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  • research
    & expertise.

Dr. Ells has presented her research and expertise at over 100 scientific meetings, symposiums and conferences. She also has over 50 peer reviewed publications and book chapters.


Current research interests include:

  • Telemedicine approaches to Retinopathy of Prematurity Management
  • Longitudinal Characteristics of Retinopathy and Long Term Outcomes
  • Laser Treatment Options and Outcomes for Pediatric Retinal Diseases
  • Safety Profile of Intravitreal treatments for Age Related Macular Degeneration and Retinopathy of Prematurity
  • Photographic Screening and Digital Imaging for Retinopathy of Prematurity
  • Shaken Baby Syndrome
  • Phenotype-genotype association in autosomal dominant familial exudative vitreoretinopathy (FEVR)and retinopathy of prematurity (ROP) caused by Frizzled-4 (FZD4) gene mutations
  • Childhood Retinal Disease

Key Research Highlights and Publications

International Classification of Retinopathy of Prematurity Symposium

Dr Ells was initiator, primary organizer and co-chair for the International Classification Symposium for Retinopathy of Prematurity which was held in Canmore, Alberta, Canada. September 14, 15, 2002. This was the first classification symposium in the last 20 years. International Classification of Retinopathy of Prematurity- Revisited. Prepared by the ad hoc committee for ROP classification. Archives of Ophthalmology; Vol 123, July 2005; pg 991-999. http://archopht.ama-assn.org/cgi/content/full/123/7/991

ROP – The Movie

In 2004 Dr. Ells and Leslie MacKeen presented the first series of longitudinal digital images of retinopathy of prematurity in a movie format at the American Association of Pediatric Ophthalmology and Strabismus. Additional videos were produced in 2008. These have served as a valuable teaching tool around the world, illustrating the dynamic documentation of the evolution of retinopathy of prematurity in video format. Journal of American Association of Pediatric Ophthalmology and Strabismus. Vol 8/4. pp 389. August 2004.

Telemedicine Approach to Screening for Severe Retinopathy of Prematurity – A Pilot Study

Dr. Ells and colleagues evaluated the use of remote reading of digital retinal photographs in the diagnosis of severe (referral-warranted) ROP. They found that longitudinal remote reading of digital photographs using the RetCam-120 system has excellent specificity and sensitivity in detecting referral-warranted ROP.

This pilot study has shown that remote reading of digital photographs has promise for telemedicine strategies in ROP screening. Ophthalmol. Vol 110, No 11, pp 2113-2117, November 2003.

Severe Retinopathy of Prematurity; Longitudinal Observation of Disease and Screening Implications

Dr. Ells worked with colleagues to test the effectiveness of ROP screening guidelines as applied to high-risk premature infants. British Ophthalmology Journal “Eye”. 2005 Feb;19(2):138-44.

Guidelines for Screening Examinations for Retinopathy of Prematurity

Dr. Ells chaired a committee of Canadian ophthalmologists with an interest and expertise in ROP to provide standardized screening guidelines which were further recommended by The Canadian Ophthalmological Society, the Canadian Association of Pediatric Ophthalmologists and the Canadian Paediatric Society. Canadian Journal of Ophthalmology, Vol. 35, No. 5, pp 252, 2000.

Canadian Ophthalmological Society

Canadian Ophthalmological Society evidence-based clinical practice guidelines for the periodic eye examination in adults in Canada. Dr. Ells was a member of the Clinical Practice Guideline Expert Committee. Can J Ophthalmol; Vol. 42, No. I, 2007. pg 39-45.

