Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Marcus H. Colyer is active.

Publication


Featured researches published by Marcus H. Colyer.


Ophthalmology | 2008

Combat Ocular Trauma Visual Outcomes during Operations Iraqi and Enduring Freedom

Eric D. Weichel; Marcus H. Colyer; Spencer Ludlow; Kraig S. Bower; Andrew S. Eiseman

OBJECTIVE To report the visual and anatomic outcomes as well as to predict the visual prognosis of combat ocular trauma (COT) during Operations Iraqi and Enduring Freedom. DESIGN Retrospective, noncomparative, interventional, consecutive case series. PARTICIPANTS Five hundred twenty-three consecutive globe or adnexal combat injuries, or both, sustained by 387 United States soldiers treated at Walter Reed Army Medical Center between March 2003 and October 2006. METHODS Two hundred one ocular trauma variables were collected on each injured soldier. Best-corrected visual acuity (BCVA) was categorized using the ocular trauma score (OTS) grading system and was analyzed by comparing initial and 6-month postinjury BCVA. MAIN OUTCOME MEASURES Best-corrected visual acuity, OTS, and globe, oculoplastic, neuro-ophthalmic, and associated nonocular injuries. RESULTS The median age was 25+/-7 years (range, 18-57 years), with the median baseline OTS of 70+/-25 (range, 12-100). The types of COT included closed-globe (n = 234; zone 1+2, n = 103; zone 3, n = 131), open-globe (n = 198; intraocular foreign body, n = 86; perforating, n = 61; penetrating, n = 32; and rupture, n = 19), oculoplastic (n = 324), and neuro-ophthalmic (n = 135) injuries. Globe trauma was present in 432 eyes, with 253 eyes used for visual acuity analysis. Comparing initial versus 6-month BCVA, 42% of eyes achieved a BCVA of 20/40 or better, whereas 32% of eyes had a BCVA of no light perception. Closed-globe injuries accounted for 65% of BCVA of 20/40 or better, whereas 75% of open-globe injuries had a BCVA of 20/200 or worse. The ocular injuries with the worst visual outcomes included choroidal hemorrhage, globe perforation or rupture, retinal detachment, submacular hemorrhage, and traumatic optic neuropathy. Additionally, COT that combined globe injury with oculoplastic or neuro-ophthalmologic injury resulted in the highest risk of final BCVA worse than 20/200 (odds ratio, 11.8; 95% confidence interval, 4.0-34.7; P<0.0005). Nonocular injuries occurred in 85% of cases and included traumatic brain injury (66%) and facial injury (58%). Extremity injuries were 44% (170 of 387 soldiers). Amputation is a subset of extremity injury with 12% (46 of 387) having sustained a severe extremity injury causing amputation. CONCLUSIONS Combat ocular trauma has high rates of nonocular injuries with better visual outcomes in closed-globe compared with open-globe trauma. The OTS is a valid classification scheme for COT and correlates the severity of injury with the final visual acuity and prognosis. Globe combined with oculoplastic or neuroophthalmologic injuries have the worst visual prognosis. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.


Journal of Trauma-injury Infection and Critical Care | 2011

Prevention of infections associated with combat-related extremity injuries

Clinton K. Murray; William T. Obremskey; Joseph R. Hsu; Romney C. Andersen; Jason H. Calhoun; Jon C. Clasper; Timothy J. Whitman; Thomas K. Curry; Mark E. Fleming; Joseph C. Wenke; James R. Ficke; Duane R. Hospenthal; R. Bryan Bell; Leopoldo C. Cancio; John M. Cho; Kevin K. Chung; Marcus H. Colyer; Nicholas G. Conger; George P. Costanzo; Helen K. Crouch; Laurie C. D'Avignon; Warren C. Dorlac; James R. Dunne; Brian J. Eastridge; Michael A. Forgione; Andrew D. Green; Robert G. Hale; David K. Hayes; John B. Holcomb; Kent E. Kester

During combat operations, extremities continue to be the most common sites of injury with associated high rates of infectious complications. Overall, ∼ 15% of patients with extremity injuries develop osteomyelitis, and ∼ 17% of those infections relapse or recur. The bacteria infecting these wounds have included multidrug-resistant bacteria such as Acinetobacter baumannii, Pseudomonas aeruginosa, extended-spectrum β-lactamase-producing Klebsiella species and Escherichia coli, and methicillin-resistant Staphylococcus aureus. The goals of extremity injury care are to prevent infection, promote fracture healing, and restore function. In this review, we use a systematic assessment of military and civilian extremity trauma data to provide evidence-based recommendations for the varying management strategies to care for combat-related extremity injuries to decrease infection rates. We emphasize postinjury antimicrobial therapy, debridement and irrigation, and surgical wound management including addressing ongoing areas of controversy and needed research. In addition, we address adjuvants that are increasingly being examined, including local antimicrobial therapy, flap closure, oxygen therapy, negative pressure wound therapy, and wound effluent characterization. This evidence-based medicine review was produced to support the Guidelines for the Prevention of Infections Associated With Combat-Related Injuries: 2011 Update contained in this supplement of Journal of Trauma.


