• Oct 2010
    AAO PPP Glaucoma Panel, Hoskins Center for Quality Eye Care
    Glaucoma
    Compendium Type: I

    INTRODUCTION

    The Preferred Practice Pattern® (PPP) guidelines have 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.


    In the process of revising this document, a detailed literature search of PubMed and the Cochrane Library was conducted on December 3, 2008 and April 24, 2009 on the of primary angle closure (PAC) for the years from January 1, 2004 to the date of the search. Details of the literature search are available in the Literature Search Details. The results were reviewed by the Glaucoma 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)


    Evidence is that which supports the value of the recommendation as it relates to the quality of care. The committee believes that it is important to make available the strength of the evidence underlying the recommendation. In this way, readers can appreciate the degree of importance the committee attached to each recommendation and they can understand what type of evidence supports the recommendation.

    The ratings of importance and the ratings of strength of evidence are given in bracketed superscripts after each recommendation. For instance, "[A:II]" indicates a recommendation with high importance to clinical care [A], supported by sufficiently rigorous published evidence, though not by a randomized controlled trial [II].

    The sections entitled "Orientation" and "Background" do not include recommendations; rather they are designed to educate and provide summary background information and rationale for the recommendations that are presented in the Care Process section. A summary of the major recommendations for care is included in Appendix 2. Appendix 3 has an algorithm for the management of patients with acute angle-closure crisis (AACC). Appendix 4 contains the International Statistical Classification of Diseases and Related Health Problems (ICD) codes for the disease entities that the PPP covers.

    ORIENTATION

    DISEASE DEFINITION

    Primary angle closure is appositional or synechial closure of the anterior chamber angle caused by multiple mechanisms.1-3 Pupil block is considered to be a key element in the pathogenesis of most instances of PAC. The pressure in the posterior chamber is higher than the anterior chamber, causing an anterior bowing of the iris, which may crowd the angle in predisposed eyes. Certain factors can increase this pressure disparity between the two chambers (e.g., pupil dilation and thickening of the crystalline lens with age), which can result in iris apposition to the anterior chamber angle structures. In a minority of cases, this can happen acutely, resulting in acute angle closure.

    Other important mechanisms play a role in angle closure, including the relative position and thickness of the ciliary body, the location of the iris insertion into the ciliary body, and the volume of the iris. Furthermore, it is clear that the crystalline lens size, shape, or position may play an important role in determining which eyes develop angle closure. Prolonged or repeated contact of the peripheral iris with the trabecular meshwork may lead to functional damage of the trabecular meshwork and the development of peripheral anterior synechiae (PAS). Angle closure may or may not be associated with elevated intraocular pressure (IOP) or glaucomatous optic neuropathy, and may occur in either an acute or chronic form. Secondary forms of angle closure can also occur (e.g., iridocorneal endothelial syndrome, inflammation, or neovascularization). This PPP focuses on PAC.

    CLASSIFICATION AND CLINICAL CHARACTERISTICS OF ANGLE CLOSURE

    Primary angle closure is generally bilateral, although 90% of acute attacks are unilateral.4,5 Patients with angle closure and those at risk may be categorized as follows:

    Primary Angle-Closure Suspect
    Iridotrabecular contact (ITC), as observed on noncompressive gonioscopy, is defined as the iris seeming to touch the anterior chamber angle at the posterior pigmented trabecular meshwork or more anterior structures. It is the hallmark of PAC. The extent of ITC required to diagnose an eye as having angle closure has been the subject of debate. Consensus holds that a person with 180 degrees or more of ITC in primary gaze on gonioscopy is at risk of angle-closure glaucoma or an acute attack of angle closure. A person with this amount or more of ITC, no PAS, and normal IOP is considered a primary angle-closure suspect (PACS).6 Only one study (carried out in south India) has reported on the natural history of these eyes. About one in four in this population developed elevation in IOP or PAS over 5 years.7,8 Further longtitudinal studies in a variety of ethnic groups are needed.

    Primary Angle Closure and Primary Angle-Closure Glaucoma
    Any eye that has at least 180 degrees of ITC and an elevated IOP or PAS with no secondary cause for the PAS is classified as having PAC. The presence of high IOP and/or PAS is evidence that the ITC noted on gonioscopy may be causing permanent changes to the eye. When glaucomatous optic neuropathy is present (as defined in the Primary Open-Angle Glaucoma PPP9), the eye has progressed from PAC to primary angle-closure glaucoma (PACG).

    Plateau iris configuration is used to refer to eyes that continue to have ITC after iridotomy, with a gonioscopic appearance of the peripheral iris closely apposed to the angle despite a deep central anterior chamber. Nearly one-third of PAC eyes treated with iridotomy have an angle that retains significant ITC.10-12 Yet, on pupil dilation, the plateau iris configuration eyes do not have a significant increase in IOP, and no longitudinal study has shown that their risk of long-term development of PACG is higher than those eyes whose angles widen more after iridotomy. Rarely, plateau iris configuration eyes do have recurrent high IOP spikes after iridotomy; these eyes are called plateau iris syndrome and require more extensive treatments.

    Acute Angle-Closure Crisis
    If much of the chamber angle is obstructed suddenly, the IOP can rise rapidly to high levels. This may cause pressure-induced corneal edema (experienced as blurred vision and occasionally as multicolored haloes around lights), a mid-dilated pupil, vascular congestion, eye pain, and/or headache; this is termed acute angle-closure crisis or AACC. High IOP may be accompanied by nausea and vomiting. Acute angle-closure crisis may be self-limited and resolve spontaneously or may occur repeatedly. Untreated, this entity may cause permanent vision loss or blindness. The fellow eye is also at high risk of AACC.

    PATIENT POPULATION

    The patient population includes individuals of all ages, most of whom are adults over 50 who have risk factors that include abnormally high transpupillary resistance to aqueous humor movement, most often in association with pupil block.

    ACTIVITY

    Diagnosis and management of a patient with angle closure on gonioscopy.

    PURPOSE 
    The purpose of treatment is to preserve visual function and maintain quality of life by preventing PACG or AACC from developing.

