Ophthalmologist (eyes)
27 years of experience

Accepting new patients
Texas Retina Associates
801 W Randol Mill Rd
Ste 101
Arlington, TX 76012
Locations and availability (4)

Education ?

Medical School Score Rankings
University of Iowa (1983)
  • Currently 4 of 4 apples
Top 25%

Awards & Distinctions ?

Castle Connolly's Top Doctors™ (2012 - 2013)
Castle Connolly Top Doctors: Texas™ (2009)
American Society of Retina Specialists
American Board of Ophthalmology
The Ocular Immunology Uveitis Foundation
American Academy of Ophthalmology

Affiliations ?

Dr. Callanan is affiliated with 14 hospitals.

Hospital Affilations



  • Medical City Dallas Hospital
    7777 Forest Ln, Dallas, TX 75230
    • Currently 4 of 4 crosses
    Top 25%
  • UT Southwestern University Hospital - St. Paul
    5909 Harry Hines Blvd, Dallas, TX 75235
    • Currently 4 of 4 crosses
    Top 25%
  • Texas Health Harris Methodist Hospital Azle
    108 Denver Trl, Azle, TX 76020
    • Currently 3 of 4 crosses
    Top 50%
  • Texas Health Presbyterian Hospital Of Dallas
  • Parkland Health & Hospital System
  • TX Health Dallas
  • Texas Health Harris Methodist Hospital Southwest Fort Worth
  • Baylor University Medical Center
  • TX Health Arlington
  • Texas Health Arlington Memorial Hospital
  • Texas Health HEB
  • Harris Methodist H E B
  • Harris Methodist - Springwood
    1608 Hospital Pkwy, Bedford, TX 76022
  • Harris Continued Care Hospital
    1301 Pennsylvania Ave, Fort Worth, TX 76104
  • Publications & Research

    Dr. Callanan has contributed to 16 publications.
    Title Diagnosis of Systemic Metastatic Retinal Lymphoma.
    Date April 2011
    Journal Acta Ophthalmologica

    Systemic metastatic retinal lymphoma (SMRL) is exceptionally rare, as systemic lymphomas most often metastasize to the uvea. We have evaluated a series of SMRL cases to elucidate the clinical and pathological features of SMRL.

    Title Characterization of Sterile Intraocular Inflammatory Responses After Intravitreal Bevacizumab Injection.
    Date December 2010
    Journal Retina (philadelphia, Pa.)

    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.

    Title Vitreous Metastases of Primary Cutaneous B-cell Lymphoma.
    Date January 2010
    Journal Ocular Immunology and Inflammation

    To describe two cases of vitreous metastases of primary cutaneous B-cell lymphoma (PCBCL).

    Title Treatment of Posterior Uveitis with a Fluocinolone Acetonide Implant: Three-year Clinical Trial Results.
    Date September 2008
    Journal Archives of Ophthalmology

    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.

    Title Intraocular Pressure in Patients with Uveitis Treated with Fluocinolone Acetonide Implants.
    Date December 2007
    Journal Archives of Ophthalmology

    OBJECTIVE: To report the incidence and management of elevated intraocular pressure (IOP) in patients with uveitis treated with the fluocinolone acetonide (FA) intravitreal implant. DESIGN: Pooled data from 3 multicenter, double-masked, randomized, controlled, phase 2b/3 clinical trials evaluating the safety and efficacy of the 0.59-mg or 2.1-mg FA intravitreal implant or standard therapy were analyzed. RESULTS: During the 3-year follow-up, 71.0% of implanted eyes had an IOP increase of 10 mm Hg or more than baseline and 55.1%, 24.7%, and 6.2% of eyes reached an IOP of 30 mm Hg or more, 40 mm Hg or more, and 50 mm Hg or more, respectively. Topical IOP-lowering medication was administered in 74.8% of implanted eyes, and IOP-lowering surgeries, most of which were trabeculectomies (76.2%), were performed on 36.6% of implanted eyes. Intraocular pressure-lowering surgeries were considered a success (postoperative IOP of 6-21 mm Hg with or without additional IOP-lowering medication) in 85.1% of eyes at 1 year. The rate of hypotony (IOP </= 5 mm Hg) following IOP-lowering surgery (42.5%) was not different from that of implanted eyes not subjected to surgery (35.4%) (P = .09). CONCLUSION: Elevated IOP is a significant complication with the FA intravitreal implant but may be controlled with medication and surgery.

