Comparative analysis of long-term results of three epithelial cell transplantation procedures for treating limbal stem cell deficiency.

This study compared the long-term outcome of different epithelial transplantation techniques to treat limbal stem cell deficiency (LSCD). We conducted a retrospective 15-year comparative systematic cohort study of patients with LSCD who underwent either cultivated limbal epithelial transplantation (CLET), simple limbal epithelial transplantation (SLET), or cultivated oral mucosal epithelial transplantation (COMET). We reviewed the demographic data, etiology, LSCD severity, best-corrected visual acuity, surgical outcomes, and complications. A total of 103 eyes of 94 patients (mean age, 45.0 ± 16.4 years) with LSCD were enrolled. The most common cause of LSCD was chemical injury (42.7 %). The median follow-up time was 75 months. The success rates of CLET, SLET, and COMET were 45.5 %, 77.8 %, and 57.8 %, respectively. The 7-year survival rates after CLET, SLET, and COMET were 50.0 %, 72.2 %, and 53.2 %, respectively. Steven-Johnson syndrome (SJS) had a significantly lower survival rate than other causes (p < 0.001), but SLET had a significantly higher survival rate than CLET (p = 0.018) and COMET (p = 0.047). Visual improvement of more than four Snellen lines was achieved in 53.1 % of successful cases and 28.2 % of failed cases. SJS, Schirmer I test <5 mm, and the presence of postoperative recurrent epithelial defects were significant risk factors for a failed surgery. All epithelial transplantation techniques had favorable long-term surgical outcomes. More than half of the patients achieved a stable ocular surface and visual acuity improvement up to 7 years postoperatively. SLET tends to have a better surgical outcome than CLET and COMET, especially in patients with SJS.

Genetic analysis of allogenic donor cells after successful allo-limbal epithelial transplantation in simple and cultivated limbal epithelial transplantation procedures.

This non-comparative cohort study investigated long-term donor cell survival after allogenic simple/cultivated limbal epithelial transplantations (allo-SLET/allo-CLET, respectively) by genetic analysis. Transplanted corneal epithelial cells, which underwent impression cytology and/or corneal-button biopsy, were examined for personal identities of autosomal short-tandem repeats; the percentages of donor cells were calculated based on matching recipient or donor buccal-DNA references. Twelve patients were included; 4 underwent allo-CLET, 8 underwent allo-SLET. Eight patients (67%) had total limbal stem cell deficiency (LSCD). Genetic analysis was performed postoperatively (mean, 55.3 months). Donor cells were detected in 4 of 12 patients (25%), all of whom underwent allo-SLET; 1 patient had a donor genotype and 3 patients had a mixed donor/recipient genotype. The longest time of donor cell detection was 30 months. Seven patients (58%) used systemic immunosuppressives at the time of genetic analysis (mean use, 22.5 months). Allogenic donor cells survived in both procedures for the long term postoperatively, which encourages the long-term use of systemic immunosuppressives. Donor cells may not be the only factor in graft survival, in that most successful cases had a recipient profile. Their presence for a specific time may promote niches for the patients' own cells to repopulate, especially for partial LSCD.

Long-term Outcomes of Boston Type I Keratoprosthesis, and Efficacy of Amphotericin B and Povidone-Iodine in Infection Prophylaxis.