Ophthalmology | 2008

Perforating Globe Injuries during Operation Iraqi Freedom

Marcus H. Colyer; Dal Chun; Kraig S. Bower; John S.B. Dick; Eric D. Weichel

OBJECTIVE To report the injury patterns associated with perforating (through-and-through) injuries of the globe and the visual impact of these injuries on patients with combat ocular trauma (COT) seen at Walter Reed Army Medical Center (WRAMC) from March 2003 through October 2006. DESIGN Retrospective, noncomparative, interventional case series. PARTICIPANTS Sixty-five eyes of 61 United States military soldiers deployed during Operation Iraqi Freedom sustaining perforating globe injuries and treated subsequently at WRAMC. INTERVENTION Principal procedures included enucleation and 20-gauge 3-port pars plana vitrectomy with or without intraocular foreign body removal. MAIN OUTCOME MEASURES Final visual acuity and rates of proliferative vitreoretinopathy, enucleation, and endophthalmitis. RESULTS Average patient age was 29 years, with an average of 200 days of postinjury follow-up (median, 97 days; range, 4-1023 days). Nineteen patients confirmed the use of eye protection at the time of injury, whereas 25 patients did not use eye protection. The median presenting visual acuity at WRAMC was no light perception (range, no light perception to hand movements). Twenty-five patients underwent primary enucleation, 1 was eviscerated, and 12 patients underwent secondary enucleation within 2 weeks of surgery. Of 19 patients undergoing pars plana vitrectomy, median visual acuity at presentation was light perception and the median final visual acuity was counting fingers, whereas 4 eyes (21%) achieved final visual acuity of better than 20/200, and in 11 (61%) of 17, proliferative vitreoretinopathy developed over a follow-up of at least 6 months. There were no cases of endophthalmitis or sympathetic ophthalmia. Neither mechanism of injury nor timing of surgery correlated with favorable outcomes. However, entry and exit wounds localized to the anterior half of the globe were associated with favorable anatomic outcome (P<0.005, Fisher exact test, 2-tailed) and visual outcome (P = 0.041, Fisher exact test, 2-tailed). CONCLUSIONS Perforating globe injuries associated with COT generally result in poor visual and anatomic outcomes despite surgical intervention. Prophylactic measures, such as eye protection, are helpful in reducing the likelihood of perforating injuries; however, novel surgical and pharmacologic therapies will be required to improve the functional and anatomic outcomes of these devastating injuries.


Eye | 2012

Endophthalmitis following open-globe injuries

Y Ahmed; A M Schimel; Avinash Pathengay; Marcus H. Colyer; Harry W. Flynn

The incidence of traumatic endophthalmitis may be decreasing due to earlier wound closure and prompt initiation of antibiotics. Risk factors for endophthalmitis include retained intraocular foreign body, rural setting of injury, disruption of the crystalline lens, and a delay in primary wound closure. The microbiology in the post-traumatic setting includes a higher frequency of virulent organisms such as Bacillus species. Recognizing early clinical signs of endophthalmitis, including pain, hypopyon, vitritis, or retinal periphlebitis may prompt early treatment with intravitreal antibiotics. Prophylaxis of endophthalmitis in high-risk open-globe injuries may include systemic broad-spectrum antibiotics, topical antibiotics, and intravitreal antibiotics to cover both Gram-positive and Gram-negative bacteria. For clinically diagnosed post-traumatic endophthalmitis, intravitreal vancomycin, and ceftazidime are routinely used. Concurrent retinal detachment with endophthalmitis can be successfully managed with vitrectomy and use of intravitreal antibiotics along with a long acting gas or silicone oil tamponade. Endophthalmitis is a visually significant complication of open-globe injuries but early wound closure as well as comprehensive prophylactic antibiotic treatment at the time of injury repair may improve visual acuity outcomes.


Current Opinion in Ophthalmology | 2008

Current trends in the management of intraocular foreign bodies.

