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.

Assessing the Risk Factors For Diagnosed Symptomatic Dry Eye Using a Smartphone App: Cross-sectional Study

Background

Dry eye (DE) is a chronic inflammatory disease of the ocular surface of the eye that affects millions of people throughout the world. Smartphone use as an effective health care tool has grown exponentially. The “Dry eye or not?” app was created to evaluate the prevalence of symptomatic DE, screen for its occurrence, and provide feedback to users with symptomatic DE throughout Thailand.

Objective

The purpose of this study was to compare the prevalence of symptomatic dry eye (DE), blink rate, maximum blink interval (MBI), and best spectacle-corrected visual acuity (BSCVA) between people with and without symptomatic DE and to identify risk factors for symptomatic DE in Thailand.

Methods

This cross-sectional study sourced data from the “Dry eye or not?” smartphone app between November 2019 and July 2020. This app collected demographic data, Ocular Surface Disease Index (OSDI) score, blink rate, MBI, BSCVA, and visual display terminal (VDT) use data. The criterion for symptomatic DE was OSDI score ≥13.

Results

The prevalence of symptomatic DE among individuals using this smartphone app in Thailand was 85.8% (8131/9482), with the Northeastern region of Thailand having the highest prevalence, followed by the Northern region. Worse BSCVA (median 0.20, IQR 0.40; P=.02), increased blink rate (median 18, IQR 16; P<.001), reduced MBI (median 8.90, IQR 10.80; P<.001), female sex (adjusted OR 1.83; 95% CI 1.59-2.09; P<.001), more than 6 hours of VDT use (adjusted OR 1.59; 95% CI 1.15-2.19; P=.004), and lower than bachelor’s degree (adjusted OR 1.30; 95% CI 1.03-1.64; P=.02) were significantly associated with symptomatic DE. An age over 50 years (adjusted OR 0.77; 95% CI 0.60-0.99) was significantly less associated with symptomatic DE (P=.04).

Conclusions

This smartphone DE app showed that the prevalence of symptomatic DE in Thailand was 85.8%. Signs and risk factors could be also evaluated with this smartphone DE app. Screening for DE by this app may allow for the development of strategic plans for health care systems in Thailand.

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.

Efficacy and outcome of simple limbal epithelial transplantation for limbal stem cell deficiency verified by epithelial phenotypes integrated with clinical evaluation

PURPOSE

To evaluate the efficacy and outcome of simple limbal epithelial transplantation (SLET) for limbal stem cell deficiency (LSCD) using epithelial phenotype detection integrated with clinical manifestation.

METHODS

This prospective multicenter study included patients with LSCD who underwent autologous SLET (autoSLET) and living-related allogenic SLET (Lr-alloSLET). All patients were assessed by slit-lamp biomicroscopy, in vivo confocal microscopy (IVCM), and impression cytology with immunofluorescence staining (ICIF) before and after surgery. The criteria for success were the presence of a clinically non-conjunctivalized cornea and corneal epithelium detected by IVCM or ICIF. Otherwise, the case would be considered a failure. Visual improvement and risk factors for SLET failure were analyzed.

RESULTS

A total of 28 eyes of 26 patients (11 autoSLET and 17 Lr-alloSLET) were included. The median age was 53 years (range, 35-63), and the follow-up time was 29.5 months (range, 17.5-39.8). The overall survival rate was 89.3% at 2 years and 75.6% at 3 years with no difference between autoSLET and Lr-alloSLET (p = 0.24). Seven eyes subsequently underwent penetrating keratoplasty. Immunohistochemistry analysis showed that all corneal buttons had corneal epithelium and limbal stem cell markers. Visual improvement was achieved in both SLET groups (p < 0.001). Failed SLET developed between 5 and 32 months postoperatively. However, absolute risk factors for SLET failure were unidentified.

CONCLUSION

The efficacy of autoSLET and Lr-alloSLET for LSCD was excellent. Limbal explants can regenerate and restore the corneal surface while maintaining the characteristics of limbal stem cells as shown by epithelial phenotype detection and immunohistochemistry integrated with clinical evaluation.

Involvement of Toll-like receptor 2 on human corneal epithelium during an infection of Pythium insidiosum

BACKGROUND

Pythium insidiosum, a pathogenic oomycete, is a common causative organism of infectious corneal ulcer. Studying the innate immune response at the ocular surface is important for better understanding of the underlying pathogenesis and host defense against P. insidiosum infection.

OBJECTIVE

The present study aims to investigate the role of Toll-like receptor (TLR)2 on human corneal epithelial cells (HCECs) in P. insidiosum infection.

METHODS

Human embryonic kidney (HEK) cells were stimulated with either P. insidiosum zoospores or hyphae. NF-κB activation was determined by spectrophotometric measurement of secreted embryonic alkaline phosphatase (SEAP) levels. The role of TLR2 in P. insidiosum infection was studied in HCECs and monocyte derived macrophages (MDMs) using anti-TLR2 neutralizing antibody. The expression levels of pro-inflammatory cytokines were determined.

RESULTS

Both P. insidiosum hypha and zoospore stimulated TLR2-dependent NF-κB activation in HEK-Blue™-hTLR2 cells in dose-dependent manner. IL-6 and IL-8, but not IL-1β, were upregulated in HCECs after stimulation with P. insidiosum. Blockade of TLR2 on HCECs altered neither IL-6 nor IL-8 expressions. In contrast, the 3 cytokines were upregulated in the stimulated MDMs and the expression levels of IL-1β and IL-8 but not IL-6 were attenuated in TLR2 blockade MDMs.

CONCLUSIONS

P. insidiosum was recognized by human TLR2 on HEK cells. The mRNA expression levels of certain cytokines were dependent of TLR2 in P. insidiosum infected MDMs but not HCECs at early stage of infection.

Association of HLA polymorphisms and acetaminophen-related Steven-Johnson syndrome with severe ocular complications in Thai population

Background/aims

To investigate the association of genetic polymorphisms of human leucocyte antigens (HLA) class I and II genes with acetaminophen-related Steven-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) who developed severe ocular complications (SOC) in the Thai population.

Methods

A prospective case–control study including 20 unrelated Thai acetaminophen-related SJS/TEN patients with SOC and 60 Thai healthy volunteers, recruited at three university hospitals in Bangkok, Thailand, from September 2014 to August 2019. HLA genes were analysed using PCR amplification followed by hybridisation with sequence-specific oligonucleotide (SSO) probes with bead-based typing kits. The carrier and gene frequencies of individual HLA alleles in patients were compared with those in control volunteers based on dominant assumption using Fisher’s exact test.

Results

Among HLA class I polymorphisms, HLA-A*33:03, HLA-B*44:03 and HLA-C*07:01 were significantly associated with acetaminophen-related SJS/TEN and SOC with high ORs (95% CI, corrected p value; Pc) in carrier frequency of 5.4 (1.8 to 16.3, Pc=0.0274), 9.0 (95% CI 2.7 to 30.4, Pc=0.0034), and 9.3 (2.8 to 30.2, Pc=0.0022), respectively. There were no significant HLA class II associations with the disease after corrected for a total number of alleles tested.

Conclusion

HLA-B*44:03 was strongly associated with acetaminophen-related SJS/TEN patients who developed SOC in Thai population. In addition, we also found moderate to strong associations with HLA-A*33:03 and HLA-C*07:01 suggesting their potential roles in the pathogenesis of SOC in acetaminophen-related SJS/TEN.

