Don Davis

University of Utah, Salt Lake City, UT, United States

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Publications (16)39.27 Total impact

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    ABSTRACT: To report outcomes in Descemet stripping automated endothelial keratoplasty (DSAEK) using donor tissue from eyes that have had previous refractive surgery and to report histopathology of the donor free cap. Retrospective case series. Preoperative and postoperative data were collected on each patient, and donor information was collected. Histopathologic evaluation was carried out on donor caps to determine the stability of the laser in situ keratomileusis (LASIK) flap and smoothness of the microkeratome cut during preparation of the donor. DSAEK was performed on 7 eyes using donors that had undergone photorefractive keratectomy (PRK) or LASIK. One patient received PRK donor tissue, had no interface haze, and had improvement in vision. All but one patient who received LASIK donor tissue had improvement in vision, and that patient had severe graft folds noted intraoperatively that persisted. Histopathologic examination of 3 donor caps showed mild to moderate dehiscence of the LASIK flap, but the cut interface was consistent with normal donor tissue preparation histopathology. We report the first case of DSAEK using PRK donor tissue, which was successful. Our experience with LASIK donor tissue was comparable to nonrefractive donor tissue with the exception of the persistent donor macrofolds in one patient.
    Cornea 10/2011; 31(5):533-7. · 1.75 Impact Factor
  • Cornea 06/2011; 30(9):1061-2; author reply 1062. · 1.75 Impact Factor
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    ABSTRACT: KIT mutations are known to occur in ~15% of chronic sun damaged cutaneous, mucosal, and acral melanomas. Melanomas with demonstrated activating mutations in KIT or platelet-derived growth factor receptor A (PDGFRA) may benefit from treatment with tyrosine kinase inhibitors. Currently, the limited data regarding KIT mutational status in ocular melanoma suggest that activating mutations are extremely rare. PDGFRA mutational status in ocular melanoma has not been determined. Seventy-five ocular melanomas (53 choroidal, 6 iris, 11 ciliary body, and 5 conjuctival) were selected from the files of the Department of Ophthalmology. High-resolution melting curve analysis and sequencing were performed to detect mutations in KIT exons 9, 11, 13, and 17 and PDGFRA exons 12 and 18. Results of mutational analysis were correlated with anatomical site and KIT (CD117) immunohistochemistry. Eight of 75 (11%) ocular melanomas contained mutations in either the KIT or PDGFRA gene. Five of 53 (9%) choroidal melanomas were associated with mutations (KIT exon 11=3; KIT exon 17=1; PDGFRA intron 18=1). Two of six (33%) iris melanomas and a single (9%) ciliary body melanoma harbored KIT exon 11 mutations. No mutations were identified in conjunctival melanomas. The distribution of KIT and PDGFRA mutations by ocular melanoma anatomical site did not reach statistical significance (P=0.393) CD117 positivity was not predictive of KIT mutational status as only 6 of 58 (10%) CD177-positive tumors harbored KIT mutations. In addition, a KIT exon 17 mutation was identified in one CD117-negative tumor. KIT and PDGFRA mutations do occur in ocular melanomas at a frequency (11%) that is similar to acral and mucosal melanomas. Limited correlation of CD117 positivity with mutational status suggests that all ocular melanomas should undergo mutational analysis to determine if imatinib therapy is appropriate.Keywords: CD117; KIT; ocular melanoma; PDGFRA
    Modern Pathology 04/2011; 24(8):1031-1035. · 5.25 Impact Factor
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    ABSTRACT: To assess the degree of capsular bag opacification in human cadaver eyes with silicone intraocular lenses (IOLs), specifically comparing the differences between round-edged IOLs and modern square-edged IOLs. John A. Moran Eye Center, University of Utah, USA. Experimental study. The eyes were immersed in 10% formalin on enucleation. They had anterior segment scanning with a very-high-frequency ultrasound (Artemis). After the eyes were sectioned at the equator, gross examination of the anterior segment was performed from the posterior aspect to assess the degree of capsular bag opacification, coverage of the IOL edge by the anterior capsule, and IOL fixation. Selected eyes also had histopathologic examination. Eighty-seven eyes with a 3-piece round-edged IOL, 43 with a 3-piece square-edged IOL, 26 with a 1-piece plate IOL, and 1 with an accommodating IOL design were included in the analyses of capsular bag opacification. Comparison between 3-piece round-edged IOLs and square-edged IOLs showed statistically significant differences in central posterior capsule opacification (PCO) (P=.0001687) and peripheral PCO (P<.0001). In eyes with square-edged IOLs, PCO had a tendency to start in areas without capsulorhexis coverage of the optic. Twenty-one of 26 eyes with a silicone plate IOL had a neodymium:YAG posterior capsulotomy for dense PCO. This first study using pseudophakic human cadaver eyes that includes a significant number of modern 3-piece silicone IOLs with square optic edges confirmed the role of this design in the prevention of PCO. No author has a financial or proprietary interest in any material or method mentioned.
