ICO Guidelines for Glaucoma Eye Care

Internaꢀonal Council of Ophthalmology Guidelines for Glaucoma Eye Care

The Internaꢀonal Council of Ophthalmology (ICO) Guidelines for Glaucoma Eye Care have been developed as a supporꢀve and educaꢀonal resource for ophthalmologists and eye care providers worldwide. The goal is to improve the quality of eye care for paꢀents and to reduce the risk of vision loss from the most common forms of open and closed angle glaucoma around the world.

Core requirements for the appropriate care of open and closed angle glaucoma have been summarized, and consider low and intermediate to high resource seꢁngs.

This is the ﬁrst ediꢀon of the ICO Guidelines for Glaucoma Eye Care (February 2016). They are designed to be a working document to be adapted for local use, and we hope that the Guidelines are easy to read and

translate.

2015 Task Force for Glaucoma Eye Care

Neeru Gupta, MD, PhD, MBA, Chairman Tin Aung, MBBS, PhD Nathan Congdon, MD Tanuj Dada, MD Fabian Lerner, MD Sola Olawoye, MD Serge Resnikoﬀ, MD, PhD Ningli Wang, MD, PhD Richard Wormald, MD

Acknowledgements

We gratefully acknowledge Dr. Ivo Kocur, Medical Oﬃcer, Prevenꢀon of Blindness, World Health Organizaꢀon (WHO), Geneva, Switzerland, for his invaluable input and parꢀcipaꢀon in the discussions of the Task Force.

We sincerely thank Professor Hugh Taylor, ICO President, Melbourne, Australia, for many helpful insights during the development of these Guidelines.

Internaꢀonal Council of Ophthalmology | Guidelines for Glaucoma Eye Care

Table of Contents

Introducꢀon

2

4

Iniꢀal Clinical Assessment of Glaucoma

Glaucoma Assessment and Equipment Needs Glaucoma Assessment Checklist
56
Approach to Open Angle Glaucoma Care Ongoing Open Angle Glaucoma Care Approach to Closed Angle Glaucoma Care Ongoing Care for Closed Angle Glaucoma
10 13 15 16
Indicators to Assess Glaucoma Care Programs ICO Guidelines for Glaucoma Eye Care
19 20

Internaꢀonal Council of Ophthalmology | Guidelines for Glaucoma Eye Care | Page 1

Introducꢀon

Glaucoma is the leading cause of world blindness aﬅer cataracts. Glaucoma refers to a group of diseases, in which opꢀc nerve damage is the common pathology that leads to vision loss. The most common types of glaucoma are open angle and closed angle forms. Worldwide, open angle and closed angle glaucoma each account for about half of all glaucoma cases. Together, they are the major cause of irreversible vision loss globally. The burden of each of these diseases varies considerably among racial and ethnic groups worldwide. For example, in western countries, vision loss from open angle glaucoma is most common, in contrast to East Asia, where vision loss from closed angle glaucoma is most common. Paꢀents with glaucoma are reported to have poorer quality of life, reduced levels of physical, emoꢀonal, and social well-being, and uꢀlize more health care resources.

High intraocular pressure (IOP) is a major risk factor for loss of sight from both open and closed angle glaucoma, and the only one that is modiﬁable. The risk of blindness depends on the height of the intraocular pressure, severity of disease, age of onset, and other determinants of suscepꢀbility, such as family history of glaucoma. Epidemiological studies and clinical trials have shown that opꢀmal control of IOP reduces the risk of opꢀc nerve damage and slows disease progression. Lowering IOP is the only intervenꢀon proven to prevent the loss of sight from glaucoma.

Glaucoma should be ruled out as part of every regular eye examinaꢀon, since complaints of vision loss may not be present. Diﬀerenꢀaꢀng open from closed angle glaucoma is essenꢀal from a therapeuꢀc standpoint, because each form of the disease has unique management consideraꢀons and intervenꢀons. Once the correct diagnosis of open or closed angle glaucoma has been made, appropriate steps can be taken through medicaꢀons, laser, and microsurgery. This approach can prevent severe vision loss and disability from sight threatening glaucoma.

In low resource seꢁngs, managing paꢀents with glaucoma has unique challenges. Inability to pay, treatment rejecꢀon, poor compliance, and lack of educaꢀon and awareness, are all barriers to good glaucoma care. Most paꢀents are unaware of glaucoma disease, and by the ꢀme they present, many have lost significant vision. Long distances from healthcare faciliꢀes, and insufficient medical professionals and equipment, add to the difficulty in treaꢀng glaucoma. A diagnosis of open or closed angle glaucoma requires medical and surgical intervenꢀons to prevent vision loss and to preserve quality of life. Prevenꢀng glaucoma blindness in underserved regions requires heightened aꢂenꢀon to local educaꢀonal needs, availability of experꢀse, and basic infrastructure requirements.

