Fungal Endophthalmitis: Clinical Characteristics, Pathogens, and Factors Affecting Visual Outcome.

AIMS: The aims of this study are to investigate the etiology, microbiological spectrum, and risk factors associated with visual outcomes of fungal endophthalmitis (FE) in a tertiary eye specialty hospital in Shanghai, China. METHODS: This was a retrospective, single-center case series. The clinical characteristics, etiology, microbiological spectrum, and management, as well as the visual outcomes, were analyzed. Logistic regression was used to analyze the factors related to visual outcomes. RESULTS: This study involved 102 eyes of 92 patients with FE, including 63 males (66.3%). The mean age was 44.4 ± 19.8 years. The most common etiology of FE was trauma (56.5%). The predominant fungal species isolated were Aspergillus spp. (31/93, 33.3%). Pars plana vitrectomy (PPV) and intravitreal antifungal agents was performed initially in 86 (84.3%) and 83 (81.4%) eyes, respectively. Only 35 (34.3%) eyes achieved final best corrected visual acuity (BCVA) of 20/400 or better. Ten (9.8%) eyes had a final BCVA of light perception or worse, and five (4.9%) had to be enucleated. The factors determining better visual outcomes included initial visual acuity better than finger-counting (FC) (odds ratio (OR) 5.811, p = 0.036), the absence of corneal infiltrate (OR 10.131, p = 0.002), and Candida species infection (OR 6.325, p = 0.011). CONCLUSIONS: Early diagnosis of FE and a timely vitrectomy, combined with an intravitreal injection of an antifungal drug, can mitigate the devastating results of intraocular fungal infection. Not being infected by Aspergillus spp., an initial BCVA that was no worse than FC, and the absence of corneal involvement were related to better visual prognosis.

Management and Prognosis of Acute Post-Cataract Surgery Endophthalmitis: A 10-Year Retrospective Analysis in Eastern China.

Acute post-cataract surgery endophthalmitis (APSE) is a serious vision-threatening complication of cataract surgery. Analysis of the management and prognosis in cases of APSE may provide better guidance for future treatment. Fifty-six patients (56 eyes) diagnosed with APSE between 2013 and 2022 were retrospectively reviewed. The incidence of APSE rate was 0.020% (95% CI: 0.011-0.029%). Intraocular cultures were positive in 18 (32.1%) cases, with 21 organisms isolated. Coagulase-negative staphylococci was the predominant isolate (12/21; 57.1%). The time from surgery to the onset of endophthalmitis was 7 days (interquartile range: 3-16) in patients with good best-corrected visual acuity (BCVA) (≥20/70) and 3 days (interquartile range: 1-8) in those with poor BCVA (<20/70). Multivariate linear regression analysis revealed that initial BCVA (logMAR) (p < 0.001), time from onset to initial intravitreal antibiotics (IVAs) (p < 0.001), and positive culture of highly virulent pathogens (p = 0.018) displayed significantly positive associations with the final BCVA (logMAR). Adjunctive use of intravitreal corticosteroids and systemic antibiotics were unrelated to a favorable final BCVA. In conclusion, the severity of the visual condition at baseline, as well as delayed treatment, are risk factors for poor visual outcomes in APSE.

[Study on rapid quality analysis method of Shengxuebao Mixture].

A rapid analysis method based on ultraviolet-visual(UV-Vis) spectroscopy, near infrared(NIR) spectroscopy and multivariable data analysis was established for quality evaluation of Shengxuebao Mixture. The contents of eight active ingredients of Shengxuebao Mixture including albiflorin, paeoniflorin, 2, 3, 5, 4'-tetra-hydroxy-stilbene-2-O-ß-D-glucopyranoside, specnuezhenide,ecliptasaponin D, emodin, calycosin-7-glucoside and astragaloside Ⅳ were simultaneously detected by using this method. HPLC-UV-MS was used as a reference method for determining the contents of these ingredients. Partial least squares(PLS) analysis was implemented as a linear method for multivariate models calibrated between UV spectrum/NIR spectrum and contents of 8 ingredients. Finally, the performance of the model was evaluated by 24 batches of test samples. The results showed that both UV-Vis and NIR models gave a good calibration ability with an R~2 value above 0.9, and the prediction ability was also satisfactory, with an R~2 value higher than 0.83 for UV-Vis model and higher than 0.79 for NIR model. The overall results demonstrate that the established method is accurate, robust and fast, therefore, it can be used for rapid quality evaluation of Shengxuebao Mixture.