    GOALS

    • Identify those patients who are at risk of developing PACG or AACC or in whom it is present
    • Manage an acute attack of angle closure
    • Reverse or prevent angle closure by using laser iridotomy and/or iridoplasty or, if necessary, incisional iridectomy to alleviate pupil block
    • Observe patients for chronic IOP elevation, progression of synechial angle closure, identification of unsuspected plateau iris by repeat gonioscopy after iridotomy, or optic nerve damage, and manage as indicated
    • Evaluate the fellow eye for evidence of angle closure or an anatomic narrow angle in AACC and appropriately perform an iridotomy
    • Educate the patient and family members about the characteristics of the disease and involve them in the management of it

    BACKGROUND

    EPIDEMIOLOGY

    There are considerable differences in the prevalence of angle closure among ethnic groups. The highest rates are reported in Inuit,13-15 Chinese,16-20 and other Asian21-29 populations; lower rates are reported in populations of African and African-derived origin30-32 and European and European-derived origin33-41 (see Table 1). Primary angle-closure glaucoma may account for nearly as many cases of glaucoma as open-angle glaucoma in some Asian populations.21,42,43 Worldwide, 0.7% of people over 40 are estimated to have angle-closure glaucoma.43 It is estimated that 21 million people worldwide will have angle-closure glaucoma in 2020.43 In China, PACG is estimated to cause unilateral blindness (visual acuity <3/60 or visual field ≤10°) in 1.5 million individuals and bilateral blindness in another 1.5 million.42

    TABLE 1. Prevalence of Angle Closure (PDF 123k)

    RISK FACTORS

    The following demographic and ocular factors have been implicated as risk factors for the presence of PAC.

    Demographic Risk Factors

    • Family history of angle closure44,45
    • Older age4,18,41
    • Female sex4,46
    • Asian or Inuit descent 15,18,47-49

    Ocular Risk Factors

    • Hyperopia50-52
    • Shallow peripheral anterior chamber depth5,50,52-58
    • Shallow central anterior chamber depth52,59-63
    • Steep corneal curvature64
    • Thick crystalline lens52,65
    • Short axial length52,65,66

    NATURAL HISTORY

    If patients with unilateral AACC and high IOP do not receive treatment, glaucomatous optic neuropathy can occur rapidly.67 Untreated fellow phakic eyes are at increased risk for developing acute angle closure.68,69 Following resolution of an AACC, there is evidence that retinal nerve fiber layer thickness significantly decreases within 16 weeks after the attack, probably consisting of both resolution of axonal swelling and frank axonal atrophy.67 In one study, 4 to 10 years following an AACC attack, 18% of eyes were blind (10% from glaucoma), 48% of eyes developed glaucomatous optic neuropathy, and 58% of eyes had vision worse than 20/40.70 Thus, visual morbidity from AACC is significant. The natural history in untreated patients with AACC and PACG is to develop progressive vision loss that may result in bilateral blindness.

    CARE PROCESS

    PATIENT OUTCOME CRITERIA

    • Preservation of visual function
    • Maintenance of quality of life

    DIAGNOSIS

    Patients may or may not have symptoms of angle closure. Primary angle-closure suspect is a diagnosis based on the presence of ITC on gonioscopy. Primary angle closure is based on a combination of the presence of ITC on gonioscopy and either elevated IOP and/or PAS.6

    Patients may be asymptomatic presenting for routine eye care, or they may present with sudden onset of symptoms and signs typical of AACC (such as pain, redness, congestion, decreased vision, corneal edema, very high IOP). The initial history and ophthalmic examination includes the components of the comprehensive adult medical eye evaluation,71 with special attention to those factors that specifically bear upon primary and secondary causes of angle closure (see below).

    History
    The patient should be asked about symptoms that suggest intermittent angle-closure attacks (e.g., blurred vision, halos around lights, eye pain, headache, eye redness).[A:III] Review of the patient's family history may identify a relative with acute angle-closure glaucoma.44,45,72 Specific questioning includes asking about the use of topical or systemic medication (e.g., sulfonamides,73 topiramate74  [e.g., Topamax; Ortho-McNeil Neurologics,Titusville, NJ], phenothiazines,75 and anticholinergics) that may induce angle narrowing.

    Ophthalmic Examination
    Components of the physical evaluation that are particularly relevant for the diagnosis and management of angle closure and AACC follow.

    Refractive status[A:III]
    Hyperopic eyes, especially in older patients, have narrower anterior chamber angles50 and are at increased risk of PAC.51 Assessment of actual refractive status by retinoscopy or manifest refraction in the AACC eye may be postponed until a subsequent visit. However, approximating the refractive status is appropriate by measuring the eyeglass power to determine the possibility of hyperopia or refracting the fellow eye.

    Pupil [A:III]

    • Size and shape (may be asymmetric or oval in involved eye during or following an acute attack)
    • Reactivity (may be poorly reactive or mid-dilated during an acute attack and tonic after an attack)
    • Relative afferent pupillary defect (may be present in chronic angle closure or asymmetric optic nerve damage)

    Slit-lamp biomicroscopy[A:III]

    • Conjunctival hyperemia (in acute cases)
    • Central and peripheral anterior chamber depth narrowing
    • Anterior chamber inflammation suggestive of a recent or current attack
    • Corneal swelling with or without microcystic edema (in acute cases)
    • Iris abnormalities, including diffuse or focal atrophy, posterior synechiae, abnormal pupillary function, irregular pupil shape, and a mid-dilated pupil (suggestive of a recent or current attack)
    • Lens changes including cataract and glaukomflecken (patchy, localized, anterior subcapsular lens opacities)
    • Corneal endothelial cell loss76-79

    Determination of IOP[A:III]
    Intraocular pressure is measured in each eye, preferably using a contact applanation method (typically Goldmann tonometry) before gonioscopy.Measuring central corneal thickness should be postponed until resolution of an acute attack.80 [A:III]

    Gonioscopy[A:III]
    Gonioscopy of both eyes should be performed on all patients in whom angle closure is suspected to evaluate the angle anatomy, appositional closure, and presence of PAS.81Compression (indentation) gonioscopy with a four-mirror or similar lens is particularly helpful to determine if visible appositional closure is actually permanent, synechial closure and, if so, for the extent of such PAS. Gonioscopy should be performed in a dark room with a bright, short (approximately 1 mm in length) beam that does not pass through the pupil to avoid inducing pupillary constriction, which can widen the angle.82

    Gonioscopic visualization of the angle may be impaired secondary to corneal edema in the setting of acute angle-closure glaucoma. Topical glycerin may be used to clear the cornea to obtain a better view. (See www.gonioscopy.org and Selected Reference Texts section for discussion of the techniques of gonioscopy.)