Characterization of limbal explant sites: Optimization of stem cell outgrowth in in vitro culture

Simple limbal epithelial transplantation (SLET) and cultivated limbal epithelial transplantation (CLET) are proven techniques for treating limbal stem cell deficiency (LSCD). However, the precise regions that are most suitable for preparing explants for transplantation have not been identified conclusively. Accordingly, this in vitro study aimed at determining ideal sites to be selected for tissue harvest for limbal stem cell culture and transplantation. We evaluated cell outgrowth potential and the expression of stem cell markers in cultures from 48 limbal explants from five cadaveric donors. The limbal explants were generated from the three specific sites: Lcor (located innermost and adjacent to the cornea), Lm (middle limbus), and Lconj (located outermost adjacent to the conjunctiva). We found that explants from the Lconj and Lm sites exhibited higher growth potential than those from the Lcor site. Transcript encoding the stem cell marker and p63 isoform, ΔNp63, was detected in cells from Lm and Lconj explants; expression levels were slightly, though significantly (p-value < 0.05), higher in Lm than in Lconj, although expression of ΔNp63α protein was similar in cells from all explants. Differential expression of ATP-Binding Cassette Subfamily G Member 2 (ABCG2) did not reach statistical significance. Immunohistochemistry by indirect immunofluorescence analysis of limbus tissue revealed that the basal layer in explant tissue from Lconj and Lm contained markedly more stem cells than found in Lcor explant tissue; these findings correlate with a higher capacity for growth. Collectively, our findings suggest that explants from the Lconj and Lm sites should be selected for limbal cell expansion for both CLET and SLET procedures. These new insights may guide surgeons toward specific limbal sites that are most suitable for stem cell culture and transplantation and may ultimately improve treatment outcomes in the patients with LSCD.

Association of IKZF1 SNPs in cold medicine-related Stevens-Johnson syndrome in Thailand

Purpose

Our meta-analysis of several ethnic groups (Japanese, Korean, Indian, Brazilian) revealed a significant genome-wide association between cold medicine-related SJS/TEN (CM-SJS/TEN) with severe ocular complications (SOC) and IKZF1 SNPs, suggesting that IKZF1 might be a potential marker for susceptibility to CM-SJS/TEN with SOC. In this study, we examined the association between CM-SJS/TEN with SOC and the IKZF1 SNPs in the Thai population.

Methods

57 CM-SJS/TEN with SOC and 171 control samples were collected at Chulalongkorn University and Mahidol University. Genomic DNA samples were genotyped for the IKZF1 SNPs at Kyoto Prefectural University of Medicine in Japan using the TaqMan SNP genotyping assay.

Results

The four SNPs previously reported to be associated with CM-SJS/TEN with SOC in the Japanese were examined in the Thai samples. Although the number of Thai cases (n = 57) was small, a significant association between CM-SJS/TEN with SOC and IKZF1 SNPs which included rs4917014 (T vs G, OR = 2.9, p = 0.0012, Pc = 0.0049), rs4917129 (T vs C, OR = 2.8, p = 0.0026, Pc = 0.010) and rs10276619 (G vs A, OR = 1.8, p = 0.012, Pc = 0.048) was identified.

Conclusion

In addition to the Japanese, Korean and Indian populations, Thai cases with CM-SJS/TEN and SOC were significantly associated with IKZF1 SNPs. With our previous report of the critical role of IKZF1 in mucocutaneous inflammation, these results suggest that IKZF1 is important in the pathogenesis of CM-SJS/TEN with SOC.

Comparison of central corneal thickness measurements in corneal edema using ultrasound pachymetry, Visante anterior-segment optical coherence tomography, Cirrus optical coherence tomography, and Pentacam Scheimpflug camera tomography

Purpose

To compare the central corneal thickness (CCT) measurements in subjects with corneal edema using ultrasound pachymetry, Visante anterior-segment optical coherence tomography (OCT), Cirrus OCT, and Pentacam Scheimpflug camera tomography.

Methods

This prospective cross-sectional study included 46 eyes of 33 patients with corneal edema and a CCT exceeding 550 μm evaluated by ultrasound pachymetry, Visante OCT, Cirrus OCT, and Pentacam. Two observers measured each eye twice. Intraobserver and interobserver reproducibility were determined and agreement among the devices calculated.

Results

CCT was measured in 40 eyes of 29 patients. Regardless of the CCT, the measurements obtained using Visante OCT, Cirrus CCT, and ultrasound pachymetry were well correlated. Interobserver and intraobserver reproducibility were high among the three devices. Pentacam overestimated the results compared with the other devices, and ultrasound pachymetry was unmeasurable in six (13%) eyes with very thick and opaque corneas. In eyes with mild corneal edema (CCT 551–650 μm), measurements from the four devices were comparable.

Conclusion

All devices reliably measured the CCT <650 μm. In eyes with edema exceeding 650 μm, CCT measurements from the Visante OCT, Cirrus OCT, and ultrasound pachymetry devices showed good reproducibility and were well correlated, while the Pentacam overestimated the values compared to the other devices. Pentacam and ultrasound pachymetry should not be used in eyes with extreme corneal edema and opacity.

Association between HLA-B*44:03-HLA-C*07:01 haplotype and cold medicine-related Stevens-Johnson syndrome with severe ocular complications in Thailand

BACKGROUND

Polymorphisms in human leucocyte antigen (HLA) class I genes have been found to be associated with cold medicine (CM)-related Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) with severe ocular complications (SOC). Because ethnic differences in genetic predisposition to SJS/TEN among different populations have been proposed, we focused on Thai patients and investigated the association between HLA class I genotypes and CM-SJS/TEN with SOC.

METHODS

This multicentre case-control study was conducted between September 2014 and August 2017. Seventy-one Thai patients with SJS/TEN with SOC and 159 healthy Thai controls were enrolled. HLA typing was performed. Genetic relationships were analysed using Fisher's exact test.

RESULTS

Of 71 patients with SJS/TEN with SOC (28 male, 43 female), 49 (69%) had a history of taking cold medications prior to SJS/TEN onset. The mean age of onset was 26.7±17.1 years (range, 2-77 years). HLA-B*44:03 (OR, 7.2, p=5.5×10^-6, pc=1.1×10^-4) and HLA-C*07:01 (OR, 6.1, p=7.1×10^-6, pc=1.1×10^-4) showed significant positive associations with Thai patients with CM-SJS/TEN with SOC. Additionally, 17 of 49 patients with CM-SJS/TEN with SOC (34.7%) significantly harboured the HLA-B*44:03 and HLA-C*07:01 haplotype compared with only 11 of 159 healthy controls (6.9%) (OR=7.1, p=5.5×10^-6).

CONCLUSIONS

HLA-B*44:03-HLA-C*07:01 haplotype is a potential risk factor for CM-SJS/TEN with SOC in the Thai population. This study supports that HLA-B*44:03 might be a common marker for CM-SJS/TEN with SOC in Eurasia populations, including European, Indian, Japanese and Thai.

High Prevalence of Ocular Surface Disease Among Glaucoma Patients in Thailand

PURPOSE

To determine the prevalence of symptoms and signs of ocular surface disease (OSD) among Thai patients with glaucoma receiving topical intraocular pressure (IOP)-lowering therapy.

METHODS

Consecutive patients with glaucoma were recruited prospectively for this cross-sectional study from Siriraj Hospital. Subjective symptoms were evaluated using the Ocular Surface Disease Index (OSDI), and objective clinical signs were evaluated using the tear breakup time (TBUT), corneal fluorescein, rose bengal staining, and the Schirmer test.

RESULTS

One hundred nine patients (56% women; mean age, 64.0 ± 13.7 years) were included. The mean number of IOP-lowering eye drops instilled daily was 3.2 ± 2.4; the mean duration of treatment was 5.4 ± 3.9 years. Forty-two (38.5%) patients reported symptoms using the OSDI. The TBUT was normal in 1 patient, and the others (99.1%) had abnormal tear quality. Fluorescein and rose bengal staining showed positive results in 35 (32.1%) and 42 (38.6%) patients, respectively. The Schirmer test showed decreased tear production in 80 (73.4%) patients. A greater number of IOP-lowering eye drops daily was associated significantly with 3.8 and 4.4 times higher odds of abnormal corneal fluorescein and rose bengal staining, respectively (95% confidence interval [CI], 1.62-9.34, P = 0.002 and 95% CI, 1.91-10.32, P = 0.001, respectively). A significant (P = 0.03, 0.04) correlation was seen between OSDI and corneal dye staining tests.