Full List of Publications

  • Pseudohypopyon in Acute Myeologenous Leukemia. A.Ells; W.N. Clarke; L.P Noel. Journal of Pediatric Ophthalmology & Strabismus, Vol 32, No. 2, March/April 1995.
  • Vicryl-mesh Wrap for the Implantation of Hydroxyapatite Orbital Implant: An Animal Model. D. Jordan; A. Ells; S. Brownstein; S. Munro; S. Grahovac; F. Raymond; S. Gilberg; L. Allen. Canadian Journal of Ophthalmology, Vol. 30, No. 5, 1995.
  • The Use of Vicryl-mesh (polyglactin – 910) for Implantation of Hydroxyapatite Orbital Implants. D. Jordan; L.H. Allen; A. Ells; S. Gilberg; S. Brownstein; S. Munro; S. Grahovac; F. Raymond. Ophthalmic Plastic and Reconstructive Surgery, Vol. II, No. 2, pp 95-99, 1995.
  • The Pediatric Eye Disease Investigator Group (PEDIG). Beck RW. American Association of Pediatric Ophthalmology and Strabismus, Vol. 2, pp 255-256, 1998.
  • Guidelines for Screening Examinations for Retinopathy of Prematurity. Ells, Chair;
  • W. Hindle; P. Harvey; C. Lyons; P. Shuckett; J. Little; R. Laroche; J. Robitaille; J. White; M. Vincer. Canadian Journal of Ophthalmology, Vol. 35, No. 5, pp 252, 2000.
  • Commentary for Screening Guidelines for Retinopathy of Prematurity. A. Ells, N.W. Hindle. Canadian Journal of Ophthalmology, Vol. 35, No. 5, pp 253, 2000.
  • Ligneous Conjunctivitis – A Case Report and Literature Review. E. Martinovic; A. Ells. Canadian Journal of Ophthalmology, Vol. 36, No. 3, pp 147-149, April 2001.
  • The Amblyopia Treatment Index. S. Cole, PhD, R. Beck, MD, PhD, P. Mike, MSPH, M. Celano, PhD, C. Drews, PhD, M. Repka, MD, J. Holmes, BM, BCh, E. Birch, PhD, R. Kraker, MSPH, K. Kip, PhD, and the Pediatric Eye Disease Investigator Group (PEDIG). Journal of American Association of Pediatric Ophthalmology and Strabismus, Vol. 5, No. 5, pp. 250-254, August 2001.
  • Product Review- Introduction to a New Digital Retinal Camera System for the Management of Retinopathy of Prematurity, M. Fielden.BSc. , A. Ells, MD, Neonatal Intensive Care. The Journal Of Perinatology- Neonatology. Vol. 14, No. 5, pp 62-66, September 2001. (non-peer reviewed)
  • Retinopathy of Prematurity Screening via Telemedicine- A. Ells. Published in the Alberta Medical Association publication- The Alberta Doctors’ Digest. Vol. 26, Number 6,pp 27-28, November/December 2001. (non-peer reviewed)
  • A Randomized Trial of Atropine vs Patching for Treatment of Moderate Amblyopia in Children. The Pediatric Eye Disease Investigator Group. Arch of Ophthalmol, Vol 120, pp 268-277, March 2002.
  • The Clinical Profile of Moderate Amblyopia in Children Younger Than 7 Years. The Pediatric Eye Disease Investigator Group. Arch of Ophthalmol, Vol 120, pp 281-287, March 2002.
  • Effective Treatment of Ligneous Conjunctivitis with Topical Plasminogen. P. Watts, MD; P. Suresh, MD; E. Mezer, MD; A. Ells, MD; M. Albisetti, MD; L. Bajzar, PhD; V. Marzinotto, RN, M. Andrew, MD; D. Rootman, MD. Am J Ophthalmol, Vol. 133, No. 4, pp 451-455, April 2002.
  • Photorefractive Keratectomy (PRK) Laser in Children. W. Astle, MD; P. Huang, MD; A. Ells, MD; R. Cox, MD; H. Vibert OC(C). J Cataract Refract Surg, Vol 28, pp 932-941, June 2002.
  • Hyperbaric Oxygen Therapy in the Treatment of Orbital Gas Gangrene. M. Fielden, BSc; E. Marinovic, MD; A. Ells, MD; Journal of American Academy of Pediatric Ophthalmology and Strabismus, Vol 6, No. 4, pp 252-254, August 2002.
  • Clinical Research in Pediatric Opthalmology: The Pediatric Eye Disease Investigator Group. Curr Opinion Ophthalmol, Vol 13, pp 337-349, 2002.
  • Regression of Severe Retinopathy of Prematurity Post-Laser Treatment. A. Ells, MD; B. Uphill, BFA, OA; M. Fielden, BSC. Arch Ophthalmol, Vol 120, No 10, pp 1404-1405, October 2002.
  • Hydroxyapatite Orbital Implant Vascularization Assessed by Magnetic Resonance Imaging. S. Klapper, MD, D.R. Jordan, MD, A. Ells, MD, S. Grahovac, MD. Ophthalmic Plastic and Reconstructive Surgery. Vol. 19, No. 1, pp 46-52, Jan, 2003.