    Anterior segment imaging
    Anterior segment imaging can be considered. There is good evidence demonstrating general agreement between findings on gonioscopy and anterior segment imaging, including ultrasound biomicroscopy (UBM) and anterior segment optical coherence tomography.83-88 These technologies may prove useful in evaluating for secondary causes of angle closure (see Differential Diagnosis section) and to elucidate plateau iris (see Figures 1 to 7).

    FIGURES 1 to 7 (PDF 292k)

    Provocative testing
    Careful gonioscopic examination and synthesis of the clinical findings have replaced the use of provocative tests to make therapeutic decisions for patients at risk for PAC.

    Other components of the initial evaluation
    Although a dilated examination may not be advisable in patients with ITC, an attempt should be made to evaluate the fundus and optic nerve head using the direct ophthalmoscope or indirect ophthalmoscopy at the slit-lamp biomicroscope with a 90-diopter lens.[A:III] For patients with PAC or PACS who are not having an acute attack, pupil dilation is not recommended until an iridotomy has been performed, since dilation can precipitate acute attacks.46 [A:III] Evaluation and documentation of the optic nerve head, retinal nerve fiber layer, and visual fields may be postponed until an acute attack is adequately treated. (See Primary Open-Angle Glaucoma PPP for a detailed description of the evaluation.9)

    Differential diagnosis 
    Because PACS and PAC tend to be bilateral, the observation of a wide open angle in the fellow eye suggests a diagnosis other than PAC. Other entities that cause secondary anterior chamber angle closure and that may be unilateral or bilateral include the following:

    • Neovascular glaucoma
    • Inflammation resulting in both PAS and posterior synechiae, which can result in a secluded pupil with iris bombé
    • Iridocorneal endothelial syndrome
    • Uveal effusion associated with systemic medications (e.g., topiramate, sulfonamides, phenothiazines, anticholinergics), retinal vascular occlusion, inflammation, tight scleral buckle, or panretinal photocoagulation
    • Suprachoroidal effusions  
    • Malignant glaucoma
    • Lens-induced angle closure (e.g., from a phacomorphic or subluxed lens)
    • Developmental disorders (e.g., nanophthalmos, retinopathy of prematurity, persistent hyperplastic primary vitreous)
    • Iris or ciliary body mass lesions or cysts
    • Other secondary causes of pupil block (e.g., aphakia without an iridectomy, phakic intraocular lens [IOL], anterior chamber IOL, silicone oil)
    • History of blunt or penetrating trauma
    • Axenfeld-Rieger syndrome
    • Epithelial downgrowth

    MANAGEMENT

    Goals
    The goals of managing a patient with PAC are as follows:

    • Reverse or prevent angle-closure process
    • Control IOP
    • Prevent damage to the optic nerve

    Primary Angle-Closure Suspect
    No completed clinical trials have documented the benefit of iridotomy for PACS, yet the relative safety of this procedure has allowed its wider use in the hope of preventing AACC and PACG. Present cross-sectional data indicates that the majority of those with PACS will not develop either PAC or PACG. In patients with ITC, and normal IOP without PAS, iridotomy may be considered to reduce the risk of developing angle closure.[A:III] Alternatively, patients with ITC may be followed for development of IOP elevation, evidence of progressive narrowing, or synechial angle closure,[A:III] since iridotomy can be associated with bothersome postoperative glare/diplopia. Hastening of cataract and posterior synechiae are occasional consequences.

    Other factors that may influence the decision to perform prophylactic laser iridotomy in PACS include the following:

    • Medication is required that may provoke pupillary block
    • Symptoms are present that suggest prior acute angle closure
    • The patient's health status or occupation/avocation makes it difficult to access immediate ophthalmic care (e.g., the patient resides in a nursing facility, travels frequently to developing parts of the world, works on a merchant vessel), or in poorly compliant patients

    Patients with PACS who have not had an iridotomy should be warned that they are at risk for AACC and that certain medicines (e.g., over-the-counter decongestants, motion-sickness medication, anticholinergic agents) could cause pupil dilation and induce AACC.46 [A:III] They should also be informed about the symptoms of AACC and instructed to notify their ophthalmologist immediately if symptoms occur.89 [A:III]

    Plateau Iris Configuration and Syndrome
    The success of prophylactic peripheral laser iridoplasty after laser iridotomy to prevent PACG and AACC in eyes with plateau iris has been reported in a case series.90 However, a recent Cochrane review found no randomized controlled trials to provide evidence to support the use of this procedure in these eyes.91 Given the lack of convincing evidence in the literature for prophylactic use of iridoplasty in these patients, and since iridoplasty can be painful for the patient and may cause inflammation, the decision of whether to observe or treat these eyes is left to the judgment of the treating ophthalmologist. Eyes with recurrent high IOP after iridotomy when the pupil is dilated (plateau iris syndrome) should undergo further therapy, including iridoplasty, chronic miotic therapy, or other surgical procedures.[A:III]

    Primary Angle Closure and Primary Angle-Closure Glaucoma
    Patients with PAC may have elevated IOP as a result of a chronic compromise of aqueous outflow due to appositional or synechial angle closure, or damage to the trabecular meshwork from previous intermittent AACC. Iridotomy is indicated for eyes with PAC or PACG.6,92 [A:III]

    Complications of laser iridotomy include increased IOP; laser burn to the cornea, lens, or retina; late onset corneal edema; development of posterior synechiae; hyphema; iritis; and the development of a ghost image in the patient's vision.

    Surgery and Postoperative Care
    The ophthalmologist who performs the laser iridotomy or incisional iridectomy has the following responsibilities:93,94 [A:III]

    • Obtain informed consent from the patient or the patient's surrogate decision maker after discussing the risks, benefits, and expected outcomes of surgery[A:III]
    • Ensure that preoperative evaluation confirms the need for surgery[A:III]
    • Perform at least one IOP check within 30 minutes to 2 hours of surgery95-97 [A:III] 
    • Prescribe topical corticosteroids in the postoperative period[A:III]
    • Ensure that the patient receives adequate postoperative care[A:III]

    Preoperative miotics facilitate laser iridotomy or iridectomy. Medications should be used perioperatively to avert sudden IOP elevation, particularly for patients who have severe disease.95 [A:III] 

    Follow-up evaluations after surgery should include the following elements:[A:III]

    • Evaluation of the patency of iridotomy
    • Measurement of IOP
    • Gonioscopy with compression/indentation to assess the extent of PAS, if it was not performed immediately after iridotomy  
    • Pupil dilation to decrease the risk of posterior synechiae formation
    • Fundus examination as clinically indicated

    Following iridotomy for PAC, persistent or progressive elevations of IOP and complications may occur for several reasons:

    • Trabecular damage or formation of synechiae may have occurred during iridocorneal apposition
    • If the iridotomy becomes occluded, pupil block may recur. Reoperation is indicated.
    • Factors other than pupil block may lead to angle closure and may have gone unrecognized until after the iridotomy. These include plateau iris syndrome and secondary causes of pupil block (see Differential Diagnosis section).
    • Angle closure may have been superimposed on pre-existing open-angle glaucoma or on another cause of IOP elevation, such as exfoliation syndrome98-101

    Additional treatment of PAC or PACG after the component of pupil block has been alleviated by iridotomy is directed at lowering IOP to prevent or retard pressure-induced optic nerve damage and is similar to the treatment of primary open-angle glaucoma.9 Reopening the angle by laser iridoplasty or surgical lysis of synechiae (goniosynechialysis) may improve aqueous outflow, especially when it is performed within 6 to 12 months of an acute attack.102-105

    Additional management for elevated IOP that threatens the optic nerve is the same as for primary open-angle glaucoma (see Primary Open-Angle Glaucoma PPP9) and includes chronic topical ocular hypotensive agents, laser trabeculoplasty if, in the judgment of the treating ophthalmologist, sufficient open trabecular meshwork exists after laser iridotomy to expect a reasonable IOP reduction, and incisional surgery (trabeculectomy or tube shunt). In addition, a growing body of evidence indicates that cataract extraction alone may lead to substantial IOP lowering in some PACG patients and can be considered as an option for treatment.106-111

    Acute Angle-Closure Crisis

    Acute attack management
    The initial treatment of AACC is aimed at lowering IOP to relieve the acute symptoms and potentially harmful high IOP. Several methods have been studied, including medical therapy alone, laser peripheral iridotomy (if the iris can be visualized and the procedure can be performed), peripheral laser iridoplasty, and paracentesis.112-114 However, most patients are treated acutely with medications, and the iridotomy is performed as soon as feasible.

    Iridotomy (or iridectomy) allows aqueous to bypass the pupil block and eliminates the pressure gradient between the posterior and anterior chambers.

    In AACC, medical therapy is usually initiated first to lower the IOP to reduce pain and clear corneal edema.[A:III] Iridotomy should then be performed as soon as possible.[A:III] Medical therapy includes some or all of the following, based on the patient's overall physical and medical status:115

    • Topical beta-adrenergic antagonists116
    • Topical alpha2-adrenergic agonists117
    • Topical or systemic carbonic anhydrase inhibitors116
    • Topical miotics116,118
    • Systemic hyperosmotic agents

    Agents that suppress aqueous humor formation (beta-adrenergic antagonists, carbonic anhydrase inhibitors) may be ineffective, because they may have decreased ability to reduce aqueous formation if the ciliary body is ischemic. As the configuration of the iris becomes less bowed with a small pupil, treatment with miotics may open the angle; however, miotic therapy is frequently ineffective when the IOP is markedly elevated because of pressure-induced ischemia of the pupillary sphincter. Often, systemic hyperosmotic agents need to be used to achieve a rapid decrease in IOP in the setting of AACC. Corneal indentation performed with a four-mirror gonioscopic lens, cotton-tipped applicator, or tip of a muscle hook may help break pupil block.119

    Laser iridotomy is the preferred surgical treatment, because it has a favorable risk-benefit     ratio.10,120,121 [A:II] Iridotomy relieves pupil block and can prevent or retard the formation of PAS. Timely treatment may prevent damage to the optic nerve, trabecular meshwork, iris, lens, and cornea. If an iridotomy cannot be performed due to corneal edema, the cornea may sometimes be cleared with topical hyperosmotic agents or anterior chamber paracentesis. Once the attack is broken, it is usually possible to perform a definitive laser iridotomy immediately or soon afterwards.122-129

    When laser iridotomy is not possible or if the AACC cannot be medically broken, laser peripheral iridoplasty (even with a cloudy cornea),128 paracentesis,114 and incisional iridectomy remain effective alternatives.[A:III] When incisional iridectomy is required and extensive synechial closure is recognized or suspected, simultaneous primary filtering surgery may be considered. Concurrent glaucomatous cupping of the optic disc often indicates a prolonged chronic course before the onset of acute symptoms, and filtering surgery can be considered, especially if the presence of considerable PAS is confirmed on gonioscopy. Filtering surgery in eyes with unbroken acute angle closure are at high risk of developing a flat anterior chamber and aqueous misdirection postoperatively.130

    Lens extraction for angle closure
    Numerous studies document that lens extraction significantly widens the anterior chamber angle in eyes with narrow, occludable angles and in angle-closure glaucoma.106-110 In prospective and retrospective studies, cataract surgery also has been shown to lower postoperative medication requirements and decrease complications compared with surgical iridectomy or trabeculectomy in angle-closure glaucoma131-140 and AACC.141 Although there is evidence that lens extraction with or without goniosynechialysis102,142-144 can substantially lower IOP, it has been documented that cataract extraction alone does not result in as low an IOP as trabeculectomy and cataract surgery.145 The risks and benefits of different procedures in eyes with angle closure should be considered when determining the most appropriate surgery.

    A randomized trial of cataract surgery soon after AACC is broken compared with routine follow-up after iridotomy alone found that individuals with high IOP (>55 mmHg) were much less likely to require IOP-lowering therapy if they had early cataract extraction.141 In this study, patients had phacoemulsification within 5.7 ± 3.3 (mean ± standard deviation) days and iridotomy within 4.3 ± 2.7 (mean ± standard deviation) days of the AACC. Early cataract surgery can be considered after AACC in patients with a high risk of developing uncontrollable IOP. However, cataract surgery in AACC eyes may have greater risk of operative complications due to the small dimensions of the chamber and the tendency for choroidal expansion.

