• AAO PPP Glaucoma Panel, Hoskins Center for Quality Eye Care
    Glaucoma

    Introduction

    These are summary benchmarks for the Academy's Preferred Practice Pattern® (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 are then given a rating that shows the strength of evidence when sufficient evidence exists.

    To rate individual studies, a scale based on the Scottish Intercollegiate Guideline Network (SIGN) is used. The definition and levels of evidence to rate individual studies are as follows:

    • I++: High quality meta-analyses, systematic reviews of randomized controlled trials (RCTs), or RCTs with a very low risk of bias
    • I+: Well-conducted meta-analyses, systematic reviews of RCTs, or RCTs with a low risk of bias
    • I-: Meta-analyses, systematic reviews of RCTs, or RCTs with a high risk of bias
    • II++: High-quality systematic reviews of case-control or cohort studies; high-quality case-control or cohort studies with a very low risk of confounding or bias and a high probability that the relationship is causal
    • II+: Well-conducted case-control or cohort studies with a low risk of confounding or bias and a moderate probability that the relationship is causal
    • II-: Case-control or cohort studies with a high risk of confounding or bias and a significant risk that the relationship is not causal
    • III: Nonanalytic studies (e.g., case reports, case series)

    Recommendations for care are formed based on the body of the evidence. The body of evidence quality ratings are defined by Grading of Recommendations Assessment, Development and Evaluation (GRADE) as follows:

    • Good quality (GQ): Further research is very unlikely to change our confidence in the estimate of effect
    • Moderate quality (MQ): Further research is likely to have an important impact on our confidence in the estimage of effect and may change the estimate
    • Insufficient quality (IQ): Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate; any estimate of effect is very uncertain

    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

    Key recommendations for care are defined by GRADE as follows:

    • Strong recommendation (SR): Used when the desirable effects of an intervention clearly outweigh the undesirable effects or clearly do not
    • Discretionary recommendation (DR): Used when the trade-offs are less certain -- either because of low-quality evidence or because evidence suggests that desirable and undesirable effects are closely balanced

    In PPPs prior to 2011, the panel rated recommendations 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) 

    This former approach, however, will eventually be phased out as the AAO adopted the SIGN and GRADE rating and grading systems.

    The 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 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 (Key elements)

    • Ocular history
    • Family history
    • Systemic history
    • Review of pertinent records
    • Current medications
    • Ocular surgery

    Initial Physical Exam (Key elements)

    • Visual acuity measurement
    • Pupil examination
    • Slit-lamp biomicroscopy of anterior segment
    • Measurement of IOP
    • Central corneal thickness
    • Gonioscopy
    • Evaluation of optic nerve head and retinal nerve fiber layer using magnified stereoscopic visualization with slit-lamp biomicroscope and through a dilated pupil
    • Appearance of the optic nerve head and, if possible, the RNFL should be documented (II++, GQ, SR)
    • Evaluation of the fundus (through a dilated pupil whenever feasible)
    • Visual field evaluation, preferably by automated static threshold perimetry
    • Excavation of the optic cup
    • Thinning of the inferior and/or superior neuroretinal rim

    Management Plan for Patients in Whom Therapy is Indicated

    • A reasonable initial goal is to set a target pressure 20% less than mean of several baseline IOP measurements based on criteria from the Ocular Hypertension Study (I+, MQ, DR)
    • The goal of treatment is to maintain the IOP in a range at which visual field loss is unlikely to significantly affect a patient’s health related quality of life over his/her lifetime (II+, MQ, DR)
    • If visual field glaucomatous damage is newly detected in a glaucoma suspect patient, it is best to repeat testing (II++, GQ, SR)
    • Clinicians should include all perimetric and other structural information in addition to digital imaging technology when formulating patient management decisions (III, IQ, SR)

    Follow-up Exam History

    • Interval ocular history
    • Interval systemic medical history and any change of systemic medications
    • Side effects of ocular medications if patient is being treated
    • Frequency and time of last glaucoma medications, and review of use, if patient is being treated

    Follow-up Physical Exam

    • Visual acuity
    • Slit-lamp biomicroscopy
    • Measurement of IOP
    • Gonioscopy is indicated when there is a suspicion of an angle-closure component, anterior chamber shallowing or unexplained change in IOP

    Follow-up Intervals

    • Visit intervals depend on the interaction between patient and disease, which is unique for every patient
    • Frequency of periodic optic nerve head and visual filed evaluation is based on risk assessment. Patients with tinner corneas, higher IOPs, disc hemorrhage, larger cup-to-disc, larger mean pattern standard deviation, or family history of glaucoma may warrant closer follow-up.

    Patient Education for Patients with Medical Therapy

    • Discuss diagnosis, number and severity of risk factors, prognosis, management plan and likelihood that therapy, once started, will be long term
    • Educate about disease process, rationale and goals of intervention, status of their condition, and relative benefits and risks of alternative interventions
    • Educate about eyelid closure and nasolacrimal occlusion when applying topical medications to reduce systemic absorption
    • Encourage patients to alert their ophthalmologist to physical or emotional changes that occur when taking glaucoma medications