[Quantitative analysis method of Shengxuebao Mixture by HPLC-UV-MS based on quality by design concept].

In this study, the HPLC-UV-MS method for the simultaneous determination of eight active ingredients of Shengxuebao Mixture were developed based on the concept of quality by design（QbD）with a stepwise optimization approach. After the analytical target profile（ATP）had been defined, albiflorin, paeoniflorin, 2, 3, 5, 4'-tetra-hydroxy-stilbene-2-O-ß-D-glucopyranoside, specnuezhenide, ecliptasaponin D, emodin, calycosin-7-glucoside, and astragaloside Ⅳ were identified as the indicator components. The resolution and the signal-to-noise ratio of indicator components were then selected as critical method attributes (CMA) for the first step optimization. According to the results collected from fractional factorial design, critical method parameters (CMP) were determined with a multiple linear regression method, which included the amount of acid addition in the mobile phase, temperature, gradient, and wavelength. After that, the amount of acid addition and the wavelength were optimized to improve the resolution and the signal-to-noise ratio of the indicator components. The peak symmetry factors of specnuezhenide and emodin were then set as CMA for the second step optimization. The Box-Behnken designed experiments were conducted. The temperature and gradient were optimized after modelling. The design space were calculated and verified. The optimized analytical method was validated, and the results showed a good precision, accuracy and stability, which means that it can be used for the quantification of the indicator components in Shengxuebao Mixture.

Characterization of Vitreous and Aqueous Proteome in Humans With Proliferative Diabetic Retinopathy and Its Clinical Correlation.

AIMS: Proliferative diabetic retinopathy (PDR) is associated with microvascular complications that cause biochemical changes in the human retina and alter the proteome of vitreous humor and aqueous humor (AH). METHODS: Human vitreous humor and AH of PDR subjects were collected. Subjects who had surgery for epiretinal membrane or macular hole served as controls. Protein profiles were obtained and analyzed after running the samples on a liquid chromatography-mass spectrometry/mass spectrometry. RESULTS: In vitreous humor, 16 unique proteins were noted in PDR patients, but not in controls. Those were associated mainly with coagulation, complement, and kallikrein-kinin systems. Under coagulation, fibrinogen and prothrombin proteins were more evident and may emphasize the importance of angiogenesis in the development of PDR. Vitreous proteins showed replicative presence in AH too. As for AH samples, we detected 10 proteins found in PDR patients, which were related to transport, coagulation, and inflammatory responses. CONCLUSIONS: We found 57 proteins in human vitreous and 39 proteins in AH. Identification of these proteins that are involved in various pathways will be helpful to understand diabetic retinopathy pathogenesis and to develop proteome as a biomarker for PDR.

Intraocular Pressure in Premature Low Birth Weight Infants.

PURPOSE: To evaluate the intraocular pressure (IOP) and central corneal thickness (CCT) in premature low birth weight (LBW) infants and their correlation with gestational age (GA). METHODS: IOP and CCT were measured in premature LBW infants (defined as a birth weight ≤ 1,500 g or birth GA ≤ 30 weeks) admitted to the neonatal intensive care unit at the University of Florida Division of Neonatology, UF Health Jacksonville. RESULTS: Ninety eyes of 45 premature LBW infants with mean birth GA of 28.2 ± 2.3 weeks and mean birth weight of 1,131.5 ± 380.1 g were evaluated. The mean IOP and CCT were 29.0 ± 9.0 mm Hg and 660.0 ± 65.0 µm, respectively. There was no correlation between the IOP and CCT (r = 0.09; P = .38). There was a negative correlation between IOP and GA (r = -0.41) and between CCT and GA (r = -0.26). CONCLUSIONS: IOP is higher and CCT is thicker in premature infants compared to adults; however, there was no correlation between IOP and CCT. [J Pediatr Ophthalmol Strabismus. 2016;53(5):300-304.].