  • A Randomized Trial of Patching Regimens for Treatment of Moderate Amblyopia in Children. The Pediatric Eye Disease Investigator Group. Arch Ophthalmol, Vol 121, pp 603-611, May 2003.
  • Epiretinal Membrane Formation in Shaken Baby Syndrome. A. Ells, MD, D. Lee, MSC; A. Kherani. J AAPOS, Vol 7, No 3, pp 223-225, June 2003.
  • A Comparison of Atropine and Patching Treatments for Moderate Amblyopia by Patient Age, Cause of Amblyopia, Depth of Amblyopia, and Other Factors. The Pediatric Eye Disease Investigator Group, Ophthalmol. Vol 110, No 8, pp 1632-7, August 2003.
  • Congenital Absence of the Inferior Rectus Muscle- Diagnosis and Management. W.F. Astle, V. Hill, A. Ells, N.T. Thanh, E. Martinovic. Journal of AAPOS: Vol 7:5, pp 339-344, October 2003.
  • Bilateral Peri-Optic Nerve Lesions in a Patient with Langerhans’ Cell Histiocytosis. V. Yuen, D.R. Jordan, S. Brownstein, M. Dorey, J.E.A. Wolff, A. Ells, M.E. Ashenhurst, R.M. Egeler. Can J Ophthalmol, Vol. 38, No. 6, pp 496-500, November 2003.
  • Telemedicine Approach to Screening for Severe Retinopathy of Prematurity- A Pilot Study. Anna Ells, Jonathan Holmes, William Astle, Geoff Williams David Leske, Michael Fielden, Brad Uphill, Penny Jennett, Marilynne Hebert. Ophthalmol. Vol 110, No 11, pp 2113-2117, November 2003.
  • A Randomized Trial of Prescribed Patching Regimens for Treatment of Severe Amblyopia in Children. The Pediatric Eye Disease Investigator Group. Am Academy of Ophthalmol. Vol 110, No 11, pp2075-2087, November 2003.
  • Impact of Patching and Atropine Treatment on the Child and Family in the Amblyopia Treatment Study. The Pediatric Eye Disease Investigator Group. Arch Ophthalmol.Vol 121, No 11, pp 1625-1632, November 2003.
  • An ROP Masquerader- Congenital Vascular Tortuosity in DiGeorges Syndrome Mimicking Significant Retinopathy of Prematurity. V. Hill, MD, S. Pietucha, BSc., A. Ells, MD. Arch Ophthalmol. 2004 Jan;122(1):132-3.
  • Severe Retinopathy of Prematurity; Longitudinal Observation of Disease and Screening Implications. A. Ells, M. Hicks, M. Fielden, A. Ingram. British Ophthalmology Journal “Eye”. 2005 Feb;19(2):138-44.
  • ROP- The Movie. A. Ells and L. MacKeen. Journal of American Association of Pediatric Ophthalmology and Strabismus. Vol 8/4. pp 389. August 2004.
  • Suspected Child Abuse Victims- Letter to the Editor. Alex Levin, Anna Ells and Susan Schloff. Ophthalmology; Vol 111, No 9, September, 2004; pg 1794-95.
  • Two-Year Follow-up of a 6-Month Randomized Trial of Atropine vs Patching for Treatment of Moderate Amblyopia in Children. The Pediatric Eye Disease Investigator Group. Arch Ophthalmol 2005; 123:149-157.
  • International Classification of Retinopathy of Prematurity- Revisited. Prepared by the ad hoc committee for ROP classification. Archives of Ophthalmology; Vol 123, July 2005; pg 991-999. Drs. Ells and Quinn are co-chairs.
  • The Photographic Screening for Retinopathy of Prematurity Study (Photo-ROP): Study Design and Baseline Characteristics of Enrolled Patients. Photo-ROP Cooperative Group. Retina. 2006. Sep;26(7 Supp).
  • Standard image of plus disease in retinopathy of prematurity. Capone A Jr, Ells AL, Fielder AR, Flynn JT, Gole GA, Good WV, Holmes JM, Holmstrom G, Katz X, McNamara JA, Palmer EA, Quinn GE, Shapiro M, Trese MG, Wallace DK. Arch Ophthalmol. 2006 Nov; 124(11):1669-70.
  • Internet-based eye care. Fielder AR, Gilbert C, Ells A, Quinn GE. Lancet. 2006 Jan 28;367(9507):300-1.
  • Canadian Ophthalmological Society evidence-based clinical practice guidelines for the periodic eye examination in adults in Canada. Clinical Practice Guideline Expert Committee. A. Ells member of this committee. Can J Ophthalmol; Vol. 42, No. I, 2007. pg 39-45.
  • Severe Retinal Injuries from Paintball Projectiles. J. Baath, A. Ells, A. Kherani, R.G. Williams. Canadian Journal of Ophthalmology- Vol 42. NO. 4.2007.
  • Fluorescein angiographic findings in an infant male with Incontinentia Pigmenti treated with laser photocoagulation. G. Devitten, A. Ells. Journal of American Association of Pediatric Ophthalmologists and Strabismus. 2007 Oct;11(5):511-2.