    Title Comparison of the Modified Early Treatment Diabetic Retinopathy Study and Mild Macular Grid Laser Photocoagulation Strategies for Diabetic Macular Edema.
    Date May 2007
    Journal Archives of Ophthalmology

    OBJECTIVE: To compare 2 laser photocoagulation techniques for treatment of diabetic macular edema: the modified Early Treatment Diabetic Retinopathy Study (ETDRS) direct/grid photocoagulation technique and a potentially milder (but potentially more extensive) mild macular grid (MMG) laser technique in which microaneurysms are not treated directly and small mild burns are placed throughout the macula, whether or not edema is present. METHODS: Two hundred sixty-three subjects (mean age, 59 years) with previously untreated diabetic macular edema were randomly assigned to receive laser photocoagulation by either the modified ETDRS (162 eyes) or MMG (161 eyes) technique. Visual acuity, fundus photographs, and optical coherence tomography measurements were obtained at baseline and at 3.5, 8, and 12 months. Treatment was repeated if diabetic macular edema persisted. MAIN OUTCOME MEASURE: Change in optical coherence tomography measurements at 12-month follow-up. RESULTS: Among eyes with a baseline central subfield thickness of 250 microm or greater, central subfield thickening decreased by an average of 88 microm in the modified ETDRS group and by 49 microm in the MMG group at 12-month follow-up (adjusted mean difference, 33 microm; 95% confidence interval, 5-61 microm; P = .02). Weighted inner zone thickening by optical coherence tomography decreased by 42 microm in the modified ETDRS group and by 28 microm in the MMG group (adjusted mean difference, 14 microm; 95% confidence interval, 1-27 microm; P = .04); maximum retinal thickening (maximum thickening of the central and 4 inner subfields) decreased by 66 and 39 microm, respectively (adjusted mean difference, 27 microm; 95% confidence interval, 6-47 microm; P = .01), and retinal volume decreased by 0.8 and 0.4 mm3, respectively (adjusted mean difference, 0.3 mm3; 95% confidence interval, 0.02-0.53 mm3; P = .03). At 12 months, the mean change in visual acuity was 0 letters in the modified ETDRS group and 2 letters worse in the MMG group (adjusted mean difference, 2 letters; 95% confidence interval, -0.5 to 5 letters; P = .10). CONCLUSIONS: At 12 months after treatment, the MMG technique was less effective at reducing optical coherence tomography-measured retinal thickening than the more extensively evaluated current modified ETDRS laser photocoagulation approach. However, the visual acuity outcome with both approaches is not substantially different. Given these findings, a larger long-term trial of the MMG technique is not justified. APPLICATION TO CLINICAL PRACTICE: Modified ETDRS focal photocoagulation should continue to be a standard approach for treating diabetic macular edema. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00071773.

    Title The White Dot Syndromes.
    Date April 2004
    Journal American Journal of Ophthalmology

    PURPOSE: To review the distinctive and shared features of the white dot syndromes, highlighting the clinical findings, diagnostic test results, proposed etiologies, treatments, and prognosis. DESIGN: Review. METHODS: Review of the literature. RESULTS: Common white dot syndromes are reviewed, including acute posterior multifocal placoid pigment epitheliopathy, birdshot chorioretinopathy, diffuse unilateral subacute neuroretinitis, multiple evanescent white dot syndrome, multifocal choroiditis with panuveitis, serpiginous choroiditis, and acute zonal occult outer retinopathy. CONCLUSIONS: The white dot syndromes are a group of disorders characterized by multiple whitish-yellow inflammatory lesions located at the level of the outer retina, retinal pigment epithelium, and choroid. For clinicians and researchers alike, they present significant diagnostic and therapeutic challenges.