Erlotinib-associated severe bilateral recalcitrant keratouveitis after corneal EDTA chelation.

PURPOSE: We report a case of erlotinib-associated severe recalcitrant bilateral keratouveitis after uneventful corneal ethylenediaminetetraacetic acid (EDTA) chelation in a patient with non-small cell lung cancer (NSCLC); discontinuation of erlotinib led to complete resolution. OBSERVATIONS: An elderly person presented with band keratopathy (BSK) of undetermined etiology in the both eyes, associated with foreign body sensation and constant tearing. The patient was on oral erlotinib treatment 150 mg PO daily for 1 year for NSCLC status post radiation therapy. Corneal EDTA chelation was performed in both eyes under topical anesthesia for BSK. Four days after surgery, the patient presented with severe pain in both eyes. Slit lamp evaluation revealed 5 mm × 7 mm epithelial defect with clear margins in the right eye and 6 × 7 mm epithelial defect with thick central corneal infiltrate in the left eye. Hypopyon was noticed in both eyes and intense inflammation obscured the details of anterior segment. Intense antibiotic treatment was initiated. After discussion with the oncology services, oral erlotinib was temporarily discontinued. This resulted in resolution of keratitis and hypopyon in both eyes, within one week. CONCLUSIONS: and importance: Systemic use of erlotinib suppresses local immunity, facilitates infection and enhances inflammatory reaction in the eye. Clinicians should be cautious and plan any ocular interventional treatment in collaboration with oncology team to prevent adverse outcomes.

Diffuse lamellar keratitis after small-incision lenticule extraction.

PURPOSE: To determine the incidence and clinical features of diffuse lamellar keratitis (DLK) after small-incision lenticule extraction (SMILE). SETTING: Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Shanghai, China. DESIGN: Retrospective case control study. METHODS: Small-incision lenticule extraction for myopia was performed from September 1, 2011, to October 31, 2013. Preoperative clinical characteristics; treatment parameters; and intraoperative and postoperative complications, including the incidence, severity, clinical outcome, and resolution of DLK, were recorded. The independent t test, chi-square test, univariate repeated measures, and multivariate linear regression analysis were used to make statistical comparisons between eyes that developed DLK and those that did not. RESULTS: The study enrolled 1112 eyes (590 patients). Eighteen eyes (1.6%) (11 patients) developed DLK. These patients presented 1 to 3 days postoperatively with mild to moderate inflammation. Thirteen eyes (72.2%) had stage 1 DLK, 4 (22.2%) had stage 2, and 1 (5.6%) had stage 3. After intensive treatment with topical corticosteroids, the stage 1 and stage 2 cases resolved within 3 weeks and the stage 3 case resolved in 1 month. The postoperative corrected distance visual acuity was the same or better than preoperatively in all eyes. There was a statistically significant increase in the incidence of DLK with thinner lenticules (P = .02) and larger diameter lenticules (P = .01), although multifactorial analysis showed lenticule thickness to be the only factor (P = .03). CONCLUSIONS: Diffuse lamellar keratitis is a potential complication after small-incision lenticule extraction, although it had a low incidence. The risk factors for DLK must be further elucidated. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

No change in anterior chamber dimensions after femtosecond LASIK for hyperopia.

