canadian ophthalmological society

Canadian Ophthalmological Society

Evidence-based Clinical Practice Guidelines for the Management of

Glaucoma in the Adult Eye

Open-angle Glaucoma: Primary Open-Angle Glaucoma Suspects

Glaucoma suspects —risk factor monitoring

RecommendationA glaucoma suspect with any number of well-established risk factors should be monitored for the development of glaucoma [Level 11].

1. Gordon MA, et al. Arch Ophthalmol2002;120:714–20.

Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the

adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1S93.

Normal Pressure Glaucoma

Normal pressure glaucoma(or POAG at normal IOPs)

• IOP associated with POAG is usually elevated above the normal distribution (i.e. >21 mm Hg).

• However, when the IOP is not elevated, it is often referred to as normal tension glaucoma or NPG.



Normal pressure glaucoma(or POAG at normal IOPs)

• The pathogenesis of NPG remains controversial, but it is:– associated with a higher prevalence of vascular

disease and migraine,– more common in older individuals, especially those

over age 55 years,– more common in women than in men,1 and– more common in the Japanese population compared

with other ethnic groups.2

1. Collaborative Normal-Tension GlaucomaStudy Group. Am J Ophthalmol 1998;126:487–97.2. Shiose Y, et al. Jpn J Ophthalmol 1991;35:133–55.



Natural history of NPG

• The natural history of NPG was evaluated in the CNTGS during the time interval before randomization and in those patients assigned to not receive treatment.1

• Approximately one-third of untreated patients showed confirmed localized VF progression at 3 years.

• Approximately one-half showed further deterioration at7 years.

• The change was typically small and slow, often insufficient to measurably affect the mean deviation index.


adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1S93.1. Collaborative Normal-Tension GlaucomaStudy Group. Am J Ophthalmol 1998;126:487–97.

Natural history of NPG (cont’d)

• There was tremendous variability in progression rates, with women and individuals with higher IOP, migraines or disc hemorrhages having a greater risk of progression.1

• Overall, a 30% reduction in IOP was effective in reducing the progression in a greater proportion of patients, compared with those receiving no treatment.

• While 35% of the control group progressed compared with 12% of the treatment group, it would hold that 65% of the untreated group did not progress during the study period.


adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1S93.1. Collaborative Normal-Tension GlaucomaStudy Group. Am J Ophthalmol 1998;126:487–97.

NPG and treatment

RecommendationNPG is a diagnosis of exclusion and therapy does not need to be initiated unless there are significant risk factors and signs of progression, or if fixation is threatened at diagnosis [Level 11].

1. Anderson DR, et al. Ophthalmology2001;108:247–53.



Pigmentary Glaucoma

Pigmentary glaucoma

• Pigmentary glaucoma is a secondary form of open-angle glaucoma produced by pigment dispersion in the anterior segment of the eye.

• It constitutes 1% of the glaucomas seen in many Western countries.

• There is a strong association between pigmentary glaucoma and moderate myopia.



Pigmentary glaucoma (cont’d)

• Features of pigmentary glaucoma consist of:– a rise of IOP with optic nerve damage and/or VF loss,

and characteristics of pigment dispersion.– There might be:

• anisocoria and heterochromia in the affected eye,

• lattice degeneration of the retina, with clumps of pigment scattered at the base of the lattice,

• retinal pigment epithelial dysfunction,

• increased risk of retinal detachment (in up to 6% of patients with pigment dispersion).1

1. Greenstein VC, et al. Arch Ophthalmol2001;119:1291–5.



• The probability of converting from pigment dispersion to pigmentary glaucoma is fairly low (10% at 5 years and 14% at 15 years).1

• The major risk factor for developing glaucoma is an initial IOP of ≥21 mm Hg at presentation.

1. Siddiqui Y, et al. Am J Ophthalmol 2003;135:794–9.



Pigmentary glaucoma (cont’d)

Treatment ofpigmentary glaucoma

• Medical, laser, and surgical options are similar to those used to treat POAG.



Laser iridotomy andpigmentary glaucoma

RecommendationIt is recommended that laser iridotomy not be routinely employed in the management of pigmentary glaucoma [Level 21,2].

1. Reistsad CE, et al. J Glaucoma 2005;14:255–59.2. Gandolfi SA, et al. Ophthalmology 1996;103:1693–5.



Laser trabeculoplasty —IOP monitoring

RecommendationIt is recommended that IOPs be checked within a few hours post-laser trabeculoplasty, especially in the presence of pigment dispersion because of the higher risk of IOP spikes [Level 11].

1. Glaucoma Laser Trial Research Group.Arch Ophthalmol 1989;107:113542.



Pseudoexfoliation Syndrome and Glaucoma

PXF syndrome and glaucoma

• PXF syndrome:– Is the most common identifiable cause of open-angle

glaucoma worldwide.1

– Is a disease of elastic tissue in the posterior chamber of the eye and other systemic sites.2

– Is more common in older age groups, with most cases occurring in people in their late 60s and early 70s.3

– May be unilateral or bilateral at presentation, and many unilateral cases become bilateral with time.

– Is more prevalent in Eastern Mediterranean and Northern European countries.

1. Ritch R. Trans Am Ophthalmol Soc 1994;92:845–944.2. Ritch R, et al. Prog Retin Eye Res 2003;22:253–75.3. Conway RM, et al. Clin Experiment Ophthalmol 2004;32:199–210.



PXF syndrome and glaucoma

• When PXF is accompanied by elevated IOP and VF and/or disc damage, it is termed PXF glaucoma.

• The percentage of PXF patients with glaucoma is different for every population.

• About 25% of persons with PXF have elevated IOP, and one-third of these have glaucoma.1,2

1. Ritch R, et al. Surv Ophthalmol 2001;45:265–315.2. Conway RM, et al. Clin Experiment Ophthalmol 2004;32:199–210.



PXF syndrome and treatment

RecommendationClose monitoring and aggressive IOP-lowering therapy are indicated in patients with PXF glaucoma due to their greater tendency to present IOP spikes, greater 24-hour IOP fluctuations, and their relatively worse prognosis compared with patients with POAG [Level 21].

1. Leske MC, et al. Ophthalmology2007;114:1965–72.



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