CONCLUSIONS

A high prevalence of OSD was found among glaucoma patients in Thailand. OSD is more prevalent in Asians than in westerners. Awareness regarding prescribing multiple IOP-lowering eye drops in Asians should be heightened to avoid ocular surface toxicity.

Ocular Injury due to Potassium Permanganate Granules

Purpose

We report a rare case of ocular injury due to potassium permanganate (KMnO₄) granules in a child.

Methods

This is a retrospective case report.

Results

A 2-year-old boy was transferred to our emergency room with severe pain in his right eye, inflamed eyelids, and brownish stains on his fingers. Chemical injury was suspected. Copious eye irrigation was immediately performed. Diffuse brownish splotches were then observed at the inferior bulbar conjunctiva. Otherwise, systemic organs were intact. Complete eye exam under general anesthesia revealed a 5-mm epithelial defect at the central cornea, along with generalized conjunctival injection and limbal ischemia, inferiorly. Multiple semi-dissolved granules of KMnO₄ trapped in the inferior fornix were identified. The chemical particles were gradually washed out and removed; however, the brownish stains remained. The patient received preservative-free steroid, antibiotic eye drops, and lubricants as regular management for mild to moderate degree of ocular burn. Pseudomembrane developed early and transformed into symblepharon within a few days after the injury. Membrane adhesion was lysed, and more aggressive medications were then substituted. Commercial amniotic membrane (PROKERA®) was also applied to promote wound healing and to prevent recurrence of symblepharon. The ocular surface was eventually restored, and corneal transparency was preserved.

Conclusion

Ocular injury with the granular form of KMnO₄ is rare. Its toxicity is comparable to concentrated KMnO₄ solution. However, the dissolved particles that had been absorbed in the stained conjunctiva were continuously released and damaged the ocular surface more than we primarily anticipated. Awareness of this condition and prompt management yield a good treatment outcome.

Effect of 0.3% Hydroxypropyl Methylcellulose/Dextran Versus 0.18% Sodium Hyaluronate in the Treatment of Ocular Surface Disease in Glaucoma Patients: A Randomized, Double-Blind, and Controlled Study

PURPOSE

To compare the efficacy and safety of 0.3% hydroxypropyl methylcellulose/dextran (HPMC/dextran) and 0.18% sodium hyaluronate (SH) in the treatment of ocular surface disease in patients using antiglaucoma drugs containing preservatives.

METHODS

This was a double-blind, randomized, parallel-group study in 70 glaucoma patients with Ocular Surface Disease Index (OSDI) score greater than 20 points and/or presence of ocular signs. Patients were randomized to receive either preservative-free 0.3% HPMC/dextran (n=35) or preservative-free 0.18% SH (n=35). Treatment was 1 drop in each eye, 4 times a day. Data were collected at baseline, at day 7 and day 28.

RESULTS

The groups were homogeneous at baseline. At day 28, both treatments showed significant improvements (P<0.05) in the mean OSDI score, lid skin and lid margin inflammation, conjunctival injection, and expressibility of meibomian glands, corneal staining score, fluorescein tear breakup time (FBUT), and Schirmer I test. However, the mean OSDI score, lid margin inflammation and conjunctival injection showed significant improvements (P<0.05) in the SH group at days 7 and 28, compared to the HPMC/dextran group. FBUT and the Schirmer I test also showed significant improvements (P<0.05) in the SH group compared to the HPMC/dextran group, at day 28. No adverse reactions were observed in either group.

CONCLUSIONS

Preservative-free artificial tear, 0.3% HPMC/dextran, and 0.18% SH, caused a significant relief of the ocular surface disease in glaucoma patients. However, 0.18% SH led to a greater improvement in ocular signs and symptoms than 0.3% HPMC/dextran.

Efficacy of cyclosporine 0.05% eye drops in Stevens Johnson syndrome with chronic dry eye

OBJECTIVE

To evaluate the efficacy of cyclosporine 0.05% (CsA) eye drops in patients with Stevens Johnson syndrome (SJS) who had chronic dry eye.

DESIGN

Prospective noncomparative interventional case series.

METHODS

Thirty cases of SJS patients who developed dry eye defined by symptoms and signs, including the Schirmer I test, the fluorescein clearance test (FCT), and corneal staining (fluorescein and Rose Bengal staining) were treated with CsA 0.05% eye drops twice daily for 6 months. Dry eye symptoms, eye injection, tear break up time (TBUT), and corneal staining were evaluated before and after the treatment at 0, 2, 4, and 6 months. The Shirmer I test and FCT were evaluated at 0 and 6 months.

RESULTS

Seventeen patients (56.67%) completed the study. Eight patients (26.67%) withdrew from the study as a result of intolerable side effects of CsA, which included pain, redness, and eyelid swelling. Five cases were lost in follow up. All 17 cases demonstrated significant improvement in dry eye symptoms, conjunctival injection, corneal staining, Schirmer I test, and FCT (P<0.05).

CONCLUSIONS

CsA 0.05% eye drops might be beneficial in the treatment of chronic dry eye associated with SJS.

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.

Risk factors for contact lens related microbial keratitis: a case-control study

OBJECTIVE

To evaluate the risk factors that may contribute to microbial keratitis in contact lens wearers.

MATERIAL AND METHOD

This prospective case-control study included 52 patients with contact lens related keratitis treated between 1 December 2006 and 15 October 2007 at the Faculty of Medicine, Siriraj Hospital. Controls were sixty-three contact lens users attending with disorders unrelated to contact lens wear All subjects with informed consent were interviewed about demographic data, types of contact lens and contact lens solutions, contact lens use past the recommended replacement date, overnight wear, and lens hygiene. Odds ratio (OR, estimates of relative risks) and 95% confidence interval (CI) were calculated through multivariable logistic regression analysis.

RESULTS

The use of contact lens past the replacement date caused the highest risk of developing microbial keratitis (OR = 9.1; CI 1.8-45.4, p = 0.005). Overnight wear of lenses (OR = 2.9, CI 1.3-6.2, p = 0.012) and poor lens hygiene (OR = 2.3, CI 1.0-5.1, p = 0.007) significantly increased the risk of microbial keratitis, respectively. None of the other risk factors showed a significant association.

CONCLUSION

The significant risk factors for contact lens related microbial keratitis in the present study were the use of contact lens past the replacement date, overnight wear, and poor lens hygiene. Thus, the appropriate advice of contact lens care and usage may reduce the risk of microbial keratitis in contact lens wearers.

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.

Stability of epitheliotrophic factors in autologous serum eye drops from chronic Stevens-Johnson syndrome dry eye compared to non-autoimmune dry eye

PURPOSE

To compare the concentrations of epitheliotrophic factors in autologous serum eye drops (ASE) prepared from sera of chronic Stevens-Johnson syndrome (SJS) patients with dry eyes to those prepared from non-autoimmune dry eye controls and to study the stability of the epitheliotrophic factors in different storage conditions.

METHODS

Twenty-percent ASE were prepared from 10 chronic SJS patients with dry eyes and 10 age-matched non-autoimmune dry eye controls. The concentrations of major epitheliotrophic factors comprising epidermal growth factor (EGF), transforming growth factor-beta1 (TGF-β1), transforming growth factor-beta2 (TGF-β2), and fibronectin in those ASE preparations were determined by enzyme-linked immunosorbent assay (ELISA) at baseline and after different storage conditions: at 4 °C for 1 week and 1 month; and at -20 °C for 1, 3 and 6 months.

