days; 1, 2, and 3 weeks; and 1, 2, 3, and 6 months after discontinuation of lens wear. Corneal thickness was measured at its center and 3.0 mm from its center. RESULTS: The uncorrected visual acuity, mean spherical equivalent, and average apical keratometric indices recovered at 2 weeks and 1 month after discontinuation of lens wear in groups I and II, respectively. Mean Sim K and corneal thickness recovered at 1 and 2 weeks in groups I and II, respectively. All of the recovered indices remained stable at 6 months. CONCLUSIONS: Recovery of corneal changes after short-term use of reverse-geometry lenses was achieved at 2 weeks in cases of low myopia (less than -3.50D) and at 1 month in cases of moderate myopia (more than -3.50D), with both remaining stable to the 6-month mark.

Screening for Prior Refractive Surgery for Corneal Donation

PURPOSE: To provide fundamental data for screening for prior refractive surgery in donor cornea. METHODS: The corneal curvature map and pachymetric measurements were analyzed in 68 eyes that had undergone corneal refractive surgery. Differences in the corneal curvature of the center and periphery, differences in the corneal thickness of the center and periphery, and the shape factor on the curvature map in postoperative eyes were compared with preoperative measurements. RESULTS: Measurement of the central corneal curvature subtracted from the peripheral corneal curvature was -1.64 +/- 0.71D in the preoperative eyes and 3.10 +/- 1.68D in the postoperative eyes. With a criterion of -0.23D, the sensitivity and specificity were 100% and 98.5%, respectively. The shape factor was 0.24 +/- 0.09 in the preoperative eyes and -0.82 +/- 0.45 in the postoperative eyes. With a criterion of 0.058, the sensitivity and specificity were both 100%. Measurement of the central corneal thickness subtracted from the peripheral corneal thickness was 97.60 +/- 25.42 micrometer in the preoperative eyes and 163.47 +/- 38.5 micrometer in the postoperative eyes. With a criterion of 123.0 micrometer, the sensitivity and specificity were 89.7% and 88.4%, respectively. CONCLUSIONS: Regional differences in corneal curvature and shape factor may be very useful parameters in screening for prior refractive surgery in donor cornea. The difference in corneal thickness may also be a useful parameter.

Isolation of Putative Limbal Epithelial Stem Cells by Fluorescein Activated Cell Sorting

PURPOSE: To analyze the isolating pattern of slow cycling cells as putative limbal epithelial stem cells (PLESCs) using Hoechst exclusive cell sorting. METHODS: Rabbits were injected with 5-bromo-2-deoxyuridine (Brd U) 1 month prior to be sacrificed. After obtaining limbal tissues, fluorescence-activated cells were sorted on a Coulter EPICS 753 after they had been incubated with Hoechst 33342 and propidium iodide. Two different methods were applied to sort PLESCs. Side-population(Sp) cells were obtained using gates with dichroic mirror to detect low Hoechst blue and red after verapamil was treated. Hoechst negative cells were obtained using gates exhibiting low Hoechst blue with a 424/44 BP filter. Brd U-retaining cells were counted and their sizes were evaluated in each gated sample to compare isolating pattern of PLESCs in each method. RESULTS: The percentages of Sp cells and of the Hoechst negative fraction were 0.96 +/- 0.79% and 16.01 +/- 13.60%, respectively(p=0.021). Homogeneity and density of the small cells were higher in Hoechst negative fraction than in Sp cells. The percentage of Brd U-retaining cells was 47.36 +/- 10.34% and 47.14 +/- 14.94% in Sp cells and Hoechst negative fraction, respectively(p>0.05), and they were 10 times higher than in non-Sp and Hoechst positive fraction(p=0.000). CONCLUSIONS: Hoechst negative exclusion without verapamil more efficiently isolated PLESCs than Sp did.