OBJECTIVE: To compare the changes in anterior chamber volume (ACV), anterior chamber depth (ACD) and anterior chamber angle (ACA) before and 6 months after femtosecond laser in situ keratomileusis (LASIK) for hyperopia using the Pentacam HR device. METHODS: A total of 24 eyes of 24 consecutive hyperopic patients undergoing femtosecond LASIK were examined preoperatively and 6 months postoperatively. Anterior chamber volume; ACDs in the central, superior, inferior, nasal, and temporal quadrants; and ACA were measured using the Pentacam HR device. Comparisons of preoperative versus postoperative values were performed using paired Student t test. Linear regression analysis was performed to evaluate correlations between ACV change, central ACD change, age, and attempted maximum ablation depth. RESULTS: Preoperative and postoperative mean ACVs were 153.6 and 158.2 µL, respectively. Preoperative and postoperative mean ACDs were 2.81, 2.28, 2.53, 2.16, and 2.61 mm, and 2.84, 2.31, 2.54, 2.16, and 2.65 mm, respectively. Preoperative and postoperative mean ACAs were 33.3° and 32.0°, respectively. There were not statistically significant differences in ACV, ACDs, and ACA from preoperatively to 6 months after femtosecond LASIK (all P>0.05). The change of central ACD was correlated significantly with age at 6 months postoperatively (R=0.18, P=0.039). CONCLUSIONS: Anterior chamber profiles, including ACV, ACA, and central and peripheral ACDs did not significantly change after femtosecond LASIK for hyperopia.

Comparison of corneal sensation between small incision lenticule extraction (SMILE) and femtosecond laser-assisted LASIK for myopia.

PURPOSE: To compare the impact on corneal sensation after small incision lenticule extraction (SMILE) and femtosecond laser-assisted LASIK (femto-LASIK) in patients with myopia. METHODS: In this prospective, nonrandomized comparative study, 71 subjects were enrolled. Thirty-eight eyes of 38 patients underwent SMILE and 33 eyes of 33 patients underwent femto-LASIK. Corneal sensation was tested with Cochet-Bonnet esthesiometry in five corneal areas preoperatively and at 1 week and 1, 3, and 6 months postoperatively. Comparison of corneal sensation was performed for the SMILE and femto-LASIK groups. Additionally, the correlations were evaluated between the postoperative corneal sensation, preoperative spherical equivalent, and ablation depth. RESULTS: All tested areas within the cap or flap demonstrated corneal hypoesthesia immediately after both surgeries. SMILE-treated eyes showed less compromised corneal sensation than femto-LASIK-treated eyes at all postoperative visits in the central, inferior, nasal, and temporal areas at the 1-week and 1-month visits. In the SMILE group, the inferior, nasal, and temporal quadrants recovered faster than other areas. In the femto-LASIK group, the sensation over the flap did not recover to preoperative levels by postoperative 6 months. There was no correlation between postoperative corneal sensation, preoperative spherical equivalent, and ablation depth in both groups. CONCLUSIONS: The impairment of corneal sensation was less significant in the SMILE group than in the femto-LASIK group and was independent of preoperative spherical equivalent or ablation depth.

Small incision lenticule extraction (SMILE) and femtosecond laser LASIK: comparison of corneal wound healing and inflammation.