RESULTS

There were no significant differences in the concentrations of EGF, TGF-β1, TGF-β2 and fibronectin in 20% ASE between the SJS and control groups (EGF: 176.9 ± 40.9 vs. 185.5 ± 36.9 pg/mL, TGF-β1: 9.5 ± 2.1 vs. 9.5 ± 1.9 ng/mL, TGF-β2: 55.3 ± 30.0 vs. 63.91 ± 45.6 pg/mL and fibronectin: 70.5 ± 20.2 vs. 62.2 ± 21.3 µg/mL, respectively). These factors were stable at 4 °C for up to 1 month. Storage at -20 °C for up to 6 months resulted in a slight decrease in TGF-β1 (SJS: from 9.5-8.4 ng/mL, p < 0.01 and control: from 9.5-8.1 ng/mL, p < 0.01).

CONCLUSIONS

The results suggested that the epitheliotrophic capacity of ASE from chronic SJS should be comparable to those from non-autoimmune dry eye patients, and that ASE should be sufficiently stable for up to 6 months, if stored properly at -20 °C.

Causes of corneal blindness: a multi-center retrospective review

OBJECTIVE

To assess prevalence and causes of corneal blindness in four hospitals in Thailand and to compare the causes between hospitals.

MATERIAL AND METHOD

A retrospective chart review of six hundred and sixty four patients records with best-corrected visual acuity not better than 6/60 in at least one eye due to corneal disease in Siriraj, Mettapracharak, Sappasitthiprasong and Banmee Hospitals in a one-year period were reviewed. The collected data included age, sex, laterality, causes of corneal blindness, and prognosis.

RESULTS

Seven hundred and sixty nine eyes with corneal blindness and a median age of 55.0 years were reviewed Leading causes of cornea blindness were corneal infection (35.6%), surgical bullous keratopathy (27.8%), and trauma (14.0%). The prevalence at Siriraj Hospital was 1.7% (498/28,728 patients). Most of the treatable cases (84.6%) underwent penetrating keratoplasty procedures and 73% of patients had a chance of recovery.

CONCLUSION

Corneal infection and surgical bullous keratopathy were the leading causes of corneal blindness.

Efficacy of amniotic membrane patching for acute chemical and thermal ocular burns

OBJECTIVE

To study the efficacy of amniotic membrane patching (AMP) for acute chemical and thermal ocular burns and compare the results with a control group.

MATERIAL AND METHOD

Fifteen patients (21 eyes) with acute ocular burn severity grading of II to IV were retrospectively reviewed. Thirteen eyes were treated with preserved AMP while eight eyes were treated with conventional treatment. Outcomes and complications were evaluated and compared between eyes in the AMP group and the control group with the same severity of burn.

RESULTS

In the AMP group, the mean age was 36.9 +/- 11.7 years (range, 20-58). The mean follow-up time was 8.0 +/- 6.8 months (range, 1-20). Complete epithelialization was achieved in 69.2% (9/13 eyes) in total, 100% (5/5 eyes), 100% (3/3 eyes) and 20% (1/5 eyes) in grade II, III and IV respectively. Mean epithelial healing time in the AMP group was 10.4 +/- 5.8 days (range, 4-20). Comparison of grade 2 and 3 burns showed that the AMP group in which patching was performed within 5 days resulted in faster epithelial healing, less corneal haze and limbal deficiency than in the group in which patching was performed after 5 days, and the control group (mean epithelial defect 7.0 +/- 2.0, 19.5 +/- 0.7, 9.9 +/- 10.8 days respectively).

CONCLUSION

Adjunctive treatment of ocular burns with AMP promoted rapid epithelial healing and reduced corneal complication. Surgery performed in the early stage tended to yield a better outcome.

Corneal injury by bee sting with retained stinger--a case report

OBJECTIVE

To report a rare case of corneal injury by bee sting with its complication and management.

MATERIAL AND METHOD

A 3-year-old boy, who was attacked by a swarm of bees, was referred for the right eye's corneal ulcer evaluation.

RESULTS

Two stingers were found and completely removed with jeweler forceps. Corneal epithelial defect, corneal edema, secondary bacterial keratitis, heterochromia iridis, and internal ophthalmoplegia were identified The corneal edema markedly improved 3 days after removing the retained bee stingers and treatment by topical antibiotics and steroids. The patient was evaluated after 1 week and 1 month and was found with permanent central corneal scar particularly at the area corresponding to the retained stinger The patient had subsequently localized traumatic anterior subcapsular cataract corresponding to where the stinger had penetrated the lens.

CONCLUSION

Corneal bee sting injury is an uncommon ocular trauma, but can result in severe sight threatening complication. Even though the response of corneal edema is well inclined to topical steroid, awareness in adjusting the clinical treatment for the particular case needs a scrutinized investigation of the infection.

Performance profile of sodium hyaluronate in patients with lipid tear deficiency: randomised, double-blind, controlled, exploratory study

AIM

To assess the short-term efficacy of hypotonic 0.18% sodium hyaluronate in patients with evaporative tear-sufficient dry eye due to lipid tear deficiency (LTD).

METHODS

This was a randomised, double-blind, controlled, exploratory study. A total of 10 patients with dry eye due to LTD were treated as follows: one drop of hypotonic 0.18% sodium hyaluronate in one eye and one drop of isotonic 0.3% hydroxypropyl-methylcellulose (HPMC)/0.1% dextran in the other eye. Non-invasive tear film break-up time (NIBUT) evaluated by using a tear scope with grid pattern and subjective ocular symptoms of dry eye were assessed at 15, 30, 60 and 90 min after instillation.

RESULTS

Both sodium hyaluronate and HPMC/dextran caused a significant (p<0.05) improvement in NIBUT and symptoms. Mean (SD) NIBUT in the sodium hyaluronate group was 3.2 (1.0), 6.4 (2.8), 5.5 (1.9), 5.3 (1.3) and 3.9 (1.7) s at 0, 15, 30, 60 and 90 min, respectively, compared with 3.6 (1.9), 5.5 (3.2), 5.0 (1.5), 4.4 (2.2) and 3.5 (1.2) s in the HPMC/dextran group. However, increase in NIBUT was significantly (p<0.05) greater and longer in the sodium hyaluronate group than in the HPMC/dextran group.

CONCLUSION

Treatment with sodium hyaluronate and HPMC/dextran eye drops is useful for treating patients with dry eye due to LTD. However, sodium hyaluronate caused a significantly (p<0.05) greater increase in NIBUT values than HPMC/dextran in such patients.

Efficacy of Subconjunctival 5-Fluorouracil and Triamcinolone Injection in Impending Recurrent Pterygium

OBJECTIVE

To study the efficacy of subconjunctival 5-fluorouracil (5-FU) and triamcinolone injection in halting the progression of impending recurrent pterygium.

DESIGN

Randomized, prospective, controlled clinical trial.

PARTICIPANTS

One hundred nine patients who had undergone pterygium excision within the previous 6 months and developed grade 3 characteristics (impending recurrent pterygium).

METHODS

A total of 109 eyes with impending recurrent pterygium were stratified randomly into 3 groups by treatment: 35 eyes served as the control group, 39 eyes received a 5-mg intralesional injection of 5-FU weekly for 2 weeks, and 35 eyes received one 20-mg intralesional injection of triamcinolone. All groups received 1% prednisolone acetate eye drops 4 times daily for 8 weeks.

MAIN OUTCOME MEASURES

Recurrence rate, success rate, and survival analysis were compared among the groups.

