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Dive into the research topics where David Callanan is active.

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Featured researches published by David Callanan.


Archives of Ophthalmology | 2008

Treatment of posterior uveitis with a fluocinolone acetonide implant: three-year clinical trial results.

David Callanan; Glenn J. Jaffe; Daniel F. Martin; Pearson Pa; Timothy L. Comstock

OBJECTIVES To evaluate the safety and efficacy of 0.59-mg and 2.1-mg fluocinolone acetonide (FA) intravitreous implants in noninfectious posterior uveitis. DESIGN A 3-year, multicenter, randomized, historically controlled trial of the 0.59-mg FA intravitreous implant in 110 patients and the 2.1-mg FA intravitreous implant in 168 patients. MAIN OUTCOME MEASURES Recurrence rate, vision, and complications. RESULTS Uveitis recurrence was reduced in implanted eyes from 62% (during the 1-year preimplantation period) to 4%, 10%, and 20% during the 1-, 2-, and 3-year postimplantation periods, respectively, for the 0.59-mg dose group (P < .01) and from 58% to 7%, 17%, and 41%, respectively, for the 2.1-mg dose group (P < .01). More implanted eyes than nonimplanted eyes had improved visual acuity (P < .01). Implanted eyes had higher incidences of intraocular pressure elevation (> or = 10 mm Hg) than nonimplanted eyes (P < .01), and glaucoma surgery was required in 40% of implanted eyes vs 2% of nonimplanted eyes (P < .01). Cataracts were extracted in 93% of phakic implanted eyes vs 20% of phakic nonimplanted eyes (P < .01). CONCLUSIONS The FA implant significantly reduced uveitis recurrence and improved or stabilized visual acuity in subjects with noninfectious posterior uveitis. Most subjects required cataract extraction, and a significant proportion required intraocular pressure-lowering surgery. APPLICATION TO CLINICAL PRACTICE The FA implant provides an alternative therapy for prolonged control of inflammation in noninfectious posterior uveitis. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00407082.


Ophthalmology | 2011

Fluocinolone Acetonide Intravitreal Implant for Diabetic Macular Edema: A 3-Year Multicenter, Randomized, Controlled Clinical Trial

P. Andrew Pearson; Timothy L. Comstock; Michael Ip; David Callanan; Lawrence S. Morse; Paul Ashton; Brian Levy; Eric S. Mann; Dean Eliott

PURPOSE We studied the 3-year efficacy and safety results of a 4-year study evaluating fluocinolone acetonide (FA) intravitreal implants in eyes with persistent or recurrent diabetic macular edema (DME). DESIGN Prospective, evaluator-masked, controlled, multicenter clinical trial. PARTICIPANTS We included 196 eyes with refractory DME. METHODS Patients were randomized 2:1 to receive 0.59-mg FA implant (n = 127) or standard of care (SOC additional laser or observation; n = 69). The implant was inserted through a pars plana incision. Visits were scheduled on day 2, weeks 1, 3, 6, 12, and 26, and thereafter every 13 weeks through 3 years postimplantation. MAIN OUTCOME MEASURES The primary efficacy outcome was ≥15-letter improvement in visual acuity (VA) at 6 months. Secondary outcomes included resolution of macular retinal thickening and Diabetic Retinopathy Severity Score (DRSS). Safety measures included incidence of adverse events (AEs). RESULTS Overall, VA improved ≥3 lines in 16.8% of implanted eyes at 6 months (P=0.0012; SOC, 1.4%); in 16.4% at 1 year (P=0.1191; SOC, 8.1%); in 31.8% at 2 years (P=0.0016; SOC, 9.3%); and in 31.1% at 3 years (P=0.1566; SOC, 20.0%). The number of implanted eyes with no evidence of retinal thickening at the center of the macula was higher than SOC eyes at 6 months (P<0.0001), 1 year (P<0.0001; 72% vs 22%), 2 years (P=0.016), and 3 years (P=0.861). A higher rate of improvement and lower rate of decline in DRSS occurred in the implanted group versus the SOC group at 6 months (P=0.0006), 1 year (P=0.0016), 2 years (P=0.012), and 3 years (P=0.0207). Intraocular pressure (IOP) ≥30 mmHg was recorded in 61.4% of implanted eyes (SOC, 5.8%) at any time and 33.8% required surgery for ocular hypertension by 4 years. Of implanted phakic eyes, 91% (SOC, 20%) had cataract extraction by 4 years. CONCLUSIONS The FA intravitreal implant met the primary and secondary outcomes, with significantly improved VA and DRSS and reduced DME. The most common AEs included cataract progression and elevated IOP. The 0.59-mg FA intravitreal implant may be an effective treatment for eyes with persistent or recurrent DME. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.