    Fellow-eye management
    The fellow eye of a patient with AACC should be evaluated, because it is at high risk for a similar event. The fellow eye should receive a prophylactic laser iridotomy promptly if the chamber angle is anatomically narrow,[A:II] since approximately half of fellow eyes of acute angle-closure patients can develop acute attacks within 5 years.68,69,89,92,146-148 These attacks can occur within days of presentation (in fact, 10% of cases present with bilateral AACC) and, therefore, consideration of immediate laser peripheral iridotomy in the fellow eye is warranted. Laser iridotomy in the fellow eye should be performed at the initial visit if the eye in AACC cannot have a successful iridotomy in the acute setting because of poor visualization of the iris due to corneal edema. Chronic miotic therapy is not an appropriate alternative, either for prophylaxis of the fellow eye or for treatment of established angle closure, and it is not a substitute for iridotomy. About 40% of fellow eyes treated with miotics can develop an acute attack within 5 years, and many eyes with angle closure can develop progressive formation of synechial angle closure with miotic use.69,148 Prophylactic laser peripheral iridotomies are effective in preventing acute angle closure in the fellow eye.147

    FOLLOW-UP EVALUATION
    The recommendations for follow-up evaluations after iridotomy for angle closure apply to ongoing management and not to visits for other purposes. Following iridotomy, patients may have an open anterior chamber angle or an anterior chamber angle with a combination of open sectors with areas occluded by PAS. Following iridotomy, patients with a residual open angle or a combination of open angle and some PAS with or without glaucomatous optic neuropathy should be followed at least annually, with special attention to repeat gonioscopy to determine interval changes such as increased extent of PAS or development of secondary angle closure from cataract progression and increased lens thickness.[A:III] Subsequent follow-up intervals depend on the clinical findings and judgment of the treating ophthalmologist.

    PROVIDER AND SETTING

    The performance of certain diagnostic procedures (e.g., tonometry, perimetry, pachymetry, optic disc imaging, and photography) may be delegated to appropriately trained and supervised personnel. However, the interpretation of results and medical and surgical management of disease require the medical training, clinical judgment, and experience of the ophthalmologist. Most diagnostic and therapeutic procedures can be undertaken safely on an outpatient basis. Hospitalization may be indicated for intensive treatment of an AACC so that patients can be monitored closely after surgical procedures associated with a high risk of serious short-term postoperative complications. It may also be indicated for patients in whom surgical complications have occurred or for patients who have special medical or social needs.

    COUNSELING/REFERRAL

    If the diagnosis or management of PAC, PACS, AACC, or PACG is in question or is refractory to treatment, consultation with or referral to an ophthalmologist with special training or experience in managing these conditions may be desirable. Patients with significant visual impairment or blindness may benefit from appropriate vision rehabilitation and social services.149 More information on vision rehabilitation, including materials for patients, is available at www.aao.org/smartsight.

    APPENDICES

    APPENDIX 1. QUALITY OF OPHTHALMIC CARE CORE CRITERIA

     Providing quality care
    is the physician's foremost ethical obligation, and is
    the basis of public trust in physicians.
    AMA Board of Trustees, 1986

    Quality ophthalmic care is provided in a manner and with the skill that is consistent with the best interests of the patient. The discussion that follows characterizes the core elements of such care.

    The ophthalmologist is first and foremost a physician. As such, the ophthalmologist demonstrates compassion and concern for the individual, and utilizes the science and art of medicine to help alleviate patient fear and suffering. The ophthalmologist strives to develop and maintain clinical skills at the highest feasible level, consistent with the needs of patients, through training and continuing education. The ophthalmologist evaluates those skills and medical knowledge in relation to the needs of the patient and responds accordingly. The ophthalmologist also ensures that needy patients receive necessary care directly or through referral to appropriate persons and facilities that will provide such care, and he or she supports activities that promote health and prevent disease and disability.

    The ophthalmologist recognizes that disease places patients in a disadvantaged, dependent state. The ophthalmologist respects the dignity and integrity of his or her patients, and does not exploit their vulnerability.

    Quality ophthalmic care has the following optimal attributes, among others.

    • The essence of quality care is a meaningful partnership relationship between patient and physician. The ophthalmologist strives to communicate effectively with his or her patients, listening carefully to their needs and concerns. In turn, the ophthalmologist educates his or her patients about the nature and prognosis of their condition and about proper and appropriate therapeutic modalities. This is to ensure their meaningful participation (appropriate to their unique physical, intellectual and emotional state) in decisions affecting their management and care, to improve their motivation and compliance with the agreed plan of treatment, and to help alleviate their fears and concerns.
    • The ophthalmologist uses his or her best judgment in choosing and timing appropriate diagnostic and therapeutic modalities as well as the frequency of evaluation and follow-up, with due regard to the urgency and nature of the patient's condition and unique needs and desires.
    • The ophthalmologist carries out only those procedures for which he or she is adequately trained, experienced and competent, or, when necessary, is assisted by someone who is, depending on the urgency of the problem and availability and accessibility of alternative providers.
    • Patients are assured access to, and continuity of, needed and appropriate ophthalmic care, which can be described as follows.
      • The ophthalmologist treats patients with due regard to timeliness, appropriateness, and his or her own ability to provide such care.
      • The operating ophthalmologist makes adequate provision for appropriate pre- and postoperative patient care.
      • When the ophthalmologist is unavailable for his or her patient, he or she provides appropriate alternate ophthalmic care, with adequate mechanisms for informing patients of the existence of such care and procedures for obtaining it.
      • The ophthalmologist refers patients to other ophthalmologists and eye care providers based on the timeliness and appropriateness of such referral, the patient's needs, the competence and qualifications of the person to whom the referral is made, and access and availability.
      • The ophthalmologist seeks appropriate consultation with due regard to the nature of the ocular or other medical or surgical problem. Consultants are suggested for their skill, competence, and accessibility. They receive as complete and accurate an accounting of the problem as necessary to provide efficient and effective advice or intervention, and in turn respond in an adequate and timely manner.
      • The ophthalmologist maintains complete and accurate medical records.
      • On appropriate request, the ophthalmologist provides a full and accurate rendering of the patient's records in his or her possession.
      • The ophthalmologist reviews the results of consultations and laboratory tests in a timely and effective manner and takes appropriate actions.
      • The ophthalmologist and those who assist in providing care identify themselves and their profession
      • For patients whose conditions fail to respond to treatment and for whom further treatment is unavailable, the ophthalmologist provides proper professional support, counseling, rehabilitative and social services, and referral as appropriate and accessible.
    • Prior to therapeutic or invasive diagnostic procedures, the ophthalmologist becomes appropriately conversant with the patient's condition by collecting pertinent historical information and performing relevant preoperative examinations. Additionally, he or she enables the patient to reach a fully informed decision by providing an accurate and truthful explanation of the diagnosis; the nature, purpose, risks, benefits, and probability of success of the proposed treatment and of alternative treatment; and the risks and benefits of no treatment.
    • The ophthalmologist adopts new technology (e.g., drugs, devices, surgical techniques) in judicious fashion, appropriate to the cost and potential benefit relative to existing alternatives and to its demonstrated safety and efficacy.
    • The ophthalmologist enhances the quality of care he or she provides by periodically reviewing and assessing his or her personal performance in relation to established standards, and by revising or altering his or her practices and techniques appropriately.
    • The ophthalmologist improves ophthalmic care by communicating to colleagues, through appropriate professional channels, knowledge gained through clinical research and practice. This includes alerting colleagues of instances of unusual or unexpected rates of complications and problems related to new drugs, devices or procedures.
    • The ophthalmologist provides care in suitably staffed and equipped facilities adequate to deal with potential ocular and systemic complications requiring immediate attention.
    • The ophthalmologist also provides ophthalmic care in a manner that is cost effective without unacceptably compromising accepted standards of quality.