There is strong support to integrate glaucoma care within comprehensive eye care programs and to consider rehabilitaꢀon aspects of care. Persistent eﬀorts to support eﬀecꢀve and accessible care for glaucoma are needed.¹

1. Universal Eye Health: A Global Acꢀon Plan 2014-2019, WHO, 2013 www.who.int/blindness/

acꢀonplan/en/.

Open Angle Glaucoma
Closed Angle Glaucoma

In open angle glaucoma, there is characterisꢀc opꢀc nerve damage and loss of visual funcꢀon in the presence of an open angle with no idenꢀfying pathology. The disease is chronic and progressive. Although elevated IOP is oﬅen associated with the disease, elevated IOP is not necessary to make the diagnosis. Risk factors for the disease include elevated intraocular pressure, increasing age, posiꢀve family history, racial background, myopia, thin corneas, hypertension, and diabetes. Paꢀents with elevated IOP or other risk factors should be followed regularly for the development of glaucoma.
In closed angle glaucoma, opꢀc nerve damage and vision loss may occur in the presence of an anatomical block of the anterior chamber angle by the iris. This may lead to elevated intraocular pressure and opꢀc nerve damage. In acute angle closure glaucoma, the disease may be painful, needing emergency care. More oﬅen the disease is chronic, progressive, and without symptoms. Risk factors for the disease include racial background, increasing age, female gender, posiꢀve family history, and hyperopia. Paꢀents with these risk factors should be followed regularly for the development of closed angle glaucoma.

 Open Angle
 Closed Angle
 Glaucomatous Opꢀc Nerve Damage
±±±
Elevated IOP
±±
Elevated IOP
Glaucomatous Opꢀc Nerve Damage Visual Field Damage
Visual Field Damage
Most paꢀents with open and closed angle forms of glaucoma are unaware they have sightthreatening disease. Mass populaꢀon screening is not currently recommended. However, all paꢀents presenꢀng for eye care should be reviewed for glaucoma risk factors and undergo clinical examinaꢀon to rule out glaucoma. Paꢀents with glaucoma should be told to alert brothers, sisters, parents, sons, and daughters that they have a higher risk of developing disease, and that they also need to be checked regularly for glaucoma. The ability to make an accurate diagnosis of glaucoma, to determine whether it is an open or closed form, and to assess disease severity and stability, are essenꢀal to glaucoma care strategies and blindness prevenꢀon.

Iniꢀal Clinical Assessment of Glaucoma

History

Assessment for glaucoma includes asking about complaints that may relate to glaucoma such as vision loss, pain, redness, and halos around lights. The onset, duraꢀon, locaꢀon, and severity of symptoms should be noted. All paꢀents should be asked about family members with glaucoma, and a detailed history should also be taken.

Table 1 - History Checklist

 Chief Complaint  Age, Race, Occupaꢀon  Social History  Possibility of Pregnancy  Family History of Glaucoma  Past Eye Disease, Surgery, or Trauma  Corꢀcosteroid Use  Eye Medicaꢀons  Systemic Medicaꢀons  Drug Allergies  Tobacco, Alcohol, Drug Use  Diabetes  Lung Disease  Heart Disease  Cerebrovascular Disease  Hypertension/Hypotension  Renal Stones  Migraine  Raynaud's Disease  Review of Systems

Iniꢀal Glaucoma Assessment

Evaluaꢀon for glaucoma is recommended as part of a comprehensive eye exam. The ability to diagnose glaucoma in its open or closed angle forms, and to evaluate its severity, are criꢀcal to glaucoma care approaches and the prevenꢀon of blindness. Core examinaꢀon and equipment needs to diagnose and monitor glaucoma paꢀents are listed in Table 2.