Steven Yeh; Marcus H. Colyer; Eric D. Weichel

Purpose of review The aim of this article is to present the recent literature on the preoperative assessment, intraoperative management and postoperative care of patients with intraocular foreign bodies and present a management algorithm. Recent findings The preoperative assessment includes an evaluation of concomitant, potentially life-threatening conditions, as well as a relevant history and ophthalmic examination. Neuroimaging, preferably with noncontrast helical computed tomography, provides excellent information about intraocular foreign body size, shape and location. The preoperative assessment provides valuable information for prognosis, counseling, and intraoperative guidance. The decision of delayed versus immediate intraocular foreign body removal must be guided by the patients medical status, availability of adequate operating facilities and staff, and the presence of clinical endophthalmitis. The administration of perioperative systemic and topical third or fourth-generation fluoroquinolones may play a role in decreasing the incidence of postoperative endophthalmitis. Intravitreal antibiotics warrant consideration in patients with a Gram stain positive for organisms, in cases suspicious for endophthalmitis, and in high-risk settings. Both the material and size of the foreign body are considerations in the choice of instrument and extraction site used (sclerotomy versus scleral tunnel) at time of pars plana vitrectomy and intraocular foreign body removal. Postoperatively, patients should be monitored closely for the development of endophthalmitis, retinal detachment and proliferative vitreoretinopathy. Summary This review summarizes the recent literature on the assessment of intraocular foreign bodies and techniques for their removal. An algorithm provides guidelines for their perioperative and operative management.


Current Opinion in Ophthalmology | 2008

Combat ocular trauma and systemic injury

Eric D. Weichel; Marcus H. Colyer

Purpose of review To review the recent literature regarding combat ocular trauma during hostilities in Operations Iraqi Freedom and Enduring Freedom, describe the classification of combat ocular trauma, and offer strategies that may assist in the management of eye injuries. Recent findings Several recent publications have highlighted features of combat ocular trauma from Operation Iraqi Freedom. The most common cause of todays combat ocular injuries is unconventional fragmentary munitions causing significant blast injuries. These explosive munitions cause high rates of concomitant nonocular injuries such as traumatic brain injury, amputation, and other organ injuries. The most frequent ocular injuries include open-globe and adnexal lacerations. The extreme severity of combat-related open-globe injuries leads to high rates of primary enucleation and retained intraocular foreign bodies. Visual outcomes of intraocular foreign body injuries are similar to other series despite delayed removal, and no cases of endophthalmitis have occurred. Despite these advances, however, significant vision loss persists in cases of perforating globe injuries as well as open and closed-globe trauma involving the posterior segment. Summary This review summarizes the recent literature describing ocular and systemic injuries sustained during Operations Iraqi and Enduring Freedom. An emphasis on classification of ocular injuries as well as a discussion of main outcome measures and complications is discussed.


Current Opinion in Ophthalmology | 2012

Update on ocular tuberculosis.

Steven Yeh; Hatice Nida Sen; Marcus H. Colyer; Michael Zapor; Keith Wroblewski

Purpose of review Despite recent downtrends, tuberculosis remains a worldwide public health concern. This review provides an update on recent demographic data, clinical and experimental data, and diagnostic modalities. Recent findings Quantitative PCR showing mycobacterial load in intraocular fluids may have an emerging role in the diagnosis of ocular tuberculosis when used in combination with ophthalmic features of tuberculosis. Recent investigations in porcine models of ocular tuberculosis have provided valuable insight into the microbiologic, histologic, and clinical features of Mycobacterium tuberculosis infection of the choroid. Differentiating features between sarcoidosis and tuberculosis include tuberculin skin test status, the presence of ocular surface disease, and the anatomic relationship between vasculitis and choroiditis. Summary The diagnosis of presumed ocular tuberculosis remains a clinical challenge with currently available diagnostic modalities. Although newer interferon-&ggr; release assays can distinguish exposure to M. tuberculosis from the Bacille–Calmette–Guérin vaccine strain, they currently lack the specificity to distinguish between latent tuberculosis infection and active tuberculosis. Continued improvement in the currently available molecular diagnostic techniques including quantitative PCR may be valuable in our ability to establish an earlier etiologic diagnosis and institute appropriate antimycobacterial therapy.


Journal of Trauma-injury Infection and Critical Care | 2011

Infection prevention and control in deployed military medical treatment facilities.

Duane R. Hospenthal; Andrew D. Green; Helen K. Crouch; Judith F. English; Jane Pool; Heather C. Yun; Clinton K. Murray; Romney C. Andersen; R. Bryan Bell; Jason H. Calhoun; Leopoldo C. Cancio; John M. Cho; Kevin K. Chung; Jon C. Clasper; Marcus H. Colyer; Nicholas G. Conger; George P. Costanzo; Thomas K. Curry; Laurie C. D'Avignon; Warren C. Dorlac; James R. Dunne; Brian J. Eastridge; James R. Ficke; Mark E. Fleming; Michael A. Forgione; Robert G. Hale; David K. Hayes; John B. Holcomb; Joseph R. Hsu; Kent E. Kester