Ophthalmology | 2013

Pharmacogenetics for Genes Associated with Age-related Macular Degeneration in the Comparison of AMD Treatments Trials (CATT)

Stephanie A. Hagstrom; Gui-shuang Ying; Gayle J. T. Pauer; Gwen M. Sturgill-Short; Jiayan Huang; David Callanan; Ivana K. Kim; Michael L. Klein; Maureen G. Maguire; Daniel F. Martin

PURPOSE To evaluate the pharmacogenetic relationship between genotypes of single nucleotide polymorphisms (SNPs) known to be associated with age-related macular degeneration (AMD) and response to treatment with ranibizumab (Lucentis; Genentech, South San Francisco, CA) or bevacizumab (Avastin; Genentech) for neovascular AMD. DESIGN Clinical trial. PARTICIPANTS Eight hundred thirty-four (73%) of 1149 patients participating in the Comparison of AMD Treatments Trials (CATT) were recruited through 43 CATT clinical centers. METHODS Each patient was genotyped for SNPs rs1061170 (CFH), rs10490924 (ARMS2), rs11200638 (HTRA1), and rs2230199 (C3), using TaqMan SNP genotyping assays (Applied Biosystems, Foster City, CA). MAIN OUTCOMES MEASURES Genotypic frequencies were compared with clinical measures of response to therapy at one year, including mean visual acuity (VA), mean change in VA, 15-letter or more increase in VA, retinal thickness, mean change in total foveal thickness, presence of fluid on OCT, presence of leakage on fluorescein angiography (FA), mean change in lesion size, and mean number of injections administered. Differences in response by genotype were evaluated with tests of linear trend calculated from logistic regression models for categorical outcomes and linear regression models for continuous outcomes. To adjust for multiple comparisons, P≤0.01 was considered statistically significant. RESULTS No statistically significant differences in response by genotype were identified for any of the clinical measures studied. Specifically, there were no high-risk alleles that predicted final VA or change in VA, the degree of anatomic response (fluid on OCT or FA, retinal thickness, change in total foveal thickness, change in lesion size), or the number of injections. Furthermore, a stepwise analysis failed to show a significant epistatic interaction among the variants analyzed; that is, response did not vary by the number of risk alleles present. The lack of association was similar whether patients were treated with ranibizumab or bevacizumab or whether they received monthly or pro re nata dosing. CONCLUSIONS Although specific alleles for CFH, ARMS2, HTRA1, and C3 may predict the development of AMD, they did not predict response to anti-vascular endothelial growth factor therapy.


Ophthalmology | 1995

Idiopathic retinal vasculitis, aneurysms, and neuro-retinitis

Tom S. Chang; G. William Aylward; Janet L. Davis; William F. Mieler; Glen L. Oliver; Alan L. Maberley; J. Donald M. Gass; David Callanan; Jay S. Duker; John H. Drouilhet; David E. Eifrig; Robert B. Feldman; Robert E. Kalina; John H. Killian; Robert B. Nussenbatt; Carmen A. Puliafito; Thomas A. Rice; Howard Schatz; Scott M. Whitcup