RESULTS

With a mean follow-up time of 10.9+/-5.5 months (range, 6-26 months), the success rates of the 5-fluorouracil and triamcinolone groups were higher than the control group (87.2%, 71.4%, and 48.6%, respectively). 5-fluorouracil was significantly (P = 0.001) more effective in inhibiting the recurrence of pterygium compared with the control group at all time points during follow-up. Kaplan-Meier survival analysis showed that the recurrence-free period of pterygium in the 5-FU group was significantly (P = 0.005) longer than that of the control group but not in the triamcinolone group compared with the controls (P = 0.063). There was no significant difference between the 5-FU group and the triamcinolone group (P = 0.362). Minimal reversible complications such as steroid-induced glaucoma and superficial punctate epitheliopathy developed during the study.

CONCLUSIONS

Intralesional injection of 5-FU and triamcinolone was more effective in inhibiting the recurrence of pterygium than topical steroid alone, with the results in the 5-FU group reaching statistical significance.

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.

Topical 0.002% Mitomycin C for the Treatment of Conjunctival-Corneal Intraepithelial Neoplasia and Squamous Cell Carcinoma

PURPOSE

To demonstrate the efficacy of topical 0.002% mitomycin C (MMC) as an adjunctive and alternative treatment in primary and recurrent conjunctival-corneal intraepithelial neoplasia (CCIN) and squamous cell carcinoma (SCC).

METHODS

The medical records of 7 patients with histopathologically confirmed CCIN and conjunctival SCC were retrospectively reviewed. All cases were treated with topical 0.002% MMC 4 times daily. The tumor size pre- and post-treatment, clinical response, and ocular complications were evaluated.

RESULTS

The mean age of the patients was 56 +/- 13.4 years. The most common presenting symptom was foreign body sensation (57.1%) with a mean duration of 2.3 +/- 3.8 months. Six patients had pathologically proven CCIN (85.7%) and 1 had SCC (14.3%). Before MMC treatment, 6 eyes (85.7%) had recurrences after surgical excision. The tumor-free period ranged from 2 to 19 months. Two patients had multiple recurrences. MMC 0.002% 4 times daily was applied for a period of 5.4 +/- 4.4 weeks (range, 2-14). All had complete tumor regression as observed clinically and confirmed by impression cytology. Side effects of MMC therapy included ocular irritation, mild conjunctival hyperemia, and punctate keratopathy. There were no serious complications detected. The mean follow-up time was 30.7 +/- 15 months (range, 2-52) with no evidence of clinical recurrence in any case.

CONCLUSIONS

Topical 0.002% MMC showed a favorable outcome as an adjunctive and alternative treatment of CCIN and SCC with regression of primary and recurrent tumors.

Tonometry after laser in situ keratomileusis treatment: a preliminary study in Thai patients

OBJECTIVE

To evaluate the change in intraocular pressure (IOP) measurement by Goldmann applanation tonometer after Laser in Situ Keratomileusis (LASIK) for myopia and myopic astigmatism, and to assess the correlation between the changes of lOP reading and the reduction of central corneal thickness (CCT) after LASIK in Thai patients.

STUDY DESIGN

Prospective correlational study.

MATERIAL AND METHOD

LASIK was performed on 65 eyes of 33 patients for correction of myopia and myopic astigmatism. IOP was measured by Goldmann applanation tonometer before and 3 months after LASIK. The correlation between the change in IOP reading and the change in central corneal thickness were evaluated.

RESULTS

IOP reading was significantly reduced by mean of 2.9 +/- 2.5 mmHg (p = 0.0001). The authors used Pearson analysis to study the correlation between the change in IOP and the reduction of CCT. In subgroup analysis the patients were divided by degree of myopia: group 1, myopia less than -3 diopters (D) (n = 14); group 2, myopia -3 to -6 D (n = 31); group 3, myopia greater than -6 D (n = 20)). The result showed more correlation in higher myopia group (Pearson; r = 0.158 in group 3, r = -0.098 in group 2 and r = -0.102 in group 1).

CONCLUSION

Goldmann applanation tonometry underestimates the IOP in thin cornea. Variability in CCT is a potent confounder of this tonometry technique. Therefore, it has important implications for considering CCT measurement incorporated with Goldmann applanation tonometry for glaucoma diagnosis especially in myopic patients who undergo LASIK surgery.

Comparison of topical lomefloxacin 0.3 per cent versus topical ciprofloxacin 0.3 per cent for the treatment of presumed bacterial corneal ulcers

PURPOSE

To compare the efficacy and safety of topical lomefloxacin 0.3 per cent with topical ciprofloxacin 0.3 per cent for treating mildly severe suspected bacterial corneal ulcers.

METHOD

This prospective, randomized, double-masked controlled clinical trial was conducted on 41 patients (41 eyes) with suspected bacterial corneal ulcers who were randomized into 2 groups: 23 patients were in the lomefloxacin group and 18 patients in the ciprofloxacin group. All of these corneal ulcers were scraped for gram's stain, KOH preparation and microbiologic cultures before starting treatment. The clinical success rate, the time to cure, the rates of treatment failures, ocular signs and symptoms and the adverse effects of the study medication were evaluated.

RESULTS

Topical lomefloxacin is equivalent clinically and statistically to topical ciprofloxacin. No statistically significant treatment differences were found between lomefloxacin (100%) and ciprofloxacin (100%) in terms of success rate. Similarly, no differences were noted in the time to cure (p > 0.05), the treatment failure, or the resolution of the clinical signs and symptoms (p > 0.05). The adverse effects of lomefloxacin were superficial punctate keratitis (26.1%) and irritation (8.7%), whereas those of ciprofloxacin were superficial punctate keratitis (22.2%), white precipitate (11.1%) and irritation (11.1%). However, no statistically significant differences of these adverse effects were found between the two groups (p > 0.05).

CONCLUSION

Lomefloxacin ophthalmic solution (0.3%) is equivalent clinically and statistically to ciprofloxacin ophthalmic solution (0.3%) for the treatment of mildly severe presumed bacterial corneal ulcers without statistically significant differences in the adverse effects and discomfort.

Corneal lattice dystrophy, a concealed ophthalmic problem in Thailand

One single family of corneal lattice dystrophy was examined and interviewed to elucidate the variety of clinical manifestations, factors associated with visual impairment, and the impact on the patient's quality of life. Forty-three out of 88 family members (48.9%) were affected. The inheritance pattern was autosomal dominant. Corneal haze grading from 1 to 4 was 5.3 per cent, 26.3 per cent, 43.4 per cent, and 25 per cent respectively. Surface irregularity grading from 1 to 4 was 18.4 per cent, 39.5 per cent, 32.9 per cent, and 9.2 per cent respectively. Forty-five per cent of the patients had VA < or = 20/200. Corneal haziness, irregularity, corneal erosion and disease duration were significantly related to visual impairment (p < 0.05). This disturbed the patient's activities such as reading (79.1%), working (62.8%) and daily life (69.8%). Corneal lattice dystrophy within the same family may present with different manifestations depending on the severity and duration of the disease and might be misdiagnosed. Inadequate knowledge among patients was susceptible to the high prevalence of the disease leading to impaired quality of life.

Amniotic membrane transplantation for reconstruction after excision of large ocular surface neoplasias

AIM

To evaluate the clinical outcome of patients in whom ocular surface reconstruction was performed using amniotic membrane transplantation (AMT) after the excision of large (>20 mm square) ocular surface neoplasias (OSN).

METHODS

A non-comparative interventional case series. In 16 eyes of 16 patients, excision of large OSN including conjunctival intraepithelial neoplasia (CIN), primary acquired melanosis, and malignant melanoma was followed by adjunctive cryotherapy and suturing of a single layer of amniotic membrane (AM) with the basement membrane side facing up to the healthy bordering tissue. Epithelial healing, complications, and tumour recurrences were analysed.

RESULTS

During a mean follow up of 23.7 (SD 11, range 11-43) months, ocular surface healing was rapid and complete in all cases. One complication of pyogenic granuloma was noted. Tumour recurrence occurred in one out of 10 CIN cases (10%), no recurrences were observed in the patients with melanotic lesions.