Infections have complicated the care of combat casualties throughout history and were at one time considered part of the natural history of combat trauma. Personnel who survived to reach medical care were expected to develop and possibly succumb to infections during their care in military hospitals. Initial care of war wounds continues to focus on rapid surgical care with debridement and irrigation, aimed at preventing local infection and sepsis with bacteria from the environment (e.g., clostridial gangrene) or the casualtys own flora. Over the past 150 years, with the revelation that pathogens can be spread from patient to patient and from healthcare providers to patients (including via unwashed hands of healthcare workers, the hospital environment and fomites), a focus on infection prevention and control aimed at decreasing transmission of pathogens and prevention of these infections has developed. Infections associated with combat-related injuries in the recent operations in Iraq and Afghanistan have predominantly been secondary to multidrug-resistant pathogens, likely acquired within the military healthcare system. These healthcare-associated infections seem to originate throughout the system, from deployed medical treatment facilities through the chain of care outside of the combat zone. Emphasis on infection prevention and control, including hand hygiene, isolation, cohorting, and antibiotic control measures, in deployed medical treatment facilities is essential to reducing these healthcare-associated infections. This review was produced to support the Guidelines for the Prevention of Infections Associated With Combat-Related Injuries: 2011 Update contained in this supplement of Journal of Trauma.


American Journal of Ophthalmology | 2011

Revisiting Diabetes 2000: Challenges in Establishing Nationwide Diabetic Retinopathy Prevention Programs

Ribhi Hazin; Marcus H. Colyer; Flora Lum; Mohammed K. Barazi

PURPOSE To evaluate the impact of the Diabetes 2000 program, an initiative launched by the American Academy of Ophthalmology in 1990 to improve nationwide screening of diabetic retinopathy (DR) and to reduce the prevalence and severity of the condition. DESIGN Retrospective, observational case study of Diabetes 2000 program. METHODS This is a perspective piece with a review of literature and personal opinions. RESULTS Patients with diabetes are likely to see an increase in the disease burdens associated with DR unless effective programs for early detection and control of DR are implemented. CONCLUSIONS Despite recent efforts to educate both patients and physicians alike about the importance of routine DR screening, the lessons learned from the Diabetes 2000 program illustrate the need for new strategies capable of improving accessibility to high-quality eye care, increasing involvement of primary care physicians in DR screening and encouraging at-risk individuals to seek testing.


Retina-the Journal of Retinal and Vitreous Diseases | 2013

Closed globe macular injuries after blasts in combat

Brandon N. Phillips; Dal Chun; Marcus H. Colyer

Purpose: To describe the macular findings after closed globe ocular injuries sustained from blasts. Methods: A retrospective chart review from February 2003 to March 2010 of all soldiers with closed globe ocular injuries sustained during combat with macular findings of trauma on examination was completed. Results: There were 36 eyes that met the inclusion criteria. The mean age of the soldiers was 29.5 years and 97% were men. The average follow-up time was 18.6 months. Improvised explosive device blasts accounted for 86% of injuries. Forty-five percent of soldiers had bilateral ocular injuries. Eight of 36 eyes (22.2%) developed a macular hole. One eye had spontaneous closure and five eyes underwent surgical repair. There was a range of macular findings from retinal pigment epitheliopathy alone to retinal pigment epitheliopathy with full-thickness atrophy. Eight eyes (22.2%) had macular scarring on examination but no optical coherence tomography study. One eye (2.8%) developed phthisis bulbi. Fifteen eyes (42%) had an orbital fracture. Seven eyes (19%) sustained optic neuropathy. Conclusion: Closed globe injuries after blasts resulted in a spectrum of macular findings. The integrity of the foveal inner segment/outer segment junction was the most important retinal factor in visual outcomes. Orbital fractures were not found to be a risk factor for developing optic neuropathy and may improve visual outcomes. The rate of long-term complications is unknown, and it is important for ophthalmologists to follow these patients closely.

Collaboration


Dive into the Marcus H. Colyer's collaboration.

Top Co-Authors

Avatar

Eric D. Weichel

Walter Reed Army Medical Center

View shared research outputs
Top Co-Authors

Avatar

Dal Chun

Walter Reed Army Medical Center

View shared research outputs
Top Co-Authors

Avatar

Kraig S. Bower

Johns Hopkins University

View shared research outputs
Top Co-Authors

Avatar

Denise S. Ryan

Walter Reed Army Medical Center

View shared research outputs
Top Co-Authors

Avatar

Michael J. Mines

Walter Reed Army Medical Center

View shared research outputs
Top Co-Authors

Avatar

Thomas P. Ward

Walter Reed Army Medical Center

View shared research outputs
Top Co-Authors

Avatar

Brian J. Eastridge

University of Texas Health Science Center at San Antonio

View shared research outputs
Top Co-Authors

Avatar

Clinton K. Murray

San Antonio Military Medical Center

View shared research outputs
Top Co-Authors

Avatar

Farhad Safi

Walter Reed Army Medical Center

View shared research outputs
Top Co-Authors

Avatar

James R. Dunne

Walter Reed Army Institute of Research

View shared research outputs
Researchain Logo
Decentralizing Knowledge