• Oct 2014
    AAO Cornea/External Disease PPP Panel, Hoskins Center for Quality Eye Care
    Cornea/External Disease


    These are summary benchmarks for the Academy’s Preferred Practice Patterns® (PPP) guidelines. The Preferred Practice Patterns series of guidelines has been written on the basis of three principles.

    • Each Preferred Practice Pattern should be clinically relevant and specific enough to provide useful information to practitioners.
    • Each recommendation that is made should be given an explicit rating that shows its importance to the care process.
    • Each recommendation should also be given an explicit rating that shows the strength of evidence that supports the recommendation and reflects the best evidence available.

    Preferred Practice Patterns provide guidance for the pattern of practice, not for the care of a particular individual. While they should generally meet the needs of most patients, they cannot possibly best meet the needs of all patients. Adherence to these Preferred Practice Patterns will not ensure a successful outcome in every situation. These practice patterns should not be deemed inclusive of all proper methods of care or exclusive of other methods of care reasonably directed at obtaining the best results. It may be necessary to approach different patients' needs in different ways. They physician must make the ultimate judgment about the propriety of the care of a particular patient in light of all of the circumstances presented by that patient. The American Academy of Ophthalmology is available to assist members in resolving ethical dilemmas that arise in the course of ophthalmic practice.

    The Preferred Practice Pattern® guidelines are not medical standards to be adhered to in all individual situations. The Academy specifically disclaims any and all liability for injury or other damages of any kind, from negligence or otherwise, for any and all claims that may arise out of the use of any recommendations or other information contained herein.

    For each major disease condition, recommendations for the process of care, including the history, physical exam and ancillary tests, are summarized, along with major recommendations for the care management, follow-up, and education of the patient. For each PPP, a detailed literature search of PubMed and the Cochrane Library for articles in the English language is conducted. The results are reviewed by an expert panel and used to prepare the recommendations, which they rated in two ways.

    The panel first rated each recommendation according to its importance to the care process. This “importance to the care process” rating represents care that the panel thought would improve the quality of the patient’s care in a meaningful way. The ratings of importance are divided into three levels.

    • Level A, defined as most important
    • Level B, defined as moderately important
    • Level C, defined as relevant but not critical

    The panel also rated each recommendation on the strength of evidence in the available literature to support the recommendation made. The “ratings of strength of evidence” also are divided into three levels.

    • Level I includes evidence obtained from at least one properly conducted, well-designed randomized controlled trial. It could include meta-analyses of randomized controlled trials.
    • Level II includes evidence obtained from the following:
      • Well-designed controlled trials without randomization
      • Well-designed cohort or case-control analytic studies, preferably from more than one center
      • Multiple-time series with or without the intervention
    • Level III includes evidence obtained from one of the following:
      • Descriptive studies
      • Case reports
      • Reports of expert committees/organizations (e.g., PPP panel consensus with external peer review) 

    PPPs are intended to serve as guides in patient care, with greatest emphasis on technical aspects. In applying this knowledge, it is essential to recognize that true medical excellence is achieved only when skills are applied in a such a manner that the patients’ needs are the foremost consideration. The AAO is available to assist members in resolving ethical dilemmas that arise in the course of practice. (AAO Code of Ethics)

    Initial and Follow-up Evaluation

    Initial Exam History

    • Ocular symptoms and signs (e.g., redness, irritation, burning, tearing, itching, crusting of eyelashes, eyelid sticking, contact lens intolerance, photophobia, increased frequency of blinking
    • Time of day when symptoms are worse
    • Duration of symptoms
    • Unilateral or bilateral presentation
    • Exacerbating conditions (e.g., smoke, allergens, wind, contact lenses, low humidity, retinoids, diet and alcohol consumption, eye makeup)
    • Symptoms related to systemic diseases (e.g., rosacea, allergy) 
    • Current and previous systemic and topical medications (e.g., antihistamines or drugs with anticholinergic effects, or drugs used in the past that might have an effect on the ocular surface [e.g., isotretinoin])
    • Recent exposure to an infected individual (e.g., pediculosis, palpebrarum [Pthirus pubis]
    • Ocular history (e.g., previous intraocular and eyelid surgery, local trauma, including mechanical, thermal, chemical, and radiation injury, history of cosmetic blepharoplasty, history of styes and/or chalazia)

    Initial Physical Exam

    • Visual acuity
    •  External examination
      • Skin
      • Eyelids
    • Slit-lamp biomicroscopy
      • Tear film
      • Anterior eyelid margin
      • Eyelashes
      • Posterior eyelid margin
      • Tarsal conjunctiva (everting eyelids)
      • Bulbar conjunctiva
      • Cornea

    Diagnostic Tests

    • Cultures may be indicated for patients with recurrent anterior blepharitis with severe inflammation as well as for patients who are not responding to therapy
    • Biopsy of the eyelid to exclude the possibility of carcinoma may be indicated in cases of marked asymmetry, resistance to therapy or unifocal recurrent chalazia that do not respond well to therapy
    • Consult with the pathologist prior to obtaining the biopsy if sebaceous cell carcinoma is suspected

    Care Management

    • Treat patients with blepharitis initially with a regimen of warm compresses and eyelid hygiene
    • A topical antibiotic such as bacitracin or erythromycin can be prescribed to be applied one or more times daily or at bedtime on the eyelids for one or more weeks
    • For patients with meibomian gland dysfunction, whose chronic symptoms and signs are not adequately controlled with eyelid hygiene, oral tetracyclines and topical antibiotics can be prescribed
    • A brief course of topical corticosteroids may be helpful for eyelid or ocular surface inflammation. The minimal effective dose of corticosteroid should be utilized and long-term corticosteroid therapy should be avoided if possible.

    Follow-Up Evaluation

    • Follow-up visits should include:
      • Interval history
      • Measurement of visual acuity
      • External examination
      • Slit-lamp biomicroscopy
    • If corticosteroid therapy is prescribed, re-evaluate patient within a few weeks to determine the response to therapy, measure intraocular pressure, and assess treatment compliance

    Patient Education

    • Counsel patients about the chronicity and recurrence of the disease process
    • Inform patients that symptoms can frequently be improved but are rarely eliminated
    • Patients with an inflammatory eyelid lesion that appears suspicious for malignancy should be referred to an appropriate specialist