CONCLUSIONS

AMT in lieu of conjunctival or mucosal autograft is an effective substrate for reconstructing the ocular surface following excision of large OSN. AMT is effective in managing large OSN by avoiding the complications that may be associated with conventional removal, specifically in cases where the limbal architecture is destroyed by surgical resection or adjuvant therapies.

Amniotic membrane grafts for nontraumatic corneal perforations, descemetoceles, and deep ulcers

PURPOSE

To describe the clinical outcome of amniotic membrane transplantation (AMT) for nontraumatic corneal perforations, descemetoceles, and deep ulcers.

DESIGN

Retrospective, noncomparative, interventional case series.

PARTICIPANTS

Thirty-four eyes of 33 consecutive patients operated on for nontraumatic corneal perforations or descemetoceles at four academic departments of ophthalmology. Associated autoimmune disorders included rheumatoid arthritis (n = 6), Stevens-Johnson syndrome (n = 3), ocular cicatricial pemphigoid (n = 2), systemic lupus erythematosus (n = 1), and one eye with Mooren's ulcer, as well as neurotrophic, or exposure keratopathy (n = 10), postinfectious nonhealing ulcers (n = 6), and postsurgery (n = 5).

INTERVENTION

Three or four layers of amniotic membrane (AM) were applied over the ulcer bed and anchored with 10-0 nylon interrupted or running sutures. A large AM piece was used as a patch to cover the entire corneal surface.

MAIN OUTCOME MEASURES

Formation of anterior chamber depth, epithelialization of the AM grafts, and stability of the corneal stromal thickness.

RESULTS

The mean follow-up period was 8.1 +/- 5.7 (ranging from 2-23) months. A successful result was observed in 28 of 34 eyes (82.3%). Of the successful cases, 23 eyes needed one AMT procedure, whereas 5 eyes needed two procedures to achieve a successful result. In five eyes, a subsequent definitive surgical procedure such as penetrating keratoplasty or lid surgery was needed. Failure was observed in six eyes with rheumatoid arthritis, neurotrophic keratopathy, or graft melting.

CONCLUSIONS

AMT is an effective method for managing nontraumatic corneal perforations and descemetoceles. It can serve as either a permanent therapy or as a temporizing measure until the inflammation has subsided and a definitive reconstructive procedure can be performed. This treatment option is also beneficial in those countries where corneal tissue availability is limited.

Single and multilayer amniotic membrane transplantation for persistent corneal epithelial defect with and without stromal thinning and perforation

AIMS

To evaluate the efficacy of amniotic membrane transplantation (AMT) in persistent corneal epithelial defect with or without stromal thinning and corneal perforation.

METHODS

28 patients (28 eyes) with persistent corneal epithelial defect unresponsive to medical treatment were given preserved human amniotic membrane transplants. The patients were divided into three groups: group A, persistent corneal epithelial defect 10 eyes; group B, epithelial defect with stromal thinning 13 eyes; and group C, corneal perforation five eyes. AMT was performed using one layer in group A and multilayers in group B and C. The causes of persistent epithelial defect were neurotrophic keratopathy (24 eyes), limbal deficiency (six eyes), exposure keratopathy (four eyes), and Mooren's ulcer (one eye).

RESULTS

Success was noted in 82.1% (23/28 eyes) in all groups, with 80% (8/10 eyes), 84.6% (11/13 eyes), and 80% (4/5 eyes) in groups A, B, and C respectively, with a mean follow up of 10.9 months (1-30 months). The mean epithelialisation time after AMT was 2.1 weeks. The healing times of groups B and C are also significantly shorter than group A (p=0.017 and 0.018, respectively). Corneal stromal thickness was significantly increased in all cases in groups B and C (p=0.006). Those with corneal perforation in group C were completely healed by multilayer AMT. There was no difference in the epithelialisation time between successful cases treated by a single operation (17 eyes) or repeated operation (six eyes). Vision improved in 18.9% (8/28 eyes) and worsened as a result of cataract formation in 2.3% (1/28 eyes). Failure was noted in 17.9% (5/28 eyes), because of corneal infection (two eyes), neurotrophic keratopathy with and without limbal deficiency (two eyes), and intractable corneal perforation (one eye). No patient developed major immediate postoperative complications or graft rejection.

CONCLUSION

Amniotic membrane can successfully treat refractory corneal epithelial defect by promoting epithelial healing and thus prevent corneal perforation. It can be used as a treatment for corneal perforation by restoring corneal stromal thickness so that emergency penetrating keratoplasty can be avoided.

Topical ketorolac tromethamine in the reduction of adverse effects of laser in situ keratomileusist

PURPOSE

To evaluate whether topical ketorolac tromethamine can reduce the adverse effect of laser in situ keratomileusis (LASIK).

DESIGN

A prospective randomized controlled clinical study.

PARTICIPANTS

Nineteen patients who underwent bilateral simultaneous LASIK performed at Siriraj Hospital.

INTERVENTION

Patients received two drops of ketorolac tromethamine in one eye immediately after surgery.

MAIN OUTCOME MEASURES

Symptoms of tearing, photophobia, foreign body sensation and pain were evaluated at 30 minutes, 6 hours and 24 hours.

RESULTS

There was no statistically significant difference in symptoms at 30 minutes. At 6 and 24 hours, ketorolac-treated eyes had significantly fewer symptoms compared to non-treated eyes.

CONCLUSIONS

Ketorolac tromethamine reduces some unfavorable symptoms within the first 24 hours after LASIK.

Amniotic membrane transplantation after the primary surgical management of band keratopathy

PURPOSE

To determine the safety and efficacy of amniotic membrane transplantation to restore and maintain a stable corneal epithelium and reduce ocular surface pain after surgical removal of band keratopathy arising from ocular causes.

METHODS

Fifteen patients (16 eyes) from two centers with band keratopathy secondary to ocular causes underwent amniotic membrane transplantation as a graft after surgical removal of calcific deposits with or without the use of ethylenediaminetetraacetic acid. In a prospective, consecutive, uncontrolled case series, the rate of corneal epithelialization and resultant surface stability were recorded over a mean follow-up period of 14.6 months.

RESULTS

Pain from ocular surface instability was the presenting complaint in 14 of 15 (93.3%) patients and resolved in all cases after the procedure even for those who experienced a recurrence of the calcific deposit. Fifteen of 16 eyes (93.7%) achieved epithelialization with a mean time to epithelial healing of 15.2 days. The only eye that failed to heal was subsequently diagnosed with total limbal stem cell deficiency. Visual acuity improved in five of nine (44%) sighted eyes and remained unchanged in four of nine (56%). No patient experienced any major surgical or medical complication after the procedure.

CONCLUSION

Amniotic membrane transplantation represents a safe and effective method to restore a stable corneal epithelium in eyes after primary surgical removal of band keratopathy arising from ocular causes.

Amniotic membrane transplantation for ocular surface reconstruction

OBJECTIVE

To study the efficacy of amniotic membrane transplantation in various indications for ocular surface reconstruction.

METHOD

Amniotic membrane transplantations were performed in 140 eyes (130 patients) for ocular surface reconstruction. The indications for the corneal group were limbal stem cell deficiency, bullous keratopathy, persistent epithelial defect, band keratopathy, prosthesis, corneal ulcer and acute chemical burn. The indications for the conjunctival group were grafts for pterygium, conjunctival tumors, symblepharon, and covering the scleral graft.

RESULTS

Success was noted in 75.7 per cent (106/140) eyes, partial success in 17.9 per cent (25/140) eyes, and failure in 6.4 per cent (9/140) eyes for a mean follow-up of 6.6 months (1-19 months). The success and partial success rate were 80.6 per cent (54/67), 14.9 per cent (10/67) in the corneal group and 71.2 per cent (52/73), 20.6 per cent (15/73) in the conjunctival group.