PURPOSE: To evaluate the long-term outcomes, anatomic retention, and complications of Boston type I keratoprosthesis (KPro). DESIGN: Retrospective, interventional case series METHODS: A retrospective chart review of implantations performed January 2008-December 2017 was conducted. Risk factors for anatomical retention and functional success were analyzed. The incidences of infections with and without antimicrobial medications were compared. RESULTS: Twenty-seven eyes of 26 patients were recruited. The most common indication for KPro surgery was failed penetrating keratoplasties (22 eyes, 81.5%). All patients had preoperative best-corrected visual acuity (BCVA) worse than 3/60. Over the mean follow-up of 83.4 ± 28.4 months, 15 eyes (55.6%) demonstrated improved BCVA. The anatomical retention rate was 88.9%, and the functional success rate was 44.4% (retained KPro with BCVA ≥ 3/60). Eyes with ocular surface disease (OSD) had significantly more complications than those without OSD. The most common complications were retroprosthetic membrane formation (15 eyes, 55.6%) and infection (13 eyes, 48.1%). Infectious keratitis was primarily caused by gram-positive bacteria, whereas endophthalmitis was chiefly caused by fungal infection. The infection incidence was significantly lower in eyes using topical 0.1% amphotericin B and 5% povidone iodine (P = .008 and .021, respectively). CONCLUSIONS: With its good retention rate and visual outcomes, Boston type I KPro could be an alternative treatment for patients with conventional penetrating keratoplasty failure, especially with appropriate patient selection and complication prevention. Standard prophylactic antibiotics with the addition of topical 0.1% amphotericin B and 5% povidone iodine might be optional effective regimens for infection prevention, especially in tropical countries.

A 5-year retrospective record review of hospital-based low-vision rehabilitation in Thailand.

PURPOSE: To investigate the quality-of-life-related goals of low-vision patients, the causes of visual impairment, and the low-vision rehabilitation services at a Thai national tertiary referral center. SUBJECTS AND METHODS: A review was conducted on the medical records of patients attending the Low Vision Rehabilitation Clinic, Siriraj Hospital, Bangkok, Thailand, between 2012 and 2016. RESULTS: A total of 992 patient records were included, comprising of 760 adults (aged over 15 years) and 232 children (aged ≤15), with a mean age of 52.2 and 5.4 years, respectively. The retina was the most common anatomic site of visual impairment. Among the adults, the most common ocular condition was retinitis pigmentosa (28.3%), followed by age-related macular degeneration (10.3%), glaucoma (10.0%), and diabetic retinopathy (9.6%). As for the children, the most common ocular conditions were cortical visual impairment (17.7%), optic nerve hypoplasia (13.4%), and retinopathy of prematurity (9.5%). More patients had low vision (a visual acuity of <6/18-3/60) than blindness (a visual acuity below 3/60). The most commonly stated goals among the adults were reading, writing, and performing near tasks (34.7%), and independent mobility (21.3%), whereas for children, the most frequently indicated goal was visual and developmental stimulation (38.4%). The services most often provided for the adults were the prescribing of visual aid devices (51.8%) and orientation and mobility training (40.7%), while the children most often received visual and developmental stimulation provided by a multidisciplinary team (33.8%). The Thai Government's Universal Health Care Coverage scheme was the most commonly used medical insurance. CONCLUSION: Data from this study can be used to improve low-vision patient care and rehabilitation services, and as input to the further development of national health care policies for low-vision patients.

Long-term result of autologous cultivated oral mucosal epithelial transplantation for severe ocular surface disease.

The present study aimed to investigate the clinical outcomes of autologous cultivated oral mucosal epithelial transplantation (COMET) on human amniotic membrane (AM) for corneal limbal stem cell deficiency (LSCD). In this prospective, noncomparative case series, 20 eyes (18 patients) with bilateral severe ocular surface disease were chosen to undergo COMET on human AM. The primary outcome was clinical success, and the secondary outcomes were the best-corrected visual acuity difference, corneal opacification, symblepharon formation, and complications. The mean patient age was 48.2 ± 15.5 years. The mean follow-up time was 31.9 ± 12.1 months (range 8-50 months). All except one eye exhibited complete epithelialization within the first postoperative week. A successful clinical outcome, defined as a stable ocular surface without epithelial defects, a clear cornea without fibrovascular tissue invasion at the pupillary area, and no or mild ocular surface inflammation, was obtained in 15 of 20 eyes (75 %). The clinical success rate at 1 year was 79.3 %, and that at 4 years (end of follow-up) was 70.5 %. Fourteen of 20 (70 %) eyes exhibited improvement in visual acuity after COMET, and some required subsequent cataract surgery (2 eyes), penetrating keratoplasty (3 eyes), or keratoprosthesis implantation (1 eye). Preoperative symblepharon was eliminated in most eyes (8 of 13, 61.5 %) after COMET combined with eyelid reconstruction when needed. The only complication was corneal perforation (1 eye) induced by a severe eyelid abnormality; treatment with a tectonic corneal graft was successful. COMET can successfully restore ocular surface damage in most eyes with corneal LSCD.