    Journal of Cataract and Refractive Surgery 04/2011; 37(4):740-8. · 2.75 Impact Factor
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    ABSTRACT: To assess capsular bag opacification and sites of initial posterior capsule opacification (PCO) in human cadaver eyes with square-edged 1-piece or 3-piece hydrophobic acrylic intraocular lenses (IOLs). John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Experimental study. Eyes were immersed in 10% formalin after enucleation and had anterior segment scanning with very-high-frequency ultrasound (Artemis). After the eyes were sectioned at the equator, gross examination of the anterior segment was performed from the posterior aspect to assess capsular bag opacification, anterior capsule coverage of the IOL edge, and IOL fixation. Selected eyes had histopathologic examination. One hundred nineteen eyes with 1-piece IOLs and 100 with 3-piece IOLs were included in the analyses of capsular bag opacification. There was no difference in central (P=.29) or peripheral (P=.76) PCO. In 63 of 84 eyes with a 1-piece IOL and peripheral PCO, the optic-haptic junction was the site of initiation. In eyes with a 3-piece IOL, initial peripheral PCO was observed at nearly the same rate whether there was full 360-degree anterior capsulorhexis overlap of the optic or no overlap (P=.13). In the latter, the site of PCO initiation was in areas lacking capsulorhexis coverage in 46% of eyes. There was no difference in central or peripheral PCO between 1-piece and 3-piece hydrophobic acrylic IOLs. With 1-piece IOLs, PCO tended to start at the optic-haptic junctions. With 3-piece IOLs, full anterior capsule coverage did not produce a statistically significant benefit with respect to PCO prevention.
    Journal of Cataract and Refractive Surgery 03/2011; 37(5):923-30. · 2.75 Impact Factor
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    ABSTRACT: We analyzed an enucleated postmortem eye from an 86-year-old donor who had a 2-loop iridocapsular intraocular lens (IOL) that had been implanted at least 30 years earlier. High-frequency ultrasound showed a relatively well-centered iris-supported optic in front of the pupil. Gross and light microscopic analyses of the eye and the IOL showed loop fixation outside the capsular bag remnants, a thickened cornea, mild attenuation of the corneal endothelium, multiple areas of iris trauma secondary to haptic abrasion, fragments of iris tissue attached to the haptics, as well as pigment dispersion within the eye with pigmented epithelial cells attached to the IOL haptics. Histopathological examination of the posterior segment was unremarkable.
    Journal of Cataract and Refractive Surgery 02/2011; 37(2):409-12. · 2.75 Impact Factor
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    ABSTRACT: To report a case of ocular surface squamous neoplasia (OSSN) masquerading as superior limbic keratoconjunctivitis (SLK). A 62-year-old woman was referred with foreign body sensation, irritation, photophobia and decreased vision in the left eye. She was initially treated for 10 months with intermittent topical corticosteroids for a presumed diagnosis of SLK. She underwent excisional biopsy of the superior conjunctiva and was found, on histopathologic evaluation, to have OSSN with moderate to marked dysplasia. This is the first reported case of OSSN masquerading with signs and symptoms of SLK. Any ocular surface lesion refractory to standard medical treatment should raise suspicion for a malignant process and warrant further cytologic or histopathologic evaluation.
    Middle East African journal of ophthalmology 01/2011; 18(1):74-6.