  • Safety Profile of Intravitreal Triamcinolone Acetonide A.L. Ells, J. Baath, A. Crichton, A. Kherani, R.G. Williams. Journal of Ocular Pharmacology and Therapeutics. 2007 Jun;23(3):304-10.
  • Evolution of retinal detachment in posterior retinopathy of prematurity: impact on treatment approach. A. Vinekar, M. Trese, A. Capone Jr, A. Ells, G. Hubbard, M. Hartnett, M. O'Keefe, S. Schwartz, C. Gonzales , A. Fielder , K. Cocker for Photographic Screening for Retinopathy of Prematurity (PHOTO-ROP) Cooperative Group. Am J Ophthalmol. 2008 Mar; 145(3):548-555.
  • The Photographic Screening for Retinopathy of Prematurity Study (Photo-ROP): Primary Outcomes. The Photographic Screening for Retinopathy of Prematurity Cooperative Group. A. Ells one of the primary authors. Retina: 28: S47–S54, 2008
  • Computerized Analysis of Retinal Vessel Width and Tortuosity in Premature Infants C. Wilson, KD Cocker, MJ Moseley, AG Smith, AL Ells, GE Quinn, AR Fielder- The Plus Disease Collaborative Group. Invest Ophthalmol Vis Sci. 2008 Aug;49(8):3577-85.
  • Dynamic documentation of the evolution of retinopathy of prematurity in video format. A Ells and Leslie MacKeen. J AAPOS. 2008 Aug: 12(4):349-351.
  • Telemedicine screening for retinopathy of prematurity in developing countries using digital retinal images: a feasibility project. Skalet AH, Quinn GE, Ying GS, Gordillo L, Dodobara L, Cocker K, Fielder AR, Ells AL, Mills MD, Wilson C, Gilbert C. J AAPOS. 2008 Jun;12(3):252-8.
  • Systematic review of digital imaging screening strategies for retinopathy of prematurity. Fielder AR, Hildebrand PL, Ells A, Lorenz B, Trese MT, Capone A Jr, Gordon RA, Wilson C, Fleck BW, Chiang MF. Pediatrics. 2009 Feb;123(2):e360-1.
  • Detection of the Optic Nerve Head in Fundus Images of the Retina Using the Hough Transform for Circles. X. Zhu, R.M. Rangayyan, A. L. Ells. Journal of Digital Imaging, Journal of Digital Imaging, Vol 23, No 3 (June), 2010: pp 332-341.
  • Promise and potential pitfalls of anti-VEGF drugs in retinopathy of prematurity. Darlow BA, Gilbert C, Quinn GE, Azad R, Ells AL, Fielder A, Zin A. Br J Ophthalmol. 2009 Jul;93(7):986.
  • Severe retinopathy of prematurity associated with FZD4 mutations. Ells A, Guernsey DL, Wallace K, Zheng B, Vincer M, Allen A, Ingram A, Dasilva O, Siebert L, Sheidow T, Beis J, Robitaille JM. Ophthalmic Genet. 2010 Mar; 31(1):37-43.
  • Detection of the Optic Nerve Head in Fundus Images of the Retina with Gabor Filters and Phase Portrait Analysis. R.M. Rangayyan, X. Zhu1, F.J. Ayres, A. L. Ells. J Digit Imaging. 2010 Aug;23(4):438-53.
  • Plus Disease: Why is it Important in Retinopathy of Prematurity? C. Solarte, A.H. Awad, C. M. Wilson, A. Ells. Middle East African Journal of Ophthalmology, Volume 17, Number 2, April - June 2010, pp 148-155.
  • The temporal and nasal retinal arteriolar and venular angles in preterm infants. Wong K, Ng J, Ells A, Fielder AR, Wilson CM. British Journal of Ophthalmology. 2011, 95 (12):1723-7.
  • Bevacizumab for retinopathy of prematurity. Gole GA, Camuglia JE, Ells AL. New England Journal of Medicine. 2011. 364(24): 2360-1.
  • Are we there yet? Bevacizumab therapy for retinopathy of prematurity. Darlow BA, Ells AL, Gilbert CE, Gole GA, Quinn GE. Arch Dis Child Fetal Neonatal Ed. 2011 Dec 30.
  • Digital image analysis in retinopathy of prematurity: A comparison of vessel selection methods. Wilson CM, Wong K, Ng J, Cocker KD, Ells AL, Fielder AR. J AAPOS 2012;16:223-228.
  • Posterior Laser Treatment for Severe Stage 3 Retinopathy of Prematurity. AL. Ells, GA. Gole, PL. Hildebrand, AD. Ingram, CM. Wilson, RG. Williams. Eye. 2013; 1:1-3.

BOOKS & BOOK CHAPTER

  • Digital Image Processing for Ophthalmology: Detection of the Optic Nerve Head. X. Zhu, R.M. Rangayyan, and A.L. Ells, Morgan & Claypool. 2011. 106 pages. ISBN: 9781608456314 paperback. ISBN: 9781608456321 ebook
  • Evidence-Based Eye Care. Kertes and Johnson. Book Chapter- Retinopathy of Prematurity. A. Ells. Published by Lippincott Williams & Wilkins. 2007. Pages 235-249.