Chronic recalcitrant bacterial infection in steroid modified interstitial (stromal) keratitis: presentation and management.

OBJECTIVE: To report histopathologically proven bacterial infection manifested multifocal interstitial (stromal) keratitis (IK) with definite previous history of prolong topical steroid use. Standard managements of bacterial keratitis did not provoke enough benefit. MATERIAL AND METHOD: A retrospective analysis of 19 eyes in 15 patients referred to Siriraj Hospital between 2004 and 2010. RESULTS: Multifocal intrastromal infiltration, with relatively quiet ocular reaction and mild inflammation were initially presented in all eyes. They all previously had been diagnosed of presumed viral keratitis, and had been given topical corticosteroid treatment for a prolonged period of time without healing. Autoimmune disease workups were all negative. Corneal scrapings showed negative culture results in all eyes. However, bacteria within stromal lamellae with absent or minimal inflammatory cells were demonstrated in all eyes by corneal biopsies. In addition, cytology results obtained from 16S rDNA sequencing revealed Stenotrophomonas maltophilia in one eye and coagulase-negative staphylococci in two eyes. No case responded well to intensive topical and systemic antibiotics. However they were successfully treated with penetrating keratoplasty (11 eyes, 57.9%) or intrastromal antibiotic injections (8 eyes, 42.1%). CONCLUSION: Bacterial infection should be a concern in prolonged chronic IK. This was considered as primary bacterial IK or bacterial superinfection in immunocompromised cornea. Early recognition and appropriately aggressive managements contribute to successful outcome. Corneal biopsy is always essential and 16S rDNA sequencing is useful in this distinct clinical entity.

Efficacy of cultivated corneal epithelial stem cells for ocular surface reconstruction.

PURPOSE: To investigate the clinical outcomes of cultivated corneal limbal epithelial transplantation (CLET) using human amniotic membrane for corneal limbal stem-cell deficiency. METHODS: Prospective, noncomparative case series. Eighteen patients (19 eyes) with severe ocular surface diseases were chosen to undergo CLET using human amniotic membrane. Twelve eyes received auto-CLET, and seven eyes received allo-CLET. Clinical outcomes of corneal surface epithelialization, conjunctivalization, inflammation, visual acuity, graft status, and complications were observed. RESULTS: Corneal epithelium cultivated on amniotic membrane (two to four layers) was positive for molecular markers p63, ABCG2, CK3, and CK12. The mean patient age was 44.7 ± 15.2 years. A successful clinical outcome, defined as corneal epithelialization without central conjunctivalization or severe inflammation, was obtained in 14 (73.7%) of 19 eyes (mean follow-up 26.1 ± 13.5 months; range 6-47). A histopathologic success, defined as absence of goblet cells at the central cornea, was achieved in 12 (63.2%) eyes. Clinical failures occurred in five (26.3%) of 19 eyes, and histopathologic failures occurred in seven (36.8%) of 19 eyes. Survival analysis at 1 year showed that the clinical success rate was 77.9% and the pathological success rate was 72.3%. Fourteen of 19 (73.7%) eyes had visual acuity improvements after CLET. Six cases underwent penetrating keratoplasty; five of these grafts remained clear after 20.4 ± 6.9 months (range, 12-31) of follow-up. Complications included infectious keratitis (three cases) and recurrent symblepharon (one case). All complicated cases had lid abnormalities. Factors affecting the final clinical outcomes were lid abnormalities, abnormal corneal stromal beds, and complications. CONCLUSION: CLET can successfully restore ocular surface damage in most cases with corneal limbal stem cell deficiency.

Refractive outcomes of femtosecond LASIK for myopic correction at Siriraj Hospital, Thailand.