The Effect of Amniotic Membrane Transplantation on the Treatment of Necrotizing Scleritis after Pterygium Excision

PURPOSE: To investigate the efficacy of amniotic membrane transplantation (AMT) in patients who were diagnosed with necrotizing scleritis after pterygium excision and who were refractory to systemic corticosteroid and immunosuppressive therapy. METHODS: Six patients who had persistent scleral melting with systemic corticosteroid or immunosuppressive agents underwent double AMT as a permanent patch graft and temporary overlying barrier. Postoperatively, the symptom improvements, reepithelization times and visual acuity changes were evaluated. RESULTS: Choroidal detachment was detected in two patients preoperatively. In all patients, ocular pain improved at 4.7 +/- 3.1 days, and reepithelization of the scleral lesions was completed at 13.2 +/- 8.1 days postoperatively. Choroidal detachment in two patients disappeared at postoperative 2 and 8 days. Complete remission was found in 5 of the 6 eyes (83.3%). One eye which achieved full epithelization in the necrotic area experienced recurrent nodular scleritis in another quadrant, resulting in remission after changing the regimen of immunosuppressive agents. Mean values of initial and final visual acuities were 0.898 logMAR and 0.428 logMAR, respectively, and the visual acuities improved in all patients. CONCLUSIONS: AMT is effective in promoting reepithelization of the necrotic area, resulting in complete remission of necrotizing scleritis in patients who were refractory to systemic corticosteroid or immunosuppressive therapy.

Adhesion Complex in Cultivated Limbal Epithelium on Amniotic Membrane after Transplantation into Chemical Burn Model

PURPOSE: To investigate adhesion complex formation in cultivated human limbal epithelium after transplantation into the chemical burn model. METHODS: human limbal epithelial cells were cultured on amniotic membrane that had not undergone dispase treatment. Laminin V was evaluated using immunohistochemistry. The adhesion complex was examined by electron microscopy. Cultured epithelium was transplanted into limbal deficient rabbits induced by chemical burn and mechanical limbal removal. The transplanted rabbits and the controls with mechanical wounding were sacrificed at 1, 2, 3, and 4 weeks. The adhesion complex was examined by electron microscopy. RESULTS: Linear staining was observed against laminin V at 4-week culture but matured adhesion complex was not found. Graft failure developed in 3 rabbits (25%) after transplantation. Morphologically identifiable hemidesmosomes appeared at 1 week and matured adhesion complex with continuous basement membrane was found at 3 weeks. The mean numbers of hemidesmosomes/2.25 micro meter were 2.3 +/- 0.9, 2.5 +/- 0.5, 5.2 +/- 1.0, and 4.0 +/- 0.9 at 1, 2, 3, and 4 weeks, respectively. The adhesion assembly nearly recovered to the level of that in the human cornea (3.7 +/- 60.11) at 3 weeks. CONCLUSIONS: Adhesion complex of cultivated limbal epithelium did not developed in vitro, but the assembly was almost completed at 3 weeks after transplantation in vivo.

Effect of the Aspheric RGP Lens on Corneal Topography and Endothelial Cell in Keratoconus

PURPOSE: To analyze the effects of the aspheric rigid gas permeable (RGP) lens on the corneal topography and endothelial cells in eyes with keratoconus. METHODS: Sixty five eyes of 35 keratoconic patients who had follow-up of more than 6 months were included in the study. Thirty eyes of 16 patients wore aspheric RGP lens, and the remaining control eyes did not wear any lens. After aspheric RGP lens fitting, visual acuity and manifest refractive error were evaluated, Slit lamp examination and corneal topography were also done. Mean cell area and density of corneal endothelial cell were measured by specular microscopy at first visit and 6 months after lens fitting. RESULTS: After lens fitting, the percentage of best corrected visual acuity of better than 20/25 was 93.3% (28 eyes). The change of astigmatism, the Steepest Simulated keratometry reading, Surface asymmetry index, Surface regularity index, and apical corneal power were significantly increased in the keratoconic cornea in aspheric lens fitting group compared to the control group (p0.05). CONCLUSIONS: Short-term wearing of aspheric RGP lens in keratoconic patients showed no effect on corneal endothelial cells. However, it increased the irregularity and steepening of the keratoconic cornea. It may indicate that mid-peripheral corneal-to-lens relationship may be inappropriate when keratoconus is fitted with aspheric lens.

The Effect of RGP Lens and Reverse Geometry Lens on Corneal Epithelial Proliferation Rate in Rabbit

