3rd Consensus Meeting:
Angle Closure and Angle Closure Glaucoma
Hollywood, FL, May 3, 2006
edited by Robert N. Weinreb and David S. Friedman
2006. xiv and 98 pages with 59 figures of which 3 in color, 1 table. Hardbound.
ISBN-10: 90 6299 210 2
ISBN-13: 978-90-6299-210-2
Published by Kugler Publications.
Click here for more information on all publications in the Consensus series.
Consensus statements
- Epidemiology, Classification and Mechanism
- Management of Acute Angle Closure Crisis
- Surgical Management of Primary Angle Closure Glaucoma
- Laser and Medical Treatment of Primary Angle Closure Glaucoma
- Laser and Medical Treatment of Primary Angle Closure Glaucoma
- Detection of Primary Angle Closure and Angle Closure Glaucoma
Epidemiology, Classification and Mechanism
Classification
- The proposed classification scheme can be used not only to classify the
natural history of angle closure, but also to determine prognosis and describe
an individual’s need for treatment at different stages of natural history of
the disease. - Additional clinical sophistication can be gained describing sequelae of
angle closure affecting the cornea, trabecular meshwork, iris, lens optic disc
and retina. Specifically, the extent of PAS, level of presenting IOP (in asymptomatic
cases) and presence of glaucomatous optic neuropathy should be noted. - Ascertaining the mechanism of angle closure (pupillary block, plateau, lens-related,
retro-lenticular) is essential for management, and it should be used in conjunction
with a classification of the stage of the disease.
Comment: Further refinement of these systems (such as the inclusion of
symptoms as a defining feature of angle closure) should be made on the basis
of peer-reviewed evidence.
Comment: Angle closure can be caused by one or a combination of abnormalities
in the relative or absolute sizes or positions of anterior segment structures
or abnormal forces in the posterior segment that may alter the anatomy of the
anterior segment. Angle closure may be understood by regarding it as resulting
from blockage of the trabecular meshwork caused by forces acting at four successive
anatomic levels: the iris (pupillary block), the ciliary body (plateau iris),
the lens (phacomorphic glaucoma), and vectors posterior to the lens (malignant
glaucoma). - Although the amount of pupillary block may vary among eyes with angle closure,
all eyes with angle closure require treatment with iridotomy.
Gonioscopy
- Gonioscopy is indispensable to the diagnosis and management of all forms
of glaucoma and is an integral part of the eye examination. - An essential component of gonioscopy is the determination that iridotrabecular
contact is either present or absent. If present, the contact should be judged
to be appositional or synechial (permanent).
Comment: The terms ‘iridotrabecular contact (stating the number of degrees)’
and ‘primary angle closure suspect’ should be substituted for ‘occludable’,
as this is more accurate.
Comment: The determination of synechial contact may require indentation
of the cornea during gonioscopy, in which case a goniolens with a diameter smaller
than the corneal diameter is preferred. - Access to a magnifying, Goldmann-style lens enhances the ability to identify
important anatomical landmarks, and signs of pathology. Although the accuracy
of indentation with this lens has not been validated, its use does complement
that of a goniolens with a diameter smaller than the corneal diameter. The ideal
standard is access to both types of lens. - Anterior segment imaging devices may augment the evaluation of the anterior
chamber angle, but their place in clinical practice still needs to be determined. - It is desirable to record gonioscopic findings in clear text. Describing
the anatomical structures seen, the angle width, the iris contour and the amount
of pigmentation in the angle are all desirable.
Management of Acute Angle Closure Crisis
- Laser iridotomy should be performed as soon as feasible in the affected
eye(s), and should also be performed as soon as possible in the contralateral
eye. - Medical management is the recommended first step in treating acute angle
closure, but the results of studies comparing this to immediate laser surgery
are not yet available. - Laser iridoplasty can be effective at breaking acute attacks and should
be considered if an attack cannot be broken by other means. - Paracentesis should be reserved for cases where other approaches have failed.