    Reviewed by: Council
    Approved by: Board of Trustees
    October 12, 1988

    2nd Printing: January 1991
    3rd Printing: August 2001
    4th Printing: July 2005


    APPENDIX 2. MAJOR RECOMMENDATIONS FOR CARE

    DIAGNOSIS

    History
    The patient should be asked about symptoms that suggest intermittent angle-closure attacks (e.g., blurred vision, halos around lights, eye pain, headache, eye redness).[A:III] Review of the patient's family history may identify a relative with acute angle-closure glaucoma.44,45,72 Specific questioning includes asking about the use of topical or systemic medication (e.g., sulfonamides,73 topiramate74  [e.g., Topamax; Ortho-McNeil Neurologics,Titusville, NJ], phenothiazines,75 and anticholinergics) that may induce angle narrowing.

    Ophthalmic Examination

    Refractive status[A:III]
    Hyperopic eyes, especially in older patients, have narrower anterior chamber angles50 and are at increased risk of primary angle closure (PAC).51 Assessment of actual refractive status by retinoscopy or manifest refraction in the acute angle closure crisis (AACC) eye may be postponed until a subsequent visit. However, approximating the refractive status is appropriate by measuring the eyeglass power to determine the possibility of hyperopia or refracting the fellow eye.

    Pupil [A:III]

    • Size and shape (may be asymmetric or oval in involved eye during or following an acute attack)
    • Reactivity (may be poorly reactive or mid-dilated during an acute attack and tonic after an attack)
    • Relative afferent pupillary defect (may be present in chronic angle closure or asymmetric optic nerve damage)

    Slit-lamp biomicroscopy[A:III]

    • Conjunctival hyperemia (in acute cases)
    • Central and peripheral anterior chamber depth narrowing
    • Anterior chamber inflammation suggestive of a recent or current attack
    • Corneal swelling with or without microcystic edema (in acute cases)
    • Iris abnormalities, including diffuse or focal atrophy, posterior synechiae, abnormal pupillary function, irregular pupil shape, and a mid-dilated pupil (suggestive of a recent or current attack)
    • Lens changes including cataract and glaukomflecken (patchy, localized, anterior subcapsular lens opacities)
    • Corneal endothelial cell loss76-79

    Determination of Intraocular Pressure[A:III]
    Intraocular pressure (IOP) is measured in each eye, preferably using a contact applanation method (typically Goldmann tonometry) before gonioscopy.Measuring central corneal thickness should be postponed until resolution of an acute attack.80 [A:III]

    Gonioscopy[A:III]
    Gonioscopy of both eyes should be performed on all patients in whom angle closure is suspected to evaluate the angle anatomy, appositional closure, and presence of peripheral anterior synechiae (PAS).81Compression (indentation) gonioscopy with a four-mirror or similar lens is particularly helpful to determine if visible appositional closure is actually permanent, synechial closure and, if so, for the extent of such PAS.

    Other components of the initial evaluation
    Although a dilated examination may not be advisable in patients with iridotrabecular contact (ITC), an attempt should be made to evaluate the fundus and optic nerve head using the direct ophthalmoscope or indirect ophthalmoscopy at the slit-lamp biomicroscope with a 90-diopter lens.[A:III] For patients with PAC or PAC suspect who are not having an acute attack, pupil dilation is not recommended until an iridotomy has been performed, since dilation can precipitate acute attacks.46 [A:III]

    Primary Angle-Closure Suspect
    In patients with ITC, and normal IOP without PAS, iridotomy may be considered to reduce the risk of developing angle closure.[A:III] Alternatively, patients with ITC may be followed for development of IOP elevation, evidence of progressive narrowing, or synechial angle closure,[A:III] since iridotomy can be associated with bothersome postoperative glare/diplopia.

    Patients with PAC suspect who have not had an iridotomy should be warned that they are at risk for AACC and that certain medicines (e.g., over-the-counter decongestants, motion-sickness medication, anticholinergic agents) could cause pupil dilation and induce AACC.46 [A:III] They should also be informed about the symptoms of AACC and instructed to notify their ophthalmologist immediately if symptoms occur.89 [A:III]

    Primary Angle Closure and Primary Angle-Closure Glaucoma
    Iridotomy is indicated for eyes with PAC or primary angle-closure glaucoma (PACG).6,92 [A:III]

    Acute Angle-Closure Crisis

    Acute attack management
    In AACC, medical therapy is usually initiated first to lower the IOP to reduce pain and clear corneal edema.[A:III] Iridotomy should then be performed as soon as possible.[A:III] Laser iridotomy is the preferred surgical treatment, because it has a favorable risk-benefit ratio.10,120,121 [A:II]

    When laser iridotomy is not possible or if the AACC cannot be medically broken, laser peripheral iridoplasty (even with a cloudy cornea),128 paracentesis,114 and incisional iridectomy remain effective alternatives.[A:III]

    Fellow-eye management
    The fellow eye of a patient with AACC should be evaluated, because it is at high risk for a similar event. The fellow eye should receive a prophylactic laser iridotomy promptly if the chamber angle is anatomically narrow,[A:II] since approximately half of fellow eyes of acute angle-closure patients can develop acute attacks within 5 years.68,69,89,92,146-148

    Surgery and Postoperative Care
    The ophthalmologist who performs the laser iridotomy or incisional iridectomy has the following responsibilities:93,94 [A:III]

    • Obtain informed consent from the patient or the patient's surrogate decision maker after discussing the risks, benefits, and expected outcomes of surgery[A:III]
    • Ensure that preoperative evaluation confirms the need for surgery[A:III]
    • Perform at least one IOP check within 30 minutes to 2 hours of surgery95-97 [A:III] 
    • Prescribe topical corticosteroids in the postoperative period[A:III]
    • Ensure that the patient receives adequate postoperative care[A:III]