Purpose: The authors describe the clinical feature of ten patients with a new syndrome characterized by the presence of retinal vasculitis, multiple macroaneurysms, neuro-retinitis, and peripheral capillary nonperfusion. Methods: The authors evaluated ten patients identified to have clinical features compatible with the syndrome of idiopathic retinal vasculitis, aneurysms and neuroretinitis (IRVAN). Clinical examination findings, sequential fundus photographs (when available), fluorescein angiograms, systemic investigations, response to therapy, and visual outcomes were reviewed. Results: Seven eyes of four patients sustained a marked decrease in visual acuity of 20/200 or worse. Visual loss was due to a combination of an exudative maculopathy and sequelae of retinal ischemia. Capillary nonperfusion was seen in all ten patients and was severe enough to warrant panretinal laser photocoagulation in six patients. Systemic investigations were uniformly noncontributory. Oral prednisone appears to have little beneficial effects on patients with this disorder. Conclusions: Patients with IRVAN have characteristic retinal features that readily identify this syndrome. An increased awareness of this rare syndrome may help to identify sight-threatening complications at an earlier stage. The authors caution against extensive medical investigations. Ophthalmology 1995;102:1089-1097


Ophthalmology | 2013

Dexamethasone Intravitreal Implant in Combination with Laser Photocoagulation for the Treatment of Diffuse Diabetic Macular Edema

David Callanan; Sunil Gupta; David S. Boyer; Thomas A. Ciulla; Michael Singer; Baruch D. Kuppermann; Ching-Chi Liu; Xiao-Yan Li; David A. Hollander; Rhett M. Schiffman; Scott M. Whitcup

PURPOSE To evaluate Ozurdex (dexamethasone intravitreal implant [DEX implant]; Allergan, Inc, Irvine, CA) 0.7 mg combined with laser photocoagulation compared with laser alone for treatment of diffuse diabetic macular edema (DME). DESIGN Randomized, controlled, multicenter, double-masked, parallel-group, 12-month trial. PARTICIPANTS Two hundred fifty-three patients with retinal thickening and impaired vision resulting from diffuse DME in at least 1 eye (the study eye) were enrolled. INTERVENTION Patients were randomized to treatment in the study eye with DEX implant at baseline plus laser at month 1 (combination treatment; n = 126) or sham implant at baseline and laser at month 1 (laser alone; n = 127) and could receive up to 3 additional laser treatments and 1 additional DEX implant or sham treatment as needed. MAIN OUTCOME MEASURES The primary efficacy variable was the percentage of patients who had a 10-letter or more improvement in best-corrected visual acuity (BCVA) from baseline at month 12. Other key efficacy variables included the change in BCVA from baseline and the area of vessel leakage evaluated with fluorescein angiography. Safety variables included adverse events and intraocular pressure (IOP). RESULTS The percentage of patients who gained 10 letters or more in BCVA at month 12 did not differ between treatment groups, but the percentage of patients was significantly greater in the combination group at month 1 (P<0.001) and month 9 (P = 0.007). In patients with angiographically verified diffuse DME, the mean improvement in BCVA was significantly greater with DEX implant plus laser treatment than with laser treatment alone (up to 7.9 vs. 2.3 letters) at all time points through month 9 (P ≤ 0.013). Decreases in the area of diffuse vascular leakage measured angiographically were significantly larger with DEX implant plus laser treatment through month 12 (P ≤ 0.041). Increased IOP was more common with combination treatment. No surgeries for elevated IOP were required. CONCLUSIONS There was no significant between-group difference at month 12. However, significantly greater improvement in BCVA, as demonstrated by changes from baseline at various time points up to 9 months and across time based on the area under the curve analysis, occurred in patients with diffuse DME treated with DEX implant plus laser than in patients treated with laser alone. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.