CONCLUSION

Amniotic membrane transplantation can solve some difficult ocular surface problems, and can be used to promote epithelial healing, reduce inflammation and scarring.

Reduction in corneal haze and apoptosis by amniotic membrane matrix in excimer laser photoablation in rabbits

PURPOSE

To determine whether preserved human amniotic membrane can reduce corneal haze and keratocyte apoptosis induced by excimer laser photoablation in rabbit corneas.

METHODS

Excimer photoablation was performed bilaterally in 30 rabbits with a 6.0 mm ablation zone and 120 microm depth using the VISX Star laser with the phototherapeutic keratectomy (PTK) mode. One eye was randomly covered by preserved human amniotic membrane secured with 4 interrupted 10-0 nylon sutures, and the other eye served as the control. The amniotic membranes were removed at 1 week, and corneal haze was graded with slitlamp biomicroscopy by 3 masked corneal specialists biweekly for the ensuing 12 weeks until the rabbits were killed. Another 18 rabbits were divided into 4 subgroups and received PTK alone, PTK with membrane, PTK with sham sutures, or PTK with tarsorrhaphy. All eyes were studied histologically, and 3 eyes in each group were studied by in situ terminal deoxynucleotidyl transferase deoxy-UTP-nick end labeling assay at 1, 3, and 7 days and 12 weeks, respectively.

RESULTS

A consistent grading of differences in corneal haze scoring between the control corneas and the amniotic-membrane-covered corneas was noted among the 3 masked observers. Organized reticular post-PTK corneal haze peaked at 7 weeks in both groups, and the corneal haze score in the amniotic-membrane-covered group was significantly less than in the control group from 7 to 12 weeks (all P < .001). Compared to the control corneas, the amniotic-membrane-covered corneas had less inflammatory response at 1 and 3 days, less keratocyte apoptosis in the ablated anterior corneal stroma at 1, 3, and 7 days (P < .001), and less stromal fibroblast cellularity and epithelial hyperplasia at 12 weeks.

CONCLUSIONS

Amniotic membrane matrix introduced at an early stage of the corneal wound healing process effectively reduced corneal haze induced by excimer laser photoablation in rabbits. Studies linking suppression of apoptosis in the acute wound-healing process with reduction of subsequent corneal scarring may have useful clinical applications.

Preserved Amniotic Membrane Transplantation for Conjunctival Surface Reconstruction

Objective. To study the efficacy of preserved human amniotic membrane in the reconstruction of conjunctival defect created during surgical removal of conjunctival lesions or symblepharon lysis.Methods. Preserved human amniotic membrane transplantation was performed in 93 eyes of 85 patients for reconstruction of various conjunctival surface problems. The indications for surgery were (1) pterygium excision (54 eyes), (2) conjunctival tumors excision (23 eyes), lysis of symblepharon (13 eyes), and covering a scleral graft (three eyes).Results. Success was noted in 69.9% (65/93) eyes, partially success in 22.6% (21/93) eyes, and failure in 7.5% (7/93) eyes with a mean follow-up of 8.9 months (1-28 months). In pterygium, conjunctival tumor, symblepharon, and scleral graft group, the success rate in each group was 70.3%, 78.3%, 53.8%, and 66.7% respectively. No serious immediate post-operative complications or graft rejection occurred.Conclusion. Amniotic membrane transplantation can be considered an alternative treatment for difficult ocular surface problems, and is effective in promoting epithelial healing, and reducing inflammation and scarring.

Amniotic membrane transplantation for acute chemical or thermal burns

PURPOSE

To determine whether preserved human amniotic membrane (AM) can be used to treat ocular burns in the acute stage.

DESIGN

Prospective, noncomparative, interventional case series.

PARTICIPANTS

Thirteen eyes from 11 patients with acute burns, 10 eyes with chemical burns and 3 with thermal burns of grades II-III (7 eyes) and grade IV (6 eyes), treated at 7 different facilities.

METHODS

Patients received amniotic membrane transplantation (AMT) within 2 weeks after the injury.

MAIN OUTCOME MEASURES

Integrity of ocular surface epithelium and visual acuity during 9 months of follow-up.

RESULTS

Ten patients were male and one patient was female; most were young (38.2 +/- 10.6 years). For a follow-up of 8.8 + 4.7 months, 11 of 13 eyes (84.63%) showed epithelialization within 2 to 5 weeks (23.7 +/- 9.8 days), and final visual acuity improved > or = 6 lines (6 eyes), 4 to 5 lines (2 eyes), and 1 to 3 lines (2 eyes); only one eye experienced a symblepharon. Eyes with burns of grade II to III showed more visual improvement (7.3 +/- 3 lines) than those with burns of grade IV (2.3 +/- 3.0 lines; P < 0.05, unpaired t test). In the group with grade II or III burns, none had limbal stem cell deficiency. All eyes in the group with grade IV burns did experience limbal stem cell deficiency.

CONCLUSIONS

Amniotic membrane transplantation is effective in promoting re-epithelialization and reducing inflammation, thus preventing scarring sequelae in the late stage. In mild to moderate burns, AMT alone rapidly restores both corneal and conjunctival surfaces. In severe burns, however, it restores the conjunctival ocular surface without debilitating symblepharon and reduces limbal stromal inflammation, but does not prevent limbal stem cell deficiency, which requires further limbal stem cell transplantation. These results underscore the importance of immediate intervention in the acute stage of eyes with severely damaged ocular surface. Further prospective randomized studies including a control group are required to determine the effectiveness of AMT in acute chemical and thermal burns of the eye.

Application of Preserved Human Amniotic Membrane for Corneal Surface Reconstruction

Objective: To evaluate the efficacy of preserved human amniotic membrane transplantation for reconstruction of the corneal surface diseases.Methods: Preserved human amniotic membrane transplantations were performed in 84 eyes of 78 patients for corneal surface reconstruction. The indications were limbal stem cell deficiency from Steven-Johnson syndrome, chemical burn and herpes keratitis (27 eyes), bullous keratopathy (26 eyes), persistent epithelial defect and dellen (17 eyes), band keratopathy (11 eyes), preparing for prosthesis (1 eye), corneal ulcer (1 eye) and acute chemical burn (1 eye).Results: Success was noted in 83.3% (70/84) eyes, partial success in 13.1% (11/84) eyes, and failure in 3.6% (3/84) eyes for an average follow-up of 10.5 months (3 - 29 months). No patient developed major immediate post-operative complications.Conclusion: Amniotic membrane transplantation can reduce inflammation, promote corneal epithelial healing, and decrease irritation in corneal surface problems.

Amniotic membrane transplantation for symptomatic bullous keratopathy

OBJECTIVE

To determine whether amniotic membrane transplantation can be used to treat symptomatic bullous keratopathy displaying poor visual potential.

METHODS

Amniotic membrane transplantation was performed at 5 centers on 50 consecutive eyes (50 patients) with symptomatic bullous keratopathy and poor visual potential. The underlying causes of bullous keratopathy included aphakia (9 eyes), pseudophakia (19 eyes), failed grafts (9 eyes), and others (13 eyes).

RESULTS

During the follow-up period of 33.8 weeks (3-96 weeks) after amniotic membrane transplantation, 43 (90%) of 48 eyes with intolerable pain preoperatively became pain free postoperatively. Among the 5 eyes with residual pain, 3 received repeated amniotic membrane transplantation, 1 required a conjunctival flap for pain relief, and 1 had reduced pain. Epithelial defects in 45 (90%) of 50 eyes created and covered by amniotic membrane healed rapidly within 3 weeks. Only 4 eyes (8%) showed recurrent surface breakdown. Epithelial edema or bullae recurred in a smaller area in 5 eyes (10%) and pseudopterygium developed in 1 eye.