PURPOSE: To investigate proliferation rate of the corneal epithelium with rigid gas permeable lens(RGP) or reverse geometry lens(RGL) wearing. METHODS: Twenty-four rabbits were fitted with either a RGP or RGL on right eye, with left eye serving as a control. They were sacrificed at 1, 3, 7, and 14 days after lens fitting. after immunohistochemistry using 5-bromo-2-deotyuridine, BrdU-labeled cells were counted in 10-medium power fields (X200) in each sample using light microscope by 1.0 mm intervals between superior limbus and the center. RESULTS: The number of BrdU-labeled cells was highest in peripheral cornea, and lowest in limbus(p<0.05). The BrdU-labeled cells of limbus increased by 127% but labeled-cells of the center decreased by 24% in RGP group after 1-day fitting. Increase of the labeled cells was observed in the mid-peripheral and central cornea by 12% and 121% each but the decrease of labelled cells was found at the limbus by 16% in RGL fitting group at 1 day. After 14days, Both RGP and RGL group showed decrease of BrdU-labeled cells in limbus by 8% each, and in the center by 32% and 63%, respectively. CONCLUSIONS: Normal rabbit cornea was characterized by different epithelial proliferation rates according to location. However these pattern was significantly altered with both RGL and RGP fitting group. The change was greater in RGL group than in RGP group. This suggested wearing the RGL might be less physiologic than RGP fitting.

The Analysis of Management of Keratoconus Using Contact Lens in Koreans

PURPOSE: To analyze the fitting characteristics of contact lens, according to the clinical findings keratoconus of in Koreans. METHODS: The topographic indices were evaluated in 106 keratoconic eyes of the 53 patients, who had been followed up for at least 1 month, and their fitting pattern parameters retrospectively analyzed. The visual acuity, epithelial erosion, glare, daily lens wearing time, pain and the changes in the topographic indices were evaluated after fitting. RESULTS: The number of eyes fitted with spherical RGP, aspherical RGP and multicurve RGP were 19, 6 and 81 eyes with mean base curve radius (BCR) of 7.67, 7.17, and 6.76 mm, respectively. The Sim K and temporal K 3 mm from the center were significantly correlated with the BCR. 77 eyes achieved visual acuity of 20/30 or better, and the mean daily wearing time was 11.6 hours. Glare and pain were reported in 4 and 7 eyes, respectively, and progression of epithelial erosion was found in 8 eyes. The mean anterior elevation and sim Kmax in lens intolerable eyes were 0.0745 mm and 59.35 D, which were significantly higher than 0.0584 mm and 54.22 D in lens tolerable eyes. No progressive keratoconic changes were observed in the topographic indices for the eyes fitted with the multicurve lenses. CONCLUSIONS: Appropriate fitting guide-lines could be established by analyzing the fitting and clinical characteristics in keratoconus.

Effect of the Spheric Multi-curve Lens on Changes of Corneal Topography and Endothelial Cell in Keratoconus

PURPOSE: To analyze the effect of the spheric multi-curve lens on the changes of corneal topography and endothelial cells in keratoconic eye. METHODS: Forty-nine eyes of 37 keratoconic patients who had been followed more than 6 months were included in the study. Twenty-six eyes of 19 patients were fitted with spheric multi-curve lens, and the remaining 23 eyes of 18 patients were followed without any lens fitting as control. After spheric multi-curve lens fitting, visual acuity, and slit lamp examination were evaluated. Changes of corneal topography and endothelial cell were evaluated at first visit and 6 months after lens fitting. RESULTS: After lens fitting, 21 eyes (80.8%) showed best corrected visual acuity of better than 20/25. The value of the steepest Sim-K, shape factor (SF), and apical corneal power on corneal topography were significantly decreased in the spheric multi-curve lens fitting group compared to the control group (p0.05). There were no significant differences in change of corneal endothelial cell density, mean cell area and percentage of hexagonal cell between the two groups (p>0.05). CONCLUSIONS: Short-term wearing of spheric multi-curve lens for 6 months in keratoconic patients showed no effect on progression of keratoconus and cornealendothelial cells.

Diagnostic Criteria for Keratoconus Using Orbscan II Slit Scanning Topography/Pachymetry System

PURPOSE: To investigate new diagnostic criteria of keratoconus using Orbscan II Slit Scanning Corneal Topography/Pachymetry System. METHODS: Eighty eyes of 45 patients with keratoconus and 100 randomly selected eyes of 50 patients without any ophthalmologic problem were enrolled in this study. Anterior elevation from BFS, posterior elevation from BFS, Sim K (maximum), and thinnest pachymetric value were evaluated using Orbscan II. Values outside 2 standard deviations from the mean value of each parameter were estimated to the upper or lower limits in diagnosing keratoconus. RESULTS: There were significant differences of all parameters of Orbscan II between the keratoconic eyes and the control (p 23.3 micro meter, posterior elevation from BFS > 49.8 micro meter, Sim K (maximum) > 47.0 D, thinnest pachymetric value < 455.0 micro meter. CONCLUSIONS: Orbscan II can provide useful information in the diagnosis of keratoconus with high sensitivity and specificity.