Transplantation | 1988

Characteristics of rejection of orthotopic corneal allografts in the rat

David Callanan; Peeler Js; Jerry Y. Niederkorn

We have employed a rat model of orthotopic corneal transplantation to study the characteristics of rejection and development of systemic immunity in the host. Lewis (LEW) rats underwent a true penetrating keratoplasty using Wistar-Furth (WF) donor corneas. A rejection incidence of 55% with a mean survival time (MST) of 17.1 days was observed using these untreated allogeneic corneas. Animals undergoing rejection of these allografts developed cytotoxic T lymphocytes (CTL) capable of lysing WF lymphoblasts in a standard 51-chromium release assay. These same rats did not have delayed-type hypersensitivity (DTH) responses when compared to skin grafted controls. Rats-with clear allografts had no demonstrable CTL or DTH activity. As expected, LEW rats that were preimmunized with WF skin grafts and subsequently received WF orthotopic corneal grafts rejected 100% of these corneas at an accelerated rate (MST = 9.7 days, P< .02). We then employed a previously described technique of using latex beads to induce migration of Langerhans cells into the central cornea of the donor graft prior to transplantation. The presence of Langerhans cells in the donor cornea resulted in a higher incidence of rejection (96%) and an accelerated rate (MST = 11.8 days, P < .02) when compared to untreated allografts. These rats also had a higher level of CTL activity and marked DTH responses. These data show that rejection of orthotopic allogeneic corneas is accompanied by the development of systemic alloimmunity as measured by CTL activity.


American Journal of Ophthalmology | 1998

Latanoprost-associated cystoid macular edema

David Callanan; Ronald L. Fellman; James A Savage

PURPOSE To report two cases in which cystoid macular edema developed after initiation of topical latanoprost for glaucoma. METHODS Case reports. One pseudophakic eye in each of two patients treated with latanoprost for glaucoma developed decreased vision and cystoid macular edema. Latanoprost was discontinued, and the cystoid macular edema was treated with topical corticosteroids and ketorolac. RESULTS After discontinuing latanoprost and starting corticosteroids and ketorolac, visual acuity improved from counting fingers to 20/60 in one patients left eye and from 20/100 to 20/25 in the other patients right eye. The macular edema resolved in both eyes. CONCLUSIONS Topical latanoprost may be associated with cystoid macular edema; this may be related to a prostaglandin-like action.


Ophthalmology | 2003

Laser treatment in fellow eyes with large drusen: Updated findings from a pilot randomized clinical trial

Maureen G. Maguire; Paul Sternberg; Thomas M. Aaberg; Daniel F. Martin; David A. Saperstein; Maureen Hyatt; James Gilman; Ray Swords; Gabriela Nemes; Lawrence J. Singerman; Thomas A. Rice; Hernando Zegarra; Michael A. Novak; Scott D. Pendergast; Z. Nicholas Zakov; John H. Niffenegger; Michelle Bartel; Susan Lichterman; Donna Knight; Kim Tilocco-DuBois; Mary Ilk; Geraldine Daley; Gregg Greanoff; John DuBois; Diane Weiss; Alice T. Lyon; Lee M. Jampol; David V. Weinberg; Beth Chiapetta; Zuzanna Strugala

PURPOSE To update the findings from the Choroidal Neovascularization Prevention Trial (CNVPT) with respect to resolution of drusen, incidence of choroidal neovascularization, and visual function. DESIGN A multicenter, randomized, controlled, pilot clinical trial. PARTICIPANTS The 120 patients enrolled in the CNVPT. Patients had signs of choroidal neovascularization or retinal pigment epithelial detachment in 1 eye and had >/=10 large (>63- micro m) drusen in the contralateral, or fellow, eye. INTERVENTION The fellow eye of 59 patients was assigned randomly to argon green laser treatment consisting of multiple 100- micro m spots at least 750 micro m from the center of the fovea. The fellow eye of the remaining 61 patients was assigned randomly to observation. MAIN OUTCOME MEASURES Change in visual acuity was the primary outcome measure. Incidence of choroidal neovascularization, resolution of drusen, change in contrast threshold, change in critical print size for reading, and incidence of geographic atrophy were secondary outcome measures. RESULTS Throughout 4 years of follow-up, there were no statistically significant differences in change in visual acuity, contrast threshold, critical print size, or incidence of geographic atrophy. With additional follow-up, the large increase in the incidence of choroidal neovascularization observed within 18 months of treatment was maintained; however, by 30 months, the incidence in the two treatment groups was the same. Most drusen resolution in treated eyes occurred within 24 months of the initial treatment. Treated eyes that received higher-intensity laser burns had an increased risk of choroidal neovascularization. Among eyes developing choroidal neovascularization in each treatment group, most lesions (two thirds or more) were composed of occult neovascularization only. CONCLUSIONS Laser treatment as applied in the CNVPT caused an excess risk of choroidal neovascularization in the first year or so after treatment. The increased early incidence of choroidal neovascularization was not associated with either a harmful or beneficial effect in this pilot study.