CONCLUSION

Amniotic membrane transplantation can be considered as an alternative to conjunctival flaps in alleviating pain, promoting epithelial healing, and preserving cosmetic appearance in patients with symptomatic bullous keratopathy and poor visual potential.

Frequent association of delayed tear clearance in ocular irritation

AIM

To explore the pathogenic role of delayed tear clearance.

METHODS

By comparing 10 patients with punctal obstruction and 20 asymptomatic normals, delayed tear clearance was diagnosed in 70 patients without apparent punctal obstruction using fluorescein clearance test.

RESULTS

The majority were older (71.4 (SD 1.2) years) and women (66%). Frequent complaints included redness, itching, mucus discharge, and crusting, which tended to be worse upon awakening. Common associated problems were medicamentosa (13%), drug induced pseudopemphigoid, ocular hypertension (27%), and glaucoma (7%). Topical non-preserved 1% methylprednisolone resulted in subjective (83%) and objective (80%) improvement and resolution of delayed tear clearance (87%).

CONCLUSION

These results indicate strong association of delayed tear clearance with intrinsically and extrinsically generated ocular surface inflammation. The presence of delayed tear clearance may set up a vicious cycle to aggravate the existing inflammation. Future prospective studies are needed to delineate the pathogenic role of delayed tear clearance in various ocular surface disorders.

Amniotic membrane transplantation with or without limbal allografts for corneal surface reconstruction in patients with limbal stem cell deficiency

OBJECTIVE

To examine whether amniotic membrane transplantation (AMT), in preparing the perilimbal stroma, enhances the success of allograft limbal transplantation (ALT).

METHODS

Thirty-one eyes of 26 consecutive patients had cytologically proven limbal deficiency resulting from chemical burns (14 eyes); Stevens-Johnson syndrome, toxic epidermal necrolysis, or pseudopemphigoid (5 eyes); contact lens-induced keratopathy (3 eyes); aniridia (3 eyes); multiple surgical procedures (2 eyes); atopy (2 eyes); or an unknown cause (2 eyes). Based on the severity of limbal deficiency, group A (mild), comprising 10 eyes, received AMT alone; group B (moderate), comprising 7 eyes, received AMT and ALT; and group C (severe), comprising 14 eyes, received AMT, ALT, and penetrating keratoplasty. All patients except those in group A received continuous oral cyclosporine.

RESULTS

Except for the 2 eyes with atopy, all amniotic membrane-covered surfaces showed rapid epithelialization (in 2 to 4 weeks) and reduced inflammation, vascularization, and scarring, and the surfaces became smooth and wettable. For the mean follow-up period of 15.4 months, 25 (83%) of 30 eyes showed visual improvement, consisting of 6 or more lines (13 eyes), 4 to 5 lines (6 eyes), or 1 to 3 lines (6 eyes). Visual improvement decreased with the severity of limbal deficiency from 8 (100%) of 8 eyes in group A to 5 (71%) of 7 eyes in group B and 11 (79%) of 14 eyes in group C. In group C, corneal graft rejection occurred in 9 (64%) of 14 eyes, and reversible early limbal allograft rejection was noted in 3 (14%) of 21 eyes of groups B and C.

CONCLUSIONS

For partial limbal deficiency with superficial involvement, AMT alone is sufficient and hence superior to ALT because there is no need to administer cyclosporine. For total limbal deficiency, additional ALT is needed, and AMT helps reconstruct the perilimbal stroma, with reduced inflammation and vascularization, which collectively may enhance the success of ALT.

Amniotic membrane transplantation for conjunctival surface reconstruction

PURPOSE

To determine whether preserved human amniotic membrane can be used to reconstruct the conjunctival defect created during surgical removal of a large lesion or during symblepharon lysis.

METHODS

Amniotic membrane transplantation was performed in six consecutive patients (seven eyes) during removal of large conjunctival lesions and in nine patients (nine eyes) during removal of conjunctival scars or symblepharon.

RESULTS

During a mean follow-up period +/- SD of 10.9 +/- 9.1 months (range, 2.2 to 34.0 months), 10 patients (11 eyes) showed successful surface reconstruction without recurrence, five patients (five eyes) showed improved visual acuity, and one patient (one eye) showed epithelialization within 3 weeks and resolution of motility restriction. Two patients (two eyes) showed partial success, with surrounding conjunctival inflammation. Three cases (three eyes) failed and exhibited recurrent scarring: one patient had received mitomycin treatment and beta radiation, whereas the transplanted amniotic membrane of the second patient was partially, and of the third patient was completely, dissolved or replaced by the inflamed pseudopterygial tissue. Two patients (two eyes) had epithelial cyst formation.

CONCLUSION

Amniotic membrane transplantation can be considered an alternative substrate for conjunctival surface reconstruction during removal for large tumors, disfiguring scars, or symblepharon, especially for those whose surrounding conjunctival tissue remains relatively normal.

Impression cytology study of epithelial phenotype of ocular surface reconstructed by preserved human amniotic membrane

OBJECTIVE

To determine the epithelial phenotype of the ocular surface reconstructed by preserved human amniotic membrane.

METHODS

Impression cytology was performed in 6 patients who received a large patch of amniotic membrane for conjunctival surface reconstruction during removal of acquired melanosis, conjunctival intraepithelial neoplasia, or bilateral inferior conjunctival chalasis, or for corneal surface reconstruction during removal of pannus associated with limbal deficiency caused by aniridia, toxic epidermal necrolysis, or chemical burn.

RESULTS

The nongoblet epithelial cells covering the amniotic membrane were uniformly smaller and the cell density was almost twice that of age- and sex-matched normal control eyes at the corresponding site, and the goblet cell density was almost 10 times that of the control (both P < .05; Student paired t test) (N = 7 eyes). Furthermore, the conjunctival epithelial phenotype with goblet cells was found on corneal surfaces of all 3 patients with limbal deficiency.

CONCLUSIONS

The success of conjunctival surface reconstruction correlated well with recovery of the conjunctival epithelial phenotype. The lack of corneal epithelial phenotype even on an avascular corneal stroma supports the concept that conjunctival transdifferentiation does not occur in vivo, and indicates that additional limbal stem cell transplantation is needed for effective corneal surface reconstruction in patients with limbal deficiency.

Comparison of conjunctival autografts, amniotic membrane grafts, and primary closure for pterygium excision

OBJECTIVE

The purpose of the study is to determine whether amniotic membrane can be used as an alternative to conjunctival autograft after pterygium excision.

DESIGN

A prospective study of amniotic membrane grafts (group A) and primary closure (group B) was compared retrospectively with conjunctival autografts (group C) in patients with pterygia.

PARTICIPANTS

Group A included 46 eyes with primary pterygia and 8 eyes with recurrent pterygia, group B had 20 eyes with primary pterygia, and group C consisted of 78 eyes with primary and 44 eyes with recurrent pterygia.

INTERVENTION

For the above three different surgeries, the amount of tissue removed was estimated from histopathologic analysis, and the result was evaluated by clinical examination.

MAIN OUTCOME MEASURES

Recurrence, survival analysis, and final appearance were compared.

RESULTS

In group A, the recurrence rate was 10.9%, 37.5%, and 14.8% for primary, recurrent, and all pterygia, respectively (mean follow-up, 11 months). These three rates were significantly higher than 2.6%, 9.1%, and 4.9% noted in group C (mean follow-up, 23 months) (P < 0.001, 0.018, and 0.01, respectively). However, the latter recurrence rate was significantly lower than 45% (mean follow-up, 5.2 months) in group B for primary pterygia (P < 0.001). The onset of recurrence was delayed significantly in group C as compared with that of groups A and B.

CONCLUSIONS

The relatively low recurrence rate for primary pterygia allows one to use amniotic membrane transplantation as an alternative first choice, especially for advanced cases with bilateral heads or those who might need glaucoma surgery later.