AIM: To evaluate and compare early corneal wound healing and inflammatory responses after small incision lenticule extraction (SMILE) versus femtosecond laser laser in situ keratomileusis (LASIK). METHODS: Thirty-six eyes of 36 rabbits underwent SMILE, while another 36 eyes of 36 rabbits were treated with femtosecond laser LASIK. All the eyes were subjected to the same refractive correction of -6.00 DS/-1.00 DC. Twelve eyes that had no surgery were included for control. After euthanisation, corneal tissue sections were evaluated with terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling (TUNEL) assay to detect apoptosis at postoperative 4 and 24 h, immunocytochemistry for Ki67 to detect keratocyte proliferation at postoperative day 3, week 1 and month 1, and immunocytochemistry for CD11b to detect inflammation at postoperative day 1, day 3 and week 1, respectively. RESULTS: No adverse effects were noted after SMILE or LASIK. Corneal healing postoperatively was uneventful in all cases. There were significantly fewer TUNEL-positive corneal stromal cells after the SMILE procedure at 4 and 24 h postoperatively (p<0.01) compared with the LASIK procedure. In addition, immunocytochemistry showed significantly fewer Ki67-positive cells in the SMILE group than those in the femtosecond laser LASIK group at day 3 and week 1 postoperatively (p<0.05), but there was little expression of Ki67 at month 1 postoperatively in both groups. The CD11b-positive cells were significantly fewer in the SMILE group at day 1, day 3 and week 1 postoperatively (p<0.01). CONCLUSIONS: SMILE induces less keratocyte apoptosis, proliferation and inflammation compared with femtosecond laser LASIK.

Confocal comparison of corneal reinnervation after small incision lenticule extraction (SMILE) and femtosecond laser in situ keratomileusis (FS-LASIK).

PURPOSE: To evaluate corneal reinnervation, and the corresponding corneal sensitivity and keratocyte density after small incision lenticule extraction (SMILE) and femtosecond laser in situ keratomileusis (FS-LASIK). METHODS: In this prospective, non-randomized observational study, 18 patients (32 eyes) received SMILE surgery, and 22 patients (42 eyes) received FS-LASIK surgery to correct myopia. The corneal subbasal nerve density and microscopic morphological changes in corneal architecture were evaluated by confocal microscopy prior to surgery and at 1 week, 1 month, 3 months, and 6 months after surgery. A correlation analysis was performed between subbasal corneal nerve density and the corresponding keratocyte density and corneal sensitivity. RESULTS: The decrease in subbasal nerve density was less severe in SMILE-treated eyes than in FS-LASIK-treated eyes at 1 week (P = 0.0147), 1 month (P = 0.0243), and 3 months (P = 0.0498), but no difference was detected at the 6-month visit (P = 0.5277). The subbasal nerve density correlated positively with central corneal sensitivity in both groups (r = 0.416, P<0.0001, and r = 0.2567, P = 0.0038 for SMILE group and FS-LASIK group, respectively). The SMILE-treated eyes have a lower risk of developing peripheral empty space with epithelial cells filling in (P = 0.0005). CONCLUSIONS: The decrease in subbasal nerve fiber density was less severe in the SMILE group than the FS-LASIK group in the first 3 months following the surgeries. The subbasal nerve density was correlated with central corneal sensitivity.

The morphology of corneal cap and its relation to refractive outcomes in femtosecond laser small incision lenticule extraction (SMILE) with anterior segment optical coherence tomography observation.

PURPOSE: To investigate the morphology of corneal caps in femtosecond laser small incision lenticule extraction (SMILE) and its relation to the refractive outcomes. METHODS: A prospective study of fifty-four corneal caps created with VisuMax femtosecond laser were examined using an Fourier-domain optical coherence tomography at 1 day, 1 week, 1 month and 6 months after SMILE. The cap thickness at nine points on each of the four meridians (0°, 45°, 90°, 135°) and the diameter were measured. Cap morphology, changes over time and its correlation with refractive outcomes were assessed. RESULTS: The mean achieved central cap thickness were (108.74±5.06) µm at 6 months and (107.32±4.81 ) µm at 1 month postoperatively, significantly thinner than that at 1 day (110.81±7.95) µm and 1 week (109.58±7.48 ) µm (P<0.05). The mean diameter on 0° meridian was (7.61±0.07) mm, significantly larger than that on 90° meridian (7.57±0.06) mm (P = 0.001). Cap morphology showed good regularity, except that the differences of points in two pairs were significant at 1 day postoperatively. The uniformity was consistent over time and the central cap thickness was thinner than those in the paracentral and peripheral areas. The refractive outcomes stabilized within 1 month. Uncorrected distance visual acuity (UDVA) was correlated to the central cap thickness at 1 day and 1 week (both rs  = 0.33, p<0.05). The uniformity index was correlated with UDVA (rs  = 0.34, p<0.05) and corrected distance visual acuity (rs  = 0.32, p<0.05) at 1 week postoperatively. CONCLUSIONS: Corneal caps of SMILE are predictable with good reproducibility, regularity and uniformity. Cap morphology might have a mild effect on refractive outcomes in the early stage. Further study should focus on the impact on the visual quality.