    Preoperative miotics facilitate laser iridotomy or iridectomy. Medications should be used perioperatively to avert sudden IOP elevation, particularly for patients who have severe disease.95 [A:III] 

    Follow-up evaluations after surgery should include the following elements:[A:III]

    • Evaluation of the patency of iridotomy
    • Measurement of IOP
    • Gonioscopy with compression/indentation to assess the extent of PAS, if it was not performed immediately after iridotomy 
    • Pupil dilation to decrease the risk of posterior synechiae formation
    • Fundus examination as clinically indicated

    FOLLOW-UP EVALUATION
    Following iridotomy, patients with a residual open angle or a combination of open angle and some PAS with or without glaucomatous optic neuropathy should be followed at least annually, with special attention to repeat gonioscopy to determine interval changes such as increased extent of PAS or development of secondary angle closure from cataract progression and increased lens thickness.[A:III] Subsequent follow-up intervals depend on the clinical findings and judgment of the treating ophthalmologist.

    COUNSELING/REFERRAL
    If the diagnosis or management of PAC, PAC suspect, AACC, or PACG is in question or is refractory to treatment, consultation with or referral to an ophthalmologist with special training or experience in managing these conditions may be desirable. Patients with significant visual impairment or blindness may benefit from appropriate vision rehabilitation and social services.149 More information on vision rehabilitation, including materials for patients, is available at www.aao.org/smartsight.  


    APPENDIX 3. ALGORITHM FOR THE MANAGEMENT OF PATIENTS WITH ACUTE ANGLE-CLOSURE CRISIS

    Algorithm for the Management of Patients with Acute Angle-Closure Crisis (PDF 27k)


    APPENDIX 4. INTERNATIONAL STATISTICAL CLASSIFICATION OF DISEASES AND RELATED HEALTH PROBLEMS (ICD) CODES

    The Primary Angle Closure Preferred Practice Pattern covers the entity of primary angle-closure glaucoma (ICD-9 #365.20) and related entities with the following ICD-9 classifications:

    • Acute angle-closure glaucoma (365.22)
    • Intermittent angle closure (365.21)
    • Chronic angle-closure glaucoma (365.23)
    • Residual stage of angle-closure glaucoma (365.24)
    • Anatomical narrow angle (365.02)

    SUGGESTED REFERENCE TEXTS

    • Allingham RR, Damji KF, Freedman S, Moroi SE, Shafranov G, Shields MB, eds. Shields' Textbook of Glaucoma. 5th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2005.
    • Alward WLM. www.gonioscopy.org. Accessed September 16, 2010.
    • Alward WLM, Longmuir RA. Color Atlas of Gonioscopy. 2nded. San Francisco, CA: American Academy of Ophthalmology; 2008.
    • Anderson DR, Patella VM. Automated Static Perimetry. 2nd ed. St. Louis, MO: CV Mosby Co.; 1999.
    • Epstein DL, Allingham RR, Shuman JS, eds. Chandler and Grant's Glaucoma. 4th ed. Baltimore, MD: Lippincott Williams and Wilkins; 1997.
    • Ritch R, Shields MB, Krupin T, eds. The Glaucomas. 2nd ed. St. Louis, MO: CV Mosby
      Co.; 1996.
    • Stamper RL, Lieberman MF, Drake MV. Becker-Shaffer's Diagnosis and Therapy of the Glaucomas. 8th ed. Philadelphia, PA: Mosby Elsevier; 2009.
    • Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 15th edition. Philadelphia, PA: Lippincott Williams & Wilkins; 2009.
    • Weinreb RN, Friedman DS, eds. Angle Closure and Angle-Closure Glaucoma. World Glaucoma Association Consensus Series - 3. The Netherlands: Kugler Publications; 2006.

    RELATED ACADEMY MATERIALS

    Basic and Clinical Science Course
         Glaucoma (Section 10, 2010-2011)

    Eye Fact Sheet
           Laser Iridotomy (2010)

    Focal Points
          Angle Closure Glaucoma Update (2009)
         Current Trends and Challenges in Glaucoma Care (2008)
         Evidence-Based Medicine in Glaucoma: Clinical Trials update (2008)             

    Ophthalmic Technology Assessments
          Aqueous Shunts in Glaucoma (2008)
         Optic Nerve Head and Retinal Nerve Fiber Layer Analysis (2007)

    Patient Education
         Glaucoma booklet (2010)
         Glaucoma brochure (2010) (Spanish: Entendiendo el Glaucoma [2010])

    Preferred Practice Patterns
         Comprehensive Adult Medical Eye Evaluation (2010)
         Primary Open-Angle Glaucoma (2010)
         Primary Open-Angle Glaucoma Suspect (2010)
         Vision Rehabilitation for Adults (2007)

    ProVision
          Glaucoma (Series 4, 2007)


    To order any of these materials, please call the Academy's Customer Service number, 866.561.8558 (U.S. only) or 415.561.8540 or visit www.aao.org/store.

    REFERENCES

    Recommendations of Care Ratings

    Care Process Ratings:

    • Level A: Most important to the care process
    • Level B: Moderately important to the care process
    • Level C: Relevant but not critical to the care process

    Strength of Evidence Ratings:

    • Level I: Randomized controlled trial or meta-analyses
    • Level II: Controlled trials, cohort, or case-control studies
    • Level III: Descriptive studies or case reports
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    PPP COMMITTEE/PANEL MEMBERS AND DISCLOSURES

    Prepared by the American Academy of Ophthalmology Glaucoma Panel

    Glaucoma Panel Members
    Bruce E. Prum, Jr., MD, Chair
    David S. Friedman, MD, MPH, PhD, American Glaucoma Society Representative
    Steven J. Gedde, MD
    Leon W. Herndon, MD
    Young H. Kwon, MD, PhD
    Michele C. Lim, MD
    Lisa F. Rosenberg, MD
    Rohit Varma, MD, MPH, Methodologist

    Preferred Practice Patterns Committee Members
    Christopher J. Rapuano, MD, Chair
    David F. Chang, MD
    Emily Y. Chew, MD
    Robert S. Feder, MD
    Stephen D. McLeod, MD
    Bruce E. Prum, Jr., MD
    R. Michael Siatkowski, MD
    David C. Musch, PhD, MPH, Methodologist

    Academy Staff
    Flora C. Lum, MD
    Nancy Collins, RN, MPH
    Doris Mizuiri
    Medical Editor: Susan Garratt
    Design: Socorro Soberano
    Reviewed by: Council
    Approved by: Board of Trustees
                        September 11, 2010

