Elizabeth P. Shen

The Effect of Topical Autologous Serum on Graft Re-epithelialization After Penetrating Keratoplasty

PURPOSE To analyze factors influencing corneal graft re-epithelialization after penetrating keratoplasty (PK) and evaluate the effect of topical autologous serum in promoting graft re-epithelialization. DESIGN Prospective interventional study. METHODS We analyzed 165 eyes of 165 patients who underwent PK between January 1, 2005 and December 31, 2007. Patients were divided into 2 groups according to routine use or non-use of postoperative 20% topical autologous serum. Postoperative slit-lamp examination after fluorescein staining was performed, and graft re-epithelialization time was recorded. Recipient/donor characteristics, surgical variables, and topical use of autologous serum were analyzed for their effects on post-PK graft re-epithelialization. Statistical analysis was performed by univariate and multivariate regression analysis using the ordinal logistic fit model to assess the potential risk factors influencing graft re-epithelialization after PK. RESULTS In univariate analysis, diabetes mellitus (DM), longer death-to-storage time and death-to-surgery time of the donor, and larger recipient size significantly delayed graft re-epithelialization (P < .05). Use of autologous serum significantly expedited graft re-epithelialization (P = .004). In multiple regression analysis, only DM in the recipient (odds ratio [OR] = 5.10, P < .001), postoperative use of autologous serum (OR = 0.54, P = .046), and larger graft size (OR = 4.44, P < .001) influenced graft re-epithelialization. The beneficial and healing effect of autologous serum is particularly significant in diabetic recipients and larger grafts. CONCLUSIONS Several factors may influence graft re-epithelialization after PK. Graft re-epithelialization time was longer in diabetic recipients and larger grafts. Use of autologous serum may be a beneficial strategy in these patients with potentially delayed epithelial healing.

Manual limbal markings versus iris-registration software for correction of myopic astigmatism by laser in situ keratomileusis.

PURPOSE: To compare the efficacy and safety of manual limbal markings and wavefront‐guided treatment with iris‐registration software in laser in situ keratomileusis (LASIK) for myopic astigmatism. SETTING: National Taiwan University Hospital, Taipei, Taiwan. METHODS: Eyes with myopic astigmatism had LASIK with a Technolas 217z laser. Eyes in the limbal‐marking group had conventional LASIK (PlanoScan or Zyoptix tissue‐saving algorithm) with manual cyclotorsional‐error adjustments according to 2 limbal marks. Eyes in the iris‐registration group had wavefront‐guided ablation (Zyoptix) in which cyclotorsional errors were automatically detected and adjusted. Refraction, corneal topography, and visual acuity data were compared between groups. Vector analysis was by the Alpins method. RESULTS: The mean preoperative spherical equivalent (SE) was −6.64 diopters (D) ± 1.99 (SD) in the limbal‐marking group and −6.72 ± 1.86 D in the iris‐registration group (P = .92). At 6 months, the mean SE was −0.42 ± 0.63 D and −0.47 ± 0.62 D, respectively (P = .08). There was no statistically significant difference between groups in the astigmatism correction, success, or flattening index values using 6‐month postoperative refractive data. The angle of error was within ±10 degrees in 73% of eyes in the limbal‐marking group and 75% of eyes in the iris‐registration group. CONCLUSION: Manual limbal markings and iris‐registration software were equally effective and safe in LASIK for myopic astigmatism, showing that checking cyclotorsion by manual limbal markings is a safe alternative when automated systems are not available. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Laser in situ keratomileusis for the correction of myopia and myopic astigmatism