Evaluation of the repeatability of the Lenstar and comparison with two other non-contact biometric devices in myopes.

BACKGROUND: The aim was to evaluate the repeatability of a new optical low-coherence reflectometric device Lenstar, as well as its agreement with the IOL Master and the Pentacam-HR system in myopes. METHODS: In a prospective study, 56 eyes of 28 myopes were examined with the Lenstar, the IOL Master and the Pentacam-HR system. The repeatability of the Lenstar was assessed. Bland-Altman plots were used to analyse the agreement between the Lenstar and the IOL Master for axial length (AL), anterior chamber depth (ACD from corneal epithelium to lens surface), keratometry readings of flattest and steepest meridian (K1 and K2) and horizontal iris width (white-to-white distance; WTW) measurements and between the Lenstar and the Pentacam-HR system for central corneal thickness (CCT), ACD (from corneal endothelium to lens surface) and K1 and K2 readings. RESULTS: The variability of the Lenstar was small for all recorded measurements. CCT measurements with the Lenstar and the Pentacam-HR system and ACD measurements with the Lenstar and the other two devices showed narrow 95% limits of agreement (LoA), which imply good agreement. In contrast, range and 95% LoA were clinically significantly different for AL, K1, K2 and WTW values between the Lenstar and the IOL Master as well as for K readings between the Lenstar and the Pentacam-HR system. CONCLUSIONS: The repeatability of the Lenstar is excellent. In clinical practice, the Lenstar and the Pentacam-HR system can be used interchangeably for CCT and ACD measurements but not for K readings. The Lenstar and the IOL Master can be used interchangeably for ACD measurements but not for AL, K readings or WTW distance values.

Impact of pupil diameter on axial growth in orthokeratology.

PURPOSE: To compare axial elongation between myopic orthokeratology (OK) contact lens and spectacle wearers, and to investigate the impact of pupil diameter on axial growth in myopic children after OK treatment. METHODS: Fifty-two Chinese children aged 9 to 14 years were enrolled in this study, 27 for the OK group and 25 for the single vision spectacle lenses (SVL) group. Subjects in each group were further divided into two subcategories according to their baseline scotopic pupil diameters. Axial length (AL) was measured at baseline and at every 6-month visit through to 24 months. Linear mixed-effect model was used to determine myopia progression (AL changes from baseline). In this model, repeated visits were taken as within-subject effect, and treatment group as well as pupil size were taken as between-subject effects. The interaction of treatment group*pupil size was analyzed. Relationships between axial growth at 24 months and baseline pupil area were analyzed in both lens groups. RESULTS: Twenty-five subjects in the OK group and 22 subjects in the SVL group completed the 24-month study. AL increased significantly throughout the observed 24-month period (F = 32.09, p < 0.001). Pupil size significantly affected axial growth (F = 15.95, p < 0.001) and different treatment modalities (OK vs. SVL) interacted with the effect of pupil size on axial growth (F = 24.66, p < 0.001). To be more specific, axial growth was significantly slower in subjects with above average pupil sizes than those with below average pupil sizes in the OK group (F = 25.04, p < 0.001). Contrarily, pupil size did not affect axial growth in the SVL group (F = 0.46, p = 0.50). Baseline scotopic pupil area was significantly correlated to axial growth in the OK group (r = 0.405, p < 0.001) but not in the SVL group (r = 0.171, p = 0.056). CONCLUSIONS: Large pupil diameters facilitate the effect of OK to slow axial growth in myopia. We speculate that this is because of enhancement of the myopic shift in the peripheral retina.