    The panel and committee members have disclosed the following financial relationships occurring from January 2009 to September 2010:

    David F. Chang, MD: Advanced Medical Optics - Consultant/Advisor; Alcon Laboratories, Inc. - Consultant/Advisor; Allergan, Inc. - Lecture fees; Calhoun Vision, Inc. - Consultant/Advisor, Equity owner; Eyemaginations, Inc. - Consultant/Advisor, Patent/Royalty; Ista Pharmaceuticals - Consultant/Advisor, Grant support; LensAR - Consultant/Advisor; Hoya - Consultant/Advisor; Peak Surgical - Consultant/Advisor; Revital Vision - Equity owner; SLACK, Inc. - Patent/Royalty; Transcend Medical - Consultant/Advisor; Visiogen, Inc. - Consultant/Advisor, Equity owner

    Emily Y. Chew, MD: No financial relationships to disclose.

    Robert S. Feder, MD: No financial relationships to disclose.

    David S. Friedman, MD, MPH, PhD: Alcon Laboratories, Inc. - Grant support; NiCox - Consultant/Advisor; Novartis Pharmaceuticals Corp. - Consultant/Advisor; ORBIS International - Consultant/Advisor; Pfizer, Inc. - Consultant/Advisor, Lecture fees, Grant support; Promedior - Consultant/Advisor; Zeiss Meditec - Grant support

    Steven J. Gedde, MD: Lumenis, Inc. - Lecture fees

    Leon W. Herndon, MD: Alcon Laboratories, Inc. - Consultant/Advisor, Lecture fees; Allergan, Inc. - Lecture fees; iScience - Lecture fees; Ista Pharmaceuticals - Consultant/Advisor, Lecture fees; Merck & Co., Inc. - Lecture fees; Optonol, Ltd. - Lecture fees; Pfizer, Inc. - Lecture fees; Reichert, Inc. - Lecture fees

    Young H. Kwon, MD, PhD: Allergan, Inc. - Consultant/Advisor; Free Educational Publications, Inc. - Equity owner; Pfizer, Inc. - Consultant/Advisor

    Michele C. Lim, MD: No financial relationships to disclose.

    Stephen D. McLeod, MD: Abbott Medical Optics - Consultant/Advisor, Equity owner; Visiogen, Inc. - Consultant/Advisor, Equity owner

    David C. Musch, PhD, MPH: Glaukos Corp. - Consultant/Advisor; MacuSight, Inc. - Consultant/Advisor; National Eye Institute - Grant support; NeoVista, Inc. - Consultant/Advisor; Neurotech USA, Inc. - Consultant/Advisor; OPKO Health, Inc. - Consultant/Advisor; Oraya Therapeutics, Inc. - Consultant/Advisor; Pfizer Ophthalmics - Grant support; Washington University - Grant support

    Bruce E. Prum, Jr., MD: Alcon Laboratories, Inc. - Grant support; Allergan, Inc. - Consultant/Advisor

    Christopher J. Rapuano, MD: Alcon Laboratories, Inc. - Lecture fees; Allergan, Inc. - Consultant/Advisor, Lecture fees; Bausch & Lomb - Lecture fees; Inspire - Lecture fees; EyeGate Pharma - Consultant/Advisor; Inspire - Lecture fees; Rapid Pathogen Screening - Equity owner; Vistakon Johnson & Johnson Visioncare, Inc. - Lecture fees

    Lisa F. Rosenberg, MD: No financial relationships to disclose.

    R. Michael Siatkowski, MD: National Eye Institute - Grant support

    Rohit Varma, MD, MPH: Alcon Laboratories, Inc. - Consultant/Advisor, Lecture fees; Allergan, Inc. - Consultant/Advisor, Grant support; Aquesys - Consultant/Advisor, Equity owner, Grant support; Bausch & Lomb Surgical - Consultant/Advisor; Genentech, Inc. - Consultant/Advisor, Grant support; Merck & Co., Inc. - Consultant/Advisor; National Eye Institute - Grant support; Optovue - Grant support; Pfizer, Inc. - Consultant/Advisor, Lecture fees, Grant support; Replenish, Inc. - Consultant/Advisor, Equity owner, Grant support

    Copyright © 2010
    American Academy of Ophthalmology
    All rights reserved

    This document should be cited as:
    American Academy of Ophthalmology Glaucoma Panel. Preferred Practice Pattern®Guidelines. Primary Angle Closure. San Francisco, CA: American Academy of Ophthalmology; 2010. Available at: www.aao.org/ppp.

    ABOUT PREFERRED PRACTICE PATTERNS

    As a service to its members and the public, the American Academy of Ophthalmology has developed a series of guidelines called Preferred Practice Patterns that identify characteristics and components of quality eye care. (See Appendix 1.)

    The Preferred Practice Pattern® guidelines are based on the best available scientific data as interpreted by panels of knowledgeable health professionals. In some instances, such as when results of carefully conducted clinical trials are available, the data are particularly persuasive and provide clear guidance. In other instances, the panels have to rely on their collective judgment and evaluation of available evidence.

    Preferred Practice Pattern guidelines provide the pattern of practice, not 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 PPPs 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. The 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.

    Preferred Practice Patternguidelines 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.

    References to certain drugs, instruments, and other products are made for illustrative purposes only and are not intended to constitute an endorsement of such. Such material may include information on applications that are not considered community standard, that reflect indications not included in approved U.S. Food and Drug Administration (FDA) labeling, or that are approved for use only in restricted research settings. The FDA has stated that it is the responsibility of the physician to determine the FDA status of each drug or device he or she wishes to use, and to use them with appropriate patient consent in compliance with applicable law.  

    Innovation in medicine is essential to assure the future health of the American public, and the Academy encourages the development of new diagnostic and therapeutic methods that will improve eye care. It is essential to recognize that true medical excellence is achieved only when the patients' needs are the foremost consideration.

    All PPPs are reviewed by their parent panel annually or earlier if developments warrant and updated accordingly. To ensure that all PPPs are current, each is valid for 5 years from the "approved by" date unless superseded by a revision. Preferred Practice Pattern guidelines are developed by the Academy's H. Dunbar Hoskins Jr., M.D. Center for Quality Eye Care without any external financial support. Authors and reviewers of PPPs are volunteers and do not receive any financial compensation for their contributions to the documents. The PPPs are externally reviewed by experts and stakeholders before publication.