Ratings of importance to the care process (A-C) and ratings of strength of evidence (I-III) are defined at the end of the "Major Recommendations" field.
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. Specific questioning includes asking about the use of topical or systemic medication (e.g., sulfonamides, topiramate [e.g., Topamax; Ortho-McNeil Neurologics, Titusville, NJ], phenothiazines, and anticholinergics) that may induce angle narrowing.
Ophthalmic Examination
Refractive Status [A:III]
Hyperopic eyes, especially in older patients, have narrower anterior chamber angles and are at increased risk of primary angle closure (PAC). 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 loss
Determination of Intraocular Pressure (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 (Aghaian et al., 2004). [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). Compression (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 (Wolfs et al., 1997). [A:III]
Management
Goals
The goals of managing a patient with PAC are as follows:
- Reverse or prevent angle-closure process
- Control intraocular pressure (IOP)
- Prevent damage to the optic nerve
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 (Wolfs et al., 1997). [A:III] They should also be informed about the symptoms of AACC and instructed to notify their ophthalmologist immediately if symptoms occur (Wilensky et al., 1993). [A:III]
Primary Angle Closure and Primary Angle-Closure Glaucoma
Iridotomy is indicated for eyes with PAC or primary angle-closure glaucoma (PACG) (Weinreb & Friedman, 2006; Saw, Gazzard, & Friedman, 2003). [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 (Quigley, 1981; American Academy of Ophthalmology Committee on Ophthalmic Procedures Assessment, 1994; Robin & Pollack, 1982). [A:II]
When laser iridotomy is not possible or if the AACC cannot be medically broken, laser peripheral iridoplasty (even with a cloudy cornea) (Lam et al., "Argon laser," 2002), paracentesis (Lam et al., "Efficacy and safety," 2002), 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 (Bain, 1957; Lowe, 1962; Wilensky et al., 1993; Saw, Gazzard, & Friedman, 2003; Edwards, 1982; Ang, Aung, & Chew, 2000; Snow, 1977).
Surgery and Postoperative Care
The ophthalmologist who performs the laser iridotomy or incisional iridectomy has the following responsibilities (American Academy of Ophthalmology, "Pretreatment assessment," 2006; American Academy of Ophthalmology, "An ophthalmologist's duties," 2006) [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 surgery (Robin, Pollack, & deFaller, 1987; Rosenblatt & Luntz, 1987; Barnes et al., 1999) [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 (Robin, Pollack, & deFaller, 1987). [A:III]
Follow-up evaluation 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 this condition may be desirable. Patients with significant visual impairment or blindness may benefit from appropriate vision rehabilitation and social services. More information on vision rehabilitation, including materials for patients, is available at www.aao.org/smartsight 
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Definitions:
Ratings of Importance to Care Process
Level A, defined as most important
Level B, defined as moderately important
Level C, defined as relevant, but not critical
Ratings of Strength of Evidence
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., Preferred Practice Pattern [PPP] panel consensus with external peer review)