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    ABSTRACT: To evaluate a model of mechanically measuring resistance to tearing of a continuous curvilinear capsulorhexis (CCC) using the entire capsular bag of fresh human cadaver eyes isolated from the eyes after complete evacuation. John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Experimental study. After the cornea and iris were removed, a 5.0 to 5.5 mm anterior CCC was created. The nucleus was hydroexpressed and the capsular bag evacuated by irrigation/aspiration. A pair of metal shoetree-shaped fixtures, designed based on human lens geometric dimensions, were implanted separately in the capsular bag and assembled together with a screw nut. After complete zonulectomy, the fixture-capsular bag assembly was removed from the eye and loaded onto a mechanical tester. The fixtures were separated at a velocity of 7.0 mm/min in 0.15 μm intervals to stretch the CCC to its rupture point. Rupture load (N) and extension were measured and graphed. Testing of 23 donor eyes a mean of 69.04 hours ± 22.72 (SD) after death showed the following mean values: CCC diameter, 5.3 ± 0.12 mm; load, 0.39 ± 0.16 N; extension at CCC tearing, 5.85 ± 1.17 mm. There was a moderately strong negative correlation between donor age and load (P = .0018). Previous mechanized methods of assessing CCC strength used excised anterior capsules or partially phacoemulsified crystalline lenses, yielding lower tension strength values. This force-displacement method may facilitate assessment of small differences between anterior capsulotomy techniques.
    Journal of Cataract and Refractive Surgery 11/2010; 36(11):1954-9. · 2.75 Impact Factor
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    ABSTRACT: We describe 2 cases in which patients with 4-looped single-piece hydrophilic acrylic intraocular lenses (IOLs) exhibited postoperative complications including capsulorhexis phimosis, decentration, tilt, hyperopic shift, and luxation leading to explantation of the IOL-capsular bag complex. The excessive capsule fibrosis led to anterior flexing of the IOL haptics in both cases, even in the presence of a capsular tension ring (CTR). Histopathological analyses revealed a thick fibrocellular tissue attached to the inner surface of the anterior capsules, corresponding to the anterior capsule opacification and folds. An amorphous substance was observed on the outer surface of the anterior capsule in the case with a CTR, suggesting pseudoexfoliation material. These and similar cases raise concerns about the postoperative behavior of highly flexible IOLs in the presence of excessive capsular bag fibrosis. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.
    Journal of Cataract and Refractive Surgery 09/2010; 36(9):1605-9. · 2.75 Impact Factor
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    ABSTRACT: To evaluate efficacy of a neodymium:YAG (Nd:YAG) laser photolysis system in removing lens epithelial cells (LECs) and characterize the effect of the laser on laminin and fibronectin involved in LEC adhesion and migration. Cadaver eyes were evaluated using the Miyake technique. The lenses were removed with phacoemulsification. The modified Nd:YAG laser was used to clean the LECs from the capsule. Only the fornix was cleaned in some eyes and the anterior subcapsular area in other eyes. Some areas were not treated and acted as controls. Standard irrigation/aspiration (I/A) removal of LECs was performed in additional eyes. The eyes were analyzed using light microscopy and immunohistochemical staining. Histopathologic evaluation showed that the laser removed the LECs from the anterior lens capsule and from the fornix. Immunohistochemical staining showed fibronectin and laminin staining in the untreated areas that was absent in the treated areas. Standard I/A removal of the LECs showed absence of cells but persistent laminin and fibronectin. Electron microscopy showed epithelial cells in untreated areas with an absence of the LECs and debris in treated areas. The laser photolysis system removed LECs from the anterior lens capsule and capsule fornix. Along with the cells, laminin, fibronectin, and cell debris remained in the untreated areas but were removed by the treatment. This treatment may be useful in preventing posterior capsule opacification.
    Journal of Cataract and Refractive Surgery 06/2010; 36(6):1003-10. · 2.75 Impact Factor
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    ABSTRACT: We studied an enucleated postmortem eye from an 82-year-old white donor who had been implanted with a Pannu "universal" intraocular lens (IOL) in the anterior chamber approximately 20 years earlier. This IOL has design features characteristic of a 1-piece, C-loop posterior chamber IOL. Magnetic resonance imaging showed a relatively well-centered IOL in the anterior chamber with haptics impinging on the iris. Gross and light microscopic analyses of the eye and the IOL showed peripheral anterior synechiae enclaving one haptic, areas of angle widening, significant attenuation of the corneal endothelium, multiple areas of iris trauma secondary to optic and haptic iris abrasion, large areas of pigment dispersion in the angle, diffuse pigment accumulation within the anterior chamber, and attenuation of the ganglion cell layer. The histopathological findings were consistent with glaucoma and chronic inflammation.