Purpose: To evaluate the efficacy, safety, predictability, and surgically induced astigmatism (SIA) of laser in situ keratomileusis (LASIK) for the correction of myopia and myopic astigmatism. Setting: Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan. Methods: This retrospective study comprised 69 eyes that had LASIK to correct myopia and 74 eyes that had LASIK to correct myopic astigmatism. The excimer laser keratectomy was performed using a Summit Apex Plus® machine. Refraction, visual acuity, and computerized corneal videokeratography data from the preoperative and postoperative examinations were collected. The astigmatic change was calculated by the Alpins vector analysis method. Results: The preoperative spherical equivalent at the glasses plane in the myopia and myopic astigmatism groups was −8.08 diopters (D) and −9.73 D, respectively. At 6 months, the spherical equivalent and residual corneal astigmatism were −0.25 D and 0.85 D, respectively, in the myopia group and −0.71 D and 0.82 D, respectively, in the myopic astigmatism group. In the myopia group, 88% of eyes were within ±1.0 D of the intended myopia correction and in the myopic astigmatism group, 85% were within ±1.0 D of the targeted spherical equivalent and 90% were within ±1.0 D of the intended astigmatism correction. The uncorrected visual acuity was 20/40 or better in 94.1% of eyes in the myopia group and 92.5% of eyes in the myopic astigmatism group. The SIA magnitude was 0.66 D with the axis randomly distributed in the myopia group. The mean astigmatism correction index was 0.97, the mean magnitude of error was 0.13 D ± 0.62 (SD), and the mean angle of error was −3.70 ± 13.73 degrees in the myopic astigmatism group. Conclusion: Laser in situ keratomileusis had similar predictability, safety, and efficacy in the treatment of myopia and myopic astigmatism. The astigmatism correction was effective, but the results suggest that subjective astigmatism of less than 1.0 D need not be treated with the Summit Apex Plus laser.

Comparison of In Vivo Confocal Microscopic findings between epi-LASIK procedures with different management of the epithelial flaps

PURPOSE To use in vivo confocal microscopy to compare the wound-healing process in epikeratome laser-assisted in situ keratomileusis (epi-LASIK) with different management of the epithelial flaps. METHODS This prospective study comprised 46 eyes in the on-flap group and 47 eyes in the off-flap group. Epithelial flaps were repositioned or removed in the on- and off-flap eyes, respectively. In vivo confocal microscopy was performed before surgery and at 1 and 2 weeks and 1, 3, and 6 months after surgery. Corneal epithelial thickness, basal/apical surface epithelial morphology, and stromal reactions were analyzed. RESULTS Complete epithelialization by slit lamp biomicroscopy was faster for mitomycin C (MMC)-treated off-flap (4.27 ± 0.70 days) than on-flap (5.84 ± 0.08 days) eyes (P = 0.01). The percentage of eyes recovering to preoperative basal epithelial cell confocal morphology in the on- and off-flap groups was 87.5% and 92.3% for MMC-treated eyes and 86.3% and 90.5% in eyes without MMC treatment at 1 month after surgery. Of the studied eyes, with or without MMC, 50% and 100% returned to their preoperative apical epithelial morphology by 3 months in the on-flap and off-flap groups, respectively. Regression analysis revealed that the repositioned flap resulted in significant delay of epithelialization and apical-basal epithelial recovery (P < 0.01). Stromal reaction did not differ significantly at any of the time points. Corneal epithelial thickness was significantly thicker in the on-flap eyes (54.2 ± 4.5 μm) than in the off-flap eyes (26.7 ± 5.8 μm) at 1 month after surgery (P < 0.01). CONCLUSIONS On- and off-flap epi-LASIK showed comparable clinical outcomes after surgery. Off-flap epi-LASIK had more rapid re-epithelialization and normalization of epithelial morphology than did on-flap epi-LASIK, when observed by in vivo confocal microscopy. (ClinicalTrials.gov number, NCT00491439.).

Comparison of corneal epitheliotrophic capacity among different human blood-derived preparations.

Purpose: To compare the corneal epitheliotrophic capacity of different human blood-derived preparations, including cord blood serum (CBS), peripheral blood serum (PBS), and fresh frozen plasma (FFP) on bovine corneal epithelial cells. Materials and Methods: The concentrations of epithelial growth factor, transforming growth factor β1, insulin-like growth factor 1, hyaluronic acid, fibronectin, albumin, glucose, and calcium in different human blood derivatives were evaluated using enzyme-linked immunosorbent assay or biochemical methods. Cultivated bovine corneal epithelial cells were incubated with various blood derivatives, and cell proliferation, migration, and differentiation were evaluated by colorimetric assay, Boyden chamber chemotaxis assay, wounding assay, scanning electron microscopy, and transepithelial electric resistance measurements. Wound closure was assessed using a scratch-induced directional wounding assay. Results: Of the 3 human blood derivatives evaluated, CBS had the highest concentrations of epithelial growth factor, transforming growth factor β1, and hyaluronic acid (P < 0.05). FFP had the lowest concentration of calcium and the highest concentration of glucose (P < 0.05). CBS demonstrated the highest ability to promote cellular proliferation, followed by PBS and FFP (P < 0.05). CBS was also the best in promoting cellular differentiation because scanning electron microscopy demonstrated coherent monolayers of flattened and polygonal-shaped cells with evenly distributed microvilli. Transepithelial electric resistance was noted to be the highest for cells incubated in CBS, indicating formation of well-differentiated cells with functional tight junction (P < 0.05). Cells cultivated with FFP were the least capable of promoting proliferation, migration, and differentiation. Conclusions: Different human blood derivatives may have different concentrations of epitheliotrophic factors. CBS is generally superior to PBS in promoting corneal epithelial proliferation and differentiation.