- Primary cataract extraction may be a treatment option, but data supporting
its use are limited.
Surgical Management of Primary Angle Closure Glaucoma
- Laser peripheral iridotomy is recommended as the primary procedure in eyes
with PACG.
Comment: LPI can be performed easily on an outpatient basis and patients
can then be monitored for response to treatment. This will allow time to undertake
elective surgery in those with uncontrolled IOP, those with advanced disease
or with co-existing cataract. LPI also serves as prophylaxis against acute angle
closure. - There is lack of evidence for recommending primary incisional surgery (without
laser PI) in eyes with PACG. - Trabeculectomy may be performed to lower IOP in eyes with chronic PAC (G)
insufficiently responsive to laser or medical therapy. - There is insufficient evidence for deciding which cases with PACG should
undergo cataract surgery alone (without trabeculectomy).
Comment: Cataract surgery alone may be considered in eyes with mild degree
of angle closure (less then 180 degrees of PAS), mild optic nerve/visual field
damage or those that are not on maximal tolerated medical therapy. - There is lack of evidence for recommending lens extraction alone in eyes
with more advanced PACG.
Comment: Published studies to date have been non-randomized with small
sample sizes and short follow up. - Combined cataract and glaucoma surgery in certain eyes may be useful to
control IOP and restore vision.
Comment: There is limited published evidence about the effectiveness
of combined cataract extraction and trabeculectomy in eyes with PACG. There
is a need for studies comparing this form of surgery with separately staged
cataract extraction and trabeculectomy - There is limited evidence about the effectiveness of goniosynechialysis
in the management of PACG.
Laser and Medical Treatment of Primary Angle Closure Glaucoma
- Laser iridotomy should be performed in all eyes with an acute episode of
angle closure, the contralateral fellow of all such eyes, and in eyes with established
angle closure causing raised intraocular pressure and/or peripheral anterior
synechiae. Eyes with anatomically narrow angles and typical symptoms of angle
closure should also be treated. Consideration can be given to laser iridotomy
in eyes with iridotrabecular apposition. - Iridoplasty can be considered in eyes with residual appositional closure
provided a patent iridotomy is present. • Medical treatment should not be used
as a substitute for laser iridotomy or surgical iridectomy in patients with
PAC or PACG. - Iridoplasty is as effective as pressure lowering medication in controlling
intraocular pressure in people with an acute attack of angle closure. - Iridoplasty is successful in relieving appositional closure due to plateau
iris configuration in asymptomatic cases.
Comment: Additional data in larger numbers of patients are needed.
Comment: Iridoplasty may also have a role in managing cases of phacomorphic
and pseudo-plateau iris configuration caused by iris cysts.
Laser and Medical Treatment of Primary Angle Closure Glaucoma
- Medical treatment should not be used as a substitute for laser iridotomy
or surgical iridectomy in patients with PAC or PACG. - Prostaglandin analogues appear to be the most effective medical agent in
lowering IOP following laser iridotomy, regardless of the extent of synechial
closure.
Detection of Primary Angle Closure and Angle Closure Glaucoma
- Angle closure case detection or opportunistic screening should be performed
in all persons forty years of age and older undergoing an eye examination. - Given the low specificity of the flashlight test, it is not recommended
for use in population-based screening or in the clinic. - A shallow anterior chamber is strongly associated with angle closure. The
use of ACD for population-based screening is as yet unproven. - Many clinicians currently perform iridotomy as prophylaxis in the presence
of any visible iridotrabecular contact.
Comment: Published evidence is lacking to justify this practice since
it is unknown whether LPI is effective at preventing AAC, PAC, and PACG from
developing in individuals with gonioscopically detected iridotrabecular contact.
Comment: Research is needed to determine racial/ethnic variations in
response to iridotomy.
Comment: Evidence is needed to evaluate the meaning of a shallow LACD
in the presence of an ‘open’ angle on gonioscopy. - There is currently no evidence in the literature supporting the standard
use of provocative tests for angle closure. A negative provocative test does
not exclude angle closure.