    Title Propionibacterium Acnes Endophthalmitis Diagnosed by Microdissection and Pcr.
    Date October 2003
    Journal The British Journal of Ophthalmology
    Title Cat Scratch Disease: Posterior Segment Manifestations.
    Date August 1999
    Journal Ophthalmology

    OBJECTIVE: To evaluate the posterior segment findings seen in ocular cat scratch disease. DESIGN: Retrospective case series. PARTICIPANTS: There were 24 patients (35 eyes) with choroidal, retinal, or optic disc manifestations of Bartonella infection evaluated at the authors' institutions over a 6-year period. MAIN OUTCOME MEASURES: Clinical and photographic records were reviewed for evidence of disc edema, macular star, foci of retinitis or choroiditis, choroidal masses, optic nerve masses, vascular-occlusive events, or other findings. RESULTS: Discrete white retinal or choroidal lesions, 50 to 3000 microm in diameter, were the most common posterior segment findings in this series of patients (83% of eyes, 83% of patients). Optic disc swelling was the second most common finding (46% of eyes, 63% of patients) followed by a macular star (43% of eyes, 63% of patients). Vascular-occlusive events were also seen (14% of eyes, 21% of patients), and the site of occlusion was found to be intimately associated with the aforementioned retinal lesions. Final visual acuity was 20/25 or better in 26 (74%) of 35 eyes and was similar in both treated and untreated patients. CONCLUSION: Isolated foci of retinitis or choroiditis were the most common ocular manifestation of cat scratch disease in the authors' patient population, but an array of posterior segment findings may occur.

    Title Diagnosis of Reactive Lymphoid Hyperplasia by Chorioretinal Biopsy.
    Date November 1994
    Journal American Journal of Ophthalmology

    We treated a patient with reactive lymphoid hyperplasia in whom the diagnosis was made by chorioretinal biopsy. Histopathologic examination and culture of the biopsied specimen allowed us to rule out a neoplastic or infectious process. The biopsy result allowed us to treat him with systemic corticosteroid alone, thus avoiding the potential harmful side effects of other medications, including antituberculous drugs. There were no surgical or postoperative complications. This study confirms the usefulness of chorioretinal biopsy for establishing a diagnosis and formulating a rational treatment plan.

    Title Accidental Skin Punctures During Ophthalmic Surgery.
    Date January 1994
    Journal Ophthalmology

    PURPOSE: Accidental skin puncture carries the risk of both hepatitis B and human immunodeficiency virus transmission. There have been studies of the incidence of these skin punctures in general surgery, but no study has focused on ophthalmic surgery. METHOD: All incident reports of skin punctures in the Bascom Palmer Eye Institute operating rooms from January 1990 through November 1991 were reviewed retrospectively. The incidence of skin puncture also was studied propsectively from December 1991 through May 1992. During the prospective phase, the healthcare worker was asked to complete an anonymous form regarding the instrument involved, whether it was clean or contaminated, the persons involved, and whether the room lights were on or off. RESULTS: There were 37 such occurrences in 14,878 operations (0.25%) during the retrospective study and 12 in 4246 operations (0.28%) in the prospective period. In only one case was the instrument contaminated by contact with a patient known to have positive serology for the human immunodeficiency virus. There were no documented seroconversions of healthcare personnel for either hepatitis B or human immunodeficiency virus. In 63% of these occurrences, the penetrating instrument was known to be definitely contaminated with the patient's blood. Only one person was handling the instrument 84% of the time. CONCLUSION: The low but present danger to ophthalmic personnel during surgical procedures justifies precautions to decrease the occurrence of skin punctures.

