Ricardo M Santaella

Duke University Medical Center, Durham, North Carolina, United States

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Publications (4)17.72 Total impact

  • Sujit Itty · Alan D Proia · Derek W DelMonte · Ricardo M Santaella · Alan Carlson · R Rand Allingham ·
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    ABSTRACT: Purpose: The aim of this study was to report a case series of epithelial downgrowth associated with Descemet stripping automated endothelial keratoplasty (DSAEK) and to explore the origin of the anterior chamber corneal epithelium. Methods: This is a case series and literature review. Results: Three histopathologically confirmed cases of epithelial downgrowth after DSAEK were identified. All cases were treated with argon laser ablation, intracameral 5-fluorouracil, and intraocular surgery. Recurrent epithelial downgrowth occurred in 2 of 3 cases. Fluorescent in situ hybridization analysis with fluorescent probes for X and Y chromosomes was used to analyze epithelial downgrowth tissues in all cases. All 3 cases were consistent with donor tissue origin of epithelial downgrowth tissue. However, this could only be confirmed in 1 case. The donor and the recipient were the same sex in 2 cases; thus, no definitive conclusion was possible in these patients. Conclusions: There have been multiple reports of epithelial downgrowth after DSAEK. We include additional evidence to support the role of donor tissue corneal cells as the source of epithelium in some of these cases. It is surprising that donor tissue would be tolerated immunologically by the patient in these cases. We propose that tolerance for donor epithelium may be mediated through anterior chamber-associated immune deviation.
    Cornea 09/2014; 33(11). DOI:10.1097/ICO.0000000000000234 · 2.04 Impact Factor
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    ABSTRACT: To establish polyhexamethylene biguanide (PHMB) as an effective treatment for Aspergillus keratitis in a novel murine model. To determine the ability of the calcineurin inhibitors tacrolimus (FK506) and cyclosporine A (CSA) to enhance the activity of PHMB, amphotericin B (AMB), and voriconazole (VCZ) against Aspergillus keratitis. In vitro studies: Broth antifungal susceptibility tests were performed with PHMB, AMB, VCZ, and FK506, individually and in combination against Aspergillus fumigatus. Minimum inhibitory concentrations (MIC) and fractional inhibitory concentration index (FICI) values were used to analyze antifungal activity. In vivo studies: A novel murine model was created to establish Aspergillus keratitis. Infected mice were randomly assigned to treatment groups receiving saline, CSA, AMB, VCZ, PHMB, AMB+CSA, VCZ+CSA, or PHMB+CSA. An ophthalmologist blinded to the treatment groups assessed disease severity daily based on a grading scale. The mean end change in disease score was compared between groups. In vitro studies: FK506 in combination with PHMB, VCZ, or AMB enhanced fungal growth inhibition. FICI values showed an additive effect between FK506 and PHMB, AMB, or VCZ. PHMB monotherapy eliminated Aspergillus growth starting at 4 μg/mL. In vivo studies: All treatment groups showed a significant improvement in disease score compared to the control group. CSA significantly worsened VCZ activity against Aspergillus keratitis. PHMB is an effective inhibitor of Aspergillus growth. Further investigation of the role of calcineurin inhibitors in the treatment for Aspergillus keratitis is warranted.
    Investigative ophthalmology & visual science 08/2011; 52(10):7309-15. DOI:10.1167/iovs.11-7739 · 3.40 Impact Factor
  • Ricardo Santaella · Terry Kim ·

    Ophthalmology 12/2010; 117(12):2445. DOI:10.1016/j.ophtha.2010.08.041 · 6.14 Impact Factor
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    ABSTRACT: To characterize and determine the effect of tamsulosin (Flomax) on the human iris dilator muscle anatomy. Retrospective, case-control study. This study comprised 51 cadaveric eyes from 27 patients (14 with a history of tamsulosin use and 13 control patients) who underwent autopsy at the Duke University Medical Center, Durham, North Carolina. Patients' records were reviewed, and age, medical, surgical, and ocular history; gender; medications; and duration and dosage of tamsulosin were recorded. Specimens were sectioned through the pupillary axis in the horizontal meridian and reviewed by light microscopy. A morphometric analysis was performed to measure the maximum and minimum iris dilator muscle thickness and the iris stromal thickness (micrometers) at 6 points in each eye. All microscopic evaluations and measurements were performed by the same masked observer. To determine whether there is a significant difference in the iris dilator muscle or stromal thickness in those patients receiving tamsulosin treatment compared with age-matched controls. The mean iris dilator muscle thickness in the tamsulosin-treated group (6.53+/-1.99 microm) was significantly thinner compared with that of the control group (8.50+/-1.61 microm) (P=0.006). There was no difference in iris stromal thickness between the 2 groups (P=0.268). There was no direct relationship between duration of tamsulosin use and iris dilator muscle or stromal thickness. Statistical significance was maintained when the iris dilator muscle thickness was compared between the groups using history of diabetes and cataract extraction as separate variables. No difference was noted when comparing the iris stromal thickness using diabetes as a separate variable. However, stromal thickness was significantly different between the groups in pseudophakic eyes (P=0.005). According to histologic examination of cadaver eyes, patients receiving tamsulosin treatment exhibited decreased iris dilator muscle thickness compared with control patients. There was no difference noted in the iris stromal thickness within the groups. We believe this finding may shed light on the pathophysiology of intraoperative floppy iris syndrome. Further studies need to be performed to assess the significance of this histologic finding.
    Ophthalmology 05/2010; 117(9):1743-9. DOI:10.1016/j.ophtha.2010.01.022 · 6.14 Impact Factor