Table 2 - Glaucoma Assessment and Equipment Needs - Internaꢀonal Recommendaꢀons

Opꢀonal Equipment

(Intermediate /
High Resource Seꢁngs)

Minimal Equipment

(Low Resource Seꢁngs)

Clinical Assessment

Visual Acuity

Near reading card or distance chart with 5 standard leꢂers or symbols
3- or 4-meter visual acuity lane with high contrast visual acuity chart
Pinhole

Trial frame and lenses

Phoropter

Refracꢀon

Reꢀnoscope, Jackson cross-cylinder

Autorefractor

Pupils

Pen light or torch Slit lamp biomicroscope Keratometer

Anterior Segment

Corneal pachymeter
Goldmann applanaꢀon tonometer
Tonopen
Portable handheld applanaꢀon

tonometer

Intraocular Pressure

Pneumotonometer
Schiotz tonometer

Anterior segment opꢀcal coherence tomography
Slit lamp gonioscopy

Angle Structures

Goldmann, Zeiss/Posner goniolenses
Ultrasound biomicroscopy

Fundus photography

Direct ophthalmoscope

Opꢀc nerve image analyzers

Confocal scanning laser ophthalmoscopy

Opꢀc Nerve

(dilated if angle open)
Slit lamp biomicroscopy with hand held 78 or 90 diopter lens

Opꢀcal coherence tomography Scanning laser polarimetry

Direct ophthalmoscope Head mounted indirect ophthalmoscope with 20 or 25 diopter lens

Fundus

12 and 30 diopter lenses 60 and 90 diopter lenses
Slit lamp biomicroscopy with 78 diopter lens

Frequency doubling technology Short wave automated perimetry
Manual perimetry or automated white on white perimetry

Visual Field

Glaucoma Assessment Checklist



Corneal Thickness



Visual Acuity

The thickness of the cornea is measured to help interpret IOP readings. Thick corneas tend to overesꢀmate the IOP reading, and thin corneas tend to underesꢀmate the reading.
Vision should be tested (undilated), unaided, and with best correcꢀon at distance and near. Central vision may be aﬀected in advanced glaucoma.



Refracꢀve Error
Intraocular Pressure

The refracꢀve error will help to understand the risk of open angle glaucoma (myopia) or closed angle glaucoma (hyperopia). Neutralizing the error is important to assessing visual acuity and visual ﬁelds.
IOP should be measured in each eye before gonioscopy and before dilaꢀon. Recording the ꢀme of IOP measurement

is recommended to account for diurnal

variaꢀon.



Pupils
Anterior Segment

Pupils should be tested for reacꢀvity and afferent pupillary defect. An afferent defect may signal asymmetric moderate to advanced glaucoma.
The anterior segment should be examined in the undilated state and aﬅer dilaꢀon (if the angle is open). Look for anterior chamber shallowing and peripheral depth, pseudoexfoliaꢀon, pigment dispersion, inflammaꢀon and neovascularizaꢀon, or other causes of glaucoma.

Lids/Sclera/ Conjuncꢀva

Evidence of inﬂammaꢀon, redness, ocular surface disease, or local pathology may point to uncontrolled IOP due to acute or chronic angle closure, or possible glaucoma drug allergy, or other disease.



Cornea

The cornea should be examined for edema, which may be seen in acute or chronic high IOP. Note that IOP readings are underesꢀmated in the presence of corneal edema. Corneal precipitates may indicate inﬂammaꢀon.

Glaucoma Assessment Checklist (cont’d)



Angle Structures

The angle should be examined for the presence of iris contact with the trabecular meshwork in a dark room seꢁng. The locaꢀon and extent, and whether it is due to apposiꢀonal or synechial closure, should be determined by indentaꢀon gonioscopy. The presence of inﬂammaꢀon, pseudoexfoliaꢀon, neovascularizaꢀon, and other pathology should be noted.

Open angle on gonioscopy



Iris

The iris should be examined for mobility and irregularity, the presence of anterior and posterior synechiae, and pseudoexfoliaꢀon at the pupil margin. Forward bowing, peripheral angle crowding, and iris inserꢀon should be noted in addiꢀon to the presence of inﬂammaꢀon, neovascularizaꢀon, and other pathology.



Lens

The lens should be examined for cataract, size, posiꢀon, posterior synechiae, pseudoexfoliaꢀon material, and evidence of inﬂammaꢀon.

Closed angle on gonioscopy with no structures visible Plateau iris with peripheral iris roll
Pseudoexfoliaꢀon deposits at the pupil margin



Opꢀc Nerve

The opꢀc nerve should be evaluated for characterisꢀc signs of glaucoma. The degree of opꢀc nerve damage helps to guide iniꢀal treatment goals.

• Early opꢀc nerve damage may include a cup ≥0.5, focal reꢀnal nerve ﬁber layer defects, focal rim thinning, verꢀcal cupping, cup/disc asymmetry, focal excavaꢀon, disc hemorrhage, and departure from the ISNT rule (rim thickest inferiorly, then superiorly, nasally and temporally).