    Title Choroidal Neovascularization Associated with Choroidal Nevi.
    Date July 1993
    Journal Archives of Ophthalmology

    OBJECTIVE--We undertook a retrospective study of all choroidal nevi with overlying neovascularization seen at Bascom Palmer Eye Institute, Miami, Fla, to determine long-term effects on vision and whether the presence of neovascularization represented increased malignant potential of the lesion. DESIGN--A computer search of patients with a coded diagnosis of both a choroidal nevus and choroidal neovascularization was performed. Cases in which the neovascularization was directly overlying the nevus were used for the study. RESULTS--The records of 23 patients followed up for a mean of 6.5 years were reviewed for visual acuity, effect of treatment, and change in the size of the choroidal lesion. Fifteen of the 23 patients had a final visual acuity in the affected eye of 20/200 or better. Five of six patients treated with laser had visual improvement of 2 or more lines. Only one of these lesions showed any growth, and this was after 17 years of no growth. CONCLUSIONS--Choroidal neovascularization associated with choroidal nevi can have profound effects on vision. Laser treatment, when indicated, is effective and may be safely performed. The clinical course of these lesions, to date, does not indicate any clinically significant malignant transformation.

    Title Oral Therapy in Diffuse Unilateral Subacute Neuroretinitis.
    Date June 1992
    Journal Archives of Ophthalmology

    Diffuse unilateral subacute neuroretinitis is an endemic disease associated with severe visual loss in the southeastern and midwestern United States and the Caribbean. It is caused by a single nematode that may wander in the subretinal space for many months or years. Until recently, the only effective treatment has involved the difficult and time-consuming biomicroscopic detection of the worm followed by photocoagulation. This report describes the use of oral thiabendazole in four patients with presumed diffuse, unilateral, subacute neuroretinitis. Serial fundus photography was used to detect evidence of early destruction of the worm.

    Title Successful Oral Therapy for Diffuse Unilateral Subacute Neuroretinitis.
    Date May 1992
    Journal Transactions of the American Ophthalmological Society
    Title Histopathology of Rejected Orthotopic Corneal Grafts in the Rat.
    Date May 1989
    Journal Investigative Ophthalmology & Visual Science

    We have used an orthotopic graft model in the rat to study the histologic characteristics of corneal allograft rejection. Unrejected allogeneic grafts could not be distinguished from clear syngeneic grafts. Although donor Langerhans cells are necessary for the development of delayed-type hypersensitivity (DTH), the histopathological characteristics of rejecting corneal allografts in immunologically naive hosts were identical regardless of the presence or absence of donor Langerhans cells. By contrast, preimmunization had a dramatic effect on the histology of graft rejection. Untreated allografts placed onto pre-immunized recipients underwent a marked cellular necrosis accompanied by minimal inflammation that easily distinguished these grafts from the previous groups. These results suggest that neither the presence nor absence of DTH responsiveness correlates with the histopathological events that accompany corneal graft rejection. However, preimmunization leads to a different histologic pattern of rejection that is characterized by an intense cellular necrosis.

    Title Presentation of the H-y Antigen on Langerhans' Cell-negative Corneal Grafts Downregulates the Cytotoxic T Cell Response and Converts Responder Strain Mice into Phenotypic Nonresponders.
    Date December 1988
    Journal The Journal of Experimental Medicine

    We have used the murine cornea is an allograft model to investigate the relative roles of graft-derived IA+ APC (Langerhans' cells) and host-derived APC during the induction of CTL responses to H-Y. The natural exclusion of LC from the immunizing corneal graft led to a specific state of unresponsiveness to H-Y in responder strain mice, while inclusion of LC resulted in responsiveness. Failure to respond to H-Y could not be attributed to the absence of H-Y or IA antigen expression on the surface of LC-deficient grafts but instead, appeared to be due to active suppression of the T helper cell response during in vivo priming. Reprocessing of the H-Y antigen by host APC did not occur after immunization with H-Y presented on H-2-incompatible grafts unless presented initially by graft-derived LC. H-2 as well as some non-H-2 alloantigens were presented to the host without a requirement for donor-derived LC. Thus there appear to be differential requirements for the processing and presentation of alloantigens.

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