The Effect of RGP Lens and Reverse Geometry Lens on Apoptosis in Rabbit Cornea

PURPOSE: To investigate the cytotoxic effect of rigid gas permeable(RGP) and reverse geometry lens(RGL) on rabbit corneal cells. METHODS: In 36 white rabbits, right eyes were worn with either RGP or RGL. Left eyes were served as control. The rabbits were sacrificed at 1, 3, 7, 14 days after fitting and 7, 14 days after removal. Morphological changes of the basal epithelial cells and stromal keratocytes were observed using the light and transmission electron microscopy. The samples were examined after TUNEL staining in 3 high power fields (x400). RESULTS: In control eyes, 2.26% of central corneal epithelial cells showed apoptosis. After RGP wearing, the epithelial apoptosis decreased by 0.32% compared to control eyes(2.17%) at 14 days(p<0.001), and returned to 1.55% at 14 days after lens removal(2.04% in control, p=0.161). After RGL wearing, the degree of apoptosis was also lower than control(3.22%) by 0.30% at 14 days(p=0.003). However, it increased to 0.75% at 14 days after lens removal(1.67% in control, p=0.077). A few TUNEL positive fibroblasts were found in superficial stroma in both RGP and RGL group, but not in control eyes. CONCLUSIONS: Both RGP and RGL wearing may decrease the degree of apoptosis in corneal epithelium and lead the apoptosis in corneal stroma. The degree of apoptosis was recovered after lens removal, suggesting the process might to be reversible. The fitting with RGL induced apoptosis of keratocyte more than the fitting with RGP did. It suggests that the RGL wearing may be less physiologic than RGP wearing.

Effect of Reverse Geometry Lens on Correction of Moderate-degree Myopia and Cornea

PURPOSE: To evaluate the effect of reverse geometry lens (RGL) on correction of moderate degree myopia and cornea in patients of moderate-degree myopia. METHODS: 48 eyes of 82 eyes were chosen to wear reverse geometry lens and the remaining 34 eyes were fitted with rigid gas permeable (RGP) lens. The subjects were tested three days, one, two weeks, one, two and three months after fitting the lens. Uncorrected visual acuity, manifested refractive error, corneal thickness and corneal endothelial cell count were evaluated. corneal topography were performed. RESULTS: The uncorrected visual acuity was increased at 0.05 LogMAR after two weeks. and manifested refractive error decreased during the first months, thereafter stabilizing to -0.2 D (diopters). Corneal thickness was 540.4 micrometer and 583.0 micrometer in the center and mid-periphery, decreased to 505.2 micrometer and 572.7 micrometer, respectively, three months after RGL fitting (p<0.05). Endothelial cell count was 2663.5 cells/mm2 and 2541.5 cells/mm2 in the center and mid-periphery, 3 months after RGL fitting and endothelial cell count was not significantly different compared with that of pre-fitting. There was no statistical difference between RGL fitting group and RGP fitting group in the change of corneal endothelial cell count. CONCLUSIONS: RGL was found to be effective in correction of moderate-degree myopia. It had minimal effect on corneal endothelium, in short-term usage, however, the change of corneal thickness suggests that RGL fitting may effect on corneal epithelium and stroma.

Clinical Outcomes of Penetrating Keratoplasty and Limbal Transplantation from the Same Versus Different Donor Graft

PURPOSE: To evaluate the difference of the central graft rejection after penetrating keratoplasty and limbal allograft transplantation from different donors vs from the same donor. MATERIAL and METHODS: Three patients diagnosed with chemical burn and one with Stevens-Johnson syndrome were included. Three patients underwent penetrating keratoplasty and limbal allograft transplantation from different donors and one underwent the same operation from the same donor. Mean follow-up was 13 months. Visual acuity, re-epithelization and endothelial rejection were examined. RESULTS: Re-epithelization occurred within 3 to 14 days (mean 8.7 days) in three eyes with chemical burn. Visual acuities ranged from light perception to 20/100. Endothelial rejection developed in the eye transplanted from the same donor. Re-epithelization failed in the eye with Stevens-Johnson syndrome even though limbal graft transplantation and cultivated limbal epithelium transplantation were performed repeatedly. CONCLUSIONS: Corneal endothelial rejection seemed to decrease after penetrating keratoplasty and limbal allograft transplantation from different donors.