• Moderate to advanced opꢀc nerve damage may include a large cup ≥ 0.7, diffuse reꢀnal nerve fiber defects, diffuse rim thinning, opꢀc nerve excavaꢀon, acquired pit of the opꢀc nerve, and disc hemorrhage.

Reꢀnal nerve ﬁber layer defect
Thinning of the inferior rim

Advanced glaucoma with 0.9 verꢀcal cup
Disc hemorrhage at 5 o’clock



Fundus

The posterior pole should be evaluated for the presence of diabeꢀc reꢀnopathy, macular degeneraꢀon, and other reꢀnal disorders. See the ICO Guidelines for Diabeꢀc Eye Care at:

www.icoph.org/downloads/ICOGuidelinesforDiabeꢀcEyeCare.pdf.



The Visual Field

Preserving visual funcꢀon is the goal of all glaucoma management. The visual field is a measure of visual funcꢀon that is not captured by the visual acuity test. Visual field tesꢀng idenꢀfies, locates, and quanꢀfies the extent of field loss. The presence of visual field damage may indicate moderate to advanced disease. Monitoring the visual field is important to determine disease instability as seen below.

Progressive vision loss over ꢀme

Approach to Open Angle Glaucoma Care

A diagnosis of open angle glaucoma requires medical and possible surgical intervenꢀon to prevent vision loss and to preserve quality of life. Once a diagnosis of open angle glaucoma is made, paꢀent educaꢀon should begin regarding the nature of the disease, the need to lower IOP, along with discussions of treatment opꢀons. Paꢀents should be informed of the need to alert ﬁrst degree relaꢀves for the need of a glaucoma examinaꢀon.

The ﬁnancial, physical, social, emoꢀonal, and occupaꢀonal burdens of glaucoma treatment opꢀons should be carefully considered for each paꢀent. Recommendaꢀons, risks, opꢀons, and consequences of no treatment, should be discussed with all paꢀents in language that is understandable to the paꢀent or caregiver. Classifying glaucoma disease as early, or moderate to advanced, can help to guide IOP treatment goals and approaches. A simpliﬁed approach to iniꢀaꢀng care in glaucoma paꢀents is summarized below in Table 3.

Table 3 - Iniꢀaꢀng Open Angle Glaucoma Care - Internaꢀonal Recommendaꢀons

Glaucoma Severity
Suggested IOP
Reducꢀon

Findings

Treatment Consideraꢀons

Medicaꢀon or

Opꢀc Nerve Damage
Lower IOP

≥25%

Early

±

Laser trabeculoplasty
Visual Field Loss

Medicaꢀon or

Laser trabeculoplasty or
Opꢀc Nerve Damage
Trabeculectomy ± Mitomycin C

or Tube (± cataract removal and intraocular lens [IOL]) and/or
Lower IOP ≥25 – 50%

Moderate/ Advanced

+

Visual Field Loss
Cyclophotocoagulaꢀon (or cryotherapy)

Medicaꢀon and/or

Blind Eye

Lower IOP

≥25 – 50% (If painful)

End-stage

(Refractory glaucoma)
Cyclophotocoagulaꢀon

(or cryotherapy) and

±

Pain
Rehabilitaꢀon Services

Low resource seꢁngs pose unique challenges depending on the region. Parꢀcular aꢂenꢀon should be given to compliance with treatments and the capacity of the paꢀent to obtain and use medicaꢀon. If a paꢀent cannot aﬀord the cost of drugs, iniꢀal laser trabeculoplasty would be favored wherever equipment and experꢀse are available. If resources to manage glaucoma are insuﬃcient, referral

is indicated.

Table 4 - Medicines for Glaucoma Care: Internaꢀonal Recommendaꢀons

Essenꢀal Medicines
Opꢀonal Medicines

(Intermediate /
High Resource Seꢁngs)

Eye Drops

(Low Resource Seꢁngs)

Anestheꢀc Diagnosꢀc

Tetracaine 0.5% Fluorescein 1% Tropicamide 0.5%

Pupil Constricꢀng Pupil Dilaꢀng

Pilocarpine 2% or 4% Atropine 0.1, 0.5, or 1% Homatropine or cyclopentolate

Anꢀ-Inﬂammatory Anꢀ-Infecꢀves

Prednisolone 0.5% or 1% Oﬂoxacin 0.3%, gentamycin 0.3% or azithromycin 1.5%