Corneal astigmatic change after photorefractive keratectomy and photoastigmatic refractive keratectomy.

Purpose: To evaluate and compare the efficacy, safety, predictability, and surgically induced astigmatism (SIA) of photorefractive keratectomy (PRK) and photoastigmatic refractive keratectomy (PARK). Setting: Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan. Methods: In this retrospective study, 70 eyes were treated for myopia and 70 eyes were treated for myopic astigmatism. Refraction, corneal topography, slitlamp findings, and visual acuity in the 2 groups at 1, 3, and 6 months were evaluated and compared. Vector analysis was performed to determine the SIA in both groups. Results: The mean preoperative spherical equivalent at the glasses plane in the PRK and PARK groups was –6.06 diopters (D) and –7.18 D, respectively. At 6 months, the mean reduction in astigmatism in the PARK group was 61.0%. Predictability was within ±1.0 D in 85.2% of eyes in the PRK group and 62.5% in the PARK group. An uncorrected visual acuity of 20/40 or better was achieved in 91.8% and 83.9% of eyes, respectively. The mean SIA was 0.64 D in the PRK group, with a general with‐the‐rule axis shift. The results of vector analysis were more favorable when calculated from refractive values than from Sim‐K corneal topography values. The mean astigmatism correction index and index of success calculated from refractive data were 0.75 and 0.38 in the PARK group. The mean magnitude and angle of error were 0.22 ± 0.52 D and –2.13 ± 24.41 degrees, respectively. Conclusion: Photorefractive keratectomy and PARK were effective and safe procedures for the correction of myopia and myopic astigmatism. However, SIA occurred with spherical myopic treatments. This small SIA may be a confounding factor in low astigmatic treatments.

Correlation of Pseudomonas aeruginosa genotype with antibiotic susceptibility and clinical features of induced central keratitis.

PURPOSE To determine the association of type III secretion system (T3SS) genotype with antibiotic susceptibility, serotypes, and clinical manifestation of centrally located Pseudomonas aeruginosa keratitis. METHODS Clinical characteristics of P. aeruginosa keratitis cases from 2001 to 2011 were analyzed. Each strain was serotyped and genotyped for T3SS exotoxin genes. Antibiotic sensitivity and minimum inhibitory concentrations were determined with agar dilution method. Prognostic factors affecting final visual outcomes and time to re-epithelialization were analyzed using linear and Cox regression models. RESULTS Forty-four invasive and 28 cytotoxic strains were identified. Invasive strains occurred mostly in males (P = 0.03) with older age (P = 0.009) and ocular surgery or trauma history (P = 0.006), poor presenting (P = 0.04) and final (P < 0.0001) best spectacle-corrected visual acuity (BSCVA), and larger infiltration size (P = 0.03). Cytotoxic strains were associated with contact lens wear (P < 0.0001). Poor prognostic factors for final BCVA after adjusting for sex, age, and contact lens wear included invasive strains (P = 0.02), larger infiltration area (P = 0.02), deeper infiltrations (P = 0.02), and presence of hypopyon (P = 0.09). Factors affecting complete re-epithelialization time included invasive strains (P = 0.02), infiltration area (P = 0.01), depth (P = 0.02), and hypopyon (P = 0.03) after adjusting for age and sex. Serotypes 2, 6, and 11 were more commonly found among all isolates. A trend to increased fluroquinolone resistance is noted for invasive strains, although not reaching statistically significant difference. CONCLUSIONS Cytotoxic strains are associated with contact lens wear while invasive strains are related to poor prognosis and increased resistance to fluoroquinolones. Clinicians should be aware of the two different genotypes of P. aeruginosa affecting prognosis.

Nontuberculous mycobacterial ocular infections--comparing the clinical and microbiological characteristics between Mycobacterium abscessus and Mycobacterium massiliense.