Retina-the Journal of Retinal and Vitreous Diseases | 2010

Characterization of sterile intraocular inflammatory responses after intravitreal bevacizumab injection.

Deborah Y. Chong; Rajiv Anand; Patrick D Williams; Jawad A Qureshi; David Callanan

Purpose: The purpose of this study was to determine the frequency and characteristics of sterile intraocular inflammation occurring after intravitreal bevacizumab (IVB) (Avastin, Genentech, South San Francisco, CA) injection and to analyze whether a repeat IVB or intravitreal ranibizumab (IVR) (Lucentis, Genentech) injection after an episode of postinjection inflammation elicits a repeat inflammatory reaction. Methods: A retrospective case series evaluated 16,166 IVB injections administered between 2006 and 2008. Patients with postinjection inflammation were analyzed for the number of previous injections, time from prior injection to incident injection, presenting signs and symptoms, treatment, visual acuity, time from onset to resolution and recovery of vision, and whether repeat injection caused recurrent inflammation. Results: The incidence of sterile intraocular inflammation after IVB injection resolving with topical antibiotics and steroids alone was 0.27% (44 of 16,166). The average number of prior IVB injections in the ipsilateral eye was 2.8 ± 0.4 with 10 cases occurring with first-time injections. The average time from injection to recovery of visual acuity was 53 ± 18 days, and from injection to resolution of inflammation was 37 ± 5 days. Thirty-six cases received subsequent IVB or intravitreal ranibizumab, and there were three episodes of recurrent inflammation with repeat IVB. The average follow-up was 17 ± 1 month. Conclusion: In most cases of sterile intraocular inflammation after IVB, visual acuity returned to baseline, and intraocular inflammation rarely recurred with repeat IVB or intravitreal ranibizumab.


Retina-the Journal of Retinal and Vitreous Diseases | 2006

Treating chronic noninfectious posterior segment uveitis: The impact of cumulative damage: Proceedings of an expert panel roundtable discussion

Quan Dong Nguyen; David Callanan; Pravin U. Dugel; David G. Godfrey; Debra A. Goldstein; Jacob T. Wilensky

Chronic noninfectious posterior segment uveitis refers to inflammation of the retina, choroid, vitreous, or optic nerve, and may result in permanent vision loss. The inflammation can be constant, or characterized by periodic exacerbations on an underlying baseline of inflammation. Recent studies indicate that this vision loss often results from cumulative damage over multiple recurrences of inflammation, rather than from a single initiating event. Most forms of local therapy provide only transient suppression of inflammation, and the use of systemic agents may be limited by serious side effects. The course of uveitis may, therefore, be marked by recurrent episodes of inflammation, each contributing to progressive and permanent loss of visual acuity. The goal of uveitis treatment should not only be to suppress inflammation when it recurs but also to attain complete remission of inflammation, and thus prevent complications such as cystoid macular edema (CME) and permanent cumulative damage. The RETISERT intravitreal implant offers sustained local control of inflammation without the systemic side effects that limit standard immunosuppressive and oral corticosteroid therapies. The recommendation of the expert panel was that RETISERT is a useful addition to the armamentarium for the treatment of chronic noninfectious posterior segment uveitis and may help to prevent cumulative damage from repeated occurrences of inflammation, especially when vision can be improved rather than only stabilized.

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Jerry Y. Niederkorn

University of Texas Southwestern Medical Center

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David S. Boyer

University of Southern California

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