OBJECTIVE: To evaluate refractive outcomes of myopic femtosecond LASIK at Siriraj Hospital, Thailand. MATERIAL AND METHOD: A retrospective study of patients who underwent femtosecond LASIK at SiLASIK center Siriraj hospital, Mahidol University, Thailand,from April 2009 to April 2010 was conducted. All patients had completely normal preoperative eye examination. All LASIK procedures were performed using Intralase femtosecond laser (Abbott Medical Optics Inc (AMO)) and VISX star S4 excimer laser (AMO). Postoperative follow-up included visual acuity (ETDRS chart) and manifest refraction at 1 day, 1 week, 1 month and 3 months. The flap thickness was evaluated at 3 months using Visante optical coherence tomography (OCT Carl Zeiss Meditec). RESULTS: One hundred and twenty eight eyes of 64 patients were included in the study. Mean preoperative manifest refraction spherical equivalent (MRSE) was -5.47 +/- 2.28 diopters (range, -1.88 to -12.63 diopters). At 3 months post-operation, the MRSE was -0.26 +/- 0.39 diopters (range, + 0.25 to -2.00 diopters) and 95.31% were within + 1.00 diopter of intended correction. There was 98% of eyes achieved uncorrected distance visual acuity (UDVA) 20/40 or better and 73% achieved UD VA 20/20 or better There was 31% of eyes gained one line and 15% lost 1 line of corrected distance visual acuity (CDVA). The mean error of flap thickness (difference between actual and intended central flap thickness) was + 0.23 +/- 1.77 microm for 120 microm flap setting and + 0.22 +/- 0.97 microm for 110 microm flap setting. The flap morphology was planar configuration. CONCLUSION: Myopic femtosecond LASIK at Siriraj Hospital provided satisfactory refractive outcomes and high accuracy of the flap thickness.

Causes of visual impairment in Thai diabetic patients in the visual rehabilitation clinic.

BACKGROUND: Visual disability from diabetic retinopathy is one of many public health problems. Knowing the causes of blindness and low vision in diabetic patients will help in policy planning in order to reduce diabetic complications and prevent blindness. OBJECTIVE: To study the causes of visual impairment, blindness and related factors in diabetic patients who registered at the visual rehabilitation clinic, Siriraj Hospital, Mahidol University, Bangkok. MATERIAL AND METHOD: A retrospective study of 133 diabetic patients who registered at the visual rehabilitation clinic between January 2007 and December 2010 was conducted. The patients were divided into 2 groups: a low vision group (VA in the better eye < 6/18-3/60) and a blindness group (VA in the better eye < 3/60--No light perception). The history of diabetic mellitus, associated systemic diseases, laboratory investigations, ocular changes and treatment were recorded. The causes of visual impairment and blindness were collected and analyzed. RESULTS: Of a total of 133 diabetic patients, 93 cases (69.9%) were in a low vision group and 40 cases (30.1%) were in a blindness group. The causes of visual impairment were proliferative diabetic retinopathy (84.6%), retinal detachment (37.2%), macular edema and scar (25.9%), optic atrophy (143%), neovascular glaucoma (11.7%) and vitreous hemorrhage (4.9%). Tractional retinal detachment (p-value < 0.001) and optic atrophy (p-value = 0.021) were the associated factors causing blindness in visual disability patients with statistical significance. Optic atrophy (38 eyes) occurred post vitrectomy in 19 eyes. CONCLUSION: Visual disability in diabetic patients is caused by the complications of diabetic retinopathy and its management. The prevention of disease progression, especially macular edema and proliferative diabetic retinopathy, will decrease the rate of visual impairment and blindness.

Precision analysis of posterior corneal topography measured by Visante Omni: repeatability, reproducibility, and agreement with Orbscan II.