Purpose To analyze the clinical characteristics of nontuberculous mycobacterial (NTM) ocular infections and the species-specific in vitro antimicrobial susceptibility. Material and Methods In 2000 to 2011 at the National Taiwan University Hospital, multilocus sequencing of rpoB, hsp65 and secA was used to identify NTM isolates from ocular infections. The clinical presentation and treatment outcomes were retrospectively compared between species. Broth microdilution method was used to determine the minimum inhibitory concentrations of amikacin (AMK), clarithromycin (CLA), ciprofloxacin (CPF), levofloxacin (LVF), moxifloxacin (MXF) and gatifloxacin (GAF) against all strains. The activities of antimicrobial combinations were assessed by the checkerboard titration method. Results A total of 24 NTM strains (13 Mycobacterium abscessus and 11 Mycobacterium massiliense) were isolated from 13 keratitis, 10 buckle infections, and 1 canaliculitis cases. Clinically, manifestations and outcomes caused by these two species were similar and surgical intervention was necessary for medically unresponsive NTM infection. Microbiologically, 100% of M. abscessus and 90.9% of M. massiliense ocular isolates were susceptible to amikacin but all were resistant to fluoroquinolones. Inducible clarithromycin resistance existed in 69.3% of M. abscessus but not in M. massiliense isolates. None of the AMK-CLA, AMK-MXF, AMK-GAF, CLA-MXF and CLA-GAF combinations showed synergistic or antagonistic effect against both species in vitro. Conclusions M. abscessus and M. massiliense are the most commonly identified species for NTM ocular infections in Taiwan. Both species were resistant to fluoroquinolones, susceptible to amikacin, and differ in clarithromycin resistance. Combined antimicrobial treatments showed no interaction in vitro but could be considered in combination with surgical interventions for eradication of this devastating ocular infection.

Stem Cell Factor and Thymic Stromal Lymphopoietin Overexpression With Correlation to Mast Cells in Superior Limbic Keratoconjunctivitis.

Purpose: To investigate the differential expression of stem cell factor (SCF) and thymic stromal lymphopoietin (TSLP) and their correlation to mast cells, between patients diagnosed with superior limbic keratoconjunctivitis (SLK) and normal subjects. Methods: A laboratory investigation included 22 surgical specimens of the superior bulbar conjunctiva from 17 patients with medically refractory SLK and 5 control subjects who underwent cataract or retinal surgery. Protein expression of tryptase, SCF, and TSLP in conjunctival specimens was detected by immunohistochemistry. The number of mast cells was correlated with immunohistochemistry intensity of SCF and TSLP. Results: In patients with SLK, higher immunostaining intensity of SCF and TSLP was found in the conjunctival epithelium than that in the conjunctival subepithelial stroma. SCF and TSLP staining in the conjunctival epithelium was significantly more intense in patients with SLK than in normal subjects. In addition, there was a significant correlation between the number of tryptase (+) mast cells in conjunctival subepithelial stroma and TSLP immunointensity in the conjunctival epithelium and subepithelial stroma. Conclusions: Overexpression of SCF and TSLP was found in the conjunctival epithelium of patients with SLK. Significant correlation between TSLP grading and the number of mast cells was also found. SCF and TSLP may be involved in promoting mast cell migration and activation contributing to the pathogenesis of SLK.

Is being female a risk factor for shallow anterior chamber? The associations between anterior chamber depth and age, sex, and body height

Aim of Study: To analyze the association between anterior chamber depth (ACD) and age, sex, and body height (BH). Materials and Methods: One thousand four hundred eighty eyes of 1480 adults 40 years of age and older receiving preoperative evaluation for cataract surgery were recruited consecutively from June 1, 2006, to December 31, 2010. ACD was measured with the Zeiss IOLMaster. Univariate and multivariate linear regression models were used to analyze the correlations, and receiving operator characteristic (ROC) curves and the area under the curve (AUC) were used for evaluating the predictability of an ACD less than 2.70 mm. Results: ACD was negatively correlated with age and positively correlated with BH in both univariate and multivariate regression analysis (P < 0.001). Sex was associated with ACD in univariate analysis, but not after adjustment with age and BH. In predicting an ACD less than 2.70 mm, the AUCs of ROC curves for ‘age and sex’, ‘age and BH’, and ‘age, sex, and BH’ were 0.687, 0.689, and 0.689, respectively. Conclusion: Age and BH were independent associating factors of ACD; however, sex was not. Older people and shorter ones likely had shallower ACD, and therefore were predisposed to Primary angle closure glaucoma (PACG). The predictability of ACD by age and BH solely was low, and adding sex did not increase it.