    Journal of Cataract and Refractive Surgery 03/2010; 36(3):512-6. · 2.75 Impact Factor
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    ABSTRACT: We report the histopathology of epithelial overgrowth in the Boston type I keratoprosthesis. The epithelium shows an inconsistent number of layers and basement membrane and goblet cells are absent. Epithelialization of the keratoprosthesis optic would have multiple advantages, but the limitation of vision makes tolerating the overgrowth difficult.
    Clinical Ophthalmology 01/2010; 4:1069-71.
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    ABSTRACT: As techniques for cataract surgery have evolved, spontaneous intraocular lens (IOL) dislocation has decreased overall. However, since 2006 the Intermountain Ocular Research Center has received an increased number of explanted IOLs within the capsular bag forwarded for pathologic evaluation. Late, spontaneous dislocation of IOLs results from zonular insufficiency and zonulysis that has been associated with pseudoexfoliation, trauma, and other risk factors. The findings of 86 consecutive cases of this complication, analyzed in the laboratory, are described. Retrospective case series. Eighty-six IOLs explanted within the capsular bag, submitted in formalin. Standard light microscopy of specimens, as well as questionnaire sent to explanting surgeons and patient chart review, when available. Lens design, material, and abnormalities; capsular bag anomalies; patient demographic data; surgical dates; and presence or absence of known risk factors. This series included polymethyl methacrylate, silicone, and hydrophobic acrylic lenses, manufactured with both 1-piece and 3-piece designs. The mean time from surgery to spontaneous IOL dislocation was 8.5 years. The main conditions associated with the cases of IOL dislocation were as follows: pseudoexfoliation, 50%; prior vitreoretinal surgery, 19%; history of trauma, 6%; uveitis, 2%; and none or unknown, 23%. Patients with any type of IOL are at risk for late in-the-bag dislocation. Pseudoexfoliation and vitreoretinal surgery were the most common associated conditions in this series. Regardless of the presence of known risk factors, IOLs dislocated on average 8.5 years after phacoemulsification and IOL implantation.
    Ophthalmology 05/2009; 116(4):664-70. · 5.56 Impact Factor
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    ABSTRACT: We analyzed an enucleated eye obtained postmortem from an 86-year-old donor who had been implanted with a hydrophilic acrylic bag-in-the-lens 4 months earlier. To our knowledge, this is the first donor eye implanted with this design to undergo pathological analysis. High-frequency ultrasound showed a well-centered IOL, fixated at the level of the capsular bag. Gross and light microscopic analyses of the eye showed that if anterior and posterior capsule openings are well stretched around the optic of this IOL design, proliferative/regenerative material is potentially confined to the intercapsular space of the capsular bag remnant outside the optic rim.
    Journal of Cataract and Refractive Surgery 01/2009; 34(12):2163-5. · 2.53 Impact Factor
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    ABSTRACT: The tenth annual survey of complications associated with foldable intraocular lenses (IOLs) requiring explantation or secondary intervention was sent to members of the American Society of Cataract and Refractive Surgery and the European Society of Cataract and Refractive Surgeons. Preoperative data about visual acuity, patient signs and symptoms, and complications requiring IOL removal were evaluated. Complications were then tabulated for each of the following major foldable IOL groups: 1-piece (plate) silicone, 1-piece hydrophobic acrylic with haptics, 3-piece silicone, 3-piece hydrophobic acrylic, 3-piece hydrophilic acrylic (hydrogel), 3-piece unknown, multifocal acrylic, and multifocal silicone. One hundred forty-two surveys were returned for evaluation. Dislocation/decentration, incorrect IOL power, glare/optical aberrations, and IOL calcification were the most common reasons for removing foldable IOLs. Good surgical technique, accurate IOL power measurements, and high manufacturing standards for foldable IOL materials and designs are the most important factors in preventing complications.
    Journal of Cataract and Refractive Surgery 10/2008; 34(9):1584-91. · 2.53 Impact Factor
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    ABSTRACT: A 64-year-old man with gout presented with history of an enlarging mass in the left upper eyelid causing mechanical ptosis. The patient underwent excisional biopsy. The histopathologic findings confirmed the diagnosis of gouty tophus of the eyelid.
    Ophthalmic plastic and reconstructive surgery 01/2008; 24(5):404-6. · 0.69 Impact Factor