Role of the Fas pathway in Pseudomonas aeruginosa keratitis.

PURPOSE: The role of the Fas pathway was tested in Pseudomonas aeruginosa-infected mouse cornea by contrasting the responses of FasL(-/-) and wild-type (WT) mice. METHODS: TUNEL staining, real-time RT-PCR, immunostaining, and ELISA assay were used. RESULTS: Compared with WT (resistant) mice, BALB/c FasL(-/-) exhibited significantly elevated bacterial counts and polymorphonuclear leukocyte numbers at 1 and 3 days postinfection (p.i.) and worse outcomes from disease. Similar bacterial challenges in C57BL/6 FasL(-/-) compared with WT mice also led to worsened disease as evidenced by earlier corneal perforation in the susceptible mouse strain. Intense TUNEL staining of apoptotic cells was seen earlier (1 day vs. 3 days) p.i. in BALB/c WT than in knockout mice, This earlier apoptotic pattern correlated with increased expression of caspases 3, 8, and 9 and BAX and with decreased expression of the antiapoptotic molecule Bcl-2. Furthermore, expression levels of the proinflammatory molecule TNF-alpha and its receptor, MIP-2, inducible nitric oxide synthase (iNOS), and nitrite also were significantly elevated in the infected cornea of BALB/c FasL(-/-) compared with WT mice. In vitro, LPS-stimulated Mphi from BALB/c FasL(-/-) mice expressed significantly less caspase 3 and 9, BAX, and IL-10 and more TNF-alpha, MIP-2, and IL-1beta than did cells from WT mice. CONCLUSIONS: Fas-FasL interaction in the cornea balances the host innate immune response to improve disease outcome by promoting earlier apoptosis and regulating proinflammatory cytokines/chemokines and nitric oxide (nitrite) production. Dysregulation of this interaction contributes to bystander tissue damage, enhancing nutrients for bacterial growth and worsened disease outcome after P. aeruginosa infection.

Substance P delays apoptosis, enhancing keratitis after Pseudomonas aeruginosa infection.

PURPOSE: Apoptosis was examined after Pseudomonas aeruginosa corneal infection in C57BL/6 (B6, susceptible) and BALB/c (resistant) mice. METHODS: TUNEL staining, real-time RT-PCR, polymorphonuclear neutrophils (PMNs) and macrophage (Mphi) depletion, and immunostaining were used. RESULTS: Intense TUNEL staining was seen in BALB/c versus B6 cornea at 1 versus 3 days after infection (PI) and correlated with mRNA levels for caspase-3. TUNEL staining (with or without PMN depletion) and PMN immunostaining revealed the PMN as the major apoptotic cell for both groups. Next, B6 mice with high corneal levels of the antiapoptosis neuropeptide, substance P (SP), were treated with the SP antagonist, Spantide I (with/without Mphi depletion), resulting in earlier apoptosis and diminished disease only when M(phi)s were present. SP interactions with M(phi)s were explored further by eliciting cells from both groups and stimulating them with lipopolysaccharide (LPS), with or without SP. LPS with SP treatment decreased the number of apoptotic M(phi)s in B6 but not BALB/c mice and correlated with reduced mRNA expression of NK-1R (major SP receptor) on BALB/c cells. In addition, mRNA expression for IL-12 was upregulated in LPS-stimulated B6 M(phi)s, although cells from BALB/c mice expressed more IL-10. CONCLUSIONS: These studies provide evidence that PMN apoptosis is delayed in the cornea of B6 versus BALB/c mice after bacterial infection; that in B6 mice, blocking SP interaction with the NK-1R promotes earlier apoptosis and improves disease outcome; that M(phi)s regulate PMN apoptosis; and that M(phi)s from B6 versus BALB/c mice differ in expression of the NK-1R and cytokines produced after LPS challenge.