PURPOSE: To evaluate the repeatability and reproducibility of posterior corneal curvature and posterior corneal elevation best-fit sphere (BFS) obtained with the Visante Omni (Carl Zeiss Meditec) and to compare the results with the Orbscan II (Bausch & Lomb). METHODS: Thirty eyes from 30 healthy volunteers were included in this study. All patients were examined 5 times with the Visante Omni and Orbscan II by 2 independent operators. The posterior corneal curvature (3- and 6-mm zone) and posterior corneal elevation BFS (5- and 8-mm zone) were generated for each system. Intraoperator repeatability and interoperator reproducibility and agreement between the systems were evaluated using the intraclass correlation coefficient (ICC) and the Bland-Altman method. RESULTS: The repeatability of posterior corneal curvature and posterior corneal elevation BFS measured by the Visante Omni was high for all analysis zones (ICC, 0.99 to 1.00). The reproducibility also showed similar results (ICC, 0.99 to 1.00). Agreement between the Visante Omni and Orbscan II was high for posterior corneal curvature (ICC, 0.94 to 0.97) and posterior corneal elevation BFS (ICC, 0.96 to 0.98) with 95% limits of agreement at -0.26 to 0.22 diopters for posterior corneal curvature and 0.11 to 0.69 mm for posterior corneal elevation BFS. CONCLUSIONS: The Visante Omni provides good repeatability and reproducibility of posterior corneal topography. Overall agreement with the Orbscan II system was high.

Production and activity of matrix metalloproteinase-9 on the ocular surface increase in dysfunctional tear syndrome.

PURPOSE: To evaluate production and activity of metalloproteinase (MMP)-9 on the ocular surface of patients with dysfunctional tear syndrome (DTS) and determine any correlation between MMP-9 activity and clinical parameters. METHODS: Forty-six patients with newly diagnosed DTS and 18 control subjects were recruited. Complete ocular surface examinations were performed. Tear MMP-9 activity was assessed with an MMP-9 activity assay in 1 microL of unstimulated tear fluid. Using conjunctival epithelial cells from 19 patients with DTS and 16 controls, levels of MMP-9 and its regulating cytokine mRNA transcripts were evaluated by semiquantitative real-time PCR. RESULTS: Each of four DTS severity-based groups had significantly higher mean MMP-9 activities than did the control group, which was 8.39 +/- 4.70 ng/mL. The DTS4 group had the highest MMP-9 activity (381.24 +/- 142.83 ng/mL), for which the mean was significantly higher than that of other DTS groups. In addition, patients with DTS had significantly higher levels of IL-1beta, IL-6, TNF-alpha, and TGF-beta1 mRNA transcripts in their conjunctival epithelia than did the control subjects. Tear MMP-9 activities showed significant correlation with symptom severity scores, decreased low-contrast visual acuity, fluorescein tear break-up time, corneal and conjunctival fluorescein staining, topographic surface regularity index (SRI), and percentage area of abnormal superficial corneal epithelia by confocal microscopy. CONCLUSIONS: Tear MMP-9 activity was significantly higher in patients with DTS. This activity was associated with increased mRNA expression of MMP-9 and its regulating genes and correlated strongly with clinical parameters. MMP-9 appears to be a potentially useful biomarker for diagnosing, classifying, and monitoring DTS.

Human corneal epithelium-derived thymic stromal lymphopoietin links the innate and adaptive immune responses via TLRs and Th2 cytokines.

PURPOSE: To explore the crucial role of the human corneal epithelium-derived proallergic cytokine thymic stromal lymphopoietin (TSLP) in initiation and regulation of immune responses. METHODS: Primary corneal epithelial cells, established from donor limbal explants, were treated with 11 microbial ligands and proinflammatory and Th2 cytokines, alone or in combination. TSLP mRNA and protein were determined by real-time PCR and ELISA, respectively. NF-kappaB activation was detected by immunostaining and Western blot. RESULTS: TSLP was found to be expressed by human corneal epithelium and its cultures. TSLP in corneal epithelial cells were largely induced in a concentration-dependent fashion by polyI:C, flagellin, and FSL-1, the ligands for toll-like receptor (TLR)-3, -5, and -6, respectively. Compared with the control, TSLP mRNA was increased by 60-, 12- and 8-fold and TSLP protein increased by 67-, 19- and 7-fold by these three ligands, respectively. The proinflammatory (TNF-alpha and IL-1beta) and Th2 (IL-4 and IL-13) cytokines moderately induced TSLP expression and production. IL-4 and -13 strongly synergized with PolyI:C, flagellin, and TNF-alpha to promote TSLP production in ex vivo tissues and in vitro cultures of corneal epithelium. PolyI:C, flagellin, or TNF-alpha also induced NF-kappaB p65 protein nuclear translocation. The NF-kappaB inhibitor quinazoline blocked p65 nuclear translocation and further suppressed TSLP expression and production induced by these stimuli. CONCLUSIONS: These findings provide the first evidence of TSLP induction in the human eye and suggest the novel phenomenon that human corneal epithelium-derived TSLP may serve as a link between the innate and adaptive immune responses. TSLP may become a novel therapeutic target for allergic and inflammatory ocular surface diseases.

Sterility of non-preservative eye drops.

OBJECTIVES: To assess microbial contamination of common non-preservative eye drops stored at 4 degrees C and non-preservative fortified antibiotic eye drops used in a hospital inpatient setting. MATERIAL AND METHOD: A prospective study of the sterility of non-preservative eye drops was examined by dividing the patients into 2 groups. Group 1 composed of 5 samples of each ophthalmic preparation, which consisted of fortified antibiotics (vancomycin, cefazolin, gentamicin, and amikacin), non-preservative steroid eye drops (1% methylprednisolone and 0.01% dexamethasone), and 20% autologous serum stored at 4 degrees C. Group 2 was composed of 28 samples of fortified vancomycin and 23 samples of fortified amikacin used in an inpatient setting for 1 week and kept in 4 degrees C for 28 days. The contamination was assessed at the day of preparation and then at day 4, 7, 14, 21, 28 of all medications except autologous serum was done up to day 84. The sterility was examined by the culturing on tryptic soy broth and thioglycolate broth. RESULTS: In group 1 and 2, no contamination was detected in any samples within 4 weeks and up to 12 weeks for autologous serum. CONCLUSION: Non- preservative topical eye drops can be safely kept at 4 degrees C without contamination for 4 weeks and 12 weeks for 20% autologous serum drop. For topical antibiotics, under a strict protocol for preparation and usage might be used without significant risk of bacterial contamination for 4 weeks.

Corneal characteristics in myopic patients.

OBJECTIVES: To evaluate the characteristics of the cornea in myopic patients. MATERIAL AND METHOD: A retrospective study of 420 eyes in 210 patients who visited the Excimer Laser Surgery Clinic at Siriraj Hospital, Mahidol University from January 1999 to June 2002 was conducted. All cases that were eligible for myopic refractive surgery were included in the present study. A preoperative ocular examination was done in a fashionable method, including manifest refraction and Orbscan Topography to evaluate corneal thickness, corneal curvature and corneal diameter Statistical analysis was performed to identify the characteristics of the cornea in the patients. RESULTS: The mean age of the patients was 31.66 +/- 7.77 years. (ranging from 16-51). The mean manifest refraction (spherical equivalent) was -4.9 +/- 2.29 diopters (ranging from -0.50 to -13.75). The mean corneal diameter (white to white) was 11.60 mm +/- 0.37 mm (ranging from 10.8-12.9). The thinnest point of the cornea varied from 409 to 597 microns (mean = 522.55) and located mostly in the infero-temporal quadrant of the eye (23.69% in the right and 32.05% in the left). The mean curvature of the corneal was 44.6 +/- 13.8 diopters (ranging from 39.05-47.65). The mean corneal astigmatism was 1.34 +/- 0.71 diopters and 93.96% were with the rule astigmatism. Positive angle kappa was found in 408 eyes (97%) but all cases were within a 0.5 mm horizontal and 0.3 mm vertical radius from the pupillary axis. CONCLUSION: Characteristics of the cornea in Thai myopic patients were demonstrated in the present study. Most of the cornea showed with the rule astigmatism with positive angle kappa and the thinnest point, located